Nanoencapsulation of Green Tea Catechins : Cellular uptake, Transepithelial transport, and Bioefficacy of Epigallocatechin-3-gallate

Abstract

Abstract Green tea catechins (GTCs) are known for their anti-oxidant activity due to presence of Epigallaocatechin-3-gallate (EGCG). Excessive degradation and poor intestinal absorption render it ineffective. Present study is focused on enhancing the cellular uptake and intestinal absorption of EGCG through nanoencapsulated GTCs (GTC-NPs) in Caco-2 cell lines, with the ultimate goal of enhancing its bioefficacy using chitosan nanocarriers. The stability, cytotoxicity and cellular uptake studies of EGCG from GTCs and GTC-NPs were studied. The net flux and net efflux were estimated to understand the overall transepithelial transport in a polarised Caco-2 monolayer. Intestinal absorption prediction studies were carried out at different temperatures as well using different absorption stimulators. H2O2-induced oxidative stress was applied to determine the protective effect of EGCG from GTCs and GTC-NPs. The results of the study showed stability of EGCG from GTCs and GTC-NPs in HBSS buffer (pH 7.4 and pH 6.5) with reducing agent (ascorbic acid) up to 95% and 97%, respectively. Cellular uptake studies showed 3-fold improvement in the uptake of EGCG from GTC-NPs. Transepithelial transport studies have confirmed 5.6-fold increase in flux and 3.9-fold decrease in the efflux of EGCG with nano-encapsulation. The cytotoxicity studies against H2O2-induced oxidative stress confirmed the increased bioefficacy of nano-encapsulated GTCs. These findings are encouraging and demonstrates that the use of EGCG in drug delivery systems with the enhanced bio-asbsorption and bio-efficacy.