Antiviral Activities of Artemisia vulgaris L. Extract Against Herpes Simplex Virus

Abstract Herpes simplex virus type 1 (HSV-1) is a double-stranded DNA virus belonging to the α herpesvirus subfamily. It often leads to herpes simplex virus encephalitis (HSE), keratitis, and cold sores. Currently, acyclovir is approved by the FDA for clinical use, but with the use of this drug, HSV-1 resistance frequently becomes increasingly intense and recurrent. Therefore, it is increasingly urgent to explore the anti-HSV-1 mechanism of other nonnucleoside analogs and natural compounds. Artemisia vulgaris L., belonging to the Compositae family, genus Artemisia, is often used as a traditional Chinese medicine as both medicine and food. Its leaves have multiple biological functions, such as anti-inflammatory, antibacterial, insecticidal, antitumor, antiviral, antioxidant and immune regulation functions. We collected and isolated a variety of A. vulgaris L. samples from Tangyin County, Henan Province and then screened the A. vulgaris L. leaf extracts for anti-HSV-1 activity. The results of the plaque reduction test showed that the crude extract of A. vulgaris L.-Fr.8.3 had anti-HSV-1 activity, and we further verified the anti-HSV-1 activity of Fr.8.3 at the DNA, RNA and protein levels. Moreover, we found that Fr.8.3 also had a broad spectrum of antiviral activity. Finally, we explored its anti-HSV-1 mechanism, and the results showed that Fr.8.3 exerted an anti-HSV-1 effect by acting directly on the virus itself. Then, the extracts were screened on HSV-1 surface glycoproteins and host cell surface receptors for potential binding ability by molecular docking, which further verified the phenotypic results. LC-MS analysis showed that 1 and 2 were the two main components of the extracts. Docking analysis suggested that compounds from extract 1 might similarly cover the binding domain between the virus and the host cells, thus interfering with virus adhesion to cell receptors, which provides new ideas and insights for clinical drug development for herpes simplex virus type 1.