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Abstract: epigallocatechin-3-gallate (EGCG) has shown remarkably anti-cancer activity, with its bioactivity being related to reactive conditions, such as pH and metal ions. The present study investigated the degradation of EGCG and its effect on prostate cancer cell in the presence of Cu²⁺. EGCG was incubated with prostate cancer cells, LNCaP, pretreated with or without Cu²⁺. EGCG in F-12 medium was quantified using HPLC and the viability of cells was assessed by gel electrophoresis, flow cytometry, and electron microscope. The results of HPLC showed that EGCG degraded completely within 12 h in F-12 medium with or without Cu²⁺. Gel electrophoresis and flow cytometry did not detect apoptosis of LNCaP cells when they were incubated with EGCG. Electron microscopy examination revealed that EGCG-Cu²⁺ complex led to damage of cytoplasm membrane in LNCaP cells. It was speculated that not EGCG, but its oxide and complex with Cu²⁺, are the bioactive components responsible for its cytotoxicity to LNCaP prostate cancer cells.

[1] Chung, L.Y., Cheung, T.C., Kong, S.K., Fung, K.P., Choy, Y.M., Chan, Z.Y., Kwok, T.T., 2001a. Induction of apoptosis by green tea catechins in human prostate cancer DU145 cells. Life Sciences, 68(10):1207-1214.

[2] Chung, J.Y., Park, J.O., Phyu, H., Dong, Z.G., Yang, C.S., 2001b. Mechanisms of inhibition of the Ras-MAP kinase signaling pathway in 30.7b Ras 12 cells by tea polyphenols (-)-epigallocatechin-3-gallate and theaflavin-3,3'-digallate. The FASEB Journal, 15:2022-2024.

[3] Cutter, H., Wu, L.Y., Kim, C.D., Morre, J., Morre, D.M., 2001. Is the cancer protective effect correlated with growth inhibitions by green tea (-)-epigallocatechin gallate mediated through an antioxidant mechanism? Cancer Lett, 162(2):149-154.

[4] Gupta, S., Ahmad, N., Nieminent, A.L., Mukhtar, H., 2000. Growth inhibition, cell-cycle dysregulation, and induction of apoptosis by green tea constituent (-)-epigallocatechin-3-gallate in androgen-sensitive and androgen-insensitive human prostate carcinoma cells. Toxicology and Applied Pharmacology, 164(1):82-90.

[5] Gupta, S., Hussain, T., Mukhtar, H., 2003. Molecular pathway for (-)-epigallocatechin-3-gallate-induced cell cycle arrest and apoptosis of human prostate carcinoma cells. Archives of Biochemistry and Biophysics, 410(1):177-185.

[6] Hatano, T., Hori, M., Hemingway, R.W., Yoshida, T., 2003. Size exclusion chromatographic analysis of polyphenol-serum albumin complexes. Phytochemistry, 63(7):817-823.

[7] Hiipakka, R.A., Zhang, Z., Wei, D., Qing, D., Liao, S., 2002. Structure-activity relationship for inhibition of human 5α-reductases by polyphenols. Biochemistry Pharmacology, 63(6):1165-1176.

[8] Hoshino, N., Kimura, T., Yamaji, A., Ando, T., 1999. Damage to the cytoplasmic membrane of Escherichia Coli by catechin-copper (II) complexes. Free Radic Biol Med, 27(11-12):1245-1250.

[9] Kenshi, K., Hiroshi, T., Nozomi, Y., Satoru, E., Shinya, M., Shuneki, S., 1997. Inhibitory action of (-)-epigallocatechin gallate on radiation-induced mouse oncogenic transformation. Cancer Lett, 112(2):135-139.

[10] Kimura, T., Hoshino, N., Yamaji, A., Hayakawa, F., Ando, T., 1998. Bactericidal activity of catechin-copper (II) complexes on Escherichia coli ATCC11775 in the absence of hydrogen peroxide. Lett Appl Microbiol, 27:328-330.

[11] Kumamoto, M., Sonda, T., Nagayama, K., Tabata, M., 2001. Effects of pH and metal ions on antioxidative activities of catechins. Biosci Biotechnol Biochem, 65:126-132.

[12] Liang, Y.C., Lin-shiau, S.Y., Chen, C.F., Lin, J.K., 1997. Suppression of extracellular signals and cell proliferation through EGF receptor binding by (-)-epigallocatechin gallate in human A431 epidermoid carcinoma cells. J Cell Biochem, 67(1):55-65.

[13] Liao, S., Umekita, Y., Guo, J., Kokontis, J.M., Hiipakka, R.A., 1995. Growth inhibition and regression of human prostate and breast tumors in athymic mice by tea epigallocatechin gallate. Cancer Lett, 96(2):239-243.

[14] Lin, J.K., 2002. Cancer chemoprevention by tea polyphenols through modulating signal transduction pathways. Arch Pharm Res, 25(5):561-571.

[15] Lu, Y.P., Lou, Y.R., Xie, J.G., Peng, Q.Y., Liao, J., Yang, C.S., Huang, M.T., Conney, A.H., 2002. Topical applications of caffeine or (-)-epigallocatechin gallate (EGCG) inhibit carcinogenesis and selectively increase apoptosis in UVB-induced skin tumors in mice. Proc Natl Acad Sci USA, 99(19):12455-12460.

[16] Mira, L., Fernandez, M.T., Santos, M., Rocha, R., Florencio, M.H., Jennings, K.R., 2002. Interactions of flavonoids with iron and copper ions: a mechanism for their antioxidant activity. Free Radic Res, 36:1199-1208.

[17] Nakagawa, K., Okuda, S., Miyazawa, T., 1997. Dose-dependent incorporation of tea catechins, (-)-epigallocatechin-3-gallate and (-)-epigallocatechin into human plasma. Biosci Biotechnol Biochem, 61:1981-1985.

[18] Nihal, A., Sanjay, G., Hasan, M., 2000. Green tea polyphenol epigallocatechin-3-gallate differentially modulates nuclear factor κb in cancer cells versus normal cells. Archives of Biochemistry and Biophysics, 376(2):338-346.

[19] Paschka, A.G., Butler, R.C., Young, Y.F., 1998. Induction of apoptosis in prostate cancer cell lines by the green tea component, (-)-epigallocatechin-3-gallate. Cancer Lett, 130(1):1-7.

[20] Roy, M., Chakrabarty, S., Sinha, D., Bhattacharya R.K., Siddiqi, M., 2003. Anticlastogenic, antigenotoxic and apoptotic activity of epigallocatechin gallate: a green tea polyphenol. Mutation Research, 523-524:33-41.

[21] Unno, T., Takeo, T., 1995. Absorption of (-)-epigallocatechin gallate into the circulation system of rates. Biosci Biotechnol Biochem, 59:1558-1559.

[22] Unno, T., Kondo, K., Itakura, H., Takeo, T., 1996. Analysis of (-)-epigallocatechin gallate in human serum obtained after ingesting green tea. Biosci Biotechnol Biochem, 60:2066-2068.

[23] Yang, C.S., Lee, M.J., Chen, L.S., 1999. Human salivary tea catechin levels and catechin esterase activities: implication in human cancer prevention studies. Cancer Epidemiology Biomarkers & Prevention, 8:83-89.

[24] Yoshioka, H., Senba, Y., Saito, K., Kimura, T., Hayakawa, F., 2001. Spin-trapping study on the hydroxyl radical formed from a tea catechin-Cu (II) system. Biosci Biotechnol Biochem, 65:1697-1706.

[25] Yu, H.N., Yin, J.J., Shen, S.R., 2004. Growth inhibition of prostate cancer cells by epigallocatechin gallate in the presence of Cu²⁺. J Agric Food Chem, 52(3):464-466.