Protective effects of oleanolic acid oligoglycosides on ethanol- or indomethacin-induced gastric mucosal lesions in rats

Abstract

We examined the effects of various oleanolic acid oligoglycosides obtained from traditional herbs on ethanol- or indomethacin-induced gastric mucosal lesions in rats and on gastric secretion in pylorus-ligated rats. Test samples were given orally to fasted rats 1 h before absolute ethanol (1.5 ml rat , p.o.) or indomethacin (30 mg kg , s.c.) treatment, or ligation of the pylorus. Oleanolic acid 3- O-monodesmosides [oleanolic acid 3- O-glucuronide ( 1, 20–50 mg kg ), momordin Ic ( 2, 5–50 mg kg ), and 28- O-deglucosyl-chikusetsusaponins IV ( 5, 10–50 mg kg ) and V ( 7, 10–50 mg kg )] were found to show protective effects on ethanol-induced gastric mucosal lesions, whereas oleanolic acid 3,28- O-bisdesmosides [momordin IIc (3), chikusetsusaponins IV (4) and V (6)], oleanolic acid 28- O-monodesmoside [compound O (8)], and their common aglycon [oleanolic acid ( 9)] showed no such effects. Oleanolic acid 3- O-monodesmosides ( 1, 2, and 5) also showed protective effects on indomethacin-induced gastric mucosal lesions. 28- O-Deglucosyl-chikusetsu-saponin V ( 7) did not inhibit the indomethacin-induced lesions, while chikusetsusaponins V ( 6, 50 mg kg ) had the gastroprotective effect. These active saponins ( 1, 2, 4–7, 10–50 mg kg ) did not decrease the gastric secretion by oral administration in pylorus-ligated rats.