Acute and subchronic toxicological assessment of Byrsocarpus coccineus Schum. and Thonn. (Connaraceae) leaf aqueous extract

Abstract

Summary: This study was conducted to determine the safety profile of Byrsocarpus coccineus (Connaraceae) by carrying out the acute and subchronic toxicological assessment of its aqueous leaf extract. In the acute toxicity test, mice were administered orally with the extract up to 10 g/kg and intraperitoneally at doses of 50 – 800 mg/kg. Animals were then observed for behavioural changes, signs of toxicity, and mortality within 24 h. Surviving mice were monitored for 7 days for signs of delayed toxicity. In the subchronic toxicity test, rats were daily treated with the extract at doses of 40, 200, and 1000 mg/kg orally, for 30 days and 60 days. Control animals received distilled water and all animals were weighed at 7 days interval. At the end of the test periods, haematological, biochemical, and urinary parameters were determined in blood, serum, and urine samples respectively and vital organs macroscopically examined and weighed. In the acute toxicity test, the extract was practically non-toxic showing no mortality and visible signs of delayed toxicity. The LD 50 , given intraperitoneally, was estimated to be 158.4 mg/kg. Administered for 30 days, the extract did not produce any significant ( P < 0.05) effect on haematological and biochemical parameters and vital organs. In the 60 day study, the extract elicited significant ( P < 0.05) increases in platelet and WBC count and reductions in levels of liver enzymes (AST, ALT, and ALP), total cholesterol, HDL, triglycerides, and total protein. The weight of the kidneys, spleen, epididymis, and testes were not significantly affected but significant changes were observed in the weight of the liver (↑), heart (↓), and lungs (↑). Generally, B. coccineus did not significantly affect body weight and urinary parameters. Results obtained in this study suggest that the aqueous leaf extract of B. coccineus is safe when administered orally with potential beneficial effects as immunostimulant, hepatoprotective, and hypocholestrolemic agent, when administered over a long period of time. Industrial relevance: The use of herbal remedies by all stratums of people is on the increase worldwide. The aqueous leaf extract of B. coccineus administered orally has shown great promise as a phytotherapeutic agent based on results of previous pharmacological investigations. In view of the importance of toxicological evaluation in drug and standardized herbal remedy development, this study was conducted to evaluate the extract for its acute and subchronic effects. The safety of the extract administered orally was established and other potential benefits in the treatment of human diseases were identified.