Prophylactic administration of magnesium isoglycyrisinate (9 and 18 mg/kg/day) significantly reduced serum ALT and AST levels in rats treated with 20 mg/kg methotrexate (intravenously), and attenuated methotrexate-induced liver fibrosis, hepatocyte apoptosis, and reduced serum malondialdehyde levels more than glutathione, 80 mg/kg/day. This evidence concerns the gene GPT and Hepatic fibrosis.