Toxicological Study of the Aqueous Extract of the Stem Bark of Rauvolfia vomitoria (Apocynaceae)

Background and Objective: Rauvolfia vomitoria is a plant used in traditional medicine in Togo. This study aims to determine the chemical composition of this plant and then assess its toxicity to larvae of Artemia salina and Wistar rats, respectively. Materials and Methods: Cytotoxicity was studied in larvae of Artemia salina. Acute and subchronic toxicity tests were performed orally on female Wistar rats. The acute toxicity study was carried out with a concentration of 5000 mg/kg of aqueous extract and the subchronic toxicity study which lasted for 28 days was carried out with doses of 75, 150 and 300 mg/kg. Results: Phytochemical screening revealed the presence of alkaloids, flavonoids, tannins and saponins. Larval cytotoxicity revealed a lethal concentration LC₅₀ of 1.205 mg/mL. Acute toxicity at 5000 mg/kg of extract in rats caused apathy, drowsiness and difficulty moving without causing death. The lethal oral dose LD₅₀ in rats is therefore greater than 5000 mg/kg of body weight. Exposure of rats to doses of 75, 150 and 300 mg/kg of extract resulted in a significant increase in relative liver weight without an increase in body weight. Hematological and biochemical tests carried out at the end of 28 days showed no significant variation. Histological analysis of the liver of treated rats confirmed the presence of liver lesions. Conclusion: Rauvolfia vomitoria is toxic at 300 mg/kg in chronic administration in Wistar rats. It causes damage to the liver among other things.