Effect of ergosterol-enriched extracts obtained from Agaricus bisporus on cholesterol absorption using an in vitro digestion model

Ergosterol-enriched extracts obtained from Agaricus bisporus were incorporated into lard, butter and white chocolate as food carriers to study their potential as ingredients with hypocholesterolemic properties to design functional foods. Lard was selected and supplemented with several concentrations of cholesterol and ergosterol, beta-sitosterol (as control) and two types of ergosterol-enriched extracts obtained by supercritical fluid extraction (SFE) and accelerated solvent extraction (ASE). The prepared food combinations were submitted to a specific in vitro digestion model, their dietary mixed micelle (DMM) fractions isolated and administrated to Caco2 cell cultures. Ergosterol was as effective as some phytosterols such as sitosterol, in the displacement of cholesterol from the DMMs when applied to the food matrix in a ratio (1:2, w/w, cholesterol:sterol). The ASE extract was not effective but addition of the SFE extract provoked a 67% reduction in the DMM cholesterol content. Lard supplementation with fungal beta-glucans able to bind bile-acids enhanced the cholesterol displacement from the DMMs induced by the sterols although it also reduced ergosterol incorporation. Fungal sterols also impaired proper cholesterol transport through Caco2 monolayers.