Cholesterol elimination

Cholesterol elimination is the primary physiological process by which the body removes excess cholesterol, a critical function as mammals lack the enzymes to degrade the cholesterol sterol ring. The process occurs mainly in the liver via two distinct pathways: the conversion of cholesterol into bile acids through the rate-limiting enzyme cholesterol 7 alpha-hydroxylase (CYP7A1), and the direct secretion of free cholesterol into bile mediated by the ABCG5/G8 heterodimeric transporters [3][6][17]. These biliary components are then transported to the small intestine, where they are either excreted in the feces or reabsorbed via the enterohepatic circulation. Disruptions in this pathway lead to cholesterol accumulation, promoting hypercholesterolemia, atherosclerosis, and cardiovascular disease [11][12]. Therapeutic strategies to enhance elimination include bile acid sequestrants that prevent reabsorption and NPC1L1 inhibitors like ezetimibe that block intestinal sterol uptake, both of which increase the net removal of cholesterol from the systemic circulation [4][5][11].

Other names

Reverse cholesterol transportBile acid synthesis pathwayBiliary cholesterol excretionFecal neutral sterol excretion

Bile acid sequestration in the intestinal lumen; inhibition of NPC1L1-mediated intestinal cholesterol absorption; transcriptional upregulation of CYP7A1 via FXR antagonism or LXR activation; promotion of biliary sterol transport via ABCG5/ABCG8 activation.