Nutrients
Green tea catechin derivatives with different alkyl chain length and aromatic ring substitutions at the 3-hydroxyl group, synthesized from epigallocatechin (EGC) and (+)-catechin (C) (Song et al., 2007).
Herbs and Herbal Extracts
Green tea catechin derivatives
Effects and Interactions
Green tea catechin derivatives have a broad spectrum activity against various subtypes of influenza viruses.
Mechanisms
The antiviral activity of the herbal extract may be mediated by interaction with hemagglutinin (HA) segment of influenza at the initial stage of infection. The derivatives had inhibitory effects for six influenza subtypes tested, including A/H1N1, A/H3N2 and B type, H2N2, and H9N2 avian influenza virus. The compounds suppressed the adsorption of the viruses by red blood cell (RBC).
In addition, green-tea extract (GTE) can inhibit acidification of endosomes and lysosomes in a concentration-dependent manner (Imanishi et al., 2002). Within as early as 5 to 15 min after infection and depending on the virus strains, the growth of influenza A and B viruses could be suppressed when the cells were treated with GTE. One of major catechin molecules and active components in GTE is (-) epigallocatechin (EGC), which has the inhibitory effects on virus growth similar to that of the whole GTE.
References
Imanishi, N., Tuji, Y., Katada, Y., et al. (2002) Additional inhibitory effect of tea extract on the growth of influenza A and B viruses in MDCK cells. Microbiol Immunol 46, 491-4.
Song, J. M., Park, K. D., et al. (2007) Biological evaluation of anti-influenza viral activity of semi-synthetic catechin derivatives. Antiviral Res 76, 178-185.
