Abstract
We explored the beneficial effects of GW7647, a peroxisome proliferator activated receptor α (PPARα) agonist, and metformin, an anti-diabetic drug on an advanced nonalcoholic steatohepatitis (NASH) model in rodents and investigated the possible mechanisms involved. Mice were fed control chow or a choline-deficient l-amino acid-defined diet containing 45% fat (HF-CDAA). The mice fed HF-CDAA diets for 16 weeks were divided into four groups: the no treatment (HF-CDAA), HF-CDAA containing 1000 mg/kg metformin, HF-CDAA containing 10 mg/kg GW7647, and HF-CDAA with both metformin and GW7647 groups. Metformin alone slightly deteriorated the aspartate and alanine aminotransferase (AST/ALT) values, whereas co-treatment with GW7647 and metformin greatly suppressed liver injury and fibrosis via activation of the AMP-activated protein kinase (AMPK) pathway. Further study revealed that co-treatment decreased the expression of inflammatory-, fibrogenesis-, and endoplasmic reticulum (ER) stress-related genes and increased the oxidized nicotinamide adenine dinucleotide (NAD)/reduced nicotinamide adenine dinucleotide (NADH) ratio, suggesting the superiority of co-treatment due to restoration of mitochondrial function. The additive benefits of a PPARα agonist and metformin in a HF-CDAA diet-induced advanced NASH model was firstly demonstrated, possibly through restoration of mitochondrial function and AMPK activation, which finally resulted in suppression of hepatic inflammation, ER stress, then, fibrosis.
Zinc supplementation reverses alcohol-induced steatosis in mice through reactivating hepatocyte nuclear factor-4α and peroxisome proliferator-activated receptor-α