Cholesterol 7α-hydroxylase (CYP7A1)

Cholesterol 7α-hydroxylase is a cytochrome P450 heme enzyme encoded by the CYP7A1 gene. It catalyzes the first and rate-limiting step in the classic pathway converting cholesterol into 7α-hydroxycholesterol—a precursor for primary bile acids. This process is essential for maintaining normal lipid digestion/absorption and regulating systemic cholesterol levels. The enzyme is primarily expressed in the liver’s endoplasmic reticulum. Its activity is tightly regulated via negative feedback from bile acids acting through nuclear receptors like FXR; dysregulation contributes to metabolic disorders including fatty liver disease, hypercholesterolemia, and inflammation/fibrosis in hepatic tissue

Other names

Cholesterol 7-alpha-monooxygenaseCytochrome P450 7A1CYP7A1

Drugs that target or modulate this enzyme typically act by altering bile acid synthesis through feedback mechanisms involving nuclear receptors such as farnesoid X receptor (FXR). FXR activation represses CYP7A1 expression, reducing bile acid production; conversely, inhibition or reduced activity increases cholesterol levels