The anti-ulcerogenic potential of the leaf methanol extract of Aloe buettneri
A. Berger was investigated using three methods of gastric lesion induction in experimental Wistar rats (150-200 g) and mice (20-25 g): 1. HCl/ethanol-induced gastic lesions, 2. Indomethacin-HCl/ethanol-induced gastric lesions, and 3, Pylorus ligation-induced gastric lesions. Mice were used in acute and sub acute toxicity tests. Oral administration of the extract of Aloe buettneri
to the rats and mice (500-1000 mg/kg) dose-dependently prevented the formation of acute gastric lesions induced using the three experimental techniques. The dose-dependent reduction of lesion formation was accompanied by a significant increase in gastric mucus production in mice. Inhibition of lesion formation was 22 and 54 % in mice, 25 and 77% in rats for the doses of 500 and 1000 mg/kg when the HCl/ethanol mixture was given. Pre-treatment, by oral route, with indomethacin significantly reduced the ability of the extract to inhibit the formation of HCl/ethanol-induced lesions, inhibition dropping to 11% for the dose of 1000 mg/kg. When the rats were subjected to pylorus ligation, the level of lesion inhibition was 36 and 68% for the two doses of extract. Gastric acid secretion reduced to 88 and 79mEq/l compared with105 mEq/l for the controls. Acute toxicity studies did not reveal toxic effects up to the dose of 10 g/kg. However, sub acute studies revealed toxicity effects in heart (pericarditis), lung (diffuse alveolar disease) and liver (chronic active hepatitis) tissue. These results confirm the ethnomedical use of Aloe buettneri
in the management of gastroduodenal ulcer disease and suggest that toxic effects may result from prolonged intake of high doses of the extract.