Acute and sub-acute toxicity of the aqueous extract from the stem bark of Tetrapleura tetrapteura Taub. (Fabaceae) in mice and rats

Ethnopharmacological relevance: Tetrapleura tetrapteura Taub. is a leguminous multipurpose tree (Fabaceae) indigenous to tropical Africa. Fruits, seeds and stem bark infusions or decoctions of Tetrapleura tetrapteura Taub. are used to treat many diseases, such as gastric ulcer, rheumatism, malaria, hypertension and hyperlipidemia. Aim of the study: This work was conducted to evaluate the acute and sub-acute toxicity of the aqueous extract of Tetrapleura tetrapteura Taub. (AETT) stem barks. Materials and methods: For the study of acute toxicity, single oral doses of 2000 mg/kg and 5000 mg/kg of AETT were administrated to male and female Balb/c mice, followed by observation of mice for 14 days. In the study of sub-acute toxicity, 48 albino wistar rats of both genders were randomly divided into six groups of 8 animals and they were daily and orally administrated for twenty eight days. The animal's test groups and satellite test group were administrated with the extract (AETT) at the doses of 100, 200 and 400 mg/kg and 400 mg/kg respectively. On the 29th day, the satellite group (control 2 and satellite 400 mg/kg) were observed during two more weeks. General behavior changes, mortality, body weight of animal, water and food intake were recorded during the study period. At the end of each treatment period, biochemical and hematological parameters were measured and histological examinations of liver and kidneys sections performed. Results: Up to 5000 mg/kg single dose administration of AETT for fourteen days registered no death animal. In sub-acute study, no mortality was recorded in various experimental groups. Significant reductions in body weight, water and food intake were recorded in all treated animals. Relative weights of liver, kidneys, stomach, spleen, lungs, and heart of treated animals remained unchanged. Significant increases in the number of platelets as well as in serum ALAT level were recorded in rats, treated with 400 mg/kg of AETT. Female rat liver histology showed, at a higher dose of AETT, a slight congestion of portal vein. Conclusion: AETT is safe after therapeutic (200 mg/kg) or acute administration. Higher dose (400 mg/kg) administered for longer period showed signs of liver toxicity.