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The present study describes antimicrobial and free radical scavenging capacity (RSC) together with the effects on lipid peroxidation (LP) of Melissa officinalis essential oil. The chemical profile of essential oil was evaluated by the means of gas chromatography-mass spectrometry (GC-MS) and thin-layer chromatography (TLC). RSC was assessed measuring the scavenging activity of essential oil on the 2,2-diphenyl-1-picrylhydrazyl (DPPH(*)) and OH(*) radicals. The effect on LP was evaluated following the activities on Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. The antimicrobial activity was tested against 13 bacterial strains and six fungi. The examined essential oil exhibited very strong RSC, reducing the DPPH radical formation (IC(50) = 7.58 microg/mL) and OH radical generation (IC(50) = 1.74 microg/mL) in a dose-dependent manner. According to the GC-MS and TLC (dot-blot techniques), the most powerful scavenging compounds were monoterpene aldehydes and ketones (neral/geranial, citronellal, isomenthone, and menthone) and mono- and sesquiterpene hydrocarbons (E-caryophyllene). Very strong inhibition of LP, particularly in the Fe(2+)/H(2)O(2) system of induction (94.59% for 2.13 microg/mL), was observed in both cases, also in a dose-dependent manner. The most effective antibacterial activity was expressed on a multiresistant strain of Shigella sonei. A significant rate of antifungal activity was exhibited on Trichophyton species.

The potential antifungal effects of Thymus vulgaris L., Thymus tosevii L., Mentha spicata L., and Mentha piperita L. (Labiatae) essential oils and their components against 17 micromycetal food poisoning, plant, animal and human pathogens are presented. The essential oils were obtained by hydrodestillation of dried plant material. Their composition was determined by GC-MS. Identification of individual constituents was made by comparison with analytical standards, and by computer matching mass spectral data with those of the Wiley/NBS Library of Mass Spectra. MIC’s and MFC’s of the oils and their components were determined by dilution assays. Thymol (48.9%) and p-cymene (19.0%) were the main components of T. vulgaris, while carvacrol (12.8%), α-terpinyl acetate (12.3%), cis-myrtanol (11.2%) and thymol (10.4%) were dominant in T. tosevii. Both Thymus species showed very strong antifungal activities. In M. piperita oil menthol (37.4%), menthyl acetate (17.4%) and menthone (12.7%) were the main components, whereas those of M. spicata oil were carvone (69.5%) and menthone (21.9%). Mentha sp. showed strong antifungal activities, however lower than Thymus sp. The commercial fungicide, bifonazole, used as a control, had much lower antifungal activity than the oils and components investigated. It is concluded that essential oils of Thymus and Mentha species possess great antifungal potential and could be used as natural preservatives and fungicides.

Essential oils of Matricaria chamommilla, Mentha piperita, M. spicata, Lavandula angusti folia, Ocimum basilicum, Thymus vulgaris, Origanum vulgare, Salvia officinalis, Citrus limon and C. aurantium and their components; linalyl acetate, linalool, limonene, a-pinene, b-pinene, 1,8-cineole, camphor, carvacrol, thymol and menthol were assayed for inhibitory activity against the three major pathogens of the button mushroom, Agaricus bisporus, i.e. the fungi Verticillium fungicola and Trichoderma harzianum and the bacterium Pseudomonas tolaasii. The highest and broadest activity was shown by the Origanum vulgare oil. Carvacrol possessed the highest antifungal activity among the components tested.

Aromatic plant species of genus Thymus are important medicinal plants, highly recommended due to a range of therapeutic properties of their essential oil (thyme oil): antirheumatic, antiseptic, antispasmodic, antimicrobial, cardiac, carminative, diuretic and expectorant. Oil is also beneficial in boosting the immune system, and helps to fight colds, flu, infectious diseases and chills. It is proved to be a urinary antiseptic, being very helpful for cystitis and urethritis. Scientific validation of traditional uses, and phytochemical and bioactivity evaluation of essential oils from Thymus serpyllum, Thymus algeriensis and Thymus vulgaris was performed. GC/MS analysis revealed thymol as major component of T. algeriensis, T. vulgaris and T.serpyllum, with a contribution of 56.02%, 48.92% and 38.50%, respectively. The three essential oils (EOs) exhibited a significant antimicrobial activity against all the tested strains, T. serpyllum oil being the most potent (MIC 2.5-5 µg/mL, MBC 5-10 µg/mL; MIC 1-2 µg/mL, MFC 2-4 µg/mL). In addition, T. serpyllum oil revealed the highest antioxidant activity in all the assays and was also the most effective one against all the tested cell lines, presenting GI 50 values of 7.02-52.69 µg/mL. Moreover, the EOs did not show any toxicity, at the tested concentrations (<400 µg/mL), for porcine liver primary cell culture. In addition to their traditional use in food and cosmetics, the great potential of the tested Thymus essential oils for application in oral disease and anticancer treatments, encourage further investigation.

Our findings alone, along with the potential use of phenolic compounds that are widespread in nature, may imply their potential use as preservatives in the food industry.

The whole, fresh involucral bracts of cardoon, Cynara cardunculus L. (Compositae), were extracted with EtOH and aqueous suspension of obtained EtOH extract was partitioned successively with CHCl 3 , EtOAc and n-BuOH, leaving residual water extract. All obtained extracts were evaluated on their antioxidant and antimicrobial properties. The antioxidant potential was evaluated using following in vitro methods: FRAP (Ferric Reducing Antioxidant Power) assay, and scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Antimicrobial activity was estimated using microdilution technique against food-borne, mycotoxin producers and human pathogenic bacteria and micromycetes. Following bacteria were tested: Salmonella typhimurium, Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, as well as micromycetes: Aspergillus niger, Aspergillus ochraceus, Aspergillus flavus, Penicillium ochrochloron, Penicillium funiculosum, Trichoderma viride, Fusarium tricinctum and Alternaria alternata. Results showed that all extracts possess concentration dependent antioxidant activity. In biological assays, C. cardunculus extracts showed antimicrobial activity comparable with standard antibiotics.

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