Anthocyanins and phenolic acids from a wild blueberry (Vaccinium angustifolium) powder counteract lipid accumulation in THP-1-derived macrophages

Purpose: Blueberries are a rich source of anthocyanins (ACNs) and phenolic acids (PA), which are hypothesized to protect against development of atherosclerosis. The present study examined the effect of an ACN- and PA-rich fractions, obtained from a wild blueberry powder, on the capacity to counteract lipid accumulation in macrophages derived from monocytic THP-1 cells. In addition, we tested the capacity of pure ACNs and their metabolites to alter lipid accumulation.Methods: THP-1-derived macrophages were incubated with fatty acids (500 \u3bcM oleic/palmitic acid, 2:1 ratio) and different concentrations (from 0.05 to 10 \u3bcg mL 121) of ACN- and PA-rich fractions, pure ACN standards (malvidin, delphinidin and cyanidin 3-glucoside), and metabolites (syringic, gallic and protocatechuic acids). Lipid accumulation was quantified with the fluorescent dye Nile red.Results: Lipid accumulation was reduced at all concentrations of the ACN-rich fraction tested with a maximum reduction at 10 \u3bcg mL 121 ( 1227.4 %; p < 0.0001). The PA-rich fraction significantly reduced the lipid accumulation only at the low concentrations from 0.05 \ub5g mL 121 to 0.3 \ub5g mL 121, with respect to the control with fatty acids. Supplementation with pure ACN compounds (malvidin and delphinidin-3-glucoside and its metabolic products (syringic and gallic acid)) reduced lipid accumulation especially at the low concentrations, while no significant effect was observed after cyanidin-3-glucoside and protocatechuic acid supplementation.Conclusions: The results demonstrated a potential role of both the ACN- and PA-rich fractions and single compounds in the lipid accumulation also at concentrations close to that achievable in vivo