Evaluation of acute and subacute toxicity of Alstonia congensis Engler (Apocynaceae) bark and Xylopia aethiopica(Dunal) A. Rich (Annonaceae) fruits mixtures used in the treatment of diabetes

The present study was carried out to evaluate acute and subacute toxicity of a hydroalcoholic extract of a mixture (1:1) of A. congensis bark and X. aethiopica fruits used locally in the treatment of diabetes.Acute toxicity of the extract was evaluated in Swiss albino mice. The animals were fed with the hydroalcoholic extract between the doses of 1.0 to 20.0 g/kg body weight and were observed continuously for the first 4 h and for every hour for the next 24 h, then 6 hourly for 48 h. Wistar rats were also fed with different doses of the extract for 30 days and effects on biochemical parameters evaluated (subacute toxicity model). The LD50 of the extract was found to be above 20.0 g/Kg bodyweight. There was reduction in the plasma glucose and low-density lipoprotein (LDL)-cholesterol levels, and increase in high-density lipoprotein (HDL)-cholesterol level in the treated animals. A significantincrease in the body weight was observed for groups treated with lower doses of the extract while groups treat with higher doses showed no significant weight increase. Aspartate aminotransferases (AST) and alanine aminotransferases (ALT) levels were not affected at lower doses of the extract but there was increase in creatinine levels in all the treated animals. The extract demonstrated good hypoglycaemic effects by lowering the plasma sugar level and also had some beneficial and reduction effects on cardiovascular risk factors. There was no evidence of drug-induced symptoms or death at all the doses of the extract administered in acute study but subacute results revealed a tendency to cause kidney problems on a long-term use