The effects and mechanisms of epigallocatechin-3-gallate on reversing multidrug resistance in cancer

Background: Many natural and dietary compounds with low toxicity and fewer adverse side effects can suppress multidrug resistance (MDR) in cancers, which is a principal challenge during cancer chemotherapy. Epigallocatechin-3-gallate (epigallocatechin gallate, EGCG), the major flavanol (also named as catechin) found in green tea (Camellia sinensis), has the potential to reverse MDR when used as an anticancer agent. Pharmaceutical significance and therapeutic feasibility of EGCG provide a novel strategy for the treatment of drug resistant cancers. Scope and approach: In this review, we provide a detailed overview of the role of EGCG in the reversal of MDR in different types of cancers, and information on the possible use of natural products alone or in combination with chemotherapy for cancer treatment. Key findings and conclusions: EGCG can be used for cancer treatment. It increases the potency of several chemotherapeutics such as doxorubicin, cisplatin, and tamoxifen, in vivo and in vitro, in many cancers. MDR reversal by EGCG is facilitated by a plethora of mechanisms including oxidative and antioxidative responses, altered cell death and survival responses, suppression of oncogenic transcription factors, modulating the tumor micro environment, and regulating multiple signal transduction pathways.