Abstract

Gastro-duodenal ulcers are diseases that constitute a major public health problem all over the world and particularly in Côte d'Ivoire. The aim of this study was to evaluate the acute toxicity and gastric anti-ulcer activity of an aqueous extract of the leaves of Macaranga barteri (AEMb). Acute toxicity was carried out using the Organization for Economic Co-operation and Development (OECD) Guidelines 420. The anti-ulcer activity of AEMb was evaluated using four models of gastric ulcer induction which are HCl/ethanol solution, ibuprofen solution, pylorus ligation and cold restraint stress in rats. The parameters assessed were mucus production, ulcer surface, ulcer index, pH, acid concentration and volume of gastric contents. Cimetidine, aluminium hydroxide and ranitidine were used as anti-ulcer standard drugs. The results of this preventive gastric anti-ulcer study revealed that for doses ranging from 62.5 to 500 mg/kg body weight (b.w), AEMb dose dependently prevented gastric lesion formation (p<0.001) in the four models. The inhibition values were 98.96, 94.11, 90.73 and 96.89% on ulcerations induced respectively by HCl/ethanol, ibuprofen, pylorus ligation and cold restraint stress at the dose of 500 mg/kg b.w. This cytoprotective action was accompanied by a significant increase in gastric mucus production. These results suggested that the preventive anti-ulcer activity of AEMb may be due to a cytoprotective effect. The median acute toxicity LD₅₀ value of AEMb was higher than 5000 mg/kg b.w. This extract was classified as nontoxic in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Phytochemical compounds such as polyphenols, saponins, alkaloids, sterols and polyterpenes found out in AEMb could be responsible for its effects. In conclusion, the antigastric ulcer and the non-toxic effects of the aqueous extract of M. barteri could justify its use in traditional medicine for the treatment of gastro-duodenal ulcers. 

Key words: Acute toxicity, gastric ulcer, rat, Macaranga barteri.