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1: Cancer Lett. 2006 Jan 10; [Epub ahead of print]

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Influence of galangin on HL-60 cell proliferation and survival.

Bestwick CS, Milne L.

Molecular Nutrition Group, Gut Health Programme, Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK.

The effect of galangin, a flavonol component of India root spice and the 'herbal' medicine propolis, on HL-60 human leukaemia cell survival is characterised. Galangin (1-100muM) exerted an antiproliferative effect that, with dose and exposure longevity, was progressively associated with an elevated hypodiploid DNA content and expression of the active form of caspase-3, principally prior to membrane damage. At >/=50muM, plasmamembrane phosphatidylserine exposure was observed. There was no evidence for intracellular oxidative stress as an orchestrator of cytotoxicity and significant phagocyte-like differentiation was not detected. We discuss whether such cytotoxicity will be therapeutically exploitable or contribute to cancer prevention within a pharmacological or dietary context.

PMID: 16413113 [PubMed - as supplied by publisher]

2: Life Sci. 2005 Dec 20; [Epub ahead of print]

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Therapeutic effect of paclitaxel and propolis on lipid peroxidation and antioxidant system in 7,12 dimethyl benz(a)anthracene-induced breast cancer in female Sprague Dawley rats.

Padmavathi R, Senthilnathan P, Chodon D, Sakthisekaran D.

Department of Medical Biochemistry, University of Madras, Taramani campus, Chennai-600 113, Tamilnadu, India.

Breast cancer is one of the most common cancers in women of developed and developing countries. The optimum management of which requires a multidisciplinary approach including the use of certain biochemical and molecular markers. The effect of propolis along with paclitaxel on 7,12 dimethyl benz(a)anthracene (DMBA) induced experimental breast cancer was investigated in female Sprague Dawley rats. Female Sprague Dawley rats were divided into five groups of six animals each. Group I served as normal control animal. Group II animals received DMBA (20 mg in 0.5 ml sunflower oil and 0.5 ml of saline) i.p. to develop mammary tumor by the end of 90 days. Group III were breast cancer animals treated with 33 mg paclitaxel/kg body weight (bw) weekly once for 4 weeks. Group IV were breast cancer-bearing animals treated with 50 mg propolis/kg bw for 30 days. Group V were breast cancer-bearing animals treated with both paclitaxel and propolis as mentioned above. Administration of paclitaxel and propolis effectively suppressed breast cancer, which is revealed by the decrease in the extent of lipid peroxidation (LPO) with concomitant increase in the activities of enzymic antioxidants (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) and non-enzymic antioxidants (reduced glutathione (GSH), Vitamin C and Vitamin E) levels when compared to breast cancer-bearing animals treated with either paclitaxel or propolis alone. From our results, we conclude that propolis is a potent antioxidant and, when given in combination with paclitaxel, offers maximum protection against DMBA induced mammary carcinogenesis.

PMID: 16375927 [PubMed - as supplied by publisher]

3: Am J Kidney Dis. 2005 Dec;46(6):e125-9.

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Acute renal failure induced by a Brazilian variety of propolis.

Li YJ, Lin JL, Yang CW, Yu CC.

Department of Nephrology, Chang Gung Memorial Hospital, Taipei, Taiwan.

Propolis is a resinous substance collected by honeybees and used in hive construction and maintenance. Cumulative evidence suggests that propolis may have anti-inflammatory, antibiotic, antioxidant, antihepatotoxic, and antitumor properties. In addition to topical applications, products containing propolis have been used increasingly as dietary supplements. Although reports of allergic reactions are not uncommon, propolis is reputed to be relatively nontoxic. Its systemic toxicity is rarely reported and hence may be underestimated. This is the first report of propolis-induced acute renal failure. A 59-year-old man required hemodialysis for acute renal failure. The patient had cholangiocarcinoma and had ingested propolis for 2 weeks before presentation. Renal function improved after propolis withdrawal, deteriorated again after reexposure, and then returned to a normal level after the second propolis withdrawal. This case indicates that propolis can induce acute renal failure and emphasizes the need for vigilance and care when propolis is used as a medicine or dietary supplement.

Publication Types:

       Case Reports

PMID: 16310564 [PubMed - indexed for MEDLINE]

4: Int J Radiat Oncol Biol Phys. 2005 Nov 15;63(4):1252-61.

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Caffeic acid phenethyl ester preferentially sensitizes CT26 colorectal adenocarcinoma to ionizing radiation without affecting bone marrow radioresponse.

Chen YJ, Liao HF, Tsai TH, Wang SY, Shiao MS.

Department of Radiation Oncology, Mackay Memorial Hospital, Taipei, Taiwan.

PURPOSE: Caffeic acid phenethyl ester (CAPE), a component of propolis, was reported capable of depleting glutathione (GSH). We subsequently examined the radiosensitizing effect of CAPE and its toxicity. METHODS AND MATERIALS: The effects of CAPE on GSH level, GSH metabolism enzyme activities, NF-kappaB activity, and radiosensitivity in mouse CT26 colorectal adenocarcinoma cells were determined. BALB/c mouse with CT26 cells implantation was used as a syngeneic in vivo model for evaluation of treatment and toxicity end points. RESULTS: CAPE entered CT26 cells rapidly and depleted intracellular GSH in CT26 cells, but not in bone marrow cells. Pretreatment with nontoxic doses of CAPE significantly enhanced cell killing by ionizing radiation (IR) with sensitizer enhancement ratios up to 2.2. Pretreatment of CT26 cells with N-acetyl-L-cysteine reversed the GSH depletion activity and partially blocked the radiosensitizing effect of CAPE. CAPE treatment in CT26 cells increased glutathione peroxidase, decreased glutathione reductase, and did not affect glutathione S-transferase or gamma-glutamyl transpeptidase activity. Radiation activated NF-kappaB was reversed by CAPE pretreatment. In vivo study revealed that pretreatment with CAPE before IR resulted in greater inhibition of tumor growth and prolongation of survival in comparison with IR alone. Pretreatment with CAPE neither affected body weights nor produced hepatic, renal, or hematopoietic toxicity. CONCLUSIONS: CAPE sensitizes CT26 colorectal adenocarcinoma to IR, which may be via depleting GSH and inhibiting NF-kappaB activity, without toxicity to bone marrow, liver, and kidney.

PMID: 16253780 [PubMed - indexed for MEDLINE]

5: Br J Pharmacol. 2005 Dec;146(8):1139-47.

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Caffeic acid phenethyl ester modulates Helicobacter pylori-induced nuclear factor-kappa B and activator protein-1 expression in gastric epithelial cells.

Abdel-Latif MM, Windle HJ, Homasany BS, Sabra K, Kelleher D.

Department of Clinical Medicine, Dublin Molecular Medicine Centre and Trinity Centre for Health Sciences, St James's Hospital, Dublin 8, Ireland.

Caffeic acid phenethyl ester (CAPE), an active component of propolis from honeybee hives (honeybee resin), has anti-inflammatory, anti-carcinogenic and anti-bacterial properties. This study was designed to investigate the anti-inflammatory effects of CAPE on Helicobacter pylori-induced NF-kappaB and AP-1 in the gastric epithelial cell line AGS. Electrophoretic mobility shift assay was used to measure NF-kappaB- and AP-1-DNA binding activity. Western blotting was used to detect IkappaB-alpha and COX-2 expression in AGS cells cocultured with H. pylori. The antiproliferative effect of CAPE was measured by MTT assay. Our results showed that caffeic phenethyl ester inhibits H. pylori-induced NF-kappaB and AP-1 DNA-binding activity in a dose (0.1-25 microg ml(-1) approximately 0.35-88 microM) and time- (15-240 min) dependent manner in AGS cells. Maximum inhibition by CAPE was observed at concentrations of 25 microg ml(-1) ( approximately 88 microM) CAPE prevented H. pylori- and cytokine-induced degradation of IkappaB-alpha protein. Pretreatment of AGS cells with CAPE also blocked cytokine- and mitogen-induced NF-kappaB and AP-1 expression. Furthermore, CAPE suppressed H. pylori-induced cell proliferation and production of the cytokines TNF-alpha and IL-8. In addition, CAPE blocked H. pylori-induced COX-2 expression. The inhibition of such transcription by CAPE could result in suppression of many genes during H. pylori-induced inflammation, and also provide new insights into the anti-cancer and anti-inflammatory properties of CAPE.

PMID: 16247412 [PubMed - in process]

6: Cancer Lett. 2005 Oct 15; [Epub ahead of print]

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Dietary artepillin C suppresses the formation of aberrant crypt foci induced by azoxymethane in mouse colon.

Shimizu K, Das SK, Baba M, Matsuura Y, Kanazawa K.

Department of Life Science, Graduate School of Science and Technology, Kobe University, Rokkodai, Nada-ku, Kobe 657-8501, Japan.

Artepillin C, a prenylated phenylpropanoid found specifically in Brazilian propolis, has been shown to be a bioavailable antioxidant. In this study, artepillin C was tested for colon cancer-preventing activity using azoxymethane-challenged ddY mice. Oral doses of 80 and 160mg/kg body weight of propolis or 10mg/kg of artepillin C (equi-amounts to 160mg propolis) reduced significantly the frequency of colonic aberrant crypt foci (ACF) by 39.2, 43.7 and 43.4%, respectively. In liver of the mice, glutathione S-transferase and NADPH:quinone reductase activity increased with the doses of propolis or artepillin C, and an antioxidant-responsive element (ARE) was found to be activated for binding DNA. Artepillin C is considered to suppress the formation of colonic ACF through the activation of ARE and induction of phase II enzymes in liver.

PMID: 16236434 [PubMed - as supplied by publisher]

7: Mol Carcinog. 2005 Dec;44(4):293-9.

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Artepillin C in Brazilian propolis induces G(0)/G(1) arrest via stimulation of Cip1/p21 expression in human colon cancer cells.

Shimizu K, Das SK, Hashimoto T, Sowa Y, Yoshida T, Sakai T, Matsuura Y, Kanazawa K.

Department of Life Science, Graduate School of Science and Technology, Kobe University, Kobe, Japan.

Potential chemopreventive agents exist in foods. Artepillin C in Brazilian propolis was investigated for its effects on colon carcinogenesis. We had found that artepillin C was a bioavailable antioxidant, which could be incorporated into intestinal Caco-2 and hepatic HepG2 cells without any conjugation and inhibited the oxidation of intracellular DNA. Artepillin C was then added to human colon cancer WiDr cells. It dose-dependently inhibited cell growth, inducing G(0)/G(1) arrest. The events involved a decrease in the kinase activity of a complex of cyclin D/cyclin-dependent kinase 4 and in the levels of retinoblastoma protein phosphorylated at Ser 780 and 807/811. The inhibitors of the complex, Cip1/p21 and Kip1/p27, increased at the protein level. On the other hand, Northern blotting showed that artepillin C did not affect the expression of Kip1/p27 mRNA. According to the experiments using isogenic human colorectal carcinoma cell lines, artepillin C failed to induce G(0)/G(1) arrest in the Cip1/p21-deleted HCT116 cells, but not in the wild-type HCT116 cells. Artepillin C appears to prevent colon cancer through the induction of cell-cycle arrest by stimulating the expression of Cip1/p21 and to be a useful chemopreventing factor in colon carcinogenesis.

PMID: 16224795 [PubMed - indexed for MEDLINE]

8: J Nutr Biochem. 2005 Oct 5; [Epub ahead of print]

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Inhibitory effects of caffeic acid phenethyl ester on cancer cell metastasis mediated by the down-regulation of matrix metalloproteinase expression in human HT1080 fibrosarcoma cells.

Hwang HJ, Park HJ, Chung HJ, Min HY, Park EJ, Hong JY, Lee SK.

Department of Pharmacy, College of Pharmacy, Ewha Woman's University, Seodaemun-Ku, Seoul 120-750, South Korea.

Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine. Recent study also revealed that CAPE has several biological activities including antioxidation, anti-inflammation and inhibition of tumor growth. The present study investigated the effect of CAPE on tumor invasion and metastasis by determining the regulation of matrix metalloproteinases (MMPs). Matrix metalloproteinases, which are zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix (ECM) as well as nonmatrix substrates. On this line, we examined the influence of CAPE on the gene expression of MMPs (MMP-2, MMP-9, MT1-MMP), tissue inhibitor of metalloproteinase-2 (TIMP-2) and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent decreases in MMP and TIMP-2 mRNA levels were observed in CAPE-treated HT1080 human fibrosarcoma cells as detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Gelatin zymography analysis also exhibited a significant down-regulation of MMP-2 and MMP-9 expression in HT1080 cells treated with CAPE compared to controls. In addition, CAPE inhibited the activated MMP-2 activity as well as invasion, motility, cell migration and colony formation of tumor cells. These data therefore provide direct evidence for the role of CAPE as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of malignant cells.

PMID: 16214327 [PubMed - as supplied by publisher]

9: Biol Pharm Bull. 2005 Oct;28(10):1928-33.

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Effects of local administration of propolis and its polyphenolic compounds on tumor formation and growth.

Orsolic N, Terzic S, Mihaljevic Z, Sver L, Basic I.

Department of Animal Physiology, Faculty of Science, University of Zagreb; 10000 Zagreb, Rooseveltov trg 6, Croatia.

Many dietary constituents are chemopreventive in animal models, and experiments with cultured cells are revealing various potential mechanisms of action. Compounds classified as blocking agents can prevent, or greatly reduce, initiation of carcinogenesis, or suppressing agents can act on cell proliferation. Caffeic acid (CA) and caffeic acid phenethyl ester (CAPE), members of the polyphenolic compounds, are present in high concentrations in medicinal plants and propolis, a natural beehive product. A water-soluble extract of propolis (WSDP) and two components of propolis, CA and CAPE were investigated for direct antitumor activity in vivo and in vitro. The local presence of CA and CAPE in the tissue caused a significant delay in tumor formation and increased life span 29.30 to 51.73%, respectively. CA and CAPE, but not WSDP, significantly suppressed human HeLa cervical carcinoma cell proliferation in vitro. Based on these results, we postulate that the antitumor activity of polyphenolic compounds includes direct cytotoxic effects on tumor cells.

PMID: 16204948 [PubMed - indexed for MEDLINE]

10: Biomed Pharmacother. 2005 Dec;59(10):561-70. Epub 2005 Aug 10.

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Antitumor, hematostimulative and radioprotective action of water-soluble derivative of propolis (WSDP).

Orsolic N, Basic I.

Department of Animal Physiology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, Croatia.

Several studies suggest that dietary supplementation with antioxidant can influence the response to chemotherapy as well as the development of adverse side effects caused by treatment with chemotherapeutic agents. Using CBA mouse model, we investigated a clinically potential use of a water-soluble derivative of propolis (WSDP) in the treatment of various cytopenias induced by radiation and/or chemotherapy. Also, the antimetastatic efficiency of WSDP given intraperitoneally alone or in combination with chemotherapeutic agents and their effects on the blood leukocytes count as well as on hematopoiesis were studied. Tumor was a transplantable mammary carcinoma (MCa) of CBA mouse. Metastases in the lung were generated by injecting viable tumor cells intravenously (iv). WSDP (50 or 150 mg/kg) exerted a significant antimetastatic effect (P < 0.001) when given either before or after tumor cell inoculation. In combined treatment WSDP and Epirubicin profoundly inhibited metastasis formation; this synergistic effect is maximal when Epirubicin and WSDP were administrated after tumor cell inoculation. Positive outcome of combined treatment with WSDP and Epirubicin was also found regarding the number of red and white blood cells in peripheral blood while in mice treated with Epirubicin alone the significant drop in all hematological parameters was noticed on day 13 after tumor cell inoculation. Furthermore, when WSDP (50 mg/kg) was given perorally (po) for 20 consecutive days an increased number of exogenous CFUs was found in treated mice. WSDP given either for 20 or 40 days increased cellularity of hematopoietic tissue and the number of leucocytes in peripheral blood; prolonged treatment with WSDP also elevated myeloid and megakaryocytic types of CFUs. To conclude, these findings indicate that the combination of WSDP with chemotherapeutics could increase the antimetastatic potential of chemotherapeutic agents; these findings suggest the benefits of potential clinical trials using WSDP combined with chemotherapeutic agents in order to maximize their antitumor activity and minimize postchemotherapeutic or radiotherapeutic deteriorated reactions.

PMID: 16202559 [PubMed - indexed for MEDLINE]

11: Leuk Res. 2005 Nov;29(11):1343-6.

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Evaluation of Manisa propolis effect on leukemia cell line by telomerase activity.

Gunduz C, Biray C, Kosova B, Yilmaz B, Eroglu Z, Sahin F, Omay SB, Cogulu O.

Ege University, Faculty of Medicine, Department of Medical Biology, Izmir, Turkey.

Propolis is a resinous substance which is used by bees to repair and maintain their hives. It has more than 180 compounds including flavonoids, phenolic acids and its esters which have anti-inflammatory, antibacterial, antiviral, immunomodulatory, antioxidant and antiproliferative effects. Propolis is shown to inhibit cell division and protein synthesis. However the exact mechanism underlying antitumor effect is not clearly described. On the other hand progressive telomere shortening to a critical level results with senescence of normal cells by inducing apoptosis and telomerase prevents erosion of telomeres. In this study we aimed to evaluate hTERT ratios in propolis-treated T-cell acute lymphoblastic leukemia (CCFR-CEM) cell line. Cell counts and cell viability of propolis-treated and propolis-free T-cell acute lymphoblastic leukemia (CCFR-CEM) cell line were assessed by trypan blue dye exclusion test and MTT assay. The LightCycler instrument was used (online real-time PCR) for the quantification of hTERT in CCFR-CEM cell line. The hTERT ratio significantly decreased 60 and 93% after 24 and 72 h respectively compared to the initial value of the cells incubated with propolis. It had almost no cytotoxic effect and caused 30, 30, 22 and 12% decrease in cell counts after 24, 48, 72 and 96 h respectively which is statistically significant. In conclusion propolis may show antitumor and apoptotic effect via inhibiting telomerase expression besides the mechanisms which have been described previously.

PMID: 16055186 [PubMed - indexed for MEDLINE]

12: Int Immunopharmacol. 2005 Oct;5(11):1652-7.

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Effects of Turkish pollen and propolis extracts on respiratory burst for K-562 cell lines.

Aliyazicioglu Y, Deger O, Ovali E, Barlak Y, Hosver I, Tekelioglu Y, Karahan SC.

Department of Biochemistry, Faculty of Medicine, Ondokuz Mayis University, Samsun, 55139, Turkey.

Bee-collected pollen and propolis are apicultural products which are composed of nutritionally valuable substances and contain considerable amounts of polyphenol substances which may act as potent antioxidants. We wanted to show if respiratory burst within a cancer cell lines could be influenced when incubated with pollen and propolis extracts or not. Pollen and propolis extracts at concentrations of 50, 25, 12.5 and 0 mg/ml were prepared by dimethyl sulfoxide (DMSO). K-562 cell cultures and mononuclear cell (MNC) cultures prepared from a peripheral blood sample to serve as control cells were incubated with extracts for 24 h. Determination of respiratory burst was carried out by intracellular dichlorofluorescein (DCFH) test by using flow-cytometric fluorescence analysis. While about 90% and 66% fluorescence was detected at zero concentrations for both K-562 and MNC cultures, fluorescence positivity decreased (between 3.8% and 11.8%) as concentrations of both propolis and pollen extracts increased for K-562 cell culture, but unchanged (between 20% and 83%) for MNC culture. It was concluded that pollen and propolis extracts inhibit respiratory burst within cancer cell lines probably by their antioxidant potentials.

PMID: 16039555 [PubMed - indexed for MEDLINE]

13: Clin Chim Acta. 2005 Dec;362(1-2):57-64. Epub 2005 Jul 6.

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Caffeic acid phenyl ester in propolis is a strong inhibitor of matrix metalloproteinase-9 and invasion inhibitor: isolation and identification.

Jin UH, Chung TW, Kang SK, Suh SJ, Kim JK, Chung KH, Gu YH, Suzuki I, Kim CH.

Department of Biochemistry and Molecular Biology, Dongguk University College of Oriental Medicine and National Research Laboratory for Glycobiology, Kyungbuk, Korea.

BACKGROUND: Propolis has been used as a folk medicine and has several proven biological activities. Herbal remedies recommended for cancer therapies in Korea. METHODS: Matrix metalloproteinase (MMP)-9-inhibitory activity of propolis has been assessed. CAPE as an acting compound was isolated and molecular structure was determined. Anti-invasion activity of CAPE was assayed using hepatocarcinoma cells. RESULTS: Propolis ethanol extracts showed a strong inhibitory effect of MMP-9 activity, which is known to be involved in tumor cell invasion and metastasis in a concentration-dependent manner on zymography. Assay guided fractionation led to the isolation of a caffeic acid phenyl ester (CAPE) as the compound responsible for the anti-MMP-9 activity. CAPE was obtained by reversed-phase HPLC, and its structure was elucidated by fast atom bombardment mass spectrometry and tandem mass spectrometry. The purified CAPE inhibited MMP-9 activity with the IC(50) of 1.0-2.0 nmol/l. CONCLUSIONS: CAPE possesses selective antiproliferative activity toward hepatocaricoma cell line Hep3B, but not primary cultured mouse hepatocytes.

PMID: 16004979 [PubMed - indexed for MEDLINE]

14: Biol Pharm Bull. 2005 Jun;28(6):1025-30.

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Two related cinnamic Acid derivatives from Brazilian honey bee propolis, baccharin and drupanin, induce growth inhibition in allografted sarcoma s-180 in mice.

Mishima S, Ono Y, Araki Y, Akao Y, Nozawa Y.

API Co. Ltd., R&D, Gifu, Japan.

Honey bee propolis is rich in cinnamic acid derivatives. Baccharin and drupanin from Brazilian honey bee propolis are cinnamic acid derivatives that contain prenyl moieties. We previously isolated these two compounds and demonstrated that they induce an apoptotic event in several tumor cell lines. In this study, we examined the tumoricidal activity of baccharin and drupanin in mice allografted with sarcoma S-180 and also studied the genotoxic effects on normal splenocytes using the alkaline single cell gel (comet) assay. We found that both baccharin and drupanin effectively suppressed growth of the tumor. Furthermore, these compounds induced a significant genotoxic effect on the tumor cells in comparison with normal splenocytes. Thus, baccharin and drupanin are potent tumor suppressive components of honeybee propolis.

PMID: 15930739 [PubMed - indexed for MEDLINE]

15: Biochem Pharmacol. 2005 Jun 15;69(12):1815-27.

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Chrysin induces G1 phase cell cycle arrest in C6 glioma cells through inducing p21Waf1/Cip1 expression: involvement of p38 mitogen-activated protein kinase.

Weng MS, Ho YS, Lin JK.

Graduate Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei 10018, Taiwan.

Flavonoids are a broadly distributed class of plant pigments, universally present in plants. They are strong anti-oxidants that can inhibit carcinogenesis in rodents. Chrysin (5,7-dihydroxyflavone) is a natural and biologically active compound extracted from many plants, honey, and propolis. It possesses potent anti-inflammatory, anti-oxidant properties, promotes cell death, and perturbing cell cycle progression. However, the mechanism by which chrysin inhibits cancer cell growth remains poorly understood. Therefore, we developed an interest in the relationship between MAPK signaling pathways and cell growth inhibition after chrysin treatment in rat C6 glioma cells. Cell viability assay and flow cytometric analysis suggested that chrysin exhibited a dose-dependent and time-dependent ability to block rat C6 glioma cell line cell cycle progression at the G1 phase. Western blotting analysis showed that the levels of Rb phosphorylation in C6 glioma cells exposed to 30 microM chrysin for 24h decreased significantly. We demonstrated the expression of cyclin-dependent kinase inhibitor, p21(Waf1/Cip1), to be significantly increased, but the p53 protein level did not change in chrysin-treated cells. Both cyclin-dependent kinase 2 (CDK2) and 4 (CDK4) kinase activities were reduced by chrysin in a dose-dependent manner. Furthermore, chrysin also inhibited proteasome activity. We further showed that chrysin induced p38-MAPK activation, and using a specific p38-MAPK inhibitor, SB203580, attenuated chrysin-induced p21(Waf1/Cip1) expression. These results suggest that chrysin exerts its growth-inhibitory effects either through activating p38-MAPK leading to the accumulation of p21(Waf1/Cip1) protein or mediating the inhibition of proteasome activity.

PMID: 15869744 [PubMed - indexed for MEDLINE]

16: J Dent Res. 2005 May;84(5):468-73.

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Properties of BK(Ca) channels in oral keratinocytes.

Shieh DB, Yang SR, Shi XY, Wu YN, Wu SN.

Institute of Oral Medicine, National Cheng Kung University Medical College, No. 1, University Road, Tainan 701, Taiwan.

Keratinocytes are important for epithelial antimicrobial barrier function. The activity of ion channels can affect the proliferation of keratinocytes. Little is known about Ca2+-activated K+ currents in these cells. Ion currents in normal human oral keratinocytes were characterized with a patch-clamp technique. In whole-cell configuration, depolarizing pulses evoked K+ outward currents (I(K)) in oral keratinocytes. Iberiotoxin (200 nM) and paxilline (1 microM) suppressed I(K); however, neither apamin (200 nM) nor 5-hydroxydecanoate (30 microM) had any effects on it. Caffeic acid phenethyl ester, a compound of honeybee propolis, increased I(K) with an EC50 value of 12.8 +/- 1.2 microM. In inside-out patches, a BK(Ca) channel was observed in keratinocytes, but not in oral squamous carcinoma (OCE-M1) cells. Caffeic acid phenethyl ester or cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate applied to the intracellular surface of a detached patch increased BK(Ca)-channel activity. The results demonstrate that the properties of BK(Ca) channels in normal human oral keratinocytes are similar to those described in other types of cells. Caffeic acid derivatives can also stimulate BK(Ca)-channel activity directly.

PMID: 15840785 [PubMed - indexed for MEDLINE]

17: Biol Pharm Bull. 2005 Apr;28(4):694-700.

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Synergistic antitumor effect of polyphenolic components of water soluble derivative of propolis against Ehrlich ascites tumour.

Orsolic N, Kosalec I, Basic I.

Department of Animal Physiology, Faculty of Science, University of Zagreb, Croatia.

Effect of two preparation (Croatian and Brazilian) of water-soluble derivative of propolis (WSDP), caffeic acid, quercetin, chrysin, naringenin (components present in WSDP) on the development of Ehrlich ascites tumour (EAT) was evaluated. Test components (50 mg/kg) were given perorally or intraperitoneally 2 h prior the intraperitonel injection of EAT (2 x 10(6)) cells. It was observed that all test compounds effectively inhibited tumour growth and the proliferation of EAT. The volume of ascitic fluid induced by EAT cells and total number of cells present in the peritoneal cavity was markedly reduced in EAT-bearing mice treated with test components. In treated mice the number of polymorphonuclear (PMN) cells in the peritoneal cavity was increased while the number of macrophages was decreased. The macrophage spreading activity revealed that WSDP and all test compounds affected the functional state of macrophages increasing their tumorcidal activity; the effect of WSDP was most pronounced indicating synergistic effect of components present in WSDP. Antitumor activity of WSDP may be the result of different specific mechanism(s) of flavonoids present as compared to individual flavonoid given alone. It is likely that the part of antitumor efficacy of test components against EAT cells was the results of increased activity of macrophages.

PMID: 15802812 [PubMed - indexed for MEDLINE]

18: Nat Prod Res. 2005 Feb;19(2):183-8.

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Natural product propolis: chemical composition.

Sahinler N, Kaftanoglu O.

Mustafa Kemal University, Faculty of Agriculture, Department of Animal Science, Hatay, Turkey.

The chemical composition of propolis from East Mediterranean (Hatay, Adana and Mersin) was studied in order to determine the major compounds by using GC-MS. In this study, the ethanolic extract of propolis prepared by mixing 1900mL 70% ethanol and 100g propolis was used. Chemical analysis of propolis extracts indicated that the propolis samples had high concentrations of the aromatic acids, esters and other derivatives which are responsible for the anti-bacterial, anti-fungal, anti-viral, anti-inflammatory and anti-cancer properties of propolis such as benzyl cinnamate, methyl cinnamate, caffeic acid, cinnamyl cinnamate and cinnamoylglcine besides the most common compounds as fatty acid, terpenoids, esters, alcohols hydrocarbons and aromatic acids.

PMID: 15715264 [PubMed - indexed for MEDLINE]

19: FEBS Lett. 2005 Jan 31;579(3):705-11.

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Chrysin suppresses lipopolysaccharide-induced cyclooxygenase-2 expression through the inhibition of nuclear factor for IL-6 (NF-IL6) DNA-binding activity.

Woo KJ, Jeong YJ, Inoue H, Park JW, Kwon TK.

Department of Immunology, School of Medicine, Keimyung University, 194 DongSan-Dong Jung-Gu, Taegu 700-712, South Korea.

Chrysin is a natural, biologically active compound extracted from many plants, honey and propolis. It possesses potent anti-inflammation, anti-cancer and anti-oxidation properties. The mechanism by which chrysin suppresses COX-2 expression remains poorly understood. In the present report, we investigated the effect of chrysin on the expression of COX-2 in lipopolysaccharide (LPS)-activated Raw 264.7 cells. Chrysin significantly suppressed the LPS-induced COX-2 protein and mRNA expression in a dose-dependent manner. The ability of chrysin to suppress the expression of the COX-2 was investigated using luciferase reporters controlled by various cis-elements in COX-2 promoter region. Mutational analysis and electrophoretic mobility shift assay verified that nuclear factor for IL-6 was identified as responsible for the chrysin-mediated COX-2 downregulation. These results will provide new insights into the anti-inflammatory and anti-carcinogenic properties of chrysin.

PMID: 15670832 [PubMed - indexed for MEDLINE]

20: Ann N Y Acad Sci. 2004 Dec;1030:501-7.

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Inhibition of cyclooxygenase-2 expression and restoration of gap junction intercellular communication in H-ras-transformed rat liver epithelial cells by caffeic acid phenethyl ester.

Lee KW, Chun KS, Lee JS, Kang KS, Surh YJ, Lee HJ.

Department of Food Science and Technology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, South Korea.

One of the most frequent defects in human cancers is the uncontrolled activation of the ras signaling pathways. Increased expression of cyclooxygenase-2 (COX-2) and inhibition of gap junction intercellular communication (GJIC) have been frequently observed in several forms of human malignancies. The present study investigated the effects of caffeic acid phenethyl ester (CAPE), a chemopreventive phytochemical derived from honey propolis, on COX-2 expression and GJIC in Harvey-ras-transformed WB-F344 rat liver epithelial cells (H-ras WB cells). H-ras induced COX-2 expression in WB-F344 rat liver epithelial cells (WB cells). H-ras WB cells also exhibited complete inhibition of GJIC and predominant unphosphorylation of connexin 43 (Cx43), a major protein modulating GJIC. CAPE significantly inhibited the constitutive expression of COX-2 and restored the disrupted GJIC through the phosphorylation of Cx43 at a concentration of 12.5 microM in H-ras WB cells. Although the molecular basis for the cancer chemopreventive activity of CAPE is not completely understood, several studies suggest that CAPE is a potent and specific inhibitor of the transcription factor nuclear factor kappaB (NF-kappaB) activation. We also found that CAPE significantly inhibited H-ras-induced NF-kappaB DNA-binding activity without affecting the activation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase, which are major intracellular molecules involved in the Ras signaling pathways. In conclusion, CAPE may exert cancer chemopreventive effects through the inhibition of COX-2 expression and the restoration of disrupted GJIC induced by H-ras, possibly by targeting NF-kappaB.

PMID: 15659835 [PubMed - indexed for MEDLINE]

21: Environ Mol Mutagen. 2005;45(1):8-16.

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Modifying effect of propolis on dimethylhydrazine-induced DNA damage but not colonic aberrant crypt foci in rats.

de Lima RO, Bazo AP, Said RA, Sforcin JM, Bankova V, Darros BR, Salvadori DM.

Departamento de Patologia, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, Sao Paulo, Brazil.

Propolis is a honeybee product with several biological and therapeutic properties, including antimutagenic and anticarcinogenic activities. The effects of an aqueous extract of propolis (AEP) were evaluated on the formation of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) and DNA damage in the colon of male Wistar rats by the ACF and Comet assays, respectively. AEP was administered orally at 0.01%, 0.03%, 0.1%, and 0.3% in the drinking water, which resulted in doses of approximately 12, 34, 108, and 336 mg/kg body weight/day. Animals were also given a single subcutaneous injection of 40 mg/kg DMH and sacrificed 4 hr later for evaluating DNA damage, or 4 doses of 40 mg/kg DMH, administered 2 doses/week for 2 weeks, and sacrificed 12 weeks after the last injection for evaluating ACF development in the distal colon. Administration of AEP either simultaneously with or after the DMH treatment resulted in no statistically significant reduction of ACF. In contrast, 0.01%, 0.03%, and 0.3% AEP, given simultaneously with DMH, reduced DNA damage induction in the mid and distal colon. However, 0.3% AEP alone increased DNA damage in the colon. In conclusion, AEP had no effect on the formation of DMH-induced ACF in rat colon, but it modulated DMH-induced DNA damage in colon cells. Further investigations are recommended in order to establish the conditions under which propolis produces either protective or deleterious effects. 2004 Wiley-Liss, Inc.

PMID: 15605358 [PubMed - indexed for MEDLINE]

22: Life Sci. 2004 Dec 17;76(5):545-58.

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Chilean propolis: antioxidant activity and antiproliferative action in human tumor cell lines.

Russo A, Cardile V, Sanchez F, Troncoso N, Vanella A, Garbarino JA.

Department of Biological Chemistry, Medical Chemistry and Molecular Biology, University of Catania, v.le A. Doria 6, 95125 Catania-Italy.

Propolis, a natural product derived from plant resins collected by honeybees, has been used for thousands of years in traditional medicine all over the world. The composition of the propolis depends upon the vegetation of the area from where it was collected and on the bee species. In this study, we investigated the antioxidant activity of a propolis sample, provided by NATURANDES-CHILE, collected in a temperate region of central Chile. In addition, this natural compound was tested for its antiproliferative capacity on KB (human mouth epidermoid carcinoma cells), Caco-2 (colon adenocarcinoma cells) and DU-145 (androgen-insensitive prostate cancer cells) human tumor cell lines. Results showed that this Chilean propolis sample exhibits interesting biological properties, correlated with its chemical composition and expressed by its capacity to scavenge free radicals and to inhibit tumor cell growth.

PMID: 15556167 [PubMed - indexed for MEDLINE]

23: Biochem Biophys Res Commun. 2004 Dec 24;325(4):1215-22.

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Chrysin-induced apoptosis is mediated through caspase activation and Akt inactivation in U937 leukemia cells.

Woo KJ, Jeong YJ, Park JW, Kwon TK.

Department of Immunology, School of Medicine, Keimyung University, 194 DongSan-Dong Jung-Gu, Taegu 700-712, Republic of Korea.

Chrysin is a natural, biologically active compound extracted from many plants, honey, and propolis. It possesses potent anti-inflammation, anti-cancer, and anti-oxidation properties. The mechanism by which chrysin initiates apoptosis remains poorly understood. In the present report, we investigated the effect of chrysin on the apoptotic pathway in U937 human promonocytic cells. We show that chrysin induces apoptosis in association with the activation of caspase 3 and that Akt signal pathway plays a crucial role in chrysin-induced apoptosis in U937 cells. Furthermore, we have shown that inhibition of Akt phosphorylation in U937 cells by the specific PI3K inhibitor, LY294002 significantly, enhanced apoptosis. Overexpression of a constitutively active Akt (myr-Akt) in U937 cells inhibited the induction of apoptosis, activation of caspase 3, and PLC-gamma1 cleavage by chrysin. Together, these findings suggest that the Akt pathway plays a major role in regulating the apoptotic response of human leukemia cells to chrysin and raise the possibility that combined interruption of chrysin and PI3K/Akt-related pathways may represent a novel therapeutic strategy in hematological malignancies.

PMID: 15555556 [PubMed - indexed for MEDLINE]

24: Oncol Res. 2004;14(9):415-26.

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Resveratrol and propolis as necrosis or apoptosis inducers in human prostate carcinoma cells.

Scifo C, Cardile V, Russo A, Consoli R, Vancheri C, Capasso F, Vanella A, Renis M.

Department of Biological Chemistry, Medicinal Chemistry and Molecular Biology, University of Catania, Viale Andrea Doria, 6, 95125 Catania, Italy.

Vegetables and fruit help the prevention and the therapy of several kinds of cancer because they contain micronutrients, a class of substances that have been shown to exhibit chemopreventive and chemotherapeutic activities. In the present study the effects of resveratrol (100 and 200 microM), a phytoalexin found in grapes, and of the ethanolic extract of propolis (50 and 100 microg/ml), a natural honeybee hive product, were tested in androgen-resistant prostate cancer cells (DU145), a cell line resembling the last stage of prostate carcinoma. A comparison between the activity of these micronutrients and vinorelbine bitartrate (Navelbine), a semi-synthetic drug normally used in the therapy of prostate cancer, was conducted. Several biochemical parameters were tested, such as cell viability (MTT assay), cell membrane integrity (lactate dehydrogenase release), cell redox status (nitric oxide formation, reactive oxygen species production, reduced glutathione levels), genomic DNA fragmentation (COMET assay) with special attention on the presence of apoptotic DNA damage (TUNEL test), and possible mitochondrial transmembrane potential alteration (deltapsi). Our results point out the anticancer activity of resveratrol and propolis extract in human prostate cancer, exerting their cytotoxicity through two different types of cell death: necrosis and apoptosis, respectively. The data obtained suggest the possible use of these micronutrients both in alternative to classic chemotherapy, and in combination with very low dosage of vinorelbine (5 microM).

PMID: 15490973 [PubMed - indexed for MEDLINE]

25: J Agric Food Chem. 2004 May 19;52(10):3083-8.

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Identification of metabolites in plasma and urine of Uruguayan propolis-treated rats.

Kumazawa S, Shimoi K, Hayashi K, Ishii T, Hamasaka T, Nakayama T.

Laboratory of Functional Food Science and COE Program in the 21st Century, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.

Propolis is a resinous substance collected by honeybees from various plant sources. It is extensively used in food and beverages to improve health and prevent diseases such as heart disease, diabetes, and cancer. To investigate the absorption and metabolism of the components in propolis, in the present study, we administered ethanol extracts of Uruguayan propolis (poplar type propolis) orally to rats and analyzed their plasma and urine by high-performance liquid chromatography with photodiode array and mass spectrometric detection. After deconjugation of the components by beta-glucuronidase/sulfatase treatment of the specimen, pinobanksin 5-methyl ether, pinobanksin, kaempferol, chrysin, pinocembrin, and galangin were detected in plasma of rats orally administered propolis. These compounds were detected also in urine after beta-glucuronidase/sulfatase treatment. Furthermore, pinobanksin 5-methyl ether, pinobanksin, chrysin, pinocembrin, and galangin were present in the urine also in free form. These results suggest that flavonoids in propolis are metabolized and circulate in the body after oral administration of propolis.

PMID: 15137857 [PubMed - indexed for MEDLINE]

26: Biol Pharm Bull. 2004 May;27(5):727-30.

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Inhibitory effect of propolis on the growth of human leukemia U937.

Aso K, Kanno S, Tadano T, Satoh S, Ishikawa M.

Department of Pharmacology and Toxicology, Cancer Research Institute, Tohoku Pharmaceutical University, Sendai, Japan.

We have investigated the effect of propolis (CB Propolis) on the growth of human histiocytic lymphoma U937 cells. We found that propolis strongly inhibited the growth of the cells and macromolecular synthesis in a dose- and time-dependent manner by apoptosis. Propolis at 0.015-0.5 microl/ml showed antitumor activity with an IC(50) of 0.18 microl/ml for 3 d. It also inhibits DNA, RNA and protein synthesis with an IC(50) of 0.08, 0.17 and 4.3 microl/ml, respectively. The inhibitory effect on DNA synthesis was partially irreversible. Moreover, an apoptotic DNA ladder and chromatin condensation were observed in the same concentration range in which cell growth was inhibited. The caspase inhibitor, Z-Asp-CH(2)-DCB, prevented DNA fragmentation. These results suggest that the antitumor activity of propolis occurs through the induction of apoptosis. Propolis may be useful as a cancer chemopreventive and chemotherapeutic agent.

PMID: 15133255 [PubMed - indexed for MEDLINE]

27: J Exp Zoolog A Comp Exp Biol. 2004 May 1;301(5):389-400.

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Stage-dependent modulation of limb regeneration by caffeic acid phenethyl ester (CAPE)--immunocytochemical evidence of a CAPE-evoked delay in mesenchyme formation and limb regeneration.

Brudzynski K, Carlone R.

Bee-Biomedicals Inc. St. Catharines, Ontario, Canada L2T 3T4.

Caffeic acid phenethyl ester (CAPE), a natural compound of bee propolis, selectively inhibits proliferation of transformed cells in several cancer models in vitro. To examine in vivo CAPE function, we used the newt regeneration blastema as a model system wherein the processes of de-differentiation and subsequent proliferation of undifferentiated cells mimic changes associated with oncogenic transformation and tumorigenesis. We have shown that a single dose of CAPE significantly increased cell proliferation at the stages of blastema growth and re-differentiation. At the de-differentiation stage, CAPE significantly stimulated proliferation of wound epidermis keratinocytes, but decreased proliferation in the blastema mesenchyme. Immunohistochemistry with a mesenchymal cell marker, vimentin, revealed a highly significant reduction of vimentin staining in the mesenchyme of CAPE-treated regenerates (p<0.001). These results, together with morphological observations indicate that, at the de-differentiation stage, CAPE stimulated wound re-epithelization, increased keratinocyte proliferation and increased thickness of the wound epidermis. However, CAPE inhibited mesenchyme formation and proliferation. The functional consequence of the CAPE inhibitory action was a delay in limb regeneration.
Copyright 2004 Wiley-Liss, Inc.

PMID: 15114646 [PubMed - indexed for MEDLINE]

28: Nutr Cancer. 2003;47(2):156-63.

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Inhibitory effect of water-soluble derivative of propolis and its polyphenolic compounds on tumor growth and metastasizing ability: a possible mode of antitumor action.

Orsolic N, Sver L, Terzic S, Tadic Z, Basic I.

Department of Animal Physiology, Faculty of Science, University of Zagreb, Zagreb, Croatia.

Polyphenolic compounds are widely distributed in the plant kingdom and display a variety of biological activities, including chemoprevention and tumor growth inhibition. Propolis is made up of a variety of polyphenolic compounds. We compared how the routes of administration of polyphenolic compounds deriving from propolis and of propolis itself affect the growth and metastatic potential of a transplantable mammary carcinoma (MCa) of the CBA mouse. The influence of tested compounds on local tumor growth was also studied. Metastases in the lung were generated by 2 x 10(5) tumor cells injected intravenously (IV). A water-soluble derivative of propolis (WSDP) and polyphenolic compounds (caffeic acid, CA, and CA phenethyl ester, CAPE) were given to mice per os (PO) or intraperitoneally (IP) before or after tumor cell inoculation. Tested compounds significantly decreased the number of lung colonies. When mice were inoculated with 10(5) MCa cells in the exact site of subcutaneous injection of different doses of WSDP, CA, or CAPE, tumor growth was inhibited, and survival of treated mice was prolonged. Antitumor activity, according to the results obtained, is mostly related to the immunomodulatory properties of the compounds and their capacity to induce apoptosis and necrosis. In conclusion, results presented here indicate that WSDP, CA, and CAPE could be potential useful tools in the control of tumor growth in experimental tumor models when administrated PO; because PO administration is the easiest way of introducing a compound used for prevention and/or cure of any disease, it is likely that this article has reached the goal of the investigation.

PMID: 15087268 [PubMed - indexed for MEDLINE]

29: Arch Biochem Biophys. 2004 Apr 15;424(2):181-8.

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Antioxidative bioavailability of artepillin C in Brazilian propolis.

Shimizu K, Ashida H, Matsuura Y, Kanazawa K.

Department of Life Science, Graduate School of Science and Technology, Kobe University, Rokkodai, Nada-ku, Kobe 657-8501, Japan.

Propolis has strong antioxidative activity. We investigated here whether this activity was available in intestinal Caco-2 and hepatic HepG2 cells. Phenolics in Brazilian propolis, extracted with ethyl acetate after the removal of resin and wax with 90% methanol, included artepillin C at 21 mmol/100 g, p-coumaric acid and cinnamic acid relatives 24mmol, kaempferol and its derivatives 9.4 mmol, naringenin 2.8 mmol, isosakuranetin 0.9 mmol, chrysin at 0.8 mmol/100 g, and several minor components. When the extract was added to the apical side of Caco-2 monolayers, artepillin C was specifically incorporated into the cells and released to the basolateral side mostly without conjugation. Then, artepillin C was added to HepG2 cells and exposed to reactive oxygens. Artepillin C prevented oxidative damage dose-dependently, and suppressed lipid peroxidation evaluated with thiobarbituric acid reactive substances by 16% and the formation of 8-hydroxy-2'-deoxyguanosine in DNA by 36% at a concentration of 20microM. Artepillin C is a bioavailable antioxidant.

PMID: 15047190 [PubMed - indexed for MEDLINE]

30: J Med Food. 2003 Winter;6(4):387-90.

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Effects of chrysin on urinary testosterone levels in human males.

Gambelunghe C, Rossi R, Sommavilla M, Ferranti C, Rossi R, Ciculi C, Gizzi S, Micheletti A, Rufini S.

Department of Clinical and Experimental Medicine, Division of Sports Medicine-Laboratorio delle Attivita Motorie e Sportive, University of Perugia, Perugia, Italy.

The equilibrium of sexual hormones in both sexes is controlled in vertebrates by the enzyme aromatase, a member of the cytochrome P450 superfamily, which catalyzes the conversion of androstenedione and testosterone into estrone and estradiol, respectively. Flavonoids are diphenolic compounds present in whole grains, legumes, fruits, and vegetables that are strongly implicated as protective in coronary heart disease, stroke, and cancer. One flavonoid, chrysin, found in high concentrations in honey and propolis, has been shown to be an inhibitor of aromatase enzyme activity. These foods are often used as supplements, particulary by sportsmen for their energetic and antioxidant properties. The aim of this study was to verify if daily treatment for 21 days with propolis and honey, containing chrysin, would modify urinary concentrations of testosterone in volunteer male subjects. In fact, aromatase inhibition by chrysin could block the conversion of androgens into estrogens with a consequent increase of testosterone, eventually measurable in urine samples. The obtained data did not show alterations of the levels of testosterone in the volunteers after 7, 14, and 21 days of treatment in comparison with baseline values and compared with measurements on the control subjects at the same time. In conclusion, the use of these foods for 21 days at the doses usually taken as oral supplementation does not have effects on the equilibrium of testosterone in human males.

PMID: 14977449 [PubMed - indexed for MEDLINE]

31: J Agric Food Chem. 2003 Dec 31;51(27):7907-12.

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Inhibitory effect of caffeic acid phenethyl ester on angiogenesis, tumor invasion, and metastasis.

Liao HF, Chen YY, Liu JJ, Hsu ML, Shieh HJ, Liao HJ, Shieh CJ, Shiao MS, Chen YJ.

Department of Medical Research and Radiation Oncology, Mackay Memorial Hospital, Taipei 104, Taiwan.

Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine and has several proven biological activities. The present study investigated the effect of CAPE on angiogenesis, tumor invasion, and metastasis. A cytotoxicity assay of CAPE in CT26 colon adenocarcinoma cells showed a dose-dependent decrease in cell viability but no significant influence on the growth of human umbilical vein epithelial cells (HUVEC). A low concentration of CAPE (1.5 microg/mL) inhibited 52.7% of capillary-like tube formation in HUVEC culture on Matrigel. CAPE (6 microg/mL)-treated CT26 cells showed not only inhibited cell invasion by 47.8% but also decreased expression of matrix metalloproteinase (MMP)-2 and -9. Vascular endothelial growth factor (VEGF) production from CT26 cells was also inhibited by treatment with CAPE (6 microg/mL). Intraperitoneal injection of CAPE (10 mg/kg/day) in BALB/c mice reduced the pulmonary metastatic capacity of CT26 cells accompanied with a decreased plasma VEGF level. CAPE treatment also prolonged the survival of mice implanted with CT26 cells. These results indicate that CAPE has potential as an antimetastatic agent.

PMID: 14690372 [PubMed - indexed for MEDLINE]

32: Biochem Pharmacol. 2004 Jan 1;67(1):53-66.

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Propolin C from propolis induces apoptosis through activating caspases, Bid and cytochrome c release in human melanoma cells.

Chen CN, Wu CL, Lin JK.

Graduate Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Section 1, Jen-Ai Road, 100, ROC, Taipei, Taiwan.

We had demonstrated that two prenylflavanones, propolin A and propolin B, isolated and characterized from Taiwanese propolis, induced apoptosis in human melanoma cells and significantly inhibited xanthine oxidase activity. Here, we have isolated a third compound called propolin C. The chemical structure of propolin C has been characterized by NMR and HRMS spectra, and was identical to nymphaeol-A. However, no biological activities of this compound have ever been reported. In the present study, propolin C effectively induced a cytotoxic effect on human melanoma cells, with an IC(50) of about 8.5 microM. DNA flow cytometric analysis indicated that propolin C actively induced apoptosis in human melanoma cells and there is a marked loss of cells from the G2/M phase of the cell cycle. To address the mechanism of the apoptosis effect of propolin C, we evaluated the effect of propolin C on induction of apoptosis-related proteins in human melanoma cells. The levels of procaspase-8, Bid, procaspase-3, and poly(ADP-ribose) polymerase were decreased in dose- or time course-dependent manners. Moreover, propolin C was capable of releasing cytochrome c from mitochondria to cytosol. The findings suggest that propolin C may activate a mitochondria-mediated apoptosis pathway. On other hand, propolin C is a potential antioxidant agent and shows a strong capability to scavenge free radicals and inhibit on xanthine oxidase activity with IC(50) of about 17.0microM. In conclusion, the isolation and characterization of propolin C from bee propolis are described for the first time, and this compound is a powerful inducer of apoptosis in human melanoma cells.

PMID: 14667928 [PubMed - indexed for MEDLINE]

33: Mutat Res. 2003 Nov;544(2-3):195-201.

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Dietary components may prevent mutation-related diseases in humans.

Ribeiro LR, Salvadori DM.

Programa de Pos-Graduacao em Patologia, Faculdade de Medicina de Botucatu-UNESP, 18618-000 Botucatu, SP, Brazil.

Since it is not always possible to reduce human exposure to mutagens, attempts have been directed to identify potential antimutagens and anticarcinogens for use in protecting the population against environmental disease. The purpose of this paper is to provide the reader with information about the antimutagenic and anticarcinogenic potentials of some dietary constituents and foods widely consumed in Brazil, and to reinforce diet as a key factor in determining genomic stability and preventing human diseases. In this report, we have summarized data that show interactive effects between some dietary components and specific chemical mutagens or carcinogens using in vitro and in vivo short- or medium-term assays. The summary indicates that certain dietary compounds may be useful agents for disease prevention.

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PMID: 14644321 [PubMed - indexed for MEDLINE]

34: Clin Chim Acta. 2003 Dec;338(1-2):11-6.

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Protective role of Egyptian propolis against tumor in mice.

El-khawaga OA, Salem TA, Elshal MF.

Chemistry Department, Faculty of Science, Mansoura University, Mansoura City, Egypt.

BACKGROUND: Propolis has numerous biologic activities including antibiotic, antifungal, antiviral and anti-inflammatory properties. The present work is aimed to study the effect of crude Egyptian propolis on tumor in mice induced by Ehrlich ascitis carcinoma (EAC) cell line. RESULTS: The administration of propolis (160 mg/kg body weight), by gastric intubation 2 h before the intraperitoneal injection of EAC, effectively inhibited tumor growth and the proliferation of EAC. The tumor volume was markedly reduced from 7+/-0.9 ml in EAC-infected mice to 1.6+/-0.95 ml in propolis-treated mice. Also, the lipid peroxide level which was 13.3+/-1.24 nmol malodialdehyde (MDA)/mg protein in EAC infected mice was significantly decreased to 3.3+/-2.1 nmol MDA/mg protein. Reduced glutathione (GSH) and glutathione S-transferase (GST) concentrations were markedly increased in propolis-treated mice. This effect was associated with inhibition of cell cycle progression and induction of apoptosis. Administration of propolis 2 h before injection of EAC arrested cells in G0/G1 phase and resulted in a decrease in the viability, DNA, total RNA and protein level of tumor cells. CONCLUSIONS: Crude Egyptian propolis has a strong inhibitory activity against tumors. The anti-tumor mechanism may be mediated by preventing oxidative damage and induction of apoptosis.

PMID: 14637260 [PubMed - indexed for MEDLINE]

35: Biochem Pharmacol. 2003 Dec 15;66(12):2281-9.

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Involvement of tumor suppressor protein p53 and p38 MAPK in caffeic acid phenethyl ester-induced apoptosis of C6 glioma cells.

Lee YJ, Kuo HC, Chu CY, Wang CJ, Lin WC, Tseng TH.

Department of Chemistry, National Changhua University of Education, Changhua, Taiwan, ROC.

Caffeic acid phenethyl ester (CAPE), an active component of propolis, has many biological and pharmacological activities including antioxidant, anti-inflammation, antiviral action, and anticancer effect. Our previous studies showed that CAPE exhibited significant cytotoxicity in oral cancer cells. Herein we further investigated the cytotoxicity potential of CAPE and the mechanism of its action in C6 glioma cells. The data exhibited that C6 glioma cells underwent internucleosomal DNA fragmentation 24 hr after the treatment of CAPE (50 microM). The proportion of C6 glioma cells with hypodiploid nuclei was increased to 24% at 36 hr after the exposure. Further results showed that CAPE induced the release of cytochrome c from mitochondria into cytosol, and the activation of CPP32. CAPE application also enhanced the expression of p53, Bax, and Bak. Finally, the potential signaling components underlying CAPE induction of apoptosis were elucidated. We found that CAPE activated extracellular signal-regulated kinase (ERKs) and p38 mitogen-activated protein kinase (p38 MAPK) in C6 glioma cells. More importantly, p38 kinase formed a complex with p53 after the treatment of CAPE for 0.5 hr. The expression of p53, phospho-serine 15 of p53, and Bax, and inactivate form of CPP32 was suppressed by a pretreatment of a specific p38 MAPK inhibitor, SB203580. The resultant data suggest that p38 MAPK mediated the CAPE-induced p53-dependent apoptosis in C6 glioma cells.

PMID: 14637186 [PubMed - indexed for MEDLINE]

36: Biol Pharm Bull. 2003 Jul;26(7):1057-9.

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Cell growth inhibitory effect of cinnamic acid derivatives from propolis on human tumor cell lines.

Akao Y, Maruyama H, Matsumoto K, Ohguchi K, Nishizawa K, Sakamoto T, Araki Y, Mishima S, Nozawa Y.

Gifu International Institute of Biotechnology, Kakamigahara, Japan.

A cell growth inhibitory effect of drupanin and baccharin, ingredients of propolis, was found in human cancer cell lines. These compounds induced apoptosis in the cells characterized by morphological and nucleosomal DNA fragmentation analysis. Their effects were less potent compared with that of artepillin C, which is a known anticancer compound from propolis. Importantly, HL60 cells were more sensitive to drupanin than were Con A-stimulated peripheral blood lymphocytes, whereas the potency of artepillin C was the opposite of that of drupanin.

PMID: 12843641 [PubMed - indexed for MEDLINE]

37: J Nat Prod. 2003 Apr;66(4):503-6.

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Cytotoxic prenylflavanones from Taiwanese propolis.

Chen CN, Wu CL, Shy HS, Lin JK.

Graduate Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-ai Road, Taipei, Taiwan 100, Republic of China.

Two new prenylflavanones, propolin A (2) and propolin B (3), were isolated and characterized from Taiwanese propolis. Both compounds were found to have cytotoxic properties against three cancer cell lines. DNA content analyses and DNA fragmentation indicated that propolin A (2) efficiently induced apoptosis in cancer cell lines, but had no effect on the cell cycle program. Furthermore, both propolin A (2) and B (3) are potential antioxidant agents and show strong scavenging effects against most types of free radicals.

PMID: 12713401 [PubMed - indexed for MEDLINE]

38: Cancer Lett. 2003 Apr 25;193(2):155-9.

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Inhibitory effects of propolis granular A P C on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis in A/J mice.

Sugimoto Y, Iba Y, Kayasuga R, Kirino Y, Nishiga M, Alejandra Hossen M, Okihara K, Sugimoto H, Yamada H, Kamei C.

Department of Pharmacology, Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan.

We examined the effect of propolis granular A. P. C on lung tumorigenesis in female A/J mice. Lung tumors were induced by the tobacco-specific carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) administered in drinking water for 7 weeks in mice maintained on an AIN-76A semi-synthetic diet. Propolis granular A. P. C (100 mg/kg body wt.) was administered orally daily for 6 days/week from 1 week before NNK administration and throughout the experiment. Sixteen weeks after the NNK treatment, the mice were killed and the number of surface lung tumors was measured. The number of lung tumors in mice treated with NNK alone for 7 weeks (9.4 mg/mouse) was significantly more than in that observed in control mice. Propolis granular A. P. C significantly decreased the number of lung tumors induced by NNK. These results indicate that propolis granular A. P. C is effective in suppressing NNK-induced lung tumorigenesis in mice.

PMID: 12706872 [PubMed - indexed for MEDLINE]

39: J Ethnopharmacol. 2003 Feb;84(2-3):265-73.

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Immunomodulation by water-soluble derivative of propolis: a factor of antitumor reactivity.

Orsolic N, Basic I.

Department of Animal Physiology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10 000 Zagreb, Croatia.

The antimetastatic efficacy of a water-soluble derivative of propolis (WSDP) was studied. Tumor was a transplantable mammary carcinoma of CBA mouse. Metastases in the lung were generated by 2 x 10(5) viable tumor cells i.v. WSDP was given intraperitoneally at doses of 50 or 150 mg/kg before or after tumor cell inoculation. Therapies reduced the number of metastases in the lung and tumor growth was suppressed significantly by WSDP. It is likely that antimetastatic activity of the WSDP is mainly mediated by immunomodulatory activity. Changes in several immunological parameters such as production of lymphocyte activating factor by peritoneal macrophages and the efficacy of those macrophages to kill tumor cell in vitro, responses of lymphocytes to mitogen, and weight and cellularity of spleen, respectively, correlated well with antimetastatic properties of the WSDP. Based on results we postulate that the antimetastatic activity of propolis includes a pronounced immunomodulatory activity mainly toward augmentation of nonspecific antitumor resistance in mice via macrophage activation. Copyright 2002 Elsevier Science Ireland Ltd.

PMID: 12648825 [PubMed - indexed for MEDLINE]

40: Fitoterapia. 2002 Nov;73 Suppl 1:S38-43.

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Effect of a propolis extract and caffeic acid phenethyl ester on formation of aberrant crypt foci and tumors in the rat colon.

Borrelli F, Izzo AA, Di Carlo G, Maffia P, Russo A, Maiello FM, Capasso F, Mascolo N.

Department of Experimental Pharmacology, University of Naples 'Federico II', Via D. Montesano 49, 80131, Naples, Italy.

We have studied the effect of propolis and its main active ingredient caffeic acid phenetyl ester (CAPE) on formation of aberrant crypt foci (ACF) and tumors in the rat colon in vivo. CAPE (50 mg/kg i.p.) reduced the formation of ACF and tumor induced by azoxymethane, while propolis ethanolic extract was without effect. These results suggest a potential anti-carcinogenesis of CAPE but not propolis.

PMID: 12495708 [PubMed - indexed for MEDLINE]

41: Cancer Biother Radiopharm. 2002 Oct;17(5):553-62.

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Antitumor and anticytopenic effects of aqueous extracts of propolis in combination with chemotherapeutic agents.

Suzuki I, Hayashi I, Takaki T, Groveman DS, Fujimiya Y.

Department of Clinical Nutrition, Faculty of Health Sciences, Suzuka University of Medical Science, Suzuka, Mie 510-0293, Japan.

Using an ICR mouse model bearing a syngeneic Ehrlich ascitis carcinoma, the present study was undertaken to examine the effects of crude, water-soluble propolis (CWSP) on tumor progression, chemotherapeutic efficacy, and hematopoiesis in the peripheral blood. It was demonstrated that CWSP, administered subcutaneously, resulted in marked regression of tumor growth in mice, at the early phase after tumor inoculation (CWSP, p < 0.05 vs. saline control). Molecular analysis indicated that the CWSP is composed of 8.4% protein, 4.2% quercetin plus a variety of saccharides with a molecular weight of 29 kDa. Orally administered CWSP did not produce any regression for the observation period (oral CWSP, p > 0.05 vs. saline control). Peritoneal injection of CWSP into neonatal mice resulted in an increased lymphocyte/polymorphonuclear leukocyte ratio activity, indicating the potential activation of lymphoid cell lineages. These observations suggest that subcutaneously injected CWSP could regulate the development of tumors by possibly stimulating multicellular immunity. In addition, oral administration of CWSP concurrently with 5-fluorouracil (5-FU) or mitomycin C (MMC), significantly increased tumor regression as compared with the respective chemotherapy alone, illustrating the adjuvant effect of orally administered CWSP for tumor regression when combined with chemotherapeutic agents. To examine further the potential usefulness of CWSP for chemotherapeutic regimens, which induce profound multilineage hematopoietic suppression, mice that received CWSP orally in addition to a 5-FU or MMC were followed for absolute numbers of platelets and white and red blood cells. The oral administration of CWSP significantly ameliorated the cytopenia induced by 5-FU, resulting in recovery of white as well as red blood cell counts (5-FU plus CWSP, p < 0.05 vs. 5-FU alone or water control; white blood cells on day 15, red blood cells on day 25), but no marked effects on platelet counts was observed (5-FU plus CWSP, p > 0.05 vs. 5-FU alone or water control). On the other hand, CWSP significantly reduced all three MMC-induced cytopenias, especially at the later stage of the chemotherapeutic course (after day 30), suggesting repetitive requirements of oral administration of CWSP. In summary, subcutaneous administration of an aqueous CWSP resulted in marked regression of transplanted tumors. Orally administered CWSP combined with chemotherapeutic agents significantly increased tumor regression and ameliorated the cytopenia induced by the chemotherapeutic agents alone. These results suggest the benefits of potential clinical trials using CWSP combined with chemotherapeutic agents in order to maximize enhanced immunity while potentially minimizing postchemotherapeutic deteriorated reactions.

PMID: 12470425 [PubMed - indexed for MEDLINE]

42: Isr Med Assoc J. 2002 Nov;4(11 Suppl):919-22.

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       Isr Med Assoc J. 2002 Nov;4(11 Suppl):944-6.

The effect of herbal remedies on the production of human inflammatory and anti-inflammatory cytokines.

Barak V, Birkenfeld S, Halperin T, Kalickman I.

Immunology Laboratory for Tumor Diagnosis, Department of Oncology, Hadassah University Hospital, Jerusalem, Israel.

BACKGROUND: Some herbal remedies are sold as food additives and are believed to have immune-enhancing properties. OBJECTIVES: To study the effect of five herbal remedies--Sambucol Black Elderberry Extract, Sambucol Active Defense Formula and Sambucol for Kids (with known antiviral properties), Protec and Chizukit N (containing propolis and Echinacea, claimed to be immune enhancers)--on the production of cytokines, one of the main components of the immune system. METHODS: The production of four inflammatory cytokines (interleukin-1 beta, tumor necrosis factor alpha, and IL-6 and IL-8) and one anti-inflammatory cytokine (IL-10) was tested using blood-derived monocytes from 12 healthy donors. RESULTS: The Sambucol preparations increased the production of five cytokines (1.3-6.2 fold) compared to the control. Protec induced only a moderate production of IL-8 (1.6 fold) and IL-10 (2.3 fold) while Chizukit N caused only a moderate increase in IL-10 production (1.4 fold). Both Protec and Chizukit N caused moderate decreases in IL-1 beta, TNF alpha and IL-6 production. Lipopolysaccharide, a known activator of monocytes, induced the highest levels of cytokine production (3.6-10.7 fold). CONCLUSIONS: The three Sambucol formulations activate the healthy immune system by increasing inflammatory and anti-inflammatory cytokines production, while the effect of Protec and Chizukit N is much less. Sambucol could therefore have immunostimulatory properties when administered to patients suffering from influenza (as shown before), or immunodepressed cancer or AIDS patients who are receiving chemotherapy or other treatments.

PMID: 12455180 [PubMed - indexed for MEDLINE]

43: J Ethnopharmacol. 2002 Oct;82(2-3):89-95.

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Estrogenic effects of ethanol and ether extracts of propolis.

Song YS, Jin C, Jung KJ, Park EH.

Bioanalysis and Biotransformation Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul, South Korea.

Propolis obtained from honeybee hives has been used in Oriental folk medicine as an anti-inflammatory, anti-carcinogenic, or immunomodulatory agent. The potential estrogenic activity of propolis was investigated in vitro using the MCF-7 human breast cancer cell proliferation, human estrogen receptor (hER) binding and yeast-based steroid receptor transcription, and in vivo using the immature rat uterotrophic effect. Treatments with ethanol extract of propolis (EEP) and ether extract of propolis (REP) enhanced MCF-7 cell proliferation in concentrations ranging from 0.8 to 4 microg/ml. Both EEP and REP competed for binding of [3H]17beta-estradiol to the hER with IC(50) values of 9.14 and 9.72 microg/ml, respectively. In yeast estrogen receptor transcription assay, both EEP and REP were found to be estrogenic with EC(50) values of 9.48, and 8.55 microg/ml, respectively. Animals treated with EEP or REP for 4 days (500-1000 mg/kg per day, s.c.) exhibited significant dose-dependent increases in uterine wet weight. However, in the yeast androgen and progesterone receptor transcription assays, either EEP or REP was found not to be active. The results suggest that propolis produces estrogenic effects through activation of estrogen receptors.

PMID: 12241982 [PubMed - indexed for MEDLINE]

44: Z Naturforsch [C]. 2002 Mar-Apr;57(3-4):372-8.

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Polyisoprenylated benzophenones in cuban propolis; biological activity of nemorosone.

Cuesta-Rubio O, Frontana-Uribe BA, Ramirez-Apan T, Cardenas J.

Instituto de Farmacia y Alimentos, Universidad de la Habana, Cuba.

The Copey tree (Clusia rosea) has a large distribution in Cuba and its floral resin is a rich source of polyisoprenylated benzophenones. To determine the presence of these natural products, we carried out a study by HPLC of 21 propolis samples produced by honey bees (Apis mellifera) from different provinces of Cuba. Nemorosone resulted to be the most abundant polyisoprenylated benzophenone and the mixture of xanthochymol and guttiferone E was also observed, but in minor proportion. We studied the biological activity of the pure natural product nemorosone and its methyl derivatives. We found that nemorosone has cytotoxic activity against epitheloid carcinoma (HeLa), epidermoid carcinoma (Hep-2), prostate cancer (PC-3) and central nervous system cancer (U251). It also exhibited antioxidant capacity. Methylated nemorosone exhibited less biological activity than the natural product.

PMID: 12064743 [PubMed - indexed for MEDLINE]

45: J Nat Prod. 2002 May;65(5):673-6.

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Constituents of Chinese propolis and their antiproliferative activities.

Usia T, Banskota AH, Tezuka Y, Midorikawa K, Matsushige K, Kadota S.

Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, 2630-Sugitani, Toyama 930-0194, Japan.

Two new flavonoids, 3-O-[(S)-2-methylbutyroyl]pinobanksin (1) and 6-cinnamylchrysin (2), were isolated from the EtOAc-soluble fraction of the MeOH extract of Chinese propolis, along with 12 known compounds (3-14). The structures of the isolated compounds were elucidated on the basis of spectroscopic and chemical analyses. The isolated compounds were tested for their antiproliferative activity toward five different cancer cell lines. Benzyl caffeate (13) and phenethyl caffeate (14) showed potent antiproliferative activity toward tested cell lines with a selective activity toward colon 26-L5 carcinoma cell line (EC(50) values: 13, 1.01; 14, 0.30 microM).

PMID: 12027739 [PubMed - indexed for MEDLINE]

46: Teratog Carcinog Mutagen. 2002;22(3):183-94.

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Protective action of propolis on the rat colon carcinogenesis.

Bazo AP, Rodrigues MA, Sforcin JM, de Camargo JL, Ribeiro LR, Salvadori DM.

Departamento de Patologia, Faculdade de Medicina, UNESP, Botucatu, Sao Paulo, Brazil.

Propolis is a honeybee product with several biological and therapeutical properties. Its effect on the process of colon carcinogenesis and DNA damage were evaluated in the male Wistar rats using the aberrant crypt foci (ACF) assay and the comet assay, respectively. For both tests, animals were treated with the colon carcinogen 1,2 dimethylhydrazine (DMH, 40 mg/kg, s.c.) for 2 weeks (two injections/week) in order to induce both DNA damage and ACF. The animals were divided into groups that received propolis (ethanolic extract) at three different doses (10, 30, and 90 mg/kg b.w., by gavage), either simultaneously or after DMH treatment. For the comet assay, peripheral blood samples were collected 4 h after the last DMH treatment. All animals were sacrificed at the 5th week for evaluation of ACF. The results show that only the intermediate dose (30 mg/kg) of propolis, administered after DMH initiation, is significantly associated to a smaller number of aberrant crypts in the distal colon. No effect on DNA damage in peripheral blood cells, however, was verified by the comet assay. These data suggest that propolis has a protective influence on the process of colon carcinogenesis, suppressing the development of preneoplastic lesions, and probably exerts no protection against the initiation of carcinogenesis. Copyright 2002 Wiley-Liss, Inc.

PMID: 11948629 [PubMed - indexed for MEDLINE]

47: J Ethnopharmacol. 2002 Apr;80(1):67-73.

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Antiproliferative activity of the Netherlands propolis and its active principles in cancer cell lines.

Banskota AH, Nagaoka T, Sumioka LY, Tezuka Y, Awale S, Midorikawa K, Matsushige K, Kadota S.

Department of Natural Products Chemistry, Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, 2630-Sugitani, 930-0194, Toyama, Japan.

The MeOH extract of the Netherlands propolis showed promising antiproliferative activity toward highly liver-metastatic murine colon 26-L5 carcinoma with an EC(50) value of 3.5 microg/ml. Further, antiproliferative activity-guided purification of the MeOH extract led us to isolate four flavonoids (1-4), seven cinnamic acid derivatives (5-11) and two new glycerol derivatives (12, 13), whose structures were elucidated on the basis of spectral analysis. The isolated compounds were tested for their antiproliferative activity against murine colon 26-L5, murine B16-BL6 melanoma, human HT-1080 fibrosarcoma and human lung A549 adenocarcinoma cell lines. The benzyl (9), phenethyl (10) and cinnamyl caffeates (11) possessed potent antiproliferative activities with EC(50) values of 0.288, 1.76 and 0.114 microM, respectively, toward colon 26-L5 carcinoma. These caffeates were considered to be active constituents of the Netherlands propolis in their antiproliferative activity. The antioxidative activity of these caffeates may play an important role in their antiproliferative activities.

PMID: 11891088 [PubMed - indexed for MEDLINE]

48: Cancer Lett. 2002 Jan 10;175(1):53-61.

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Caffeic acid phenethyl ester inhibits nitric oxide synthase gene expression and enzyme activity.

Song YS, Park EH, Hur GM, Ryu YS, Lee YS, Lee JY, Kim YM, Jin C.

Bioanalysis and Biotransformation Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, 130-650, Seoul, South Korea.

Since nitric oxide (NO) synthesized by inducible nitric oxide synthase (iNOS) has been known to be involved in inflammatory and autoimmune-mediated tissue destruction, modulation of NO synthesis or action represents a new approach to the treatment of inflammatory and autoimmune diseases. Caffeic acid phenethyl ester (CAPE), an active component of honeybee propolis, has been identified to show anti-inflammatory, anti-viral and anti-cancer activities. The present study, therefore, examined effects of CAPE on iNOS expression and activity of iNOS enzyme itself. Treatment of RAW 264.7 cells with CAPE significantly inhibited NO production and iNOS protein expression induced by lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma). CAPE also inhibited iNOS mRNA expression and nuclear factor-kappa B (NF-kappaB) binding activity in a concentration-dependent manner. Furthermore, transfection of RAW 264.7 cells with iNOS promoter linked to a chloramphenicol acetyltransferase reporter gene, revealed that CAPE inhibited the iNOS promoter activity induced by LPS plus IFN-gamma through the NF-kappaB sites of the iNOS promoter. In addition, CAPE directly interfered with the catalytic activity of murine recombinant iNOS enzyme. These results suggest that CAPE may exert its anti-inflammatory effect by inhibiting the iNOS gene expression at the transcriptional level through the suppression of NF-kappaB activation, and by directly inhibiting the catalytic activity of iNOS.

PMID: 11734336 [PubMed - indexed for MEDLINE]

49: Arch Virol. 2001 Aug;146(8):1517-26.

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Effect of propolis extract on malignant cell transformation by moloney murine sarcoma virus.

Huleihel M, Ishano V.

The Institute for Applied Biosciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.

An aqueous extract of propolis was found to significantly inhibit NIH/3T3 cell malignant transformation by Moloney murine sarcoma virus (MuSV-124). The inhibitory effect of propolis extract was most effective when it was added 2 h before infection or at the time of infection. The continuous presence of propolis extract in the culture medium was essential for full prevention of malignant cell transformation. When treatment with propolis extract was terminated, five to ten days post-infection, there was a significant recovery in cell transformation. These results suggest that propolis extract inhibits a late step after provirus integration into the host genome. Addition of propolis extract after infection with MuSV significantly inhibited cell transformation. The inhibitory effect of propolis appeared to be the result of the inhibition of primary--not secondary--infections, since MuSV-124 yields a virus-nonproducing infection.

PMID: 11676414 [PubMed - indexed for MEDLINE]

50: Anticancer Res. 2001 May-Jun;21(3B):1665-71.

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PM-3, a benzo-gamma-pyran derivative isolated from propolis, inhibits growth of MCF-7 human breast cancer cells.

Luo J, Soh JW, Xing WQ, Mao Y, Matsuno T, Weinstein IB.

Herbert Irving Comprehensive Cancer Center, Columbia Presbyterian Medical Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.

Propolis has numerous biologic activities including antibiotic, antifungal, antiviral and anti-inflammatory properties. Several components isolated from propolis have been shown to have anticancer activity. This study demonstrates that the compound PM-3 (3-[2-dimethyl-8-(3-methyl-2-butenyl)benzopyran]-6-propenoic acid) isolated from Brazilian propolis markedly inhibits the growth of MCF-7 human breast cancer cells. This effect was associated with inhibition of cell cycle progression and induction of apoptosis. Treatment of MCF-7 cells with PM-3 arrested cells in the G1 phase and resulted in a decrease in the protein levels of cyclin D1 and cyclin E. PM-3 also inhibited the expression of cyclin D1 at the transcriptional level when examined in cyclin D1 promoter luciferase assays. Induction of apoptosis by PM-3 occurred within 48 hours after treatment of MCF-7 cells. The MCF-7 treated cells also displayed a decrease in the level of the estrogen receptor (ER) protein and inhibition of estrogen response element (ERE) promoter activity. Therefore, PM-3 merits further investigation with respect to breast cancer chemoprevention or therapy.

PMID: 11497245 [PubMed - indexed for MEDLINE]

51: Mol Carcinog. 2001 Jun;31(2):83-9.

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Suppression of cell transformation and induction of apoptosis by caffeic acid phenethyl ester.

Nomura M, Kaji A, Ma W, Miyamoto K, Dong Z.

Hormel Institute, University of Minnesota, Austin, Minnesota 55912, USA.

Caffeic acid phenethyl ester (CAPE), which is derived from the propolis of honeybee hives, has been shown to block tumor promotion and to have toxic effects on several cancer cells. The mechanism of the anti-tumor promotion activity of CAPE is unclear, however. In this study, we found that CAPE suppressed 12-O-tetradecanoylphorbol-13-acetate-induced cell transformation and induced apoptosis in mouse epidermal JB6 Cl 41 cells. No difference in induction of apoptosis was observed between normal lymphoblasts and sphingomyelinase-deficient cell lines. Although CAPE treatment of two p53 mutant tumor cell lines, NCI-H358 and SK-OV-3, and p53-deficient (p53(-/-)) cells caused the cleavage of caspase-3 as well as DNA fragmentation, caspase-3 cleavage was seen early (at 6 h) only in cells expressing wild-type p53 (p53(+/+)) and Cl 41 cells. These results suggested that p53 may be involved in the early stage of CAPE-induced apoptosis. The p53-dependent transcription activation occurred 2 h after treatment with CAPE and reached a maximum at 6 h in Cl 41 p53 DNA-binding sequence stable transfectant cells. In addition, phosphorylation of p53 at serine 15 and serine 392 was induced in Cl 41 cells within 6 h after treatment with CAPE. Therefore, CAPE may induce apoptosis through p53-dependent and p53-independent pathways and its anti-tumor promotion activity may have occurred through the induction of apoptosis. Copyright 2001 Wiley-Liss, Inc.

PMID: 11429785 [PubMed - indexed for MEDLINE]

52: Mutat Res. 2001 May;488(2):135-50.

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Anti-genotoxicity of galangin as a cancer chemopreventive agent candidate.

Heo MY, Sohn SJ, Au WW.

College of Pharmacy, Kangwon National University, Chunchon 200, South Korea.

Flavonoids are polyphenolic compounds that are present in plants. They have been shown to possess a variety of biological activities at non-toxic concentrations in organisms. Galangin, a member of the flavonol class of flavonoid, is present in high concentrations in medicinal plants (e.g. Alpinia officinarum) and propolis, a natural beehive product. Results from in vitro and in vivo studies indicate that galangin with anti-oxidative and free radical scavenging activities is capable of modulating enzyme activities and suppressing the genotoxicity of chemicals. These activities will be discussed in this review. Based on our review, galangin may be a promising candidate for cancer chemoprevention.

Publication Types:


PMID: 11344041 [PubMed - indexed for MEDLINE]

53: Virchows Arch. 2001 Mar;438(3):259-70.

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Pulmonary carcinogenesis induced by ferric nitrilotriacetate in mice and protection from it by Brazilian propolis and artepillin C.

Kimoto T, Koya-Miyata S, Hino K, Micallef MJ, Hanaya T, Arai S, Ikeda M, Kurimoto M.

Hayashibara Biochemical Laboratories Inc., Fujisaki Institute, Fujisaki 675-1, Okayama 702-8006, Japan.

In experiments using the renal carcinogen ferric nitrilotriacetate (Fe-NTA) in male ddY mice, primary pulmonary cancers were also induced in bronchiolar and alveolar tissues. 4-Hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), products of oxidative processes, increased in bronchiolar and alveolar cells after administration of Fe-NTA. These substances disappeared after oral administration of propolis or artepillin C, as shown histochemically, and correlated with an anticancer prophylactic effect of propolis and artepillin C. From our investigation, lipid peroxidation seems to play an important role in pulmonary carcinogenesis. Malignant progression from adenoma of bronchiolar or alveolar origin to malignant tumors has been proposed to involve a stepwise transformation. In our study, adenomas developed into adenocarcinomas and large cell carcinomas after treatment with Fe-NTA. In contrast, after oral administration of propolis or artepillin C, adenomas did not progress to carcinomas. Instead of developing into large cell cancers, as induced by Fe-NTA in control mice, adenomas showed remarkable proliferation of macrophages and local anti-oxidant activity after treatment with either propolis or artepillin C. Propolis and artepillin C therefore appear to inhibit lipid peroxidation and the development of pulmonary cancers.

PMID: 11315623 [PubMed - indexed for MEDLINE]

54: Anticancer Res. 2001 Jan-Feb;21(1A):221-8.

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Apoptosis of human leukemia cells induced by Artepillin C, an active ingredient of Brazilian propolis.

Kimoto T, Aga M, Hino K, Koya-Miyata S, Yamamoto Y, Micallef MJ, Hanaya T, Arai S, Ikeda M, Kurimoto M.

Fujisaki Institute, Hayashibara Biochemical Laboratories Inc., Fujisaki 675-1, Okayama 702-8006, Japan.

Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) is an active ingredient of Brazilian propolis that possesses anti-tumor activity. When Artepillin C was applied to human leukemia cell lines of different phenotypes, namely, lymphocytic leukemia (7 cell lines of T-cell, 5 cell lines of B-cell), myeloid and monocytic leukemia and non-lymphoid non-myeloid leukemia cell lines in vitro, Artepillin C exhibited potent cytocidal effects and induced marked levels of apoptosis in all the cell lines. The most potent effects were observed in the T-cell lines. Apoptotic bodies and DNA fragmentation were induced in the cell lines after exposure to Artepillin C. DNA synthesis in the leukemia cells was clearly inhibited and disintegration of the cells was confirmed microscopically. Apoptosis of the leukemia cells may be partially associated with enhanced Fas antigen expression and loss of mitochondrial membrane potential. In contrast, although Artepillin C inhibited the growth of pokeweed mitogen (PWM)-stimulated normal blood lymphocytes, it was not cytocidal to normal unstimulated lymphocytes. These results suggested that Artepillin C, an active ingredient of Brazilian propolis, has anti-leukemic effects with limited inhibitory effects on normal lymphocytes.

PMID: 11299738 [PubMed - indexed for MEDLINE]

55: In Vivo. 2001 Jan-Feb;15(1):17-23.

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Diverse biological activities of healthy foods.

Kobayashi N, Unten S, Kakuta H, Komatsu N, Fujimaki M, Satoh K, Aratsu C, Nakashima H, Kikuchi H, Ochiai K, Sakagami H.

Fujimi Bee House, Shiki, Saitama, Japan.

Diverse biological activities of 7 healthy foods [powdered pine needle, citrate-fermented sesame, powdered coffee, royal jelly, propolis, pollen and white sesame oil (extracted by super critical state (40 degrees C, 350 atmospheric pressure))] were investigated. The pine needle, sesame and powdered coffee was also extracted successively by ethanol and hot water, and lyophilized. The pine needle and coffee extracts, and propolis showed higher in vitro cytotoxic, bactericidal and oxidation activity, as compared with other 4 lipophilic healthy foods. However, propolis showed slightly lower, but significant cytotoxic and bactericidal activity with much reduced oxidation potential. ESR spectroscopy demonstrated that the cytotoxic activity of these extracts was closely related to their radical generation and O2- scavenging activities. Healthy food components may have both pro-oxidant and anti-oxidant properties. Pre-treatment of mice with pine needle, sesame or powdered coffee extract significantly reduced the lethality of bacterial infection, possibly due to their host-mediated action. These extracts failed to reduce the cytophatic effect of HIV-1 (human immunodeficiency virus) infection in MT-4 cells. No apparent acute toxicity was detected in mice by oral administration of 10 g/kg of these extracts. This data suggest the medicinal efficacy of healthy foods.

PMID: 11286123 [PubMed - indexed for MEDLINE]

56: Nutr Cancer. 2000;37(2):179-86.

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Modifying effects of propolis on MeIQx promotion of rat hepatocarcinogenesis and in a female rat two-stage carcinogenesis model after multiple carcinogen initiation.

Kawabe M, Lin C, Kimoto N, Sano M, Hirose M, Shirai T.

First Department of Pathology, Nagoya City University Medical School, Nagoya 467-8601, Japan.

The modifying effects of the dietary administration of water- and ethanol-extracted propolis produced in Brazil (WB and EB, respectively) on 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) promotion of rat hepatocarcinogenesis were investigated in a medium-term liver bioassay system with use of male Fischer 344 rats. The number and area of glutathione S-transferase placental form (GST-P)-positive foci in rats given 0.5% WB were significantly increased compared with the group given MeIQx alone. Furthermore, the numbers of GST-P-positive foci were higher in rats given 0.1% WB or EB than in those given the basal diet alone. The modifying effects of propolis on other organs were also examined in female Fischer 344 rats given multiple carcinogens for initiation. Rats received water- and ethanol-extracted propolis produced in Brazil and Uruguay (WB, EB, WU, and EU, respectively) in the diet after exposure to three different carcinogens. The incidence of total mammary tumors was significantly lower in rats given EU than in the control group. These results indicate that a water extract of propolis exerts a cocarcinogenic effect on MeIQx hepatocarcinogenesis while promoting the effect at low dose in a two-stage hepatocarcinogenesis model. Moreover, they suggest that ethanol-extracted propolis may be an inhibitor of mammary gland carcinogenesis.

PMID: 11142091 [PubMed - indexed for MEDLINE]

57: Pathol Int. 2000 Sep;50(9):679-89.

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Renal carcinogenesis induced by ferric nitrilotriacetate in mice, and protection from it by Brazilian propolis and artepillin C.

Kimoto T, Koya S, Hino K, Yamamoto Y, Nomura Y, Micallef MJ, Hanaya T, Arai S, Ikeda M, Kurimoto M.

Hayashibara Biochemical Laboratories Inc., Fujisaki Institute, Fujisaki, Okayama, Japan.

The protective effect of Brazilian propolis and its extract Artepillin C against ferric nitrilotriacetate (Fe-NTA)-induced renal lipid peroxidation and carcinogenesis was studied in male ddY mice. Fe-NTA-induced renal lipid peroxidation leads to a high incidence of renal cell carcinoma (RCC) in mice. Administration of propolis by gastric intubation 2 h before or Artepillin C at either the same time, 2 h, or 5 h before the intraperitoneal injection of Fe-NTA (7 mg Fe/kg) effectively inhibited renal lipid peroxidation. This was evaluated from the measurement of renal thiobarbituric acid-reactive substances (TBARS) or histochemical findings of 4-hydroxy-2-nonenal (4-HNE)-modified proteins and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Repeated injection of Fe-NTA (10 mg Fe/kg per day, twice a week for a total of 16 times in 8 weeks) caused subacute nephrotoxicity as revealed by necrosis and pleomorphic large nuclear cells in the renal proximal tubules, and gave rise to RCC 12 months later. A protective effect from carcinogenicity was observed in mice given propolis or Artepillin C. Furthermore, the mice given Fe-NTA only developed multiple cysts composed of precancerous lesions with multilayered and proliferating large atypical cells. Mice treated with propolis and Artepillin C also had cysts, but these were dilated and composed of flat cells. These results suggest that propolis and Artepillin C prevent oxidative renal damage and the carcinogenesis induced by Fe-NTA in mice.

PMID: 11012980 [PubMed - indexed for MEDLINE]

58: Cancer Lett. 2000 Aug 31;157(1):31-8.

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Restoration of gap junctional intercellular communication by caffeic acid phenethyl ester (CAPE) in a ras-transformed rat liver epithelial cell line.

Na HK, Wilson MR, Kang KS, Chang CC, Grunberger D, Trosko JE.

Department of Pediatrics and Human Development, National Food Safety and Toxicology Center, Michigan State University, East Lansing 48824-1317, USA.

Caffeic acid phenethyl ester (CAPE), an active ingredient of honeybee propolis, has been identified as having anti-inflammatory, anti-viral and anti-cancer properties. Since the deficiency of gap junctional intercellular communication (GJIC) has been shown to be a characteristic of most cancer cells, this study was designed to test the hypothesis that the anti-carcinogenic activity of CAPE might be related to its ability to restore GJIC in tumorigenic GJIC-deficient cells (WB-ras2 cells). The results showed that CAPE restored GJIC, phosphorylation of connexin 43 (Cx43) and its normal localization on the plasma membrane in WB-ras2 cells after 3 days at 5 microg/ml concentration. Additionally, CAPE inhibited growth in soft agar and decreased the protein level of p21(ras). The results are consistent with the hypothesis that the anti-cancer mechanism of CAPE may be mediated by its ability to restore GJIC.

PMID: 10893439 [PubMed - indexed for MEDLINE]

59: Cancer Lett. 1999 Dec 1;147(1-2):221-7.

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Post-initiation effects of a super critical extract of propolis in a rat two-stage carcinogenesis model in female F344 rats.

Kimoto N, Hirose M, Kawabe M, Satoh T, Miyataka H, Shirai T.

First Department of Pathology, Nagoya City University Medical School, Nagoya, Japan.

Post-initiation modifying effects of dietary administration of a super critical extract of propolis on major organs were examined using a two-stage carcinogenesis model. Groups of 21 or 22 F344 female rats were treated sequentially with 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN, i.g.), 7,12-dimethylbenz[a]anthracene (DMBA, i.g.), 1,2-dimethylhydrazine (DMH, s.c.) and N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN, in drinking water) during the first 3 weeks for initiation, and then administered diet containing 0.1 or 0.01% propolis for 33 weeks. Further groups were treated with the carcinogens alone, 0.1% propolis alone or basal diet alone. All surviving animals were killed at week 36, and major organs were examined histopathologically for development of preneoplastic and neoplastic lesions. The incidence and multiplicity of mammary carcinomas were significantly decreased by the 0.1 and 0.01% propolis treatments. In the urinary bladder, the incidence of PN hyperplasia but not tumors was, in contrast, significantly increased by 0.1% propolis. Similarly, the number and area of glutathione S-transferase placental form (GST-P)-positive liver foci were significantly elevated with this high dose. The results indicate that a low dose of a super critical extract of propolis may find application as a potent chemopreventor of mammary carcinogenesis.

PMID: 10660110 [PubMed - indexed for MEDLINE]

60: Int J Mol Med. 1999 Jul;4(1):29-32.

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Apoptosis induced by propolis in human hepatocellular carcinoma cell line.

Choi YH, Lee WY, Nam SY, Choi KC, Park YE.

Department of Pathology, Chun-Chon Sacred Heart Hospital, Hallym University, Chun-Chon city, Kang Won-Do 200-060, Korea.

Propolis has been reported to exhibit a wide spectrum of activities including antibiotic, antiviral, anti-inflammatory, immunostimulatory and tumor carcinostatic properties. We showed propolis induced apoptosis in a human hepatoma cell line (SNU449) by FITC-Annexin V/PI staining. We also compared the apoptosis inducing effect between Korean and Commercial (Sigma # p-1010) propolis. There was no difference on apoptosis between them.

PMID: 10373633 [PubMed - indexed for MEDLINE]

61: Cancer Detect Prev. 1998;22(6):506-15.

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Apoptosis and suppression of tumor growth by artepillin C extracted from Brazilian propolis.

Kimoto T, Arai S, Kohguchi M, Aga M, Nomura Y, Micallef MJ, Kurimoto M, Mito K.

Fujisaki Institute, Hayashibara Biochemical Laboratories, Okayama, Japan.

Artepillin C was extracted from Brazilian propolis. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) has a molecular weight of 300.40 and possesses antibacterial activity. When artepillin C was applied to human and murine malignant tumor cells in vitro and in vivo, artepillin C exhibited a cytotoxic effect and the growth of tumor cells was clearly inhibited. The artepillin C was found to cause significant damage to solid tumor and leukemic cells by the MTT assay, DNA synthesis assay, and morphological observation in vitro. When xenografts of human tumor cells were transplanted into nude mice, the cytotoxic effects of artepillin C were most noticeable in carcinoma and malignant melanoma. Apoptosis, abortive mitosis, and massive necrosis combined were identified by histological observation after intratumor injection of 500 microg of artepillin C three times a week. In addition to suppression of tumor growth, there was an increase in the ratio of CD4/CD8 T cells, and in the total number of helper T cells. These findings indicate that artepillin C activates the immune system, and possesses direct antitumor activity.

PMID: 9824373 [PubMed - indexed for MEDLINE]

62: Z Naturforsch [C]. 1997 Sep-Oct;52(9-10):702-4.

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Isolation and characterization of cytotoxic diterpenoid isomers from propolis.

Matsuno T, Matsumoto Y, Saito M, Morikawa J.

National Institute of Health, Tokyo, Japan.

The methanol extract of Brazilian propolis was fractionated by HPLC, based on HuH13 (human hepatocellular carcinoma) cell cytotoxicity assay. Two isomers of diterpenoid with a molecular formula of C20H30O3 (MW: 318.46) were isolated. The structures of these colorless compounds were determined as clerodane diterpenoids (I, 15-oxo-3, 13Z-kolavadien-17-oic acid; II, 15-oxo-3Z, 13E-kolavadien-17-oic acid).

PMID: 9374000 [PubMed - indexed for MEDLINE]

63: Pflege Z. 1997 Mar;50(3):98-102.

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[Healing naturally with propolis. With bee propolis to new health]

[Article in German]

Weichselgartner-Schroder C.

PMID: 9155449 [PubMed - indexed for MEDLINE]

64: Gan To Kagaku Ryoho. 1996 Nov;23(13):1855-9.

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[Cell cycle and apoptosis in cancer induced by the artepillin C extracted from Brazilian propolis]

[Article in Japanese]

Kimoto T, Arai S, Aga M, Hanaya T, Kohguchi M, Nomura Y, Kurimoto M.

Fujisaki Institute, Hayashibara Biochemical Labs., Inc.

PMID: 8937499 [PubMed - indexed for MEDLINE]

65: Anticancer Res. 1996 Sep-Oct;16(5A):2669-72.

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Effects of a new clerodane diterpenoid isolated from propolis on chemically induced skin tumors in mice.

Mitamura T, Matsuno T, Sakamoto S, Maemura M, Kudo H, Suzuki S, Kuwa K, Yoshimura S, Sassa S, Nakayama T, Nagasawa H.

Medical Research Institute, Tokyo Medical and Dental University, Japan.

Propolis is a resinous material gathered by honey bees from the buds and bark of certain trees and plants, and used inside their hives. Characteristic components of propolis are many kinds of flavonoid aglycones. The methanol extract of a Brazilian propolis was fractionated by HPLC, and a tumoricidal substance was isolated and characterized as a new clerodane diterpenoid (PMS-1) with a molecular formula of C20H32O3 (MW: 320). We investigated the effects of PMS-1 on skin tumorigenesis and the development of skin tumors induced by 7,12-dimethylbenz(a)anthracene application on mouse back skin. It was tentatively concluded that PMS-1 reduced the incidence of skin tumors by inhibition of DNA synthesis in a de novo pathway, and suppressed the growth of the tumors by decreasing DNA synthesis in a salvage pathway.

PMID: 8917367 [PubMed - indexed for MEDLINE]

66: Carcinogenesis. 1996 Apr;17(4):761-5.

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Inhibitory effects of caffeic acid phenethyl ester (CAPE) on 12-O-tetradecanoylphorbol-13-acetate-induced tumor promotion in mouse skin and the synthesis of DNA, RNA and protein in HeLa cells.

Huang MT, Ma W, Yen P, Xie JG, Han J, Frenkel K, Grunberger D, Conney AH.

Department of Chemical Biology, College of Pharmacy, Rutgers, State University of New Jersey, Piscataway 08855-0789, USA.

Topical application of caffeic acid phenethyl ester (CAPE), a constituent of the propolis of honeybee hives, to the backs of CD-1 mice previously initiated with 7,12-dimethylbenz inverted question marka inverted question markanthracene (DMBA) inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor promotion and the formation of 5-hydroxymethyl-2'-deoxyuridine (HMdU) in epidermal DNA. Topical application of 5 nmol TPA twice weekly for 20 weeks to mice previously initiated with 200 nmol of DMBA resulted in 18.8 skin papillomas per mouse. Topical application of 1, 10, 100 or 3000 nmol of CAPE together with 5 nmol of TPA twice a week for 20 weeks inhibited the number of skin papillomas per mouse by 24, 30, 45 or 70%, respectively, and tumor size per mouse was decreased by 42, 66, 53 or 74%, respectively. Topical application of 5 nmol of TPA twice weekly for 20 weeks to mice previously initiated with DMBA produced an average of 12.6 HMdU residues per 10(4) normal bases in epidermal DNA. Topical application of 1, 10, 100 or 3000 nmol of CAPE with 5 nmol of TPA twice weekly for 20 weeks to DMBA-initiated mice decreased the level of HMdU in epidermal DNA by 40-93%. The in vitro addition of 1.25, 2.5, 5, 10 or 20 microM CAPE to cultured HeLa cells inhibited the synthesis of DNA by 32, 44, 66, 79 or 95%, respectively, the synthesis of RNA was inhibited by 39, 43, 58, 64 or 75%, respectively, and the synthesis of protein was inhibited by 29, 30, 37, 32 or 47%, respectively. The results indicate a potent inhibitory effect of CAPE on TPA-induced tumor promotion and TPA-induced formation of HMdU in DNA of mouse skin as well as an inhibitory effect of CAPE on the synthesis of DNA, RNA and protein in culture HeLa cells.

PMID: 8625488 [PubMed - indexed for MEDLINE]

67: Anticancer Res. 1995 Sep-Oct;15(5B):1841-8.

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Apoptosis mediates the selective toxicity of caffeic acid phenethyl ester (CAPE) toward oncogene-transformed rat embryo fibroblast cells.

Su ZZ, Lin J, Prewett M, Goldstein NI, Fisher PB.

Department of Pathology, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA.

The active component of the folk medicine propolis, caffeic acid phenethyl ester (CAPE), displays selective toxicity toward cloned rat embryo fibroblast (CREF) cells transformed by a spectrum of diverse acting oncogenes. Identification of the mode of action of CAPE should provide useful information for possible applications of this compound for cancer therapy. The present study uses a series of oncogene transformed, oncogene-reverted and CAPE-resistant oncogene transformed CREF cells to investigate the mechanism underlying the increased sensitivity of transformed cells to CAPE. A direct relationship exists between the cytotoxic effects of CAPE and the induction of DNA fragmentation and apoptosis. DNA degradation into nucleosomal fragments and apoptotic shifts in DNA cell cycle profiles occur in CAPE-treated CREF cells transformed by wild-type 5 adenovirus (Ad5), a mutant Ad5 (H5hr1), the wild-type Ad5 E1A transforming gene, v-src, Ha-ras and the human papilloma virus type 18 transforming genes (HPV-18). In contrast, untransformed CREF cells, human fibroblast expression library-induced morphological revertants of Ad5- and v-src-transformed CREF cells, and Krev-1 expressing revertant Ha-ras-transformed CREF cells are resistant to CAPE-induced toxicity and apoptosis. Similarly, mutant Ad5-transformed CREF cells selected by step-wise growth in increasing concentrations of CAPE are resistant to growth inhibition and apoptosis induced by CAPE. These findings indicate that expression of the transformed phenotype by rodent cells evokes sensitivity to CAPE induced toxicity through apoptosis. The acquisition of CAPE sensitivity in rodent cells is independent of the mode of action of the oncogenic agent. CAPE may prove useful as an antiproliferative agent in cancer cells transformed by mechanistically diverse acting oncogenes.

PMID: 8572568 [PubMed - indexed for MEDLINE]

68: Cancer Res. 1995 Aug 15;55(16):3576-83.

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Apoptosis and altered redox state induced by caffeic acid phenethyl ester (CAPE) in transformed rat fibroblast cells.

Chiao C, Carothers AM, Grunberger D, Solomon G, Preston GA, Barrett JC.

Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.

Caffeic acid phenethyl ester (CAPE), which is derived from the propolis of bee hives, was shown previously to block tumor promoter- and carcinogen-generated oxidative processes in several assays and to engender differential toxicity to some transformed cells. To study the mechanisms of CAPE-induced differential cytotoxicity, nontumorigenic rat embryo fibroblasts (CREF) and adenovirus (type 5)-transformed CREF cells (Wt3A) were used. As shown by nucleosomal-length DNA degradation, morphological alterations by electron microscopy, in situ labeling of 3'-OH ends, and the appearance of a hypodiploid cell population by bivariant flow cytometry, cell death induced by CAPE in the transformed Wt3A cells was apoptosis. Under the same CAPE treatment conditions, CREF cells transiently growth arrested. Both CREF and Wt3A cells were radioresistant, suggesting deficiencies in the proteins controlling the G1 checkpoint. To explore possible mechanisms of CAPE-induced apoptosis, it was determined whether CAPE-induced toxicity was influenced by the redox state of the cells. Depletion of cellular glutathione (GSH) with buthionine sulfoximine before CAPE treatment caused CREF sensitive to CAPE-induced cell death. GSH levels were also determined in CAPE-treated CREF and Wt3A cells. The GSH level in the CREF cells was unaffected by CAPE, whereas the Wt3A cells showed a significant reduction. When the GSH levels were increased in Wt3A cells by treatment with the reducing agent, N-acetyl-cysteine before CAPE treatment, the Wt3A cells were partially rescued. Furthermore, Bcl2, which protects cells from oxidative stress, had a protective effect against CAPE-induced apoptosis in Wt3A cells. Finally, the sensitivity of Wt3A cells to a known oxidant, hydrogen peroxide (H2O2), was examined. Wt3A cells were killed by H2O2-induced apoptosis, whereas CREF cells remained resistant. When Wt3A cells were treated with catalase, a cellular enzyme that inactivates H2O2, CAPE-induced apoptosis in Wt3A cells was reduced, further proving that Wt3A cells were more sensitive than CREF cells to oxidative stress. These results suggest that CAPE can modulate the redox state of cells. Sensitivity of cells to CAPE-induced cell death may be determined by the loss of normal redox state regulation in transformed cells.

PMID: 7543016 [PubMed - indexed for MEDLINE]

69: Cancer Res. 1995 Jun 1;55(11):2310-5.

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Chemoprevention of colon carcinogenesis by phenylethyl-3-methylcaffeate.

Rao CV, Desai D, Rivenson A, Simi B, Amin S, Reddy BS.

Division of Nutritional Carcinogenesis, American Health Foundation, Valhalla, New York 10595, USA.

Previous studies from this laboratory have established that caffeic acid esters present in propolis, a natural resin produced by honey bees, are potent inhibitors of human colon adenocarcinoma cell growth, carcinogen-induced biochemical changes, and preneoplastic lesions in the rat colon. The present study was designed to investigate the chemopreventive action of dietary phenylethyl-3-methylcaffeate (PEMC) on azoxymethane-induced colon carcinogenesis and to examine the modulating effect of PEMC on phosphatidylinositol-specific phospholipase C (PI-PLC), phospholipase A2, lipoxygenase (LOX), and cyclooxygenase activities in the colonic mucosa and tumor tissues in male F344 rats. At 5 weeks of age, groups of rats were fed the control (modified AIN-76A) diet, or a diet containing 750 ppm of PEMC. At 7 weeks of age, all animals except those in the vehicle (normal saline)-treated groups were given 2 weekly s.c. injections of azoxymethane at a dose rate of 15 mg/kg body weight/week. All groups were maintained on their respective dietary regimen until the termination of the experiment 52 weeks after the carcinogen treatment. Colonic tumors were evaluated histopathologically. Both colonic mucosa and tumors were analyzed for PI-PLC, phospholipase A2, cyclooxygenase, and LOX activities. The results indicate that dietary administration of PEMC significantly inhibited the incidence and multiplicity of invasive, noninvasive, and total (invasive plus noninvasive) adenocarcinomas of the colon (P < 0.05-0.004). Dietary PEMC also suppressed the colon tumor volume by 43% compared to the control diet. Animals fed the PEMC diet showed significantly decreased activities of colonic mucosal and tumor PI-PLC (about 50%), but PEMC diet had no effect on phospholipase A2. The production of 5(S)-, 8(S)-, 12(S)-, and 15(S)-hydroxyeicosatetraenoic acids via the LOX pathway from arachidonic acid was reduced in colonic mucosa and tumors (30-60%) of animals fed the PEMC diet as compared to control diet. PEMC had no effect on the formation of colonic mucosal cyclooxygenase metabolites but inhibited the formation in colonic tumors by 15-30%. The precise mechanism by which PEMC inhibits colon tumorigenesis remains to be elucidated. It is likely that the chemopreventive action may be related, at least in part, to the modulation of PI-PLC-dependent signal transduction and LOX-mediated arachidonic acid metabolism.

PMID: 7757981 [PubMed - indexed for MEDLINE]

70: Cancer Res. 1994 Apr 1;54(7):1865-70.

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Growth suppression and toxicity induced by caffeic acid phenethyl ester (CAPE) in type 5 adenovirus-transformed rat embryo cells correlate directly with transformation progression.

Su ZZ, Lin J, Grunberger D, Fisher PB.

Department of Urology, Columbia University, College of Physicians and Surgeons, New York, New York 10032.

The active component of the honeybee hive product propolis, caffeic acid phenethyl ester (CAPE), induces a selective growth suppressive and toxic effect toward cloned rat embryo fibroblast cells transformed by adenovirus type 5 (Ad5) or the Ad5 E1A transforming gene versus untransformed cloned rat embryo fibroblast cells (Z-z. Su et al., Mol. Carcinog., 4: 231-242, 1991). The present study was conducted to determine whether CAPE-induced growth suppression/toxicity was a direct result of expression of the Ad5 E1A and E1B transforming genes or a consequence of the action of these genes resulting in the transformed state. For this investigation we used somatic cell hybrids and 5-azacytidine-treated Ad5-transformed rat embryo cells that display different stages of expression of the transformed phenotype. This series of cell lines has permitted us to determine whether expression of the transformed state and the stage of transformation progression regulates CAPE sensitivity. Evidence is presented indicating that sensitivity to CAPE is directly determined by the state of expression of the transformed progression phenotype, as opposed to simply the expression of the Ad5 E1A and E1B transforming genes. These results provide further evidence that CAPE may represent a unique compound that can specifically target progressed transformed cells for growth suppression and toxicity. An understanding of the mechanism underlying this selective effect of CAPE could result in the identification of important biochemical pathways mediating cellular transformation and progression of the transformed state.

PMID: 7511055 [PubMed - indexed for MEDLINE]

71: Cancer Res. 1993 Sep 15;53(18):4182-8.

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Inhibitory effect of caffeic acid esters on azoxymethane-induced biochemical changes and aberrant crypt foci formation in rat colon.

Rao CV, Desai D, Simi B, Kulkarni N, Amin S, Reddy BS.

Division of Nutritional Carcinogenesis, American Health Foundation, Valhalla, New York 10595.

Previous work from this laboratory established that caffeic acid esters, present in the propolis of honey bee hives, are potent inhibitors of human colon tumor cell growth, suggesting that these compounds may possess antitumor activity against colon carcinogenesis. The present study was designed to investigate (a) the inhibitory effects of methyl caffeate (MC) and phenylethyl caffeate (PEC) on azoxymethane (AOM)-induced ornithine decarboxylase (ODC), tyrosine protein kinase (TPK), and arachidonic acid metabolism in liver and colonic mucosa of male F344 rats, (b) the effects of caffeic acid, MC, PEC, phenylethyl-3-methylcaffeate (PEMC), and phenylethyl dimethylcaffeate (PEDMC) on in vitro arachidonic acid metabolism in liver and colonic mucosa, and (c) the effects of PEC, PEMC, and PEDMC on AOM-induced aberrant crypt foci (ACF) formation in the colon of F344 rats. At 5 weeks of age, groups of animals were fed diets containing 600 ppm MC or PEC (biochemical study) or 500 ppm PEC, PEMC, or PEDMC (ACF study). Two weeks later, all animals except the vehicle-treated groups were given s.c. injections of AOM, once weekly for 2 weeks. The animals intended for the biochemical study were sacrificed 5 days later and colonic mucosa and liver were analyzed for ODC, TPK, lipoxygenase, and cyclooxygenase metabolites. The animals intended for the ACF study were sacrificed 9 weeks later and analyzed for ACF in the colon. The results indicate that the PEC diet significantly inhibited AOM-induced ODC (P < 0.05) and TPK (P < 0.001) activities in liver and colon. The PEC diet significantly (P < 0.001) suppressed the AOM-induced lipoxygenase metabolites 8(S)- and 12(S)-hydroxyeicosatetraenoic acid (HETE). The animals fed the MC diet exhibited a moderate inhibitory effect on ODC and 5(S)-, 8(S)-, 12(S)-, and 15(S)-HETEs and a significant (P < 0.001) effect on colonic TPK activity. However, the MC and PEC diets showed no significant inhibitory effects on cyclooxygenase metabolism. In an in vitro study, caffeic acid and MC showed inhibitory effects on HETE formation only at a 100 microM concentration, whereas PEC, PEMC, and PEDMC suppressed in vitro HETE formation in a dose-dependent manner. AOM-induced colonic ACF were significantly inhibited in the animals fed PEC (55%), PEMC (82%), or PEDMC (81%). The results of the present study indicate that PEC, PEMC, and PEDMC, present in honey, inhibit AOM-induced colonic preneoplastic lesions, ODC, TPK, and lipoxygenase activity, which are relevant to colon carcinogenesis.

PMID: 8364913 [PubMed - indexed for MEDLINE]

72: Cancer Res. 1993 Mar 15;53(6):1255-61.

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Inhibition of tumor promoter-mediated processes in mouse skin and bovine lens by caffeic acid phenethyl ester.

Frenkel K, Wei H, Bhimani R, Ye J, Zadunaisky JA, Huang MT, Ferraro T, Conney AH, Grunberger D.

Department of Environmental Medicine, New York University Medical Center, New York 10016-6451.

Caffeic acid phenethyl ester (CAPE) was isolated from propolis (a product of honeybee hives) that has been used in folk medicine as a potent antiinflammatory agent. CAPE is cytotoxic to tumor and virally transformed but not to normal cells. Our main goal was to establish whether CAPE inhibits the tumor promoter (12-O-tetradecanoylphorbol-13-acetate)-induced processes associated with carcinogenesis. Topical treatment of SENCAR mice with very low doses (0.1-6.5 nmol/topical treatment) of CAPE strongly inhibits the following 12-O-tetradecanoylphorbol-13-acetate-mediated oxidative processes that are considered essential for tumor promotion: (a) polymorphonuclear leukocyte infiltration into mouse skin and ears, as quantified by myeloperoxidase activity; (b) hydrogen peroxide (H2O2) production; and (c) formation of oxidized bases in epidermal DNA, as measured by 5-hydroxymethyluracil and 8-hydroxylguanine. A 0.5-nmol dose of CAPE suppresses the oxidative burst of human polymorphonuclear leukocytes by 50%. At higher doses (1-10 mumol), CAPE inhibits edema and ornithine decarboxylase induction in CD-1 and SENCAR mice. Interestingly, we discovered that 12-O-tetradecanoylphorbol-13-acetate-induced H2O2 production in bovine lenses also is inhibited by CAPE. Cumulatively, these findings point to CAPE as being a potent chemopreventive agent, which may be useful in combating diseases with strong inflammatory and/or oxidative stress components, i.e., various types of cancer and possibly cataract development.

PMID: 7680281 [PubMed - indexed for MEDLINE]

73: Chem Biol Interact. 1992 Nov 16;84(3):277-90.

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Effect of caffeic acid esters on carcinogen-induced mutagenicity and human colon adenocarcinoma cell growth.

Rao CV, Desai D, Kaul B, Amin S, Reddy BS.

Division of Nutritional Carcinogenesis, American Health Foundation, Valhalla, New York.

Propolis, a honey bee hive product, is thought to exhibit a broad spectrum of activities including antibiotic, antiviral, anti-inflammatory and tumor growth inhibition; some of the observed biological activities may be due to caffeic acid (cinnamic acid) esters that are present in propolis. In the present study we synthesized three caffeic acid esters, namely methyl caffeate (MC), phenylethyl caffeate (PEC) and phenylethyl dimethylcaffeate (PEDMC) and tested them against the 3,2'-dimethyl-4-aminobiphenyl, (DMAB, a colon and mammary carcinogen)-induced mutagenicity in Salmonella typhimurium strains TA 98 and TA 100. Also, the effect of these agents on the growth of human colon adenocarcinoma, HT-29 cells and activities of ornithine decarboxylase (ODC) and protein tyrosine kinase (PTK) was studied. Mutagenicity was induced in Salmonella typhimurium strains TA 98 and TA 100 plus S9 activation using 5 and 10 micrograms DMAB and antimutagenic activities of 0-150 microM MC, 0-60 microM PEC and 0-80 microM PEDMC were determined. The results indicate that MC, PEC and PEDMC were not mutagenic in the Salmonella tester system. DMAB-induced mutagenicity was significantly inhibited with 150 microM MC, 40-60 microM PEC and 40-80 microM PEDMC in both tester systems. Treatment of HT-29 colon adenocarcinoma cells with > 150 microM MC, 30 microM PEC and 20 microM PEDMC significantly inhibited the cell growth and syntheses of RNA, DNA and protein. ODC and PTK activities were also inhibited in HT-29 cells treated with different concentrations of MC, PEC and PEDMC. These results demonstrate that caffeic acid esters which are present in Propolis possess chemopreventive properties when tested in short-term assay systems.

PMID: 1423745 [PubMed - indexed for MEDLINE]

74: Cell Mol Biol. 1992 Aug;38(5):513-27.

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Erratum in:

       Cell Mol Biol 1992 Sep;38(6):615.

Growth inhibition and modulation of antigenic phenotype in human melanoma and glioblastoma multiforme cells by caffeic acid phenethyl ester (CAPE)

Guarini L, Su ZZ, Zucker S, Lin J, Grunberger D, Fisher PB.

Division of Pediatric Hematology/Oncology, Columbia University, College of Physicians and Surgeons, New York, New York 10032.

The active component of the honeybee hive product propolis, caffeic acid phenethyl ester (CAPE), has been shown to display increased toxicity toward various oncogene-transformed cell lines in comparison with their untransformed counterparts (Su et al., 4: 231-242, 1991). This observation provides support for the concept that it is the transformed phenotype which is specifically sensitive to CAPE. In the present study, we have determined the effect of CAPE on the growth and antigenic phenotype of a human melanoma cell line, HO-1, and a human glioblastoma multiforme cell line, GBM-18. For comparison, we have also tested the effects of mezerein (MEZ), mycophenolic acid (MPA) and retinoic acid (RA), which can differentially modulate growth, differentiation and the antigenic phenotype in these human tumor cell lines. Growth of both cell lines was suppressed by CAPE in a dose-dependent fashion, with HO-1 cells being more sensitive than GBM-18 cells. The antiproliferative effect of CAPE was enhanced in both cell types if CAPE and MEZ were used in combination. Growth suppression was associated with morphological changes in H0-1 cells, suggesting induction of a more differentiated phenotype. CAPE also differentially modulated the expression of several antigens on the surface of the two tumor cell lines. These results suggest a potential role for CAPE as an antitumor agent, an antigenic modulating agent and possibly a differentiation inducing agent.

PMID: 1281753 [PubMed - indexed for MEDLINE]

75: Mol Carcinog. 1991;4(3):231-42.

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Suppression of adenovirus type 5 E1A-mediated transformation and expression of the transformed phenotype by caffeic acid phenethyl ester (CAPE).

Su ZZ, Grunberger D, Fisher PB.

Department of Urology, Columbia University, College of Physicians and Surgeons, New York 10032.

Viral transformation and DNA-transfection assays were employed to investigate the differential toxic effect of caffeic acid phenethyl ester (CAPE), an extract of the honeybee hive product propolis, on adenovirus type 5 (Ad5)-transformed cloned rat embryo fibroblast (CREF) cells. CAPE inhibited, in a dose-dependent manner, both de novo and carcinogen-enhanced transformation of CREF cells by H5hr1, the cold-sensitive (cs) host-range mutant of Ad5. CAPE had a selective inhibitory effect on Ad5-induced transformation when a wild-type (wt) Ad5 E1A gene or a cs Ad5 E1A gene (at 37 degrees C, but not at 32 degrees C) was cotransfected into CREF cells with a dominant-acting bacterial hygromycin-resistance gene. A requirement for the expression of Ad5 E1A-encoded mRNAs and transforming proteins and sensitivity to CAPE was demonstrated using CREF cells stably transformed by a cs Ad5 E1A gene and an Ad5 E1A gene under the transcriptional control of a mouse mammary tumor virus promoter. To distinguish between the effects of the two Ad5 E1A-encoded proteins of 289 amino acids (aa) and 243 aa, CREF cells were stably transformed with cDNAs encoding either the 13S or the 12S E1A mRNA. CREF cells expressing the 13S E1A-encoded 289-aa protein were more sensitive to the growth-suppressing effect of CAPE than cells producing only the 12S E1A-encoded 243-aa protein. However, the growth-suppressing and toxic effects of CAPE were greatest in cells expressing both E1A-encoded transforming proteins. Analysis of the effect of CAPE on E1A and beta-actin gene expression in wt and cs E1A and H5hr1-transformed CREF cells indicated that low levels of CAPE, which were growth suppressive, did not selectively suppress E1A expression. These results demonstrated that cellular changes induced in CREF cells by the 13S E1A-encoded 289-aa protein of Ad5, when expressed alone or in combination with the 12S E1A-encoded 243-aa protein, rendered transformed cells sensitive to the growth-suppressing and toxic effects of CAPE.

PMID: 1712205 [PubMed - indexed for MEDLINE]

76: Z Naturforsch [C]. 1989 Nov-Dec;44(11-12):1063-5.

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Antitumoral property of ethanolic extract of propolis in mice-bearing Ehrlich carcinoma, as compared to bleomycin.

Scheller S, Krol W, Swiacik J, Owczarek S, Gabrys J, Shani J.

Department of Microbiology, Silesian School of Medicine, Zabrze-Rokitnica, Poland.

Antitumoral effect of ethanolic extract of propolis (EEP) was demonstrated in mature mice-bearing Ehrlich carcinoma. Survival rate after EEP treatment was compared to that of bleomycin, given alone or in combination every two days for 36 days and followed up for 14 additional days. The survival rate at 50 days was 55% after EEP and 40% after bleomycin, while all the mice-treated with EEP + bleomycin combination demonstrated shorter survival than the controls. It is concluded that while the in vivo activity of bleomycin is reduced in the presence of cytochrome-C-reductase inhibitors (like some of the EEP components are), the antitumoral property of EEP in the tumored animal model studied is significant and lasting.

PMID: 2483616 [PubMed - indexed for MEDLINE]

77: Radiobiol Radiother (Berl). 1989;30(4):363-7.

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[The use of propolis preparations in the treatment of radioepithelitis following telegammatherapy of the pharyngeal region]

[Article in German]

Velikov P, Zanev M.

PMID: 2798801 [PubMed - indexed for MEDLINE]

78: Zhong Xi Yi Jie He Za Zhi. 1985 Aug;5(8):485-6, 452-3.

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[Treatment of oral leukoplakia with propolis: report of 45 cases]

[Article in Chinese]

Pang JF, Chen SS.

PMID: 2932253 [PubMed - indexed for MEDLINE]

79: Biochem Pharmacol. 1983 Apr 1;32(7):1141-8.

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Flavonoids, a class of natural products of high pharmacological potency.

Havsteen B.

A review has been presented of the biochemistry and pharmacology of a class of natural products, the flavonoids. These substances which are widely distributed in the plant kingdom and present in considerable quantities in common food products, spices and beverages have in a concentrated form (Propolis) been used since ancient times by physicians and laymen to treat a great variety of human diseases but they have yet to pass the tests of modern, controlled, clinical experimentation. An attempt has been made to present the fundamental evidence from the basic biological sciences which is required to stimulate the interest of the clinicians in this new field. The few existing reports on the careful pharmacodynamic, pharmacokinetic and clinical studies which have been made have been summarized to provide a basis for a full-scale investigation of the therapeutic potential of flavonoids.

Publication Types:


PMID: 6342623 [PubMed - indexed for MEDLINE]