Essential oils derived from plant extracts are precious gift by nature. These essential oils are odorous and volatile in nature and have tendency to undergo evaporation when exposed to the air. Essential oils have multiple active components which make them biologically active against several microorganism and fungi such as: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, and antifungal activity against phytopathogenic strains such as Alternaria sp, Pencillium expansum, Rhizopus stolonifer, Botrytis cinereasuch. These essential oils possess potential antioxidant properties that are highly required for human health against several diseases. The evaluation and assessment of the antioxidant and antibacterial activity performance of essential oils are highly recommended, because many commonly and traditional used “tests” are inappropriate to establishment of active principle. The future research based on isolation of compounds and their mechanism will ex...

Essential oils and ethanolic extracts of lemongrass (Cymbopgon citratus), thyme (Thymus vulgaris) and marjoram (Origanum marjorana ) were screened for their possible antioxidant and antimicrobial properties as well as their chemical compositions. According to gas chromatography (GC/ MS) were identified, 39, 16 and 54 compounds of essential oils lemongrass, thyme and marjoram, respectively. The major constituents were 9-cisretinal , δ-2-carene and isomethyl-α-ionol for lemongrass; carvacrol, 2,5-dihydroxybenzoic acid and α –pinene for thyme and 9-cis-retinal, t-butylhydroquinone and p-mentha-3,8-diene for marjoram. The major phenolic and flavonoid compounds of ethanolic extracts identified using HPLC were benzoic , coumarin , hisperidin and hispertins for lemongrass; salicylic ,ellagic , hisperidin and rosmarinic for thyme and benzoic, pyrogalol, , hisperidin and narerigin for marjoram. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. Results showed the superior of ethanolic extracts (low IC50) at lower concentrations than essential oils for scavenged DPPH. The antimicrobial activity (by disc diffusion tests) of different plant essential oils and extracts against 11 strains of microorganisms was done. The essential oils of the tested plants have a stronger antimicrobial activity than those of ethanolic extracts which did not exhibit antimicrobial activity against some microbial strains.

Plant's natural extracts such as Essential Oil, are being increasingly used as preservatives as well as in many human used products. The antimicrobial and antioxidant properties are essential for the use of such products, and therefore, their comparison with synthesized preservatives is the basis to replace the latter and for better biological activities with safer sources. The present study determined the antioxidant and antimicrobial activities of hydrodistilled EO from sixteen aromatic plants grown in Yemen. Antioxidant activity was examined by two methods: reducing power assay (RPA) and determination of antioxidant activity with thiobarbituric acid reactive substances (TBARS). Thus, on the bases of the lowest concentrations used in both methods, the antioxidant activities of the EOs according to TBARS can be sorted in the following descending order: Thymus laevigatus ˃ Clove Eugenia caryophyllus ˃ Cinnamomum zylanicum ˃ Chenopodium Ambrosioides = Eucalyptus camaldulensis = Marjoram majorana hortensis = Schinus molle ˃ Pulicaria jaubertii = Ocimum basillicum ˃ Artemisia abrotanum ˃ Conyza incana (vahl) willd ˃ Coriandrum sativum ˃ Tagetes minuta ˃ Rosmarinus officinalis ˃ Lantana camara ˃ Peppermint mentha piperita. On the other hand these activities as obtained by RPA can be arranged as follows: Clove eugenia caryophyllus ˃ Ocimum basillicum ˃ Thymus laevigatus˃ Artemisia abrotanum > Tagetes minuta ˃ Eucalyptus camaldulensis = Marjoram majorana hortensis = Cinnamomum zylanicum = Schinus molle ˃ Coriandrum sativum = Conyza incana (vahl) willd = Lantana camara ˃ Chenopodium Ambrosioides = Pulicaria jaubertii ˃ Peppermint mentha piperita = Rosmarinus officinalis .The obtained EOs were screened against both gram-negative bacteria, gram-positive bacteria, and against three fungal species (Aspergillus flavus, Fusarium oxyporium, and Candida albicans). Most of these EOs have shown important antibacterial and antifungal effects against the tested strains. Some of the obtained EOs are promising as sources of natural antioxidants and antimicrobial agents in cosmetics and pharmaceutical applications.

The antimicrobial and antioxidant activities of extracted essential oils in some aromatic plants were determined. Phytochemical screening was conducted using standard qualitative techniques, while the essential oils was extracted from the Citrus limon linn leaf, Vitex trifolia seed and Cananga odorata by modified steam distillation apparatus. Furthermor, the plant materials were tested using Antioxidant activity and Antimicrobial activity test. Citrus limon linn produced large volume essential oil (1.4 ml), Vitex trifola (0.7 ml) and Cananga odorata (0.5 ml) after 3hours of steam distillation. Antioxidant activities test using DPPH method reveals that all the essential oil determined showed positive effect, but the oil extracted from Citrus limon linn leaf could be a better antioxidant than that of Vitex tifolia and Cananga odorat when compared to commercial Ascorbic acid. The antioxidant activities of the essential oils of different plants under investigation showed a variation which may be as a result of the difference in their chemical compositions. Antimicrobial activities showed that all the essential oils were inhibited on the entire five microorganisms being used. However, Citrus limonlinn showed highest inhibition on the organisms (E. coli, S. typhi C. Kleb, P. avengunosa and S. aureus) compared to Cananga odorata and Vitex trifolia.

The essential oil of flowers (FLCO) and leaves (LLCO) of Lantana camara species growing in Egypt were obtained by hydrodistillation, and analyzed by GC/MS. Twenty six constituents were detected in the FLCO representing 95.33% of the total oil, and eighteen in the LLCO representing 95.56% of the total oil. The main constituents were: davanone (28.59%), z-caryophillene (11.21%), a-curecumene (10.26%), b-copaene and humulene (12.29%) in FLCO, and Davanone (%23.37), E-caryophillene (22.96%) and humulene (14.32%) in LLCO. Both oils exhibited in vitro antimicrobial activity against Bacillus cereus and Bacillus subtillus. Bioautography on thin-layer chromatography plates demonstrated antimicrobial of the FLCO and LLCO with an Rf values of 0.30 and 0.55. A total of 7 compounds, 3 sesquiterpenoids (humulene, davanone and caryophellen) were detected and identified using gas chromatography–mass spectrometry analysis. However, transmission electron microscopy micrographs of tested B. cereus spores confirmed the effects of these oils on morphological and ultra-structural alterations in the treated spores. Moreover, the oils showed moderate antioxidant activity and this effect was increased by increasing their concentrations. The significant antimicrobial and antioxidant activities of both oils suggest that it could serve in medical purposes, food and perfumery industries.

In this research, essential oils (EOs) were extracted through steaming from aerial parts of three plants: basil (Ocinum basilicum L.), peppermint (Mentha piperita L.) and oregano (Origanum vulgare L.) form Sibiu County, Romania. The GC-MS analysis indicated that eugenol and apiol were the major compounds in the basil EO. Timol, ɣ-terpinene, and p-cymene were the major compounds in the volatile oil extracted from oregano and menthol and methone the main components in the peppermint EO. In the first 48 h of analysis, basil EO inhibition action was the highest against Salmonella anatum (48%), followed by Aspergillus niger (26%), Bacillus cereus (21%) and Saccharomyces cerevisiae (15%); this action was maintained for 120 h for all samples. In the first 48 h, the peppermint EO showed the highest inhibition rate (50%) on B. cereus, followed by A. niger (45%), S. cerevisiae (20%) and no action against Salmonella; this action varied after 72h and 120 h by slightly increasing in case of B. c...