Effects of Zofenopril and Thymoquinone in Cyclophosphamide-Induced Urotoxicity and Nephrotoxicity in Rats; The Value of Their Anti-Inflammatory and Antioxidant Properties

Objective: The study aimed to investigate whether zofenopril (ZOF), thymoquinone (TQ), or their co-administration effectively ameliorates urotoxicity and nephrotoxicity following cyclophosphamide (CPH) treatment. Methods: A total of 48 Wister Albino female rats were divided into six groups each of eight rats; negative control (NC), positive control (PC), mesna (MS), ZOF, TQ, and ZOF+TQ groups. Normal saline, mesna, ZOF-15mg/kg, TQ-80mg/kg, and their combination were given orally for 19 days to the groups NC, MS, ZOF, TQ, and ZOF+TQ respectively. On the 17th day, a single dose of CPH 200 mg/kg was given intraperitoneally for all the groups except the NC group. Urine was collected over 24 hours before animal scarification for urinalysis. After scarification, blood, and kidney tissue were obtained for assessment of conventional kidney function parameters, novel kidney injury biomarkers, pro-inflammatory cytokines, oxidative status, complete blood count (CBC), and histopathological examination. Results: CPH disturbed the urinary excretion of urea, creatinine, and protein, and significantly elevated novel biomarkers for kidney injury including cystatin-C (Cys-C) (p=0.019) and markedly kidney injury molecule-1 (KIM-1) (p=0.27), the semiquantitative measurement of hematuria revealed significant elevation of hematuria score (p=0.0002), urine pus and protein (p=0.0005). Additionally, CBC-derived inflammatory biomarkers including neutrophil-lymphocyte ratio (NLR) (p=0.001), neutrophil-monocyte ratio (NMR) (p=0.0004), pro-inflammatory cytokine interleukin (IL)-6 (p=0.016) and tumor necrosis factor (TNF)-alpha (p<=0.007), total antioxidant capacity (TAC) (p<0.0001) were significantly increased. Evidence of obvious histopathological structural alteration was noticed in kidney tissue and bladder urothelium in CPH-treated animals. ZOF, TQ, and their co-treatment significantly prevented these deleterious effects associated with CPH treatment. Conclusion: This study demonstrated that ZOF and TQ provided uroprotective and nephroprotective effects against CPH-induced nephrotoxicity by reducing kidney injury biomarkers, and CBC-derived inflammatory markers, restoring antioxidant capacity, and improving histopathological outcomes. The suggested mechanism involves the anti-inflammatory and antioxidant activity of TQ and the sulfhydryl-angiotensin converting enzyme inhibitor ZOF.