Laxative effect of ethanol leaf extract of Vernonia amygdalina del. (Asteraceae) in wistar strain albino rats
Olufunke Adebola Sodipo, James Yakubu, Dangana Yerima Timothy and Bitrus Wampana
Vernonia amygdalina Del is derived from the leaves of a small ever-green shrub found all over Africa called Vernonia, belonging to the family Asteraceae. It is an important medicinal plant as well as a highly nutritious vegetable plant that has diverse reported medicinal values. This study focused on the phytochemical screening and investigation of the laxative activity of ethanol leaf extract of Vernonia amygdalina. Fresh leaves of the plant were collected; shade-dried, ground and extracted with ethanol using reflux method. The extract was screened for the presence of phytochemicals. The acute toxicity level was evaluated using Lorke’s method while laxative potential of the leaf was examined using loperamide-induced constipation in rats. The results obtained from this study showed the presence of carbohydrates, terpenoids, alkaloids, saponins and cardiac glycosides. The I.P. LD50 was 2154 mg/kg suggesting the plant was not toxic. The laxative effect of the extract was significant (p<0.05) and dose-dependent effect when administered treatment with extract doses of 125 mg/kg, 250 mg/kg and 500 mg/kg on Wistar strain albino rats respectively. The effect of the ethanol extract was had a significantly (p<0.05) highest laxative activity when compared to a standard drug, sodium picosulfate (a positive control). This study amply justifies the ethnomedical claim that the leaves are used as laxatives.