Toxicological assessment of aqueous and methanol leaves extracts of scoparia dulcis linn (Plantaginaceae) in wistar rats

Abstract

The leaf and whole part of Scoparia dulcis L. have been used in the management of different disorders in Nigeria and other parts of the world without documented scientific evidences of its safety to man. Hence, the current study was performed to assess the acute and sub-chronic toxicity of the aqueous and methanol leaves extracts of Scoparia dulcis in Wistar rats. The acute toxicity was conducted in two phases. In the first phase, doses of 10, 100 and 1000 mg/kg body weight of the extracts were administered orally. In the second phase, 1600, 2900 and 5000 mg/kg body weight of the extracts were administered, signs and symptoms of toxicity were monitored for 24 hours. Sub-chronic toxicity studies were carried out on Wistar rats for both extracts; haematological, biochemical and histopathological analyses after 28 days oral administration of the extracts at 500, 1000 and 1500 mg/kg body weight were conducted. The acute toxicity of all extracts was found to be greater than 5000 mg/kg which is practically non-toxic according to standard scale of toxicity. In sub-chronic test, there was significant difference (p<0.05) in the Aspartate Aminotransferase (AST) at 500 and 1000 mg/kg of aqueous extract and blood urea at 1000 mg/kg of methanol extract when compared to the control. The kidney and Liver of aqueous extract showed better physiological features when compared to that of the methanol extract. It could be concluded that prolonged oral administration of Scoparia dulcis leaf may be associated with increased risk of toxicity.