Total soy saponins improve the antioxidant capacity of the myocardium and exercise ability in exhausted rats

PURPOSE: The aim of the present study was to investigate the impact of total soy saponins (TS) on the myocardial antioxidant capacity in rats exercised to exhaustion. METHODS: The one-time exhausted treadmill model was used. All rats were divided into 4 groups: the control group, the TS group, the exhausted group, and the TS exhausted group. The TS and TS exhausted groups were fed TS at a dosage of 20 mg/kg body weight, once a day, for 2 weeks. The exhausted group was given a placebo, and the control group was not given any treatment. The treadmill speed was set at 30 m/min, and the rats (exhausted and TS exhausted groups) were trained at this speed until exhausted. The rats were decapitated and anatomized immediately after exhausted. A 10% homogenate of the myocardial tissue was prepared. RESULTS: TS significantly increased the exercise time by 20.62% (p < 0.05). As compared with the control group, the enzyme activities for catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GR) were significantly enhanced in the TS group (p < 0.01); GR and GSH-Px activity was significantly enhanced in the TS exhausted group (p < 0.01); malondialdehyde (MDA) levels were significantly decreased in the TS exhausted group (p < 0.05). As compared with the exhausted group, the GSH-Px activity was significantly enhanced in the TS exhausted group (p < 0.01); CAT, GSH-Px, and GR activities were significantly enhanced in the TS group (p < 0.01). As compared with the TS group, the CAT and GR activity in the TS exhausted group was significantly decreased (p < 0.01). CONCLUSION: TS can improve the exercised rats' antioxidant activity in their cardiac muscle to varying degrees, decrease MDA and serum AST and LDH levels, increase the exercise time, and delay the occurrence of sports fatigue.