title: Antiviral effect of aqueous extracts from species of the Lamiaceae family against Herpes simplex virus type 1 and type 2 in vitro.
abstract: Aqueous extracts from species of the Lamiaceae family were examined for their antiviral activity against Herpes simplex virus (HSV). Extracts from lemon balm (Melissa officinalis), peppermint (Mentha x piperita), prunella (Prunella vulgaris), rosemary (Rosmarinus officinalis), sage (Salvia officinalis) and thyme (Thymus vulgaris) were screened. Their inhibitory activity against Herpes simplex virus type 1 (HSV-1), type 2 (HSV-2) and an acyclovir-resistant strain of HSV-1 (ACV (res)) was tested in vitro on RC-37 cells in a plaque reduction assay. The 50% inhibitory concentrations (IC (50)) of the extracts for HSV plaque formation were determined in dose-response studies. All test compounds showed a high antiviral activity against HSV-1, HSV-2 and ACV (res). In order to identify the mode of antiviral action, the extracts were added to the cells or viruses at different stages of infection. Both types of Herpes virus including ACV (res) were considerably neutralized after treatment with the extracts prior to infection. At maximum non-cytotoxic concentrations of the extracts, plaque formation was significantly reduced by > 90% for HSV-1 and HSV-2 and > 85% for ACV (res). In time-response studies over a period of 2 hours, a clearly time-dependent activity was demonstrated. These results indicate that the extracts affect HSV before adsorption, but have no effect on the intracellular virus replication. Therefore, the extracts exert their antiviral effect on free HSV and offer a chance to use them for topical therapeutic application against recurrent HERPES infections.
authors.affiliation: Institute of Pharmacy and Molecular Biotechnology, Department of Biology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Nolkemper
authors.forename: Jürgen
authors.initials: J
authors.lastname: Reichling
authors.forename: Florian C
authors.initials: FC
authors.lastname: Stintzing
authors.forename: Reinhold
authors.initials: R
authors.lastname: Carle
authors.forename: Paul
authors.initials: P
authors.lastname: Schnitzler
mesh_terms: D000998:Antiviral Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006561:Herpes Simplex / Q000188:drug therapy; D018259:Herpesvirus 1, Human / Q000187:drug effects*; D018258:Herpesvirus 2, Human / Q000187:drug effects*; D006801:Humans; D019686:Lamiaceae; D008826:Microbial Sensitivity Tests; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D018515:Plant Leaves
chemical_list: D000998:Antiviral Agents; D010936:Plant Extracts