Combined effects of green tea supplementation and eccentric exercise on nuclear factor erythroid 2-related factor 2 activity

Purpose This study investigated whether combining eccentric exercise and green tea supplementation synergistically increased nuclear factor erythroid 2-related factor 2 (NRF2) activity, a transcription factor responsible for coordinating endogenous antioxidant expression. Methods In a double-blinded, randomized, between-subjects design, 24 males (mean [SD]; 23 [3] years, 179.6 [6.1] cm, 78.8 [10.6] kg) performed 100 drop jumps following a 6 days supplementation period with either green tea (poly)phenols (n = 12; 500 mg.d(-1)) or a placebo (n = 12; inulin). NRF2/antioxidant response element (ARE) binding in peripheral blood mononuclear cells (PBMCs), catalase (CAT) and glutathione reductase (GR) activity, 8-hydroxy-2'-deoxyguanosine (8-OHdG) excretion, and differential leukocyte counts were measured pre-, post-, 1 h and 24 h post-exercise. Results Exercise did not increase NRF2/ARE binding (p = 0.12) (fold change vs rest: green tea = [post] 0.78 +/- 0.45, [1 h] 1.17 +/- 0.54, [24 h] 1.06 +/- 0.56; placebo = [post] 1.40 +/- 1.50, [1 h] 2.98 +/- 3.70, [24 h] 1.04 +/- 0.45). Furthermore, CAT activity (p = 0.12) and 8-OHdG excretion (p = 0.42) were unchanged in response to exercise and were not augmented by green tea supplementation (p > 0.05 for all). Exercise increased GR activity by 30% (p = 0.01), however no differences were found between supplement groups (p = 0.51). Leukocyte and neutrophil concentrations were only elevated post-exercise (p < 0.001 for all). Conclusion Eccentric exercise, either performed alone or in conjunction with green tea supplementation, did not significantly increase NRF2 activity in PBMCs. Trial registration number osf.io/kz37g (registered: 15/09/21). [GRAPHICS] .

Automated summary

This study investigated the effects of combining eccentric exercise and green tea supplementation on NRF2 activity. The results showed that neither eccentric exercise alone nor in combination with green tea supplementation significantly increased NRF2 activity in peripheral blood mononuclear cells.