Effects of traditional herbal medicine on gastric mucin against ethanol-induced gastric injury in rats

The effect of the traditional herbal medicine, Rikkunshi-to and its component crude drugs, Zingiberis Rhizoma and Glycyrrhizae Radix, on the gastric mucin was studied using a method developed to separate and quantify the mucin localized in the different layers of rat gastric mucosa. The oral administration of spray-dried extract to Rikkunshi-to (1000 mg/kg), Zingiberis Rhizoma (500 mg/kg) and Glycyrrhizae Radix (500 mg/kg) significantly prevented gastric mucosal damage induced by 70% ethanol in rats. In ethanol-treated rats the mucin content of the deep mucosa was reduced, and the reduction of the deep corpus mucin content was significantly inhibited by pretreatment of Rikkunshi-to and Zingiberis Rhizoma. Rikkunshi-to and Glycyrrhizae Radix pretreatment increased the surface mucin content by 140 and 146%, respectively. The effect on the gastric mucin by each drug differed in the different layers of the gastric mucosa.