Tea catechins in cancer prevention and therapy-molecular mechanism and human relevance.

Abstract

The inhibitory activities of tea catechins against carcinogenesis and cancer cell growth have been demonstrated in a large number of laboratory studies. Many mechanisms for modulating cancer signaling and metabolic pathways have been proposed based on numerous studies in cell lines with (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active tea catechin. Nevertheless, it is not known whether many of these mechanisms indeed contribute to the anticancer activities in animals and in humans. Human studies have not yet provided strong evidence for the cancer preventive activities, nor therapeutic efficacy of tea or tea constituents. This chapter reviews the basic biochemical properties of tea catechins, their binding to key enzymes and signal transduction proteins, and other mechanisms that lead to suppression of cell proliferation, increased apoptosis, and inhibition of angiogenesis. The relevance of these mechanisms are assessed in the light of the situation in vivo. The potential challenges in the application of tea and tea-derived agents for cancer prevention and therapy are also discussed.

In Vitro and In Silico Studies of the Molecular Interactions of Epigallocatechin-3-O-gallate (EGCG) with Proteins That Explain the Health Benefits of Green Tea

“…These findings suggest that the lipid-raft clustering/67LR/aSMase can be a novel therapeutic target against multiple myeloma and possibly other types of cancer. More detailed information on 67LR is available in the comprehensive review articles by Tachibana [ 46 , 49 ] and Yang and Wang [ 6 ].…”

“…Green tea has been shown to have beneficial effects on many diseases such as cancer, metabolic syndrome (MetS), inflammatory diseases, and neurodegenerative disorders [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. The green tea component, (−)-epigallocatechin-3- O -gallate (EGCG, Figure 1 ), is believed to be a major contributor to these effects.…”

“…EGCG is a well-known anti-oxidant, and many peer-reviewed, scientific journal publications have demonstrated that the health effects of green tea are attributable to the anti-oxidative properties of green tea catechins (GTCs, Figure 1 ) including EGCG [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. For example, carcinogenesis is closely associated with reactive oxygen species (ROS) which cause DNA damage and activate nuclear factor-κB (NFκB) which modulates the expression of cancer-associated cytokines such as the tumor necrosis factor (TNF)α and enzymes such as cyclooxygenase (COX) and matrix metalloproteinases (MMPs) [ 1 ].…”

“…Moreover, several lines of evidence have demonstrated that the binding affinity of EGCG to proteins is involved in its action mechanism [ 3 , 4 , 5 , 6 ]. The present review aims to update information from such studies on EGCG-protein interaction and discuss the molecular mechanism by which green tea may exert its health-promoting actions.…”