Cytoprotective effect of epigallocatechin gallate (EGCG)-5′-O-α-glucopyranoside, a novel EGCG derivative

Epigallocatechin gallate (EGCG) is a well-studied polyphenol with antioxidant effects. Since EGCG has low solubility and stability, many researchers have modified EGCG residues to ameliorate these problems. A novel EGCG derivative, EGCG-5′ -O-α-glucopyranoside (EGCG-5′ Glu), was synthesized, and its characteristics were investigated. EGCG-5′ Glu showed antioxidant effects in cell and cell-free systems. Under SNP-derived radical exposure, EGCG-5′ Glu decreased nitric oxide (NO) production, and recovered ROS-mediated cell viability. Moreover, EGCG-5′ Glu regulated apoptotic pathways (caspases) and cell survival molecules (phosphoinositide 3-kinase (PI3K) and phosphoinositide-dependent kinase 1 (PDK1)). In another radical-induced condition, ultraviolet B (UVB) irradiation, EGCG-5′ Glu protected cells from UVB and regulated the PI3K/PDK1/AKT pathway. Next, the proliferative effect of EGCG-5′ Glu was examined. EGCG-5′ Glu increased cell proliferation by modulating nuclear factor (NF)-κB activity. EGCG-5′ Glu protects and repairs cells from external damage via its antioxidant effects. These results suggest that EGCG-5′ Glu could be used as a cosmetics ingredient or dietary supplement.