Effects of alpha-Casein on the Absorption of Blueberry Anthocyanins and Metabolites in Rat Plasma Based on Pharmacokinetic Analysis

摘要

Blueberry anthocyanins are well known for their beneficial biological activities. However, the poor bioavailability of anthocyanins limits their functional capacity in vivo. Our current study aimed to detect the effects of alpha-casein on the absorption of blueberry anthocyanins and their metabolites in rats. Blueberry anthocyanins with and without alpha-casein were intragastrically administered to two groups of rats and their blood samples were collected within 24 h. Results illustrated that rapid absorption of anthocyanins was observed in the rat plasma, but their concentration was relatively low. With the complexation of alpha-casein, the maximum concentration (C-max) of bioavailable anthocyanins and metabolites could increase by 1.5-10.1 times (P < 0.05 or P < 0.01). The promotional effect on the plasma absorption of malvidin-3-O-galactoside and vanillic acid was outstanding with the C-max ax increasing from 0.032 to 0.323 and from 0.360 to 1.902 mu g/mL, respectively (P < 0.01). Besides, the molecular docking models presented that anthocyanins could enter the structural cavity and interact with amino acid residues of alpha-casein, which was in accordance with the improved bioavailability of anthocyanins. Therefore, alpha-casein could assist more blueberry anthocyanins and their metabolites to enter blood circulation.