GPT and diabetes mellitus: Finally, the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CREA), and urea nitrogen (BUN) in plasma as well as levels of thiobarbituric acid reactive substances (TBARS) in the liver and kidney were measured to investigate the antioxidant and protective effects of G. lucidum against diabetes-related organ damage.