Objectives: Acute toxicity is defined as the toxic effects produced by single exposure of drugs by any route for a short period of time. These studies identify a single dose causing adverse effects which cause lethality. The results of the acute toxicity study can also be used to determine dosages in sub-acute toxicity studies. In the present study, modified Lorke’s method was used to determine acute toxicity.
Methodology: Seventeen (17) Wistar rats were used for the study. Twelve rats were grouped into two groups consisting of six rats each, which received a dosage of 10mg/kg, 100mg/kg and 1000mg/kg in the first phase. The second phase consisted of three groups of two rats each being administered a dosage of 1600mg/kg, 2900mg/kg and 5000mg/kg. No mortality was recorded in the first and second phases of the toxicity study. Five rats were given 1000mg/kg, 2000mg/kg, 3000mg/kg, 4000mg/kg and 5000mg/kg of n-hexane extract of Leptadenia hastata to determine the effect of the extract on the liver and kidney at these concentrations. These tissues were carefully excised and prepared for histological observation.
Results: no mortality was recorded after both phases of the toxicity study. From the micrographs, it was determined that at a dosage of 3000mg/kg and above, there was heamolysis in the parenchyma of the tissues observed which could signify tissue damage at high concentrations of extract administered.
Conclusion: n-hexane extract of Leptadenia hastata did not cause mortality in the Wister rats but it may have a toxic effect on liver and kidney tissue following administration of high doses.