Metformin ameliorates diabetes-induced hepatic ultrastructural damage and the immune biomarker CD86 and inflammation in rats

Diabetes is a known inducer of hepatic ultrastructural alterations, and the expression of the immune biomarker that involves in T-cell immunity, cluster of differentiation 86 (CD86) is increased in diabetic patients with liver cirrhosis. The antidiabetic drug metformin has not previously been used to protect against type 2 diabetes mellitus (T2DM)-induced alternations in hepatic ultrastructure and the induction of the hepatic CD86/inflammation axis in diabetic animal models induced by streptozotocin and a high fat diet. To test our hypotheses, T2DM was induced in rats (model group) and the protective animals were treated with the antidiabetic drug metformin (200 mg/kg) until being sacrificed at week 12. A profound ultrastructural damage to the hepatocytes and liver tissue injury was induced by T2DM as demonstrated by hepatocytes with dark shrunken irregular nuclei, rarefied cytoplasm with lipid droplets, mitochondria with disrupted cristae, as well as depletion of glycogen granules and damaged of liver architecture, which were effectively (<i>p</i> < .0001) protected with metformin. Metformin also suppressed diabetes-induced hepatic gene expression of CD86 and inflammation as well as glycemia and liver injury markers. Furthermore, a significant correlation between hepatocyte damage and CD86, inflammation, glycemia, and biomarkers of liver injury was observed. These findings demonstrate that diabetes is associated with the induction of the hepatic CD86/inflammation axis and hepatocyte ultrastructural alterations while being protected by metformin.