Melissa officinalis extract inhibits attachment of herpes simplex virus in vitro.
Authors: Astani A, Reichling J, Schnitzler P
BACKGROUND: Extracts and essential oils of medicinal plants are
increasingly of interest as novel drugs for antiherpetic agents, since
the herpes simplex virus (HSV) might develop resistance to commonly used
METHODS: An aqueous extract of Melissa officinalis as well as
phenolic extract compounds, i.e. caffeic acid, p-coumaric acid and
rosmarinic acid were examined for their antiviral activity against
herpes simplex virus type 1 (HSV-1) in vitro.
RESULTS: When drugs were added to HSV-1-infected cells, no
antiviral effect was observed as determined by plaque reduction assay
and analysis of expression of viral protein ICP0. However, the Melissa
extract demonstrated a high virucidal activity against HSV-1, even at
very low concentrations of 1.5 μg/ml, whereas similar results for
phenolic compounds were only achieved at 100 times higher
concentrations. Besides the virucidal activity, the Melissa extract and
rosmarinic acid inhibited HSV-1 attachment to host cells in a
dose-dependent manner. These results indicate that rosmarinic acid was
the main contributor to the antiviral activity of Melissa extract.
However, the selectivity index of Melissa extract of 875 against HSV is
superior to the selectivity indices of single constituents.
CONCLUSION: Melissa extract exhibits low toxicity, is virucidal and affects HSV-1 attachment to host cells in vitro.
PMID: 22377592 [PubMed - indexed for MEDLINE]