Effects of a low-fat diet on the hepatic expression of adiponectin and its receptors in rats with NAFLD

Abstract

Background. Non-alcoholic fatty liver disease (NAFLD) is correlated with obesity, but specific therapeutic interventions are lacking. Adiponectin is an adipokine with anti-inflammatory activity and is considered a hepatic protector. We aimed to investigate effects of a low-fat diet on the hepatic expression of adiponectin and its receptors in rats with NAFLD.Materials and methods. Sixteen male SD rats were fed a high-fat diet for 8 weeks (HFD1 group) or 16 weeks (HFD2 group) to induce NAFLD, and these rats were compared with rats on a normal diet for 8 weeks (NC1 group) or 16 weeks (NC2 group). Another group of 8 rats was fed an HFD for 8 weeks and then switched to a low-fat diet (DIET group) until the 16th week. The expression of hepatic adiponectin and its receptors was detected by western blotting, immunohistochemistry and RT-qPCR.Results. The NAFLD activity score (NAS) in the HFD groups increased from 3.2 ± 0.45 (8th week) to 6.2 ± 0.84 (16th week) (P < 0.001), reflecting the progression in the NAFLD histology. In contrast to the HFD2 group, the low-fat diet ameliorated the steatosis, ballooning degeneration and inflammation. Dietary intervention augmented the expression of adiponectin and its receptors, which was down-regulated in the HFD2 group.Conclusions. The NAFLD rat model was successfully developed by feeding the animals a high-fat diet. Adiponectin may play a role in the pathogenesis of NAFLD, especially in the progression from steatosis to NASH. The low-fat diet alleviated the histological lesions associated with NAFLD by up-regulating the expression of adiponectin and its receptors.

Keywords

• Dietary intervention
• Adipokine
• Fatty liver
• Pathology
• Pathogenesis