Many medicinal plants used in ethnomedicine have been reported to possess anti-ulcer activity. One of such plants is Plumbago zeylanica Linn. Our objective is to evaluate the anti-ulcer activity of the aqueous extract of the roots of Plumbago zeylanica Linn on aspirin and indomethacin-induced acute gastric ulceration in albino Wistar rats. The anti-ulcer activity of the aqueous root extract was assessed by determining and comparing the ulcer score, ulcer index and percentage protection of the extract with that of the negative and positive control groups. Omeprazole was used as standard drug. The extract at doses of 25, 50 and 100 mg/kg respectively produced statistically significant (P<0.05) dose-dependent inhibition of aspirin induced gastric mucosal damage. In the indomethacininduced ulcer, it was only at doses of 50 and 100 mg/kg respectively that the extract exhibited significant (p< 0.05) dose – dependent inhibition of the gastric mucosal damage. Oral acute toxicity testing showed oral LD50 to be greater than 5000 mg/kg, indicative of the wide margin of safety of the root extract. The findings indicated that the aqueous extract of the roots of Plumbago zeylanica Linn possesses anti-ulcer activity.
