[Effects of Tangeretin on cortisol stress response induced by high-intensity resistance exercise]

Objective: To investigate the effects of 4-week tangeretin supplementation on cortisol stress response induced by high-intensity resistance exercise. Methods: Twenty-four sprinters were paired and randomly divided into experimental group (EG) and control group (CG). EG orally took supplement with tangeretin (200 mg/day) and CG took placebo for 4 weeks. Before and after the 4-week intervention, all sprinters performed a set of high-intensity resistance exercise (shoulder press, squat, bench press and deadlift, 10 RM, 4 sets per movement) to stimulate their cortisol stress responses. Serum levels of cortisol, adreno-corticotropic hormone (ACTH), superoxide dismutase (SOD), white blood cell count (WBC) and blood glucose were obtained by collecting blood sample before the exercise (PRE), immediately after the exercise (P0), and at 10 (P10), 20 (P20), and 30 minutes (P30) after the exercise. Results: Compared with the same period before the intervention, after the 4-week tangeretin intervention, EXP showed significantly reduced serum cortisol level at PRE (P=0.017), P10 (P=0.010), P20 and P30 (P＜0.05 or P＜0.01), and significantly reduced WBC at PRE, ACTH at P10 (P=0.037) and WBC and ACTH at P30 (P＜0.05). Compared with CTROL, EXP showed significantly lower levels of the serum cortisol at PRE and P10 (P＜0.05), and significantly lower levels of the ACTH (P＜0.05) and WBC (P＜0.01) at P30, and significantly increased level of the SOD activity at P30 (P＜0.05). Conclusion: Tangeretin supplementation can significantly alleviate the cortisol stress response induced by high-intensity resistance exercise, inhibit the excessive secretion of cortisol, enhance antioxidant capacity, accelerate the elimination of inflammation in the body, and promote the recovery of body functions.