Clinical relevance of vitamin C among lead-exposed infertile men

A cross-sectional study was designed by targeting 120 male workers occupationally exposed to lead from a battery-manufacturing industry situated at the Patancheru industrial area, Hyderabad, Andhra Pradesh, India, to see the impact of lead on testicular dysfunction with reference to infertility. Further, the study was designed to see the in vivo effect of an antioxidant in the form of vitamin C, prophylactically administered at the dose of 1000 mg/day for five consecutive days in a week for 3 months.

Blood samples and semen samples were collected from 120 men in the study group exposed to lead, and 120 healthy human subjects, who have no history of exposures to chemicals, were selected as controls for comparison. The mean age of the workers who participated in this study falls in the range of 25-55 years. The semen samples were collected with due consent of the industrial workers to perform the conventional semen analysis and the measure of sperm DNA fragmentation by the comet assay.

Industrial workers showed a statistically significant increase in sperm motility (p<0.001), sperm total count (p<0.001), and a statistically significant decrease in abnormal sperm morphology (p<0.001) after vitamin C prophylaxis. The comet assay also showed similar results, where there is a statistically significant decrease in alkaline-labile sites and a statistically significant decrease in the mean tail length of the comet when compared to the control group (p<0.001) after vitamin C prophylaxis.

This study leads us to conclude that the lead compound interferes with the testicular function, inducing its activity and also by exerting its effect on sperm DNA, leading to fragmentation. Further, the prophylaxis with antioxidant treatment may offer protection against the reactive oxygen species (ROS)-induced DNA damage, which is a major cause in the etiology of male infertility.