Cholesterol ester and free fatty acids are modulated by policosanol in CaCo-2 intestinal cells.

Objective: To investigate policosanol absorption by brush border membrane (BBM), metabolism in CaCo-2 enterocytes, and transport of policosanol metabolites across the basolateral membrane (BLM). It was hypothesized that policosanol is partially oxidized into fatty acids and then is incorporated into other lipids.

Methods: Policosanol was emulsified with phosphatidylcholine in the culture medium. The viability of cells was assessed via an MTT (3-[4,5]dimethylthiazol-2-yl-2,5-diphenyltetrazolim) assay. Control cells received only the same amount of "vehicle" (phosphatidylcholine) without policosanol. CaCo-2 cell monolayer and medium were collected; lipid was extracted and analyzed by thin-layer chromatography (TLC) and gas liquid chromatography (GLC).

Results: Eighty-six percent of policosanol added to the cell culture medium was absorbed after 48 hours' incubation. The amount of cholesterol ester fatty acid was significantly increased both in the cells and in the basolateral medium, and was reduced in the apical medium. Policosanol increased the quantity of free fatty acids in the basolateral medium and reduced the free fatty acid content of CaCo-2 cells. Further evaluation of lipid profiles indicated that policosanol modulated the fatty acid profile of cholesterol ester in the basolateral medium.

Conclusion: It was concluded that policosanol or policosanol metabolites may modulate lipid metabolism and/or transport following absorption by the BBM, partial oxidation by the intestinal epithelium, and transport of policosanol metabolites across the BLM.