6533b870fe1ef96bd12cfdbb

RESEARCH PRODUCT

Evaluation of the cytotoxic effect of 7keto-stigmasterol and 7keto-cholesterol in human intestinal (Caco-2) cells

subject

description

The biological implications of cholesterol oxidation products have been investigated, though research on plant sterol oxidation products is scarce and in some cases contradictory. The cytotoxicity of 7keto(k)-stigmasterol versus 7keto(k)-cholesterol at different concentrations (0-120 μM) and incubation times (4-24h), in intestinal epithelial cells (Caco-2 cells) was evaluated. The 3-[4,5-dimethylthiazol-2-yl]-2,3-diphenyl tetrazolium bromide and neutral red uptake tests, mitochondrial membrane potential (ΔΨm), and relative DNA and RNA contents in the cell cycle phases were determined. Possible interaction effects between 7k-derivatives or non-oxidized stigmasterol were monitored. Endo/lysosomal activity was not impaired by either oxide. 7k-cholesterol showed a deleterious effect upon the mitochondrial compartment after 24h of exposure (120 μM), as well as upon ΔΨm when incubated at all concentrations (12/24h). Only cells incubated with 7k-cholesterol (120 μM) exhibited a decrease in RNA proportion in the G1 population. The presence of 7k-stigmasterol or stigmasterol with 7k-cholesterol reduced the deleterious metabolic effects upon mitochondrial functionality and integrity and the distribution of RNA contents in G1 and G2 phases. A decrease in the G1 phase proportion was detected in cells exposed to mixtures, without alterations in RNA content. The results obtained indicate the absence of 7k-stigmasterol cytotoxicity in Caco-2 cells and its capacity to reduce 7k-cholesterol toxicity.