What is the mechanism of action of statins?

Statins function by inhibiting the enzyme HMG-CoA reductase, which is a critical enzyme in the cholesterol biosynthesis pathway. This inhibition leads to a decrease in the synthesis of cholesterol within the liver. As a result of reduced cholesterol production, there is an upregulation of LDL receptors on the liver cells. This upregulation increases the clearance of LDL cholesterol from the bloodstream, effectively lowering total and LDL cholesterol levels.

The other options describe mechanisms related to different lipid-lowering agents, but they do not apply to statins specifically. For example, promoting bile acid reabsorption relates to bile acid sequestrants, while binding bile acids in the intestine is characteristic of these agents as well. Lowering triglyceride levels significantly is more about fibrates rather than statins, which primarily target cholesterol levels. Statins are thus distinct in their specific inhibition of HMG-CoA reductase, leading to their well-documented lipid-lowering effects.