Molecular Nutritional Study on the Bioregulatory Effects of Green Tea Polyphenols

(JSNFS Award for Excellence in Research (2019))

Abstract

Several beneficial health effects of green tea (Camellia sinensis) have been documented. These include anti-carcinogenic, anti-allergic, anti-hypertensive, anti-cardiovascular disease, and anti-hypercholesterolemic activities. The compounds responsible for these activities are a subgroup of polyphenols known as catechins. The major green tea catechins are (－)-epigallocatechin-3-gallate (EGCG) , (－)-epicatechin-3-gallate, (－)-epigallocatechin and (－)-epicatechin. Because EGCG is found only in tea from Camellia sinensis, EGCG is regarded as a characteristic constituent of green tea. EGCG is known to exhibit various biological and pharmacological properties. The 67-kDa laminin receptor (67LR) has been identified as a cell-surface EGCG receptor that confers EGCG responsiveness to many cells at physiological concentrations. 67LR has been shown to mediate the beneficial activities of this phytochemical, which include anti-cancer, anti-allergic, anti-inflammatory and insulin sensing modulation activities. MYPT1, eEF1A, protein phosphatase 2A, Akt, endothelial nitric oxide synthase, soluble guanylate cyclase, protein kinase Cδ, acid sphingomyelinase, sphingosine kinase 1 and cGMP are molecules known to be related to the bioregulatory effects of EGCG via 67LR. Some food factors potentiate the bioactivities of EGCG by modulating the EGCG-sensing pathway.