Green tea polyphenols have been suggested to exert anti-inflammatory actions in in vivo and in vitro studies. The aim of this study was to investigate the effect of green tea extract (GTE) supplementation on pro-inflammatory cytokines during a single bout of resistance exercise (RE) in obese men. Participants were ten obese men who participated in a randomized, double-blind, placebo-controlled (PL) crossover study, administered 14-day GTE (500 mg/day) supplementation and PL with a 14-day washout period. After the supplementation periods, the participants performed the RE protocol, consisting of three sets of six exercises, to failure at 75% of one repetition maximum (1RM) and 2 min rest between sets. The serum samples were collected pre- and post-RE and analyzed for TNF-α, IL-1α, and IFN-γ. RE significantly increased TNF-α and IL-1α in obese men by 15% (p=0.043) and 18.71% (p=0.003) above the pre-RE values in the PL condition, respectively. However, GTE supplementation inhibited acute RE-induced increases in the TNF-α and IL-1α levels in obese men. Moreover, changes in the IFN-γ level during RE tended to be lower in GTE compared to the PL condition. Based on the findings, it can be concluded that 14-day GTE supplementation offers protection against RE-induced increases in pro-inflammatory cytokines in obese men. These immunomodulatory effects of GTE may be, in part, due to the anti-inflammatory properties of GTE in obese men that can be considered as a potential therapeutic factor to ameliorate obesity-associated inflammation.
