Objectives: Puerariae flos has popularly been used to treat alcoholic disorders. However, the effect of Puerariae flos on alcoholic disorders in the gastrointestinal system has not been identified. We investigated the protective effect of an extract of Puerariae flos against the murine gastric mucosa. Methods: Thomsonide, the extracts containing large amounts of isoflavonoid and triterpenoid saponin, was obtained fr

om Puerriae flos via Diaion HP-20 column chromatography using water and 99.5% ethanol. It was investigated whether thomsonide, as well as geranylgeranylacetone (teprenone), a popular anti-ulcer agent developed in Japan, had a cytoprotective effect that might be related to endogenous prostaglandins, which played an important role in preventing gastric mucosal lesions. Results: Thomsonide and teprenone inhibited ethanol-induced gastric lesions. Furthermore, thomsonide increased the production of PGE2 and 6-ketoPGF1α, a stable metabolite of PGI2, in the gastric mucosa, and protective effects of thomsonide, as well as teprenone, against ethanol-induced gastric lesions were attenuated by pretreatment with indomethacin. Conclusions: These findings suggest that thomsonide, as well as teprenone, has the gastro protective effect which may be related to the cytoprotective activity of endogenous prostaglandins. The results of this study also suggest that the gastro protective effect of thomsonide may partially mitigate alcoholic disorders in the gastrointestinal tract, and support our pharmacological belief that Puerariae flos is useful for treatment of alcoholic disorders.