Protective Effect of Apigenin Against Cyclophosphamide-Induced Testicular Damage in Mice by Modulating Inflammation, Oxidative Stress, and Apoptosis and Upregulating Nrf2/HO-1 Pathway

Abstract

Background: Testicular damage is considered one of the detrimental consequences linked to the use of the chemotherapeutic compound cyclophosphamide (CP). The present in vivo study examined the possible protective effects of apigenin (AP) against CP-induced testicular damage in mice. Methods: Mice received AP (20 and 40 mg/kg/day) for 15 days, followed by a single dose of CP (150 mg/kg) at day 16. At the end of the study, the blood, tissue, and mouse epididymal sperm samples were collected. Sperm cell counts, viability, motility, and serum levels of testosterone were estimated. Oxidative stress markers, antioxidants, inflammatory, and apoptotic signaling proteins were evaluated by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry in the testicular tissue. Moreover, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels were estimated in the testes. Results: The findings showed that the CP-intoxicated mice had significantly low sperm count, viability, motility, and testosterone levels. Remarkably, the administration of 20 or 40 mg AP significantly attenuated testosterone levels and sperm measurements (p < 0.05). Likewise, treatment of CP-injected animals with AP counteracted the CP-induced histopathological changes in testes. In addition, AP administration significantly (p < 0.05) diminished the CP-induced testicular damage by boosting antioxidants such as glutathione, superoxide dismutase, and catalase, suppressing the pro-inflammatory cytokines tumor necrosis factor alpha, interleukin-1beta, interleukin-6 and nuclear factor-kappa B, and decreasing apoptosis as measured by B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (BAX), and caspase-3 levels in the testes. This was accompanied by increased Nrf2/HO-1 expression in the testicular tissue of CP-treated mice. Conclusions: AP may be a strong preventive compound against CP-induced testicular oxidative damage, inflammation, and apoptosis, possibly by stimulating Nrf2/HO-1 signaling pathway.