Evaluation of Antiphytoviral and Antibacterial Activity of Essential Oil and Hydrosol Extracts from Five <i>Veronica</i> 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 <i>Veronica</i> 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 <i>V. chamaedrys</i> EO-MAE extract, <i>V. arvensis</i> EO from both extractions and <i>V. montana, V. serpyllifolia</i>, and <i>V. persica</i> EO-HD extracts were more effective in inhibiting TMV infection. Furthermore, HY- HD extracts of <i>V. arvensis</i>, <i>V. chamaedrys</i> and <i>V. persica</i> showed significant antiphytoviral activity. HY fractions had no effect on bacterial growth, regardless of the <i>Veronica</i> 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, <i>V. chamaedrys</i> EO-MAE fraction, showed significantly better activity against <i>Listeria monocytogenes</i> and <i>Enterococcus faecalis</i>. Also, the EO-HD fraction of <i>V. arvensis</i> showed slightly better antibacterial activity. By combining extracts and using different extraction methods, valuable bioproducts can be obtained from the investigated <i>Veronica</i> species for safe use in agricultural production and food conservation.