Monica Negrea

Synergistic Antifungal, Allelopatic and Anti-Proliferative Potential of Salvia officinalis L., and Thymus vulgaris L. Essential Oils

The current study aimed to investigate the chemical composition and the synergistic potential of two essential oils (EOs), as obtained from Salvia officinalis L. (SEO), and Thymus vulgaris L. (TEO). The antifungal potential was tested in vitro against Fusarium graminearum (Fg 06_17), the herbicidal effect was studied using weed seeds of Amaranthus retroflexus (ARET), Chenopodium album (CALB), Echinochloa crus-galli (EGAL), but also wheat seeds (WS) of the Lovrin variety and tomato seeds Saint-Pierre of the variety. The GC-MS profile highlights that the mains compounds identified in SEO were: caryophyllene (25.364%), camphene (14.139%), eucalyptol (13.902%), and β-pinene (11.230%), while in TEO, the predominant phytochemicals were: γ-terpinene (68.415%) and p-thymol (24.721%). The results indicated that the tested EOs alone as well as in combination have allelopathic effect against investigated seeds, while the synergistic effect of TEO and SEO in terms of fungal growth was demonstrated at a level of 0.06%. Thyme and sage EOs exhibited in vitro anti-proliferative activity on two melanoma cell lines, namely A375 human melanoma and B164A5 mouse melanoma alone, as well as in combination. SEO was most effective in terms of decreasing the cell viability of murine and human melanoma cell lines when compared to TEO.

Chemical Composition and Antimicrobial Potential of Satureja hortensis L. in Fresh Cow Cheese

This study presents data about the chemical composition and antimicrobial effect of Satureja hortensis L. used as both dry plant and essential oil, on fresh cow’s cheese, in order to extend its shelf-life. The proximate and elemental composition of dry plant of Satureja hortensis L. highlights important level of microelements. The content of microelements increases even when small amounts of Satureja hortensis in fresh cheese were added. The addition of Satureja hortensis dry plant leads to an increase in Fe (13.46–65.54%) and Mn (8.33–88.33%) content of fresh cheese, depending on the amount of plant added. The composition of essential oil isolated from Satureja hortensis L. was analyzed by GC-MS and the main compounds found were carvacrol (19.68%), o-cymene (30.86%), and p-cymene (28.07%). In order to use Satureja hortensis L. as natural preservative in food industry, in vitro effect of plant extract and essential oil against Staphylococcus aureus Gram-positive bacteria was tested. The oil of Satureja hortensis L. showed antimicrobial activity at 0.50–1.5%, while the alcoholic extract does not inhibit Staphylococcus aureus mycelial growth. The antimicrobial effect of Satureja hortensis L. dry plant in various proportions (0.5–1.5%) and essential oil (0.1%; 0.25%; 0.5%), on fresh cow’s cheese, was assessed after 3 and 7 days by counting colonies obtained at 30°C. Results have shown that the addition of Satureja hortensis L. dry plant and essential oil led to a reduction in the total number of germs, this reduction being more significant when the essential oil was used. Regarding the effect of Satureja hortensis L. essential oil against Staphylococcus aureus inoculated in fresh cow’s cheese, the results highlight that the essential oil of Satureja hortensis L. may be a natural solution to prevent the development of this bacteria, while the ethanol extract does not prove to be effective.