CYP2E1 Background Information
The cytochrome P450s are a large and diverse family of monooxygenase enzymes which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids (1). P450 enzymes are classified into subfamilies, such as CYP1A and CYP2A, based on sequence similarities. Cytochrome P450 2E1 (CYP2E1) localizes to the endoplasmic reticulum and is induced by ethanol, the diabetic state, and starvation (1,2). The enzyme metabolizes both endogenous substrates, such as ethanol, acetone, and acetal, as well as exogenous substrates including benzene, carbon tetrachloride, ethylene glycol, and nitrosamines which are premutagens found in cigarette smoke (1-3). CYP2E1 plays an important role in alcohol metabolism and participates in the metabolic activation of various carcinogens (4-7). Chronic ethanol consumption results in the induction of hepatic CYP2E1 in humans, which may play an important role in the pathogenesis of alcoholic liver disease (5). Due to its many substrates, this enzyme may be involved in such varied processes as gluconeogenesis, hepatic cirrhosis, diabetes, and cancer (1,5,6).
