Evaluation of Ethyl Acetate, Chloroform and Toluene Fractions of Thevetia peruviana (Pers.) K. Schum Methanolic Leaf Extract for Uterotonic Activity

Thevetia peruviana (Pers.) K. Schum (Apocynacae) leaves have a reputation of abortifacient activity. We investigated traditional claim and found that methanolic leaf extract produce antifertility activity by lowering the progesterone level in rat model. Aim of the present study was to find out the chemical constituent (s) responsible for antifertility activity of methanolic leaf extract of Thevetia peruviana (Pers.). The ethyl acetate, chloroform and toluene fractions of methanolic extract of T. peruviana leaves freed from cardiac glycosides [TPL-Me-G] were selected for phytochemical investigation and in-vitro uterotonic activity. The methanolic extract of T. peruviana leaves (1.103g) was fractionated with toluene (100ml, n=20); chloroform (100ml, n=20); and ethyl acetate (100ml, n=20) in the successive order. These fractions were examined for phytoconstituents and evaluated for in-vitro uterotonic activity. The toluene fraction (TPL-T) was found to have triterpenes, flavonoids and phytosterols. Quercetin (0.8904%) is present in TPL-T. The chloroform fraction (TPL-Ch) was found to contain flavonoids, triterpenes and phytosterols. Presence of alkaloids and flavonoids (quercetin 0.1606%) were observed in ethyl acetate fraction (TPL-Et-Ac). In contrast to TPL-Et-Ac, the TPL-T and TPL-Ch induced dose dependent uterine contraction in the isolated estrogenized rat uterus model. Highest uterotonic activity was found with TPL-Me-G which has kaempferol as phyto-constituent additionally. The in-vitro uterotonic activity is not influenced by quercetin and primary contributor is kaempferol though some unknown phytoconstituent/s also contributes to uterotonic activity and synergizes the action of kaempferol too. So, further research is needed to identify other contributory unknown phytoconstituent/s for antifertility activity of methanolic leaf extract of Thevetia peruviana (Pers.).