Cancer: Lung, colorectal., head and neck

Action: Hemoprevention, chemo-preventive effects

Green tea polyphenols include compounds found in fruits and vegetables, particularly green tea Camellia sinensis [(L.) Kuntze].

Chemo-preventive Effects

Polyphenolic compounds in fruits and vegetables have been associated with lower risk of some diseases, including cancer. Recent research has shown that the polyphenolic anti-oxidants in green tea possess cancer chemo-preventive effects (Ahmad et al., 1999).

Green tea polyphenols were found to increase the activities of glutathione peroxidase, catalase, and quinone reductase in small bowel, liver, and lungs, and glutathione S-transferase in small bowel and liver. These can be implicated in relation to the cancer chemo-preventive effects of green tea polyphenols against the induction of tumors in various target organs (Khan et al., 1992).

Head and Neck Cancers

Additionally, green tea polyphenol-induced production of H2O2 may mediate apoptosis and this may also contribute to the growth-inhibitory activities in cancer cells in vitro (Yang et al., 1998).

A synergistic inhibition between green tea (-)-epigallocatechin-3-gallate and EGFR tyrosine kinase inhibitor in head and neck tumor growth was shown (Zhang et al., 2008).

References

Ahmad N, Mukhtar H. (1999). Green Tea Polyphenols and Cancer: Biologic Mechanisms and Practical Implications. Nutrition Reviews, 57(3), 78-83.

Khan SG, Katiyar SK, Agarwal R, Mukhtar H. (1992). Enhancement of Anti-oxidant and Phase II Enzymes by Oral Feeding of Green Tea Polyphenols in Drinking Water to SKH-1 Hairless Mice: Possible Role in Cancer Chemoprevention. Cancer Research, 52(14), 4050-4052.

Yang GY, Liao J, Kim K, Yurkow EJ, Yang CS. (1998). Inhibition of growth and induction of apoptosis in human cancer cell lines by tea polyphenols. Carcinogenesis, 19(4), 611-616.

Zhang X, Zhang H, Tighiouart M, Lee JE, et al. (2008). Synergistic inhibition of head and neck tumor growth by green tea (-)-epigallocatechin-3-gallate and EGFR tyrosine kinase inhibitor. Int. J. Cancer, 123(5):1005–1014