Prophylactic and Healing Activities of the Leaves Aqueous Extract of Eremomastax speciosa on Gastric Ulcers in Rats

摘要

Aims: Information provided by practitioners of Cameroonian ethnomedicine suggested that Eremomastax speciosa ( E. speciosa ) possesses antiulcer activity. This led us to evaluate the prophylactic and healing effects of this plant. Place and Duration of Study: Department of Animal Biology & Physiology (Animal Physiology Laboratory) and Department of Organic Chemistry (Laboratory of Medicinal Chemistry), Faculty of Science, University of Yaoundé I, between May 2012 and November 2013. Materials and Methods: The anti-ulcer activity of the leaf aqueous extract of E. speciosa was tested in rat using several acute gastric ulcer-inducing methods (HCl/ethanol, indomethacin-HCl/ethanol, indomethacin, absolute ethanol and cold/restraint stress). The healing effect on chronic acetic acid-induced gastric ulcers was also tested. Results: Oral administration of the extract of E. speciosa prevented the formation of acute gastric lesions induced by different necrotizing agents. The inhibition was complete (100% inhibition) at the dose of 200 and 400 mg/kg of extract for the HCl/ethanol and cold/restraint stress methods, respectively. Pre-treatment with indomethacin significantly reduced the ability of the extract to inhibit the formation of HCl/ethanol induced lesions, with inhibition dropping to 39.63% for the dose 200 mg/kg. The lowest degree of gastric protection by the extract (12.13 to 13.80%) was obtained when indomethacin was administered alone by oral route. The protective effect of the extract (200 mg/kg) was reduced significantly when absolute ethanol (27.84% inhibition) was used as the necrotizing agent compared with the HCl/ethanol solution (100%). The prophylactic actions were associated with significant increases in gastric mucus production. The healing rate of chronic acetic acid-induced ulcers was 55.40 and 77.70%, for the dose 200 and 400 mg/kg of extract, respectively. Conclusion: The prophylactic anti-ulcer effects of the extract are associated with enhanced mucus production which is an important factor in the mechanism of the healing process of chronic gastric ulcers.