PROTECTIVE EFFECTS OF METHANOL EXTRACT OF Chasmanthera dependens HOCHST STEMON ACIDIFIED ETHANOL-AND INDOMETHACIN-INDUCED GASTRIC ULCER AND APOPTOSIS IN MALE WISTAR RATS

Abstract

Gastric ulceration is a common clinical problem which may results from incessant use of drugs. Chasmanthera dependens possesses analgesic effects in experimental rats and anecdotal report exit on its gastric ulcerogenic healing property which has not been well investigated. Therefore, this study was designed to evaluate the possible biochemical mechanisms underlying the effects of Methanol Extract of Chasmanthera dependens (MECD) stem on acidified ethanol- and indomethacin-induced gastric ulcer in Wistar rats. Fresh stem of Chasmanthera dependens was collected, identified at the Department of Botany, University of lbadan, air dried, powdered and cold-extracted using methanol. One hundred and forty four rats (180-200 g) were divided into four groups. Each group was sub-divided into six sub-groups. In groups 1 and 2, sub-group 1 received 1% gum acacia (control); sub-groups 3 and 6 received MECD (400 mg/kg) and sub-groups 4 and 5 received cimetidine (50 mg/kg) for seven days. On day 7, in group 1, sub-groups 2, 3 and 4 received indomethacin (40 mg/kg) while in group 2, sub-groups 2, 3 and 4 received acidified ethanol (0.15N HCI/70% v/v EtOH) (I mL/14). In groups 3 and 4, sub-group 1 received 1% gum acacia for 14 days. On day 1, sub-groups 2, 3 and 4 received indomethacin in group 3 and acidified ethanol in group 4. Thereafter, sub-groups 3 and 6 received MECD while sub-groups 4 and 5 received cimetidine for 14 days. Gastric ulcers are scored using standard method while reduced glutathione (GSH) and malondialdehyde levels were determined spectrophotometrically. Vascular Endothelial Growth Factor (VEGE) was determined using ELISA. Cyclooxygenase-2 and inducible Nitric Oxide Synthase (iNOS) expressions were determined using immunohistochemistry and gastric mucosa apoptosis by TUNEL assay. Data were analysed using ANOVA at p=0.01. In all the groups ulcer score for sub-groups 1. 5 and 6 were 0.0±0.0. On day 7 in group 1, ulcer score was 12.3±1.2 in sub-group 2, and 2.9±0.4 and 5.4±0.5 in sub-group; 3 and 4 respectively. GSH (10.0± 1.0 ug/mg) decreased and malondialdehyde (7.3±0.5 ug MDA/mg) increased significantly in sub-group 2 compared to control (60.0±12.3 ug/mg and 2.0±0.7ug in MDA/mg respectively). Pre-exposure to MECD and cimetidine significantly reversed these levels (GSH: 75.0±5.8, 46.8±9.4 ug/mg: malondialdehyde: 3.4±0.2, 3.4±0.2ug MDA/mg respectively). In group 2, ulcer score was 13.7±0.5 in sub-group 2, and 3.0±0.5 and 5.6±0.4 in sub groups 3 and 4 respectively. GSH (3.0±1.07 ug/mg) decreased and maIondialdehyde (6.0±0.3 ug MDA/mg) increased significantly in sub-group 2 compared to control (5.4±0.4 up MDA/mg and 2.4±0.3 ug MDA/mg respectively). However, pre-exposure to MECD and cimetidine significantly reversed GSH (6.2±0.6, 4.0±1.6 ug/mg) and malondialdehyde (2.4±0.1, 2.3±0.2 ug MDA/mg) levels. On day 14, in groups 3 and 4 VEGF levels were increased in sub-groups 3 and 4 compared to sub-group 2 in both models. Also, apoptosis, cyclooxygenase-2 and iNOS expressions were significantly increased insub-group 2 when compared to sub-group 1 while these were decreased in sub-groups 3 and 4 respectively. The methanol extract of Chasmanthera dependens stem reduced the mucosa ulceration and oxidative damage induced by indomethacin and acidified ethanol in Wistar rats.