Antiviral effect of Hornstedtia bella Škorničk essential oil from the whole plant against vaccinia virus (VV)

Abstract

In the prevention of epidemic and pandemic emerging and neglected viral infections, natural products are an important source of lead compounds. Hornstedtia bella Škorničkis is a rhizomatous herb growing in the forest of central Vietnam. Hornstedtia bella essential oil (Hb EO) was recently characterised by our group as endowed of antimicrobial activity against Staphylococcus aureus Methicillin-Resistant strains. Here, we describe for the first time the evaluation of Hb EO against a spectrum of viruses responsible for important human diseases. Hb EO resulted active against Vaccinia virus (VV) (EC₅₀ values 80 μg/mL), closely related to variola virus, causative agent of smallpox. Hb EO was able to strongly reduce the viral VV titer in cell-based assay at not cytotoxic concentration and its potential mode of action was characterised by virucidal activity evaluation followed by time-of-addition assay. Furthermore, Hb EO antiviral activity was implemented in a combination study with the mycophenolic acid.

Keywords:

• Viral infections
• antiviral activity
• essential oil
• time of addition
• vaccinia virus
• combinations studies

Acknowledgement

The data used to support the findings of this study are available from the corresponding author upon request. This research was financially supported by the Italian Ministry for University and Research (MIUR) Grant PRIN 2017 Prot. 2017M8R7N9.

Disclosure statement

The authors declare that they have no conflicts of interest.

Funding

This research received no external funding.

Author contributions

Conceptualization, D.U., P.C., G.S., and M.G.D.; Data curation, G.S., G.Se., S.M.; Formal analysis, G.S, D.U., H.T.N. and M.G.D.; Funding acquisition, P.C., S.Z. and M.G.D.; Investigation, S.M, G. Se., G.S, N.T.L.; Methodology, G.Se, G.S., S.M. Project administration, P.C., S.Z., H.T.N. and M.G.D.; Resources, P.C., S.Z. and M.G.D.; Software, G.S., S.M., G.Se.; Supervision, G.S., P.C., S.Z. and M.G.D.; Validation, P.C., S.Z.; Visualization, D.U., G.S., A.C., P.C., S.Z. and M.G.D.; Writing – original draft, G.S., S.M., G.Se. and M.G.D.; Writing – review & editing, G.S.