GPT and metabolic dysfunction-associated steatohepatitis: It has been reported that supplementation of N-acetylcysteine (NAC), an antioxidant that increases tissue GSH levels by supplying cysteine for GSH synthesis, is able to rescue hepatic fibrosis mice into adulthood.23 Antioxidant therapy decreases serum levels of ALT and 8-OHdG in NASH.