Effects of fenofibrate on hepatocyte apoptosis in nonalcoholic fatty liver

Abstract

To use a rat model of nonalcoholic liver disease (NAFLD) to observe effects of the peroxisome proliferator-activated receptor-a (PPAR-a) agonist fenofibrate on hepatic steatosis in nonalcoholic fatty liver and to investigate the underlying mechanism. Sixty-six Sprague-Dawley rats were given adaptive feeding for 1 week and then randomly allocated into the following three groups: unmodeled control (group C,n =18), untreated NAFLD model (group M, n =24), and fenofibrate-treated NAFLD model (group F, n =24).Group C rats were given a normal diet, while group M and group F rats were given a high-fat diet. After model establishment, the group F rats were treated with fenofibrate (10 mg/kg/d, intraperitoneal) and the group C and group M rats were given sham-treatment with cosolvent (5 mL/kg/d, intraperitoneal). At the end of treatment weeks 4, 6 and 8, one-third of rats in each group were euthanized.Liver tissues were assessed by hematoxylin-eosin (HE) staining to determine level of steatosis and inflammaion activity, and by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling to measure changes in hepatocyte apoptosis index. Changes in expression levels of the PPAR-a receptor and apoptosis factors (bcl-2, bax and caspase-3) were assessed by reverse transcription-PCR and immunohistochemistry. The NAFLD modeled rats showed appropriate induction of hepatic steatosis, hepatic inflammation, and hepatocyte apoptosis. Compared to the group M rats, the group F rats showed lower expression of PPAR-and bcl-2 and higher expression of bax and caspase-3 at both the mRNA and protein level. Fenofibrate can ameliorate hepatic steatosis in an experimental rat model of NAFLD, and the mechanism may be associated with inhibition of hepatocyte apoptosis.