Second research Antox Repro-Protective Synergistic Role with Insulin in A Streptozotocin-Induced Diabetic Rat Model (Biochemical, Histo-Morphometric and Immunohistochemical Study) ABSTRACT Diabetes-related reproductive dysfunction is considered a major health concern. Its pathogenesis is closely linked to oxidative stress. Antox is a combination of antioxidants (selenium and vitamins A, C and E); its protective role was documented previously in animal models. Aim: was to assess the repro-protective synergistic role of Antox with insulin use on testicular and epididymal alterations in a streptozotocin-induced diabetic rat model. Material and Methods: Thirty-six rats were allocated into six equal groups: (I) not given any medication; (II) (positive control) received intraperitoneal injection of citrate buffer; (III) (Diabetic) received intraperitoneal injection of streptozotocin (50 mg/kg). The three groups were left without treatment for four weeks. (IV) (Diabetic/Insulin), (V) (Diabetic/Antox), and VI (Diabetic/Insulin/Antox) received streptozotocin, followed by four weeks of daily subcutaneous insulin injection (1 U/100 g), oral Antox (10 mg/kg/day), or both insulin and Antox, respectively. By study end, blood, semen, testis and epididymis samples were collected for biochemical, histo-pathological and tissue homogenate analyses. Results: Diabetic animals presented decreased body, testis weight, serum testosterone, sperm count, motility and impaired testicular redox homeostasis compared with control groups. Furthermore, deteriorated testicular and epididymis cytoarchitecture, with significantly decreased spermatogenesis scoring with decreased α-smooth muscle actin and androgen receptor immune-expression were detected. Insulin and Antox co-treatment to diabetic rats effectively mitigated the aforementioned parameters, compared with either drug administered alone. Conclusion: The present study clarified the potential synergistic effects of combi