Abstract Title:

Tea tannin components modify the induction of sister-chromatid exchanges and chromosome aberrations in mutagen-treated cultured mammalian cells and mice.

Abstract Source:

Phytomedicine. 2002 Apr;9(3):212-6. PMID: 1899132

Abstract Author(s):

H Imanishi, Y F Sasaki, T Ohta, M Watanabe, T Kato, Y Shirasu


The modifying effects of tannin components extracted from green tea and black tea on mutagen-induced SCEs and chromosome aberrations were studied. These tannin components did not affect spontaneous SCEs and chromosome aberrations in cultured Chinese hamster cells. The frequency of SCEs and chromosome aberrations induced by mitomycin C (MMC) or UV was enhanced by the posttreatment with tea tannin components. When cells were post-treated with tea tannin components in the presence of metabolic enzymes of rat liver (S9 mix), the modifying effects on the induction of SCEs and chromosome aberrations by mutagens were complicated. MMC- and UV-induced SCEs and chromosome aberrations were suppressed by the posttreatment with tea tannin components at low concentrations (less than or equal to 6.7 micrograms/ml) with S9 mix. At a high concentration of tea tannin components (20 micrograms/ml) with S9 mix, a co-mutagenic effect was observed. The modifying effects of tea tannin components were shown to occur in the G1 phase of the cell cycle. In cells from a patient with xeroderma pigmentosum (XP) and a normal human embryo, MMC-induced SCEs were suppressed by the posttreatment with tea tannin components in the presence of S9 mix, and enhanced in the absence of S9 mix. On the other hand, tea tannin components modified SCE frequencies in UV-irradiated normal human cells but not in UV-irradiated XP cells. Our results suggested that tea tannin components themselves inhibited DNA-excision repair and resulted in a co-mutagenic effect, while in the presence of S9 mix metabolites of tea tannin components promoted DNA-excision repair activity and resulted in an antimutagenic effect. MMC-induced chromosome aberrations in mouse bone marrow cells were suppressed by the pretreatment with green tea and black tea tannin mixture.

Additional Links

Print Options

Key Research Topics

Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get Nature's Evidence-Based Pharmacy

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Download Now

500+ pages of Natural Medicine Alternatives and Information.

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2021 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.