The study evaluated the anti-ulcerogenic activity of aqueous extract of guava (Psidium guajava) leaves extract in rats. To achieve this aim, twenty five (25) adult male albino rats weighing between 100-130 g were used for the study. The animals were assigned into different groups and treated as follows: Group 1- Control and received 0.2ml of distilled water orally, Group 2: (1ml of 75% ethanol) and were not treated, Group 3, 4 and 5 Received 500, 1000 mg/kg b w aqueous extract of Psidium guajava and 100 mg/kg b w of cimetidine orally for 5 days prior to ethanol administration. On the sixth day, ulcer was induced by oral administration of 1 ml of 75% ethanol in all the groups after an overnight fasting irrespective of the weight of the animals. All animals were euthanized one hour after induction of gastric ulceration the stomach of each animal was removed and excised along their greater curvature for determination of gastric lesion and gross identification. The number of lesion in each stomach was counted and other ulcer parameters determined. Results obtained in this present study revealed that the administration of 500 and 1000mg/kg b w of aqueous extract of Psidium guajava to animals in all groups produced significantly decreased dose dependent (p<0.05) mean ulcer index (2.0 ± 1.23, 1.0 ± 0.43 and 0.3 ± 1.02) when compared to ethanol induced ulcer untreated animals (4.7 ± 0.62).The results also showed that the animals pre-treated with various doses of aqueous extract of Psidium guajava and cimetidine (500 and 1000mg/kg b w and 100mg/kg b w) showed a significant protection as evidenced by high preventive index 0.6 ± 0.87, 0.8 ± 1.98 and 0.9 ± 2.10 when compared to ethanol induced gastric mucosal damage untreated animals. It may be concluded that the aqueous extract of extract of P. guajava produced ulcero-protective activity in ethanol induced gastric mucosal damage in wistar rats.
