Inhibition of rotavirus and enterovirus infections by tea extracts.

Epigallocatechin gallate from green tea and theaflavin digallate from black tea inhibited infections of cultured rhesus monkey kidney MA 104 cells with rotaviruses and enteroviruses. Their antiviral effects were maximally induced when directly added to virus, and their pre- and post-treatment of the cells produced much weak antiviral activity. Antiviral activity of the extracts therefore seems to be attributable to interference with virus adsorption.