Assessment of intestinal permeability of EGCG by piperine using caco-2 cell monolayer system

Abstract

(-)Epigallocatechin-3-gallate (EGGG), a flavonoid found in green tea, is known to have low bioavailability. In this study, we determine whether piperine, a natural bioenhancer, can increase the absorption rate of EGCG. Using a Caco-2 cell monolayer, permeability experiments were performed in Hanks’ balanced salt solution (HBSS) and EGCG stability was adjusted to pH 6.5 and pH 5.5 by ascorbic acid treatment. When HBSS was adjusted to pH 6.5, EGCG remained at 94.78% for up to 2 h and remained at 86.04% after 4 h and the net efflux decreased compared to the control. As a result, uptake was significantly increased in the piperine co-administered group compared to the EGCG-alone group, showing that piperine increased the permeability of EGCG in the Caco-2 cell monolayer. These results suggest that piperine inhibits EGCG glucuronidation and efflux, allowing for greater absorption of EGCG. © The Korean Society for Applied Biological Chemistry 2020.