Acute and sub-chronic oral toxicity study of methanolic extract of Caesalpinia volkensii (harms)

Abstract

Medicinal plant Caesalpinia volkensii is used to treat Malaria, conjunctivitis, retinoblastoma, and eyelid swelling as well as gonorrhoea and bilharzia. Animal toxicity information on this plant is limited. This medicinal plant was collected in Embu County in Kenya to evaluate its Acute and sub-chronic toxicity using Wistar rats. The rats were orally administered with different doses of the plants extracts. They were weighed on first day and after every 7 days during treatment with the extract. Signs of toxicity were also observed. After 28 days, the rats were sacrificed and blood samples taken for full hemogram, renal and liver function tests. Weight of internal organs was also recorded. Data was analysed using Minitab statistical software version 17. In acute toxicity studies, C. volkensii extracts did not result to death at extract dose of 2000 mg/kg body weight. In sub-chronic toxicity studies, there was no significance difference in body weight and organ weight among the groups treated with the plant extract (p>0.05). Treatment with extract dose of 1000 mg/kg body weight resulted in significant increase in total bilirubin and aspartate aminotransferase (P˂0.05). In addition, 100 mg/kg body weight resulted in significant decrease in haemoglobin and haematocrit. Qualitative phytochemical screening confirmed the presence of various phytochemicals which have the ability to protect erythrocytes from oxidative damage as well as erythropoietin stimulatory activities. It was therefore concluded that methanolic leaf extract of C. volkensii is safe for acute oral administration. However, care should be exercised in sub-chronic exposure at 1000 mg/kg body weight and above to avoid liver injury.