Bergenin (I) [477-90-7] had a dose dependent antisecretory effect on gastric secretion in pylorus ligated rats for 3-6 hr.The ED50 for gastric secretion in pylorus ligated rats for 6 hr was 210 mgI/kg for free acidity, 240 mgI/kg for total acidity, and 260 mgI/kg for gastric juice volumeI not only had dose dependent antiulcerogenic activities in rat stress-induced ulcers, but also had the same effect on exptl. ulcers induced by serotonin, reserpine, and fasting.The ED50, for exptl. ulcers from reserpine, serotonin, stress, and fasting were 64, 32, 38, and 38 mg/kg.