Protective effect of silymarin on viability, motility and mitochondrial membrane potential of ram sperm treated with sodium arsenite

Background: Sodium arsenite can impair male reproductive function by inducing oxidative stress. Silymarin is known as a potent antioxidant. Objective: This study was performed to investigate if silymarin can prevent the adverse effect of sodium arsenite on ram sperm viability, motility and mitochondrial membrane potential. Materials and Methods: Epidydimal spermatozoa obtained from ram were divided into five groups: 1) Spermatozoa at 0 hr, 2) spermatozoa at 180 min ( control), 3) spermatozoa treated with sodium arsenite ( 10 mu M) for 180 min, 4) spermatozoa treated with silymarin ( 20 mu M) + sodium arsenite ( 10 mu M) for 180 min and 5) spermatozoa treated with silymarin ( 20 mu M) for 180 min. MTT assay and Rhodamine 123 staining were used to assess sperm viability and mitochondrial membrane potential respectively. Sperm motility was performed according to World Health Organization ( WHO) guidelines. Results: Viability ( p< 0.01), nonprogressive motility ( p< 0.001) and intact mitochondrial membrane potential ( p< 0.001) of the spermatozoa were significantly decreased in sodium arsenite treated group compared to control group. In silymarin + sodium arsenite group, silymarin could significantly reverse the adverse effect of sodium arsenite on these sperm parameters compared to sodium arsenite group ( p< 0.001). In addition, the application of silymarin alone for 180 minutes could significantly increase progressively motile sperm ( p< 0.001) and decrease non motile sperm ( p< 0.01) compared to the control. Conclusion: Silymarin could compensate the adverse effect of sodium arsenite on viability, nonprogressive motility and mitochondrial membrane potential of ram sperm.