Supplementation of Jurkat T cells with green tea extract decreases oxidative damage due to iron treatment

Regular tea consumption has been associated with a reduced risk of cancer. As demonstrated in vitro, green tea contains catechins with antioxidant pro perties. We evaluated the effect of the supplementation of the Jurkat T-cel l line with green tea extract on oxidative damage. Cells grown in medium wi th or without green tea extract (10 mg/L) were treated with Fe2+ (100 mu mo l/L) as an oxidative stimulus for 2 h. Cell membrane lipid peroxidation was evaluated by fatty acids pattern analysis and malondialdehyde production i n ar-linolenic acid-loaded cells. Furthermore, oxidative DNA damage (single strand breaks) was detected in cells by the Comet assay and quantified as relative tail moment (RTM). Supplementation with green tea extract signific antly decreased malondialdehyde production (1.6 +/- 0.3 vs. 0.6 +/- 0.1 nmo l/mg protein, P < 0.05) and DNA damage (0.32 +/- 0.07 vs. 0.12 +/- 0.04 RTM , P < 0.05) after Fe2+ oxidative treatment. In control cells, there was no effect on membrane distribution of (n-3) fatty acids due to Fe2+ treatment. Cell enrichment with or-linolenic acid increased total membrane (n-3) fatt y acids. However, the oxidative treatment did not modify the distribution o f polyunsaturated fatty acids. It is likely that the observed protective ef fects can be attributed to epigallocatechin gallate, which is present mainl y (670 g/kg) in green tea extract; however, we cannot exclude contributions by other catechins. These data support a protective effect of green tea ag ainst oxidative damage.