Therapeutic effects of Nigella sativa (black seed) via antioxidant and anti-inflammatory activity in the testes of adult male mice subjected to transient scrotal hyperthermia

Abstract

Objective: In mammals, a lower testicular temperature is required for normal spermatogenesis. Testicular temperature can increase due to multiple factors, including lifestyle-related exposures, ultimately leading to damage to germ cells and impaired sperm parameters. Nigella sativa (black seed) has been reported to improve sperm parameters and exhibits a wide range of therapeutic properties. This study investigated the effects of black seed on antioxidant and anti-inflammatory activity in testicular tissue of adult male mice following scrotal hyperthermia. Methods: Twenty-four male mice were randomly assigned to control, hyperthermia, and hyperthermia+black seed (Hyper+BS) groups. In the hyperthermia group, the animals' testes were exposed to water at 43 °C for 20 minutes, five times on alternate days. In the treatment group, following induction of hyperthermia, animals received black seed (300 mg/kg/day) orally for 35 days. At the end of the experiment, animals were euthanized for histological and molecular analyses. Results: Black seed treatment conferred significant protective effects. Total sperm count and motility were significantly improved in the Hyper+BS group compared with the hyperthermia group (p≤0.0001 and p=0.0266, respectively). Black seed administration also significantly reduced tumor necrosis factor-α and interleukin-1β levels (p=0.0012 and p=0.0003, respectively). In addition, B-cell lymphoma 2 (Bcl-2) gene expression and glutathione levels were significantly increased in the Hyper+BS group (p=0.0038 and p≤0.0001, respectively). Conclusion: These findings suggest that black seed may serve as a low-risk supportive natural supplement for preserving male fertility under conditions of scrotal hyperthermia. However, its routine clinical application requires validation through well-designed human studies.