Plasma and liver levels of phytosterols and occurrence of cholestasis in rats nourisched parenterally, enterally and orally

Phytosterols have been claimed as a risk factor of Parenteral Nutrition-Associated Cholestasis (PNAC). This study aims to determine phytosterol levels in plasma and liver cells and relates them to the occurrence of cholestasis in rats receiving parenteral, enteral or standard oral diet. Plasma and liver levels of phytosterols, cholesterol and other sterol were determined in 30 weaning rats divided in 6 groups receiving parenteral nutrition (PN) with soybean oil (PNSB), PN with soybean oil plus glutamine (PNSBG), PN with olive oil (PNO), PN with structured triglycerides, soy enteral formula and chow, respectively for 5 days. Phytosterols were also determined in hepatic tissues by gas-chromatography-flame ionization detector and correlated to with liver histology findings. Among phytosterols, sitosterol had the highest plasma level in all the groups. Its highest concentrations were found in the PNBS and PNO groups. Plasma stigmaterol levels were significantly higher in the PNSB and PNSBG groups. Plasma cholestanol and campesterol levels were similar across all groups. Liver campesterol, sitosterol and stigmasterol levels were highest in the PNSB and PNSBG groups. When comparing plasma and liver tissue levels, campesterol and sitosterol were more present in the liver than in the plasma, while the opposite was true for stigmasterol. None of the liver specimens showed PNAC findings. In conclusion, phytosterols seem to accumulate more in the liver than in the plasma, particularly in rats receiving Parenteral Nutrition with soybean oil (PNSB) and Parenteral Nutrition with soybean oil plus glutamine (PNSBG). No cases of PNAC appear to occur.