Effect of hydro-methanolic leaf extract of Indigofera pulchra on gastric mucosal damage and acid secretion in rats

Abstract

Indigofera pulchra (family: fabaceae) is found throughout the tropical and subtropical regions of the world. It has been used for medicinal purposes for centuries from Sudan to the dry deciduous parts of Madagascar for variety of conditions and ailments related to stomach, intestinal, liver, circulatory and immune system support .This study was aimed at investigating the effect of hydro-methanolic extract of this plant as it affects gastric mucosal integrity and basal gastric secretions using the ethanol-induced ulcer model. Phytochemical screening of the plant revealed the presence of flavonoids, alkaloids, tannins and cardiac glycosides amongst others, while acute toxicity studies (Lorke’s method, 1983) revealed a median lethal dose above 5000mg/kg indicating that the plant is less toxic. A total of 60 rats were used for the two studies, with 30 rats for the mucosal integrity study and 30 rats for the basal acid secretion studies. The first group was subdivided into four(A,B,C,D) with subgroup A,B, and C containing five rats each, and subgroup D containing fifteen rats. Subgroup A served as normal control and was given normal saline while subgroup B represented negative control and was administered 70% ethanol, subgroup C was given cimetidine and served as positive control. Subgroup D was further subdivided into three experimental groups which contained five rats each and were administered Indigofera pulchra extract at a dose of 100mg/kg, 200mg/kg, and 400mg/kg respectively 30 minutes prior to the administration of 70% ethanol to induce gastric mucosal damage followed by pyloric ligation. The same procedure was followed in major group II to study basal gastric output. Ulcer and preventive indices were assessed for mucosal integrity while volume of gastric juice, titratable acidity and acid output were assessed for basal gastric secretions. The result showed a dose –dependent decrease in both ulcer and preventive indices. It also showed a significant (p<0.05) decrease in volume of gastric juice, titratable acidity and acid output in dose-dependent manner with the three experimental doses administered with the highest reduction at the 400mg/kg dose. The results obtained suggest that this plant extract down-regulated all those parameters which might be attributed to the presence of the phytoconstituents present in the fraction. Therefore, this plant possesses gastro protective and antisecretory effects further explaining the folkloric use of this plant in the therapy of peptic ulcer disease.

Keywords: Basal Secretions, Ethanol, Gastroprotection, Indigofera pulchra