In vitro spermicidal effect of Thevetia Peruviana leaves on human spermatozoa.

An in vitro spermicidal effect of aqua-methanolic (2:3) extract of Thevetia peruviana leaves on human spermatozoa was evaluated in a dose-dependent manner (20, 40, 80 and 160 mg/ml) at a 1:1 ratio. Sperm motility, viability, hypo-osmotic swelling (HOS) and acrosomal status and function tests were performed immediately (20 s), and after 5 and 10 min of exposure of the spermatozoa to the extract of Thevetia peruviana leaves at different dose concentrations. Nuclear chromatin decondensation (NCD) test, DNA fragmentation test and sperm revival test were also evaluated. The sperm motility was affected immediately at a dose of 20 mg/ml and reduced gradually at doses of 40 and 80 mg/ml of Thevetia peruviana extract. Complete immobilisation of spermatozoa was observed at 160 mg /ml dose of this extract treatment within 5 min. 50% immobilisation of spermatozoa (EC50) was observed at 28 mg/ml dose of Thevetia peruviana extract within 20 s. The sperm viability decreased significantly at a higher concentration of extract, and all spermatozoa were found to be non-viable after 10 min when treated with 160 mg/ml dose of Thevetia peruviana extract. HOS and NCD of spermatozoa also reduced gradually at a higher concentration of extract administration. The percentage of DNA damage in spermatozoa was four times greater than in the control group. The findings indicate that the hydro-methanolic extract of Thevetia peruviana leaves possesses appreciably potent spermicidal activity through an in vitro model, which may explore an effective vaginal contraceptive.