The misuse of pesticides has resulted in environmental pollution, which directly or indirectly affects all life on earth. Chlorpyrifos is a chlorinated organophosphorus pesticide that is commonly used in agriculture. The aim of this study was to investigate the effects of chlorpyrifos on the fertilization function of boar spermatozoa. Sperm samples from boars were subjected to varying concentrations of chlorpyrifos from 10 to 200 µM for two incubation periods, 30 min or 2 hrs. The boar spermatozoa were then evaluated for motility, motion kinematics, viability, acrosome integrity, chromatin stability, and generation of intracellular reactive oxygen species (ROS). There was a significant percentage reduction in sperm motility and motion kinematic parameters after both incubation periods (p < 0.05). The proportion of viable spermatozoa decreased after incubation for 30 min and 2 hrs in a dose-dependent manner (p < 0.05). A significantly lower percentage of normal acrosomes was observed in spermatozoa exposed to 200 µM chlorpyrifos over both incubation periods, compared to the controls. The damage to sperm DNA was significantly higher when the exposure time to chlorpyrifos was longer. There was a significant increase in the ROS levels in spermatozoa incubated with chlorpyrifos for 2 hrs (p < 0.05). From the results of the present study, it is concluded that direct exposure of boar spermatozoa to chlorpyrifos altered boar sperm characteristics, suggesting potential toxicity that may affect the male reproductive function.
Figures & Tables
Fig. 1. Chemical structure of chlorpyrifos.