Spermicidal Effects of Methanolic Extract of Cestrum parqui Leaves on Human Spermatozoa: A View through DNA Breakage and Disruption of Membrane Ultrastructure

ObjectiveTo focus on the possible mechanism about the spermicidal effect of methanolic extract of leaves of Cestrum parqui (Solanacea) on human spermatozoa.MethodsSperm motility and viability were noted according to the guideline of WHO. The morphological changes in chromatin materials and in plasma membrane at the head part of the spermatozoa were assessed under transmission electron microscopy (TEM). DNA fragmentation index (DFI) of spermatozoa in percentage was assessed by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) using kits. For confirmation of DNA breakage, gel electrophoresis of DNA was conducted using 1.2 % agarose gel.ResultsSperm viability and motility were both decreased in dose-dependent manner from 50 to 300 μg/ml of methanolic extract in respect to the control. Loss of viability and motility both were noted 100% at the dose of 300 μg/ml within 5 min. From the microphotography it has been revealed that chromatin condensation at the dose of 200 μg/ml is more than the control without any noticeable alteration in plasma membrane. In contrast, chromatin decondensation has been noticed at the dose of 300 μg/ml along with a remarkable disruption in plasma membrane. Analysis of DNA damage by TUNEL revealed a significant elevation (P<0.01) in the level of % DFI at the dose of 200 μg/ml (moderate dose) after 17 h in respect to the control. But at the dose of 300 μg/ml, no significant variation was observed in this parameter upto 24 h of exposure though a significant variation (P<0.01) was noted after 48 h of exposure compared with the control. Gel electrophoresis of DNA also followed the same type of results i.e. 200 μg/ml affected DNA integrity but other doses were ineffective in this concern.ConclusionThe extract of Cestrum parqui at moderate dose exhibited spermicidal activity by inducing apoptotic pathway but at the high dose it caused necrosis.