Anti-fatigue effects of polysaccharides extracted from Portulaca oleracea L. in mice.

Portulaca oleracea L. has been used as a food and medicinal plant for thousands of years in China. Polysaccharides extracted from P. oleracea L. (POP) are its main bioactive compound and have multiple pharmacological activities. However, anti-fatigue effects of POP have not yet been tested. This study was designed to investigate the anti-fatigue effects of POP in mice using the rotarod and forced swimming tests. The mice were randomly divided into four groups, namely normal control group, low-dose POP supplementation group, medium-dose POP supplementation group and high-dose POP supplementation group. The normal control group received distilled water and the supplementation groups received different doses of POP (75, 150 and 300 mg/kg, respectively). The POP or distilled water was administered orally and daily for 30 day. After 30 days, the rotarod and forced swimming tests were performed and then several biochemical parameters related to fatigue were determined. The data showed that POP prolonged the riding times and exhaustive swimming times of mice, decreasing blood lactic acid and serum urea nitrogen levels, as well as increasing the liver and muscle glycogen contents. These results indicated that POP had the anti-fatigue effects.