Homopterocarpin contributes to the restoration of gastric homeostasis by Pterocarpus erinaceus following indomethacin intoxication in rats.

To investigate the restorative effect of Pterocarpus erinaceus (P. erinaceus) and homopterocarpin, an isoflavonoid isolated from it, on indomethacin-induced disruption in gastric homeostasis in rats. Adult rats were divided into five groups and fasted for 48 h before treatment. Group 1 received olive oil (vehicle), group 2 received 25 mg/kg indomethacin while groups 3-5 received cimetidine (100 mg/kg), homopterocarpin (25 mg/kg) and P. erinaceus ethanolic stem bark extract (100 mg/kg) respectively. After 1 h, all the groups except group 2 were administered 25 mg/kg of indomethacin. One hour later, the rats were sacrificed and the ulcer index and other gastroprotective indices were evaluated. Indomethacin caused significant injury to the stomach of the rats as reflected in the ulcer indices (9.0±1.4) as compared with that of control (2.0±0.0). Equally, there were significant increases in gastric acid concentration and malondialdehyde level in the stomachs of the ulcerated animals compared with the control. However mucus content, reduced gluthatione level and gastric pH were significantly reduced in the ulcerated animals compared with the control. Pretreatment with either Pterocarpus bark extract or homopterocarpin reversed the effects of indomethacin on the evaluated parameters. These results indicate that both homopterocarpin and Pterocarpus extract offered gastroprotection against indomethacin-induced ulcer by antioxidative mechanism and the modulation of gastric homeostasis. The results also suggest that homopterocarpin might be responsible for, or contribute to the antiulcerogenic property of P. erinaceus.