Antiviral Substances in Plants of the Mint Family (Labiatae). III. Peppermint (Mentha piperita) and other Mint Plants.

Abstract

SummaryExtracts of various plants of the mint family (Labiatae) were studied for antiviral activity. Peppermint Mentha piperita extract had antiviral activity against Newcastle disease (NDV), herpes simplex, vaccinia, Semliki Forest, and West Nile viruses in egg and cell-culture systems. It contains a tannin with an affinity for NDV and mumps virus and a nontannin fraction with antiviral effects against herpes simplex virus. Aqueous extracts of sage (Salvia cyprea), marjoram (Origanum majorana), wild thyme (Thymus serpyllum), American pennyroyal (Hedeoma pulegioides), Crea monda (Satureia sp.) and Spanish and French thymes (Thymus sp.) all exhibited some antiviral effects against NDV. The first 6 also exhibited some antiviral effects against herpes simplex. Hyssop (Hyssopus officinalis) extracts had activity against herpes simplex virus while rosemary (Rosmarinus officinalis), horehound (Marrubiutn vulgare), and catnip (Nepeta cataria) extracts were not detectably antiviral. None of these plant extracts produced an antiviral effect superior to that of melissa (Melissa officinalis) extracts. The data suggest the existence of some biochemical relationships among plants of the mint family, especially the presence of a common tannin.