Antiviral activity of some aromatic and medicinal plants against RNA virus: preliminary study

Plant products provide alternative and successful source of lead compounds for pharmaceutical industry. The present study was aimed to evaluate, in cell-based assays, the antiviral properties of various kinds of essential oils obtained from plants that commonly grow in Sardinia, against a broad spectrum of RNA viruses. Essential oils of Helichrisum italicum ssp. microphyllum, Laurus nobilis L., Mirtus communis L., Pistacia lentiscus L., Rosmarinus officinalis L., Salvia officinalis L. and Satureja thymbra L., were extracted by hydrodistillation and analysed by GC-MS. Interestingly, the essential oil of Salvia officinalis showed moderate activity (EC50 of 54 µM) against bovine viral diarrhoea virus (BVDV), an enveloped RNA virus belonging to the Flaviviridae family that has often been used as a surrogate model for the hepatitis C virus. BVDV is responsible for several clinical manifestations in bovines, including respiratory, gastroenteric and reproductive diseases. With the aim to individuate the compounds responsible of the biological activity under examination, the major components of the oil, camphene, -pinene, limonene, 1,8-cineole, cis-thujone, camphor, (E)-caryophyllene and -humulene were tested. -Humulene resulted active against BVDV as essential oil, with fair EC50 of 40 µM.