Antiviral activities of Artemisia princeps var. orientalis essential oil and its α-thujone against norovirus surrogates.

Artemisia princeps var. orientalis is a well-known medicinal food, which has been used for the treatment of several diseases including bacterial infection. We examined the antiviral effects of the essential oil from A. princeps var. orientalis and its compounds, borneol, α-thujone and camphor, against murine norovirus-1 (MNV-1) and feline calicivirus-F9 (FCV-F9). The time-of-addition plaque assays were used to determine the ability of essential oil to interfere with viral infection. The maximum activities, following the pretreatment of FCV-F9 and MNV-1, reached 48% inhibition on FCV-F9 and 64% inhibition on MNV-1 at 0.1 and 0.01% of the essential oil, respectively. Neither borneol nor camphor exhibited an antiviral activity, whereas α-thujone, a major compound of the essential oil, showed strong inhibition on FCV-F9 and MNV-1.