NB-598 hydrochloride is a competitive squalene epoxidase (SE) inhibitor.

NB-598, an inhibitor of squalene epoxidase, on cholesterol absorption from the intestinal epithelia.?NB-598 (10 microM) inhibited the synthesis of sterol and sterol ester from [14C]acetate without affecting the synthesis of other lipids such as phospholipids (PL), free fatty acids (FFA) and triacylglycerol (TG).?When labeled lipid was apically loaded as a micellar lipid solution into Caco-2 cell cultures, NB-598 reduced basolaterally secreted radioactivity in cholesterol, cholesterol ester, PL and TG.?Furthermore, NB-598 suppressed the basolateral secretion of apolipoprotein (apo) B. When microsomes prepared from control Caco-2 cells were incubated with 10 microM NB-598, acyl CoA:cholesterol acyltransferase (ACAT) activity was inhibited slightly.?After incubating Caco-2 cells with 10 microM NB-598, a slight reduction in cellular ACAT activity was also observed.?These results suggest that suppression of the secretion of particles containing apo B and reduction of cellular ACAT activity in the intestinal epithelia are part of the mechanism of the cholesterol-lowering effect of NB-598.