Hepatoprotective, Nephroprotective, and Antioxidant Effects of Coenzyme Q10 and Metformin in Streptozotocin-Induced Diabetic Rats: A Dose-Dependent Evaluation

Abstract

Diabetes mellitus is associated with progressive metabolic dysfunction, oxidative stress, and multi-organ damage. Coenzyme Q10 (CoQ10) is an endogenous lipid-soluble antioxidant and mitochondrial cofactor with emerging therapeutic relevance in metabolic disorders. This study investigated the dose-dependent effects of CoQ10 supplementation on body weight, glycemic control, lipid profile, hepatic function, renal function, and tissue oxidative stress in streptozotocin (STZ)-induced diabetic rats, with metformin as a reference comparator. Thirty-six male Sprague-Dawley rats were randomly divided into six groups (n = 6): normal control, diabetic control, diabetic + CoQ10 100 mg/kg/day, diabetic + CoQ10 200 mg/kg/day, normal + CoQ10 200 mg/kg/day, and diabetic + metformin 200 mg/kg/day. Diabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg), and all treatments were administered daily by oral gavage for eight weeks. Diabetic control rats exhibited significant reductions in body weight, serum insulin, and HDL-C, alongside marked elevations in fasting blood glucose, HOMA-IR, total cholesterol, triglycerides, LDL-C, hepatic enzymes, bilirubin, creatinine, BUN, uric acid, and tissue malondialdehyde, with concurrent depletion of superoxide dismutase, catalase, glutathione peroxidase, and reduced glutathione in liver and kidney tissues. CoQ10 supplementation significantly and dose-dependently ameliorated all parameters, with the higher dose (200 mg/kg/day) producing outcomes statistically comparable to metformin across all endpoints. CoQ10 supplementation in non-diabetic rats produced no adverse metabolic or organ-toxic effects. These findings demonstrate that CoQ10 exerts comprehensive multi-target protective effects against STZ-induced diabetic complications through antioxidant, hepatoprotective, nephroprotective, and hypolipidemic mechanisms, supporting its potential as a therapeutic adjunct in diabetes management.