Screening of Nepalese medicinal plants for antiviral activity.

In an ethnopharmacological screening, plants used in Nepalese traditional medicine were evaluated for antiviral activity. Methanolic and methanolic-aqueous extracts derived of 23 species were assayed in two in vitro viral systems, influenza virus/MDCK cells and herpes simplex virus/Vero cells. Two species, Bergenia ligulata and Nerium indicum showed the highest antiinfluenzaviral activity with 50% inhibitory dose of 10 microg/ml. Holoptelia integrifolia and N. indicum exhibited considerable antiviral activity against herpes simplex virus. None of these extracts showed cytotoxic effects. Additionally for B. ligulata and H. integrifolia partial protease inhibitory activity was estimated.