Antiviral substances in plants of the mint family (labiatae). II. Nontannin polyphenol of Melissa officinalis.

Abstract

SummaryThe presence of gelatin did not eliminate the antiviral activity of aqueous extracts of Melissa officinalis against herpes simplex and vaccinia viruses in disc plaque-suppression tests, suggesting that a second, nontannin, antiviral substance was present. By using tannin-free preparations it was found that the nontannin polyphenol fraction produced an antiviral effect against herpes simplex and vaccinia viruses in egg and cell-culture systems. This activity was very similar to that of caffeic acid. It was not clear whether the antiviral effect of either of these materials was exclusively due to a virucidal effect. Preliminary thin layer chromatography revealed the presence of caffeic acid in melissa preparations but at levels that seemed far too low to account for the antiviral effect.