GPT and fibrosis: However, inter-group differences were not statistically significant (data are shown in our previously published article).48 Similarly, a previous study evaluating the efficacy of PRP (500 mg/d for 4 months) on hepatic steatosis and fibrosis in patients with NAFLD reported that PRP had no effect on serum levels of AST, ALT, GGT, and alkaline phosphatase in these patients.53 Nevertheless, some clinical trials with different designs have reported the beneficial effects of PRP supplementation on serum liver enzymes.