Protective Effects of Zofenopril, Thymoquinone and Their Co‐Administration Against Cyclophosphamide‐Induced Ovarian Toxicity in Rats

Cyclophosphamide (CYP) is a widely-used chemotherapeutic drug known to induce ovarian damage and infertility in women. The present study evaluated the potential protective roles of zofenopril, a sulfhydryl-containing angiotensin-converting enzyme inhibitor, and thymoquinone (ThQ), alone and in combination, against CYP-induced ovarian damage in rats. Thirty adult female rats were divided into five groups: a control group that received normal saline; a CYP-Induced group given a single intraperitoneal (IP) dose of 200 mg/kg CYP on day 17 of the experiment; and three groups pre-treated with zofenopril, ThQ, or Zofenopril+ThQ for 17 days before CYP-administration, and continuing for 2 days after CYP exposure. Animals were euthanized, and blood and ovarian tissues were collected 48 h after CYP administration. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), and estradiol (E2) levels were measured, as well as the apoptotic biomarker caspase-3, total antioxidant capacity (TAOC), and tumor necrosis factor (TNF‑α). Ovarian histomorphometry was also assessed. CYP injection induced ovarian injury, characterized by reduced serum AMH and E2 levels, increased FSH and LH levels, oxidative stress, and increased levels of inflammatory and apoptotic markers. In addition, severe ovarian atrophy, regression and degradation of ovarian follicles, and atrophic follicles were observed. Zofenopril and ThQ administration significantly mitigated these CYP-mediated effects, restoring hormone levels, reducing oxidative stress and inflammation, and improving ovarian histology compared with the CYP-Induced group. Based on the present study, zofenopril and ThQ have protective effects against CYP-induced ovarian injury; while co-administration of zofenopril+ThQ was more effective at inhibiting CYP-induced effects on TAOC, TNF‑α, and caspase-3 levels.