Effect of Inulin Intake on the Content and Susceptibility to Oxidative Damage of Cholesterol in Rat Liver Plasma Membranes

Abstract

The influence of the prebiotic inulin on the level and sensitivity to oxidative attack has been investigated in rat liver plasma membranes. The obtained results showed that the oral administration of inulin in experimental animals induced a slight decrease of the content of cholesterol in liver plasma membranes. In addition, the susceptibility of cholesterol to oxidation, which was tested with cholesterol oxidase assay, was lower in membranes isolated from inulin-fed rats. Studies were also performed on the changes in the asymmetric distribution of cholesterol between the two leaflets of the membrane bilayer in order to elucidate the reasons for the observed differences in cholesterol sensitivity to oxidation. Basically, the alterations in the oxidation of cholesterol molecules could be due either to differences in the localization of cholesterol in the external membrane monolayer and/or to changes in the structural organization of the membranes. Our studies revealed a slight reduction of the cholesterol molecules in the outer membrane monolayer, which could be one possible reason for the observed reduction of cholesterol susceptibility to oxidative damage.