Coenzyme Q10 ameliorates hepatoprotective effect of metformin in experimentally-induced type 2 diabetes mellitus in rats: a functional and histological study

Management of metabolic dysfunction–associated steatotic liver disease (MASLD) remains a significant clinical challenge. This study evaluated the efficacy of Coenzyme Q10 (CoQ10) as an adjuvant therapy to metformin in the treatment of MASLD using an experimentally induced type 2 diabetes (T2D) rat model. T2D was induced in 18 rats through a high-fat diet combined with a low dose of streptozotocin. The diabetic rats were then randomly allocated into three equal groups: untreated, metformin-treated, and metformin/CoQ10-treated. An additional six rats maintained on a normal chow diet served as the control group. Development of MASLD was confirmed through biochemical assays and histopathological analyses. Liver histology and electron microscopy were performed, along with immunohistochemistry for BAX and CD68 markers. Our results demonstrated that T2D rats exhibited impaired glucose and lipid profiles, elevated liver enzymes, and reduced adiponectin levels. These alterations were accompanied by hepatic oxidative stress, histopathological features of MASLD, fibrosis, and increased expression of BAX and CD68. Treatment with either metformin monotherapy or metformin/CoQ10 combination therapy significantly ameliorated the biochemical and histopathological manifestations of MASLD, as well as reduced the expression of BAX and CD68 in the liver. Importantly, combined metformin/CoQ10 therapy exerted a stronger hepatoprotective effect than metformin alone.