Modulatory Effects of Zinc and Cystine on Diisononyl Phthalate-Induced Male Reproductive Injury

1. This study investigated the combined effects of zinc and cystine on reproductive damage induced by diisononyl phthalate (DiNP) in male rats.2. A total of 28 rats were randomly assigned to four groups (n = 7 per group) and treated for 45 days. Group 0 (Control) received physiological saline, Group G1 (positive control) received a zinc- cystine combination at a dose of 5 mg zinc + 50 mg cystine/kg body weight, Group 2 received DiNP alone (15 mg/kg body weight), whereas Group 3 received DiNP in combination with zinc (5 mg/kg body weight) and cystine (50 mg/kg body weight).3. Hormonal parameters, including luteinizing hormone (LH), Follicle-stimulating hormone (FSH), and testosterone, were measured. Sperm concentration, motility, speed, and vitality were also evaluated, together with testicular oxidative stress markers, including GSH, GSH-Px, MDA, and SOD.4. The results showed that the zinc-cystine combination significantly alleviated the reproductive and oxidative damage induced by DiNP exposure. Improvements were observed in hormonal status, sperm quality parameters, and antioxidant defense markers compared with the DiNP-treated group.5. These findings highlight the protective potential of zinc and cystine against environmental toxin-induced reproductive dysfunction and suggest a combined effect that may have therapeutic relevance in reducing the adverse effects associated with phthalate exposure.