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

• Published in: Food and chemical toxicology Vol. 50; no. 9; pp. 3106 - 3113
• Main Authors: Alemany, L., Laparra, J.M., Barberá, R., Alegría, A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2012; Elsevier
• Subjects: 7k-Cholesterol; 7k-Stigmasterol; Biological and medical sciences; Caco-2 Cells; cholesterol; Cholesterol - toxicity; Cytotoxic effects; cytotoxicity; DNA; Drug Evaluation, Preclinical; General pharmacology; human cell lines; Humans; interphase; intestinal mucosa; Intestines - cytology; Intestines - drug effects; Medical sciences; membrane potential; Membrane Potential, Mitochondrial - drug effects; mitochondrial membrane; oxidation; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Plant sterol oxidation products; RNA; stigmasterol; Stigmasterol - toxicity; tetrazolium; toxicology; PBS; Caco-2 cells; POPs; Cytotoxic effects; MTT; DHR; COPs; DMEM; 7k-Cholesterol; Plant sterol oxidation products; ΔΨm; PI; 7k-Stigmasterol; Human; Evaluation; Digestive system; Toxicity; Biochemical compound; Gut; Lipids; Cytotoxicity; Experimental study; In vitro; Biological activity; Cholesterol; Plant; Stigmasterol; Chemical reaction; Plant origin; Oxidation; Sterol
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2012.06.036

► 7k-Stigmasterol did not cause deleterious effects in Caco-2 cells. ► The sub-cellular target of 7k-cholesterol toxicity seems to be the mitochondria. ► 7k-Stigmasterol demonstrated a capacity to reduce toxic effects of 7k-cholesterol.
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 (0–120μM) 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 (120μM), as well as upon ΔΨm when incubated at all concentrations (12/24h). Only cells incubated with 7k-cholesterol (120μM) 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.