green tea as antiviral, anti-influenza

Antiviral effect of catechins in Green Tea on influenza virus   compound catechins ((-)-epigallocatechin gallate (EGCG),... from green tea were evaluated for their ability to inhibit influenza virus replication in cell culture and for potentially direct virucidal effect. They studied H1N1 and H3N1 and added green tea catechins one hour after infecting cells with influenza…”complete inhibition was observed at 120uM (micro Moles), where we failed to obseve any release of viruses. In this assay, EGCG was by far the most effective” ... “It should be noted that the total tea extract was much more effective then any isolated or mixture pf polyphenols. This suggests that, although dietary uptake of tea would be beneficial for direct intervention of influenza virus infection, components other than catechins are more responsible for the hemagglutination inhibition…The results also suggest that, besides the known inhibitory activity on viral attachment of host cells, the antiviral activities of polyphenols are associated with different steps in the life cycle….primary target of the catechins is likely to be the membrane. The effect would be altering the physical integrity of the virus particles or host membrane.”

 

Inactivation of human type A and B influenza viruses by tea-seed saponins.
Bioscience, biotechnology, and biochemistry. 2000 Jan;64(1):184–6. The effects of a mixture of tea-seed saponins obtained from the seeds of Camellia sinensis var. sinesis on human influenza viruses types A and B were investigated. At the concentrations of 60, 80, and 100 micrograms/ml, respectively, the mixture inactivated viruses A/Memphis/1/71 (H3N2), B/Lee/40, and A/PR/8/34 (H1N1) almost completely. The mixture also inactivated type A virus A/PR/8/34 after inoculation at concentrations of 1–30 micrograms/ml dose-dependently.