The Potential of Epigallocatechin Gallate (EGCG) in Targeting Autophagy for Cancer Treatment: A Narrative Review

Autophagy is an evolutionarily conserved process for the degradation of redundant or damaged cellular material by means of a lysosome‐dependent mechanism, contributing to cell homeostasis and survival. Autophagy plays a multifaceted and context‐dependent role in cancer initiation, maintenance, and progression; it has a tumor suppressive role in the absence of disease and is upregulated in cancer cells to meet their elevated metabolic demands. Autophagy represents a promising but challenging target in cancer treatment. Green tea is a widely used beverage with healthy effects on several diseases, including cancer. The bioactive compounds of green tea are mainly catechins, and epigallocatechin‐gallate (EGCG) is the most abundant and biologically active among them. In this review, evidence of autophagy modulation and anti‐cancer effects induced by EGCG treatment in experimental cancer models is presented. Reviewed articles reveal that EGCG promotes cytotoxic autophagy often through the inactivation of PI3K/Akt/mTOR pathway, resulting in apoptosis induction. EGCG pro‐oxidant activity has been postulated to be responsible for its anti‐cancer effects. In combination therapy with a chemotherapy drug, EGCG inhibits cell growth and the drug‐induced pro‐survival autophagy. The selected studies rightly claim EGCG as a valuable agent in cancer chemoprevention.