Epigallocatechin-Gallate: Unraveling Its Protective Mechanisms and Therapeutic Potential

Epigallocatechin-gallate (EGCG), the predominant catechin in green tea, is a key constituent of tea polyphenols. Due to the EGCG's diverse biological activities of anti-inflammatory, antioxidant, and so forth, green tea is believed to exert a positive influence on a variety of diseases. And extensive research had uncovered a range of protective effects attributed to EGCG, indicating its potential to mitigate various pathological conditions. The precise mechanisms through which EGCG operates remain a subject of ongoing discussion among researchers. Reactive oxygen species (ROS), a primary culprit in oxidative stress, have been demonstrated to be reduced by EGCG. Furthermore, nuclear factor kappa-B (NF-κB), a pivotal signal molecular of inflammation progress, has been observed to be suppressed by EGCG. Sirtuins1 (Sirt1) is a histone deacetylase, the obligate substrate of which is NAD+. Evidence suggests that EGCG can enhance the activities of Sirt1 to induce autophagy to protect inflammation injury and oxidative stress in tissues and organs. Despite the promising protective effects of EGCG, its clinical use is constrained by its limited bioavailability. This review aims to consolidate the existing evidence and elucidate the mechanisms that support EGCG's protective role, as well as to explore the challenges and potential strategies for its clinical application.