Preclinical Activities of Epigallocatechin Gallate in Signaling Pathways in Cancer

Abstract

Epigallocatechin gallate (EGCG) is the main bioactive component of catechins predominantly present in various types of tea. EGCG is well known for a wide spectrum of biological activities as an anti-oxidative, anti-inflammatory, and anti-tumor agent. The effect of EGCG on cell death mechanisms via the induction of apoptosis, necrosis, and autophagy has been documented. Moreover, its anti-proliferative action has been demonstrated in many cancer cell lines. It was also involved in the modulation of cyclooxygenase-2, oxidative stress and inflammation of different cellular processes. EGCG has been reported as a promising agent target for plasma membrane proteins, such as epidermal growth factor receptor. In addition, it has been demonstrated a mechanism of action relying on the inhibition of ERK1/2, p38 MAPK, NF-κB, and vascular endothelial growth factor. Furthermore, EGCG and its derivatives were used in proteasome inhibition and they were involved in epigenetic mechanisms. In summary, EGCG is the most predominant and bioactive constituent of tea and may play a role in cancer prevention.

Beneficial Properties of Green Tea Catechins

“…The most potent bioactive ingredient in green tea is EGCG, containing eight hydroxyl groups, named as the main green tea polyphenol [20,34,35]. The cell-death-inducing effect of catechins has been previously confirmed in prostate cancer animal model [34].…”

“…The most potent bioactive ingredient in green tea is EGCG, containing eight hydroxyl groups, named as the main green tea polyphenol [20,34,35]. The cell-death-inducing effect of catechins has been previously confirmed in prostate cancer animal model [34]. Many studies have been conducted to confirm the induction of apoptosis and cell cycle arrest by EGCG, e.g., in colon cancer HCT-116 cells [36,37].…”

“…In addition, oral supplementation of EGCG induced the formation of reactive oxygen species in the mitochondria of lung cancer cells, possibly due to the limited number of antioxidant enzymes in these cells [39]. It was proven that catechins derived from green tea, while added to the medium used in cell culture, increase level of oxidative stress, leading to apoptosis [34].…”

Anti-Cancer Effects of Green Tea Epigallocatchin-3-Gallate and Coffee Chlorogenic Acid

“…These basic studies have also proposed mechanisms under which EGCG exerts these effects [ 1 , 2 , 3 , 4 , 5 ]. This review focuses mechanisms related to anti-oxidant and pro-oxidant effects, anti-inflammatory effects, anti-angiogenic effects, induction of apoptosis, modulation of epigenetic pathways and EGCG’s binding to cancer-related proteins which have been reviewed in many articles [ 26 , 34 , 35 , 36 , 37 , 38 , 39 ].…”

Epigallocatechin-3-Gallate Induces Apoptosis as a TRAIL Sensitizer via Activation of Caspase 8 and Death Receptor 5 in Human Colon Cancer Cells

“…Accumulating evidences reveal that the anti-cancer effect of green tea is exerted mainly by its polyphenolic compounds [13,14]. The major catechin derivatives in leaves of green tea are comprised of eight phenolic flavonoid constituents, such as catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate (EGCG) [15].…”