Identification of epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3''Me) and amino acid profiles in various tea (Camellia sinensis L.) cultivars

nc886, a Non-Coding RNA, Is a New Biomarker and Epigenetic Mediator of Cellular Senescence in Fibroblasts

Functional studies of organisms and human models have revealed that epigenetic changes can significantly impact the process of aging. Non-coding RNA (ncRNA), one of epigenetic regulators, plays an important role in modifying the expression of mRNAs and their proteins. It can mediate the phenotype of cells. It has been reported that nc886 (=vtRNA2-1 or pre-miR-886), a long ncRNA, can suppress tumor formation and photo-damages of keratinocytes caused by UVB. The aim of this study was to determine the role of nc886 in replicative senescence of fibroblasts and determine whether substances capable of controlling nc886 expression could regulate cellular senescence. In replicative senescence fibroblasts, nc886 expression was decreased while methylated nc886 was increased. There were changes of senescence biomarkers including SA-β-gal activity and expression of p16INK4A and p21Waf1/Cip1 in senescent cells. These findings indicate that the decrease of nc886 associated with aging is related to cellular senescence of fibroblasts and that increasing nc886 expression has potential to suppress cellular senescence. AbsoluTea Concentrate 2.0 (ATC) increased nc886 expression and ameliorated cellular senescence of fibroblasts by inhibiting age-related biomarkers. These results indicate that nc886 has potential as a new target for anti-aging and that ATC can be a potent epigenetic anti-aging ingredient.

Antioxidant and Cytoprotective Effects of (-)-Epigallocatechin-3-(3″-O-methyl) Gallate

Reactive oxygen species (ROS) are generated from diverse cellular processes or external sources such as chemicals, pollutants, or ultraviolet (UV) irradiation. Accumulation of radicals causes cell damage that can result in degenerative diseases. Antioxidants remove radicals by eliminating unpaired electrons from other molecules. In skin health, antioxidants are essential to protect cells from the environment and prevent skin aging. (-)-Epigallocatechin-3-(3″-O-methyl) gallate (3″Me-EGCG) has been found in limited oolong teas or green teas with distinctive methylated form, but its precise activities have not been fully elucidated. In this study, we examined the antioxidant roles of 3″Me-EGCG in keratinocytes (HaCaT cells). 3″Me-EGCG showed scavenging effects in cell and cell-free systems. Under H₂O₂ exposure, 3″Me-EGCG recovered cell viability and increased the expression of heme oxygenase 1 (HO-1). Under ultraviolet B (UVB) and sodium nitroprusside (SNP) exposure, 3″Me-EGCG protected keratinocytes and regulated the survival protein AKT1. By regulating the AKT1/NF-κB pathway, 3″Me-EGCG augmented cell survival and proliferation in HaCaT cells. These results indicate that 3″Me-EGCG exhibits antioxidant properties, resulting in cytoprotection against various external stimuli. In conclusion, our findings suggest that 3″Me-EGCG can be used as an ingredient of cosmetic products or health supplements.