Metformin Improves Aspects of NAFLD in Diet-Induced Obesity

Abstract

Nonalcoholic fatty liver disease (NAFLD) is known to have an intricate relationship with other metabolic diseases such as insulin resistance and obesity. While numerous studies have shown that metformin, an insulin-sensitizing agent, has beneficial effects on NAFLD, the mechanisms underlying metformin actions on NAFLD remain to be elucidated. In a recent study, the effects of metformin on the aspects of NAFLD were examined. In mice of diet-induced obesity (DIO), metformin treatment reduced hepatic steatosis and inflammation and increased the phosphorylation of liver AMP-activated protein kinase (AMPK). In the in vitro systems, metformin exhibited direct effects on hepatocyte and macrophage inflammatory responses. However, metformin appeared to have limited effects on altering adipose tissue lipid accumulation and inflammatory status. Together, metformin improves the aspects of NAFLD by reducing hepatic steatosis, and by decreasing liver inflammation due to the direct effects on suppressing hepatocyte and macrophage inflammatory responses, which all are independent of altering adiposity and adipose tissue inflammatory status.