Epigallocatechin gallate as a nutraceutical to potentially target the metabolic syndrome: novel insights into therapeutic effects beyond its antioxidant and anti-inflammatory properties

Abstract

Epigallocatechin gallate (EGCG) is one of the most abundant and powerful flavonoids contained in green tea. Because of the global increase in green tea consumption, there has been a general interest in understanding its health benefits, including its bioactive compounds like EGCG. Indeed, preclinical evidence already indicates that EGCG demonstrated a strong antioxidant and anti-inflammatory properties that could be essential in protecting against metabolic syndrome. The current review explores clinical evidence reporting on the beneficial effects of EGCG supplementation in obese subjects or patients with diverse metabolic complications that include type 2 diabetes and cardiovascular disease. The discussion incorporates the impact of different formulations of EGCG, as well as the effective doses and treatment duration. Importantly, besides highlighting the potential use of EGCG as a nutraceutical, the current review also discusses crucial evidence related to its pharmaceutical development as an agent to hinder metabolic diseases, including its bioavailability and metabolism profile, as well as its well-known biological properties.

Keywords:

• Antioxidants
• epigallocatechin gallate
• green tea
• inflammation
• metabolic syndrome
• nutraceuticals

Acknowledgements

Please note, the author, Y Ntamo, is a postdoctoral research fellow, funded by the National Research Foundation of South Africa. Whereas the work by K Ziqubu, reported herein was made possible through partial funding by the South African Medical Research Council through its Division of Research Capacity Development under the Researcher Development Award Programme. The content hereof is the sole responsibility of the authors and do not necessarily represent the official views of the funders, NRF or the SAMRC.

Author contribution

YN, BJ, KZ and PVD - concept and original draft; YN, BJ, KZ and PVD- literature search and data extraction; YN, BJ, KZ, SEM-M, BBN, TMN, SEM, SH, PO, LT and PVD- writing and final approval of the manuscript.

Conflict of interests

The authors declare no conflict of interest.

Ethics approval

This is a review of already published studies and thus it does not require ethical approval.

Consent for publication

Not applicable. No individual person’s data has been included in this manuscript.

Data availability

Data related to search strategy, study selection, and extraction items will be made available upon request after the manuscript is published.

Additional information

Funding

This work was supported in part by baseline funding from the Biomedical Research and Innovation Platform of the South African Medical Research Council (SAMRC) and the National Research Foundation (NRF) of South Africa (Grant number: 117829). The content hereof is the sole responsibility of the authors and do not necessarily represent the official views of the SAMRC or the funders.