Gastroprotective activities of a polysaccharide from the fruiting bodies of Pleurotus ostreatus in rats

In this study, a water-soluble polysaccharide (POPw) was successfully purified and identified from the fruiting bodies of Pleurotus ostreatus, with a molecular weight of 2.3 × 104 Da. POPw contained 97.1% total sugar, 0.3% uronic acid and 0.2% protein. Gas chromatography (GC) analysis suggested that POPw was composed of Glc (52.3%), Gal (25.8%), Man (10.0%), Rha (6.1%), and Ara (5.2%). Animal experiments showed that oral administration with POPw significantly inhibited acetic acid-induced gastric lesions in rats, accompanied with a significant increase in mucus synthesis and the prostaglandin production. In addition, POPw could significantly increase the level of glutathione (GSH) and the activity of superoxide dismutase (SOD), as well as decreasing the content of thiobarbituric acid-reactive substances (TBARS) in acetic acid-treated rats with gastric ulcer. These results suggested that the gastroprotective effects of POPw on mice ulcer models can be attributed to its ameliorating effect on oxidative damage and reinforcing effect of gastric mucosal resistance.