In-vivo sub-chronic toxicological evaluation of extract of Vernonia glaberrima leaves in experimental rats

The toxicological profile of a plant is an important ethnomedicinal parameter considered in drug discovery, ethno-therapeutics and safety management in vital organs. The study evaluated the 28-day repeated-dose toxicological profile of moderately polar extract of Vernonia glaberrima being investigated as a therapeutic for sleeping sickness and other parasitic infections in experimental rats. Albino rats were divided into four groups (n=10) and the fraction was administered orally once daily at doses of 0 (control), 40, 250 and 1000 mg kg-1 day-1. Food intake, body weight, organ-to-body weight, biochemical, hematological, plasma blood chemistry, serum hormone levels and histopathological examinations were evaluated on the 29th day. There was no difference in the clinical signs between the treated and untreated rats. The mean body weight of female rats treated with 250 mg kg-1 dose increased significantly (p < 0.05) on the 20th day with no difference in the food intake. All the changes in the blood chemistry, hematology and serum hormone levels cannot be considered to be of toxicological importance. A statistically significant elevation (p < 0.05) was observed in the liver-to-body weight (3.21 to 3.89 g 100g-1) of male rats and in the kidney- (0.67 to 0.98 g 100g-1) and brain-to-body (0.58 to 0.72 g 100g-1) weights of female rats in the 1000 mg kg-1 groups. The histopathological examination showed that there was no definitive association between the lesions in the liver and the treatments. The present data, in addition to folklore, has further demonstrated its safety and the need for the isolation of non-toxic bioactive constituents, especially from the dichloromethane fraction.