Investigation of anti-ulcer effect of Abelmoschus esculentus L. on acute gastric mucosal injury

Abelmoschus esculentus L. (Malvaceae), is a medicinal plant widely used in Turkish traditional medicine for the treatment of various diseases such as ulcers and gastritis. In the present study, we evaluated the gastroprotective effect of Abelmoschus esculentus L. extract (AEE) against ethanol-induced acute gastric mucosal injury in animal models. Wistar rats were administered with 500, 250 or 100mg/kg AEE; 20mg/kg famotidine (Fam); and 75 mg/kg quercetin (Que). Following a 60 min period, all the rats were given 1mL of ethanol (80%). One hour after the administration of ethanol, all groups were sacrificed. The area of stomach tissue and gross lesions were approximately calculated. The results were translated to the term of "total ulcer area/total gastric area" and these were expressed as an ulcer index. Malondialdehyde (MDA) which is sign of oxidative stress and reduced glutathione (GSH) levels were measured in whole blood; ascorbic acid, β-carotene and retinol which is prove antioxidant property levels were measured in serum. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) were measured in erythrocytes. Mucosal edema, hemorrhage, inflammation, epithelial cell erosion and interleukins (IL-6, IL-1β) were evaluated in gastric tissue sections. Bioelement levels were examined in homogenized tissues. Up to at 5000 mg/kg, the extract produced (AEE) no sign of toxicity in animals. AEE-500, 250, 100, Fam-20 and Que-75 inhibited ulcer formation by 81.0, 67.5, 67.0, 76.3 and 72.4%, respectively. The oxidant levels decreased significantly in the all study groups compared within ethanol group (p<0.001). Serum β-carotene and retinol levels significantly increased 40.2 and 45.4% in AEE-500 group. The level of GPx is highest in AEE-500 mg/kg group, and this value is close to the sham group. When SOD values were compared, the groups administered with AEE-100 and 500 mg/kg were higher than the ethanol group (p<0.001 and p<0.01). When CAT results were evaluated, the values of AEE-250 and 500 mg/kg groups were statistically significant compared to the ethanol group (p<0.01). In parallel with the antioxidant enzymes, the Cu, Zn, Fe, Se and Ca bioelements are significantly increased when compared with the ethanol group. AEE-500 significantly decreased edema, hemorrhage and inflammation scores compared with ethanol group (p<0.05). In AEE-500, 250 and Fam-20 groups, apoptosis significantly decreased (p<0.001), while AEE-500, 250 and Fam-20 groups showed a higher percentage of cell proliferation compared with ethanol group (p<0.001). Particularly in groups administered with AEE-500 mg/kg, IL-6 and IL-1β levels were significantly reduced compared to the ethanol group. Our in vivo data indicate that Abelmoschus esculentus L. extract (AEE) has a gastroprotective effect against ethanol and could reduce the gastric ulcer as seen from biochemical and histopathological results. We suggest that Abelmoschus esculentus L. extract (AEE) could be a possible therapeutic antiulcer agent.