Abstract

Agave sisalana is commonly used by local communities to treat mucosal inflammation and control gastro-intestinal parasites in chickens. However, information on toxicity of A. sisalana is limited. This study conducted acute, sub-acute and chronic tests to assess the potential toxicity of the plant on rats. The A. sisalana aqueous leaf extract was prepared following the procedures of the communities. The test extract was orally administered to the rats using a bulbed steel needle. For each test, twenty-five rats were randomly divided into five groups each treated as follows: Group 1 (control) received 1 mL/day of distilled water and groups 2 to 5 received 50, 100, 200 and 400 mg/kg of A. sisalana test extract, respectively. Mortality, behavioral and physiological changes were monitored for 72 h, 14 and 35 days in acute, sub-acute and chronic tests, respectively. Haematological, biochemical and histopathological examinations were conducted in sub-acute and chronic tests. No mortality, behavioral or physiological changes were noticed in the acute test. Mortality rate for 50 and 100 mg/kg doses of sub-acute and chronic test respectively was 20%. Chronic test (200 mg/kg) had 40% mortality rate. For sub-acute and chronic tests, 100 and 200 mg/kg doses, mean corpuscular volume was low; potassium, alanine transaminase and aspartate transaminase were high. Cardiac vascular congestion was noted for all doses. Spleens of rats on 200 and 400 mg/kg had mild siderosis. The study concluded that A. sisalana is potentially toxic when used continually for more than 14 days especially in doses 50, 200 and 400 mg/kg body weight.

Key words: Agave sisalana leaf extract, biochemistry, haematology, histopathology, livestock health.