Transport of gallocatechin gallate and catechin gallate in high-temperature-processed green tea extract from gastrointestinal tract to brain by an in vitro bio-mimic model system coupled with sequential cell cultures

Abstract The aim of this study was to evaluate the transport of gallocatechin gallate (GCG), catechin gallate (CG) and their metabolites in high-temperature-processed green tea extract (HTP_GTE) from the gastrointestinal tract to blood-brain barrier (BBB) with an in vitro bio-mimic model system with sequential cell cultures including Caco-2, HepG2 and HBMECs. Transports from the GI to BBB, the final concentrations of GCC and CG were 18.95 ± 3.24 μM and 5.11 ± 0.83 μM, respectively. Metabolites detected in BBB after systemic circulation were identified as glucuronide or sulfate conjugated form. Results suggest that GCG, CG and their metabolites in HTP_GTE are capable of reaching the brain by oral intake of HTP_GTE, implying that HTP_GTE could be utilized as a natural functional material for the prevention of degenerative brain diseases.