Evaluation of Antiphytoviral and Antibacterial Activity of Essential Oil and Hydrosol Extracts from Five Veronica Species

Agricultural production without pollution is possible using bioactive plant compounds, which include essential oils as important substances of plant origin. The aim of this study was to evaluate the antiphytoviral and antibacterial potentials of lipid (essential oil, EO) and water (hydrosol, HY) extracts from five Veronica species (Plantaginaceae) obtained by Clevenger hydrodistillation (HD) and microwave-assisted extraction (MAE), with analysis by gas chromatography coupled with mass spectrometry. The antiphytoviral activities of both extracts were tested on local host plants infected with tobacco mosaic virus (TMV). The antibacterial potential was tested against ten strains of opportunistic pathogens using the broth microdilution test. Species V. chamaedrys EO-MAE extract, V. arvensis EO from both extractions and V. montana, V. serpyllifolia, and V. persica EO-HD extracts were more effective in inhibiting TMV infection. Furthermore, HY- HD extracts of V. arvensis, V. chamaedrys and V. persica showed significant antiphytoviral activity. HY fractions had no effect on bacterial growth, regardless of the Veronica species tested, likely due to the fact that the maximum concentrations of the HY fractions tested in this study were low (1.83 and 2.91 mg/mL). EOs showed significant antibacterial activity independent of the extraction method. Notably, V. chamaedrys EO-MAE fraction, showed significantly better activity against Listeria monocytogenes and Enterococcus faecalis. Also, the EO-HD fraction of V. arvensis showed slightly better antibacterial activity. By combining extracts and using different extraction methods, valuable bioproducts can be obtained from the investigated Veronica species for safe use in agricultural production and food conservation.