Intestinal absorption of phenolic acids in Rhus chinensis extracts by in situ single-pass perfusion model in rats

Abstract

The intestinal absorption properties of four main effective components(gallic acid, ocinolglucoside, ethyl gallate and penta-O-galloyl-β-D-glucose) in Rhus chinensis extracts were investigated by in situ single-pass intestinal perfusion model in rats. The liquid accumulation of perfusion was corrected by gravimetry. The HPLC method was established to determine the concentration of the four effective components in the intestinal perfusion. It showed significant differences(P<0.05) in absorption rate constant(K_a) and effective permeability(P_(eff)) among the three concentrations of components, and the absorption of the four effective components in different intestinal segments was saturated at high concentrations. At the same concentration, there were significant differences in K_a and P_(eff) of the four components in each intestinal segment(P<0.05). The order of K_a and P_(eff) of the four components in the intestine was penta-O-galloyl-β-D-glucose>ethyl gallate>gallic acid>ocinolglucoside, with significant differences between them(P<0.05). In conclusion, gallic acid, orpheolglucoside, ethyl gallate and pentacyl-glucose could be absorbed in the whole intestine. Their absorption rate and permeation ability were related to the intestinal section and the perfusate concentration. These results indicated potential active transport or facilitated diffusion in the intestinal transport process of the four effective components.