Background: Theophylline is a methyl-xanthine derivative that has antioxidant effect and influences the sperm parameters. Zinc sulfate has been investigated as an antioxidant supplemen- tation for stimulating spermatozoa. We aimed to evaluate the possible effects of the co-administration of theophylline and zinc sulfate on sperm chromatin integrity, viability and reactive oxygen species (ROS) level in subfertile men. Materials and Methods: Patients participated in this study were referred to Rastak Infertility Treatment Center, Sina Hospital for infertility treatment. They were divided into four groups: Placebo, theophylline, theophylline + zinc sulfate and zinc sulfate. The sperm viability and sperm chromatin integ- rity were analyzed using the Eosin-Nigrosine and Aniline blue staining respectively and the sperm ROS level was analyzed using Chemiluminescence assay before and after three months of oral treatment. Data was analyzed statistically using the re- peated measurements ANOVA and the means were considered significantly different at P<0.05. Results: Sperm chromatin integrity and viability increased sig- nificantly in all three groups compared to the placebo group but this increase was significantly higher in the theophylline + zinc sulfate group than the theophylline and zinc sulfate groups. Sperm ROS level increased significantly in the theophylline group, while it showed a significant reduction in the zinc sul- fate group compared to the placebo. There was no significant difference in the mean sperm ROS level in the theophylline + zinc sulfate group compared to the placebo. Conclusion: Theophylline and zinc sulfate, as two antioxi- dants, could improve the sperm chromatin integrity and viabil- ity. Zinc sulfate could reduce the increasing sperm ROS level that is from the side effects of theophylline.
