Abstract

The aim of this study was to determine the effects of Astragalus membranaceus polysaccharides (AMP) on oxidative damage in skeletal muscle of exhaustive exercise rats. The animals were divided into four groups at random, with eight rats in each group. Group 1, assigned as a control group, received normal saline (vehicle); groups 2 to 4 received AMP at different dosages (50, 100 and 200 mg/kg bw) respectively for 30 successive days. Rats were made to perform an exhaustive running test on a treadmill at a final speed of 30 m/min, 10% grade, at approximately 70 to 75% VO₂max. The mean endurance times of running on a treadmill to exhaustion of each rat were examined. And skeletal muscle samples were collected for determining the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and levels of malondialdehyde (MDA). The results showed groups 2 to 4 significantly increased in exhaustive exercise time compared with groups 1. MDA concentration of skeletal muscle of the groups 2 to 4 were significantly decreased compared with that of the groups 1. The antioxidant enzyme activities of SOD, GSH-Px and CAT of skeletal muscle of the groups 2 to 4 significantly increased compared with that of the groups 1. It is concluded that AMP supplementation increased performance of exhaustive exercise of rats. And it is beneficial for increasing antioxidant status and inhibits oxidative stress induced by exhaustive exercise.

Key words: Astragalus membranaceus polysaccharides, oxidative damage, exhaustive exercise, rats