Ganoderenic acid A is a triterpenoid originally isolated from G. lucidum that has enzyme inhibitory activities. It is an inhibitor of β-glucuronidase (IC50 = 0.12 mg/ml in rat liver microsomes). Ganoderenic acid A (100 mg/kg) reduces increases in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) in a rat model of liver injury induced by carbon tetrachloride (CCl4). It also inhibits aldose reductase by 54.2% when used at a concentration of 100 μg/ml.