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

Abstract

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.

Keywords: Artemisia princeps var. orientalis; Essential oil; Feline calicivirus; Murine norovirus; α-Thujone.

Fig. 1

Inhibitory effects of Artemisia princeps var. orientalis essential oil on (A) FCV-F9 and (B) MNV-1. The essential oil was added at different time points during virus infection. The reduction of relative plaque formation (%) was evaluated using plaque assay oil (EO). DMSO and 2TU were used as the untreated control and positive control, respectively. All measurements were analyzed in triplicate. A single asterisk denotes significant decrease of plaque formation (%) relative to untreated control (p < 0.05)

Fig. 2

Antiviral effect of α-thujone from the essential oil against (A) FCV-F9 (B) MNV-1. The effects of α-thujone against FCV-F9 and MNV-1 were evaluated as PFU reduction (log₁₀ PFU/mL) using plaque assay in the pretreatment of virus with α-thujone at concentration from 250 µM to 25 mM. DMSO and 2TU were used as the untreated and positive control, respectively. All measurements were analyzed in triplicate