Inhibitory activity of Melissa officinalis L. extract on Herpes simples virus type 2 replication

Melissa officinalis L. (Lamiaceae) is used in folk medicine for nervous complaints, lower abdominal disorders and, more recently, for treating Herpes simplex lesions. In this work the antiviral activity of a hydroalcoholic extract of lemon balm leaves against the Herpes simplex virus type 2 (HSV-2) was assessed. Lemon balm showed to reduce the cytopathic effect of HSV-2 on Vero cells, in the range of non-toxic concentrations of 0.025-1 mg mL(-1) (with reference to the starting crude herbal material). Our experiments support the use of lemon balm for treating Herpes simplex lesions and encourage clinical trials on this medicinal plant.