"Anti-infective properties of Epigallocatechin-3-gallate (EGCG), a component of Green Tea." - GreenMedInfo Summary

Consumption of green tea (Camellia sinensis) has been shown to cause many physiological and pharmacological health benefits. In the past two decades several studies reported that epigallocatechin-3-gallate (EGCG), the main constituent of green tea, has anti-infective properties. Antiviral activities of EGCG with different modes of action were described for viruses from diverse families like Retroviridae, Orthomyxoviridae and Flaviviridae and including important human pathogens like human immunodeficiency virus, influenza A virus and the hepatitis C virus. Furthermore, the molecule interferes with the replication cycle of DNA viruses like hepatitis B virus, herpes simplex virus and adenovirus. Most of these reports demonstrated antiviral properties within physiological concentrations of EGCG in vitro. In contrast, the minimum inhibitory concentrations against bacteria were 10 to 100 fold higher. Nevertheless, antibacterial effects of EGCG alone and in combination with different antibiotics were intensively analyzed against a number of bacteria including multidrug-resistant strains like methicillin-resistant Staphylococcus aureus or Stenotrophomonas maltophilia. Furthermore, the catechin EGCG has antifungal activity against human pathogenic yeasts like Candida albicans. Although the mechanistic effects of EGCG are not fully understood, there are hints indicating EGCG binds to lipid membranes and has influence on the folic acid metabolism of bacteria and fungi by inhibiting the cytoplasmic enzyme dihydrofolate reductase. This review summarizes the current knowledge and future perspectives about the antibacterial, antifungal and antiviral effects of the green tea substance EGCG.