Antibacterial Activity Of Essential Oils Research Articles

Chemical Composition, Antioxidant and Antibacterial Activities of Essential Oil and Phytochemical Screening of Extracts of Aerial Parts of Thymus atlanticus

Thymus plants has been used for several beneficial health properties including antioxidant and antibacterial activities. The aim of this study was to determine the chemical composition, antioxidant and antibacterial potential in vitro of aerial part of Thymus atlanticus essential oil and phytochemical screening of the extracts. Results showed that carvacrol was the major component of the essential oil (85.13%). Phytochemical screening of the extracts showed that gallic tannins, flavonols, triterpenes, sterols and mucilage are present on high amount. Antioxidant activity (IC50), total phenolic and total flavonoid content of the extract obtained by soxhlet method and using hydromethanolic solvent recorded the highest values (0.029 mg/mL, 5.92 mg GAE/g and 0.86 mg QE/g respectively) compared to other extracts. The IC50 of the essential oil was equal to 0.990 µg/mL and therefore has exhibited an antioxidant power higher than the extracts. The essential oil of Thymus atlanticus showed a strong antimicrobial activity against Escherichia coli compared to the fifteen pathogenic bacteria with an average inhibition zone of 32±1.0 mm and minimum inhibitory concentration of 0.3 µL/ mL. These findings indicate that Thymus atlanticus essential oil and extracts could be a source of potential antioxidant and antibacterial natural compound.

Evaluation of Antibacterial Activity of Essential Oils of Melaleuca cajuputi Powell

Melaleuca cajuputi Powell is a tree species belonging to the family Myrtaceae and is widely used in traditional medicine. This study was conducted to investigate the antibacterial activities of essential oils of M. cajuputi Powell. Antibacterial activity was tested against Gram positive and Gram negative bacteria using the agar disc diffusion method. The essential oils of M. cajuputi were found to exert antibacterial activity against all of the tested bacteria, including Staphylococcus aureus, Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Escherichia coli. The zones of inhibition for S. aureus, S. pyogenes, MRSA, E. coli, and K. pneumoniae were 12.7 mm, 10.7 mm, 10.0 mm, 8.7 mm and 9.3 mm respectively, against 0.714% (w/w) of the essential oils. These results highlighted that Gram negative bacteria are less susceptible to the essential oils of M. cajuputi. A large zone of inhibition might be a sign of a leaching antimicrobial agent. These findings suggest that M. cajuputi is a potential natural antibacterial agent.

Antibacterial activity of essential oils from Brazilian plants and their major constituents against foodborne pathogens and spoilage bacteria

ABSTRACT This study aimed at determining antibacterial activities of three essential oils (EOs) and their major constituents against foodborne pathogenic bacteria and food spoilage ones. The EOs were tested by the broth microdilution method on 96-well microplates, followed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) (µg/mL) determination. EOs from Psidium cattleianum Sabine, Cryptocarya aschersoniana Mez. and Ocotea dispersa Nees (Mez.) leaves showed strong antibacterial activity since their MIC and MBC values ranged between 20 and 250 µg/mL. Good activity of EOs under analysis can be mostly attributed to high concentrations of viridiflorol, limonene and α-eudesmol. EOs were analysed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). The three major commercial terpenes (viridiflorol, limonene and α-eudesmol) were evaluated individually and revealed MIC and MBC values between 20 and 62.5 µg/mL. The findings may serve as an important natural alternative to prevent bacterial growth in food products.

Antibacterial activity of essential oils and hydrosols extracted from some Moroccan Mentha species (L.)

Hydrosols (HYDs) have attracted a great interest this last decade by the scientific community. Although, studies about HYDs remain limited compared to those dealt with essential oils (EOs). These magic waters have found a huge interest in the cosmetic, food and phytotherapeutic industries. Their biological activities have not yet been assessed. The aim of this present work was to evaluate the antibacterial activity of three HYDs and to compare this activity to that of EOs from Mentha species facing some bacteria strains that caused various human diseases and infections. M. pulegium, M. suaveolens and M. spicata were collected from Azrou (Moroccan Middle-Atlas). Their EOs and HYDs were tested on six bacteria strains: S. aureus, E. coli BLSE, E. coli (wild-type), Ps. aeruginosa, Ps. putida, and P. mirabilis, using the micro-dilution and agar diffusion methods. The chemical compositions of three HYDs were different from the EOs; they were rich in hydrophilic and oxygenated compounds and lack in hydrocarbon constituents. The qualitative evaluation of the antimicrobial activity showed strong power for all the tested EOs by highlighting zones of inhibition with diameters exceeding 20 mm, thus showing significant sensitivity of the treated bacteria. These results were confirmed by quantifying this activity by MIC and MBC values, thus demonstrating their antibacterial power. As for HYDs, they have also shown their inhibitory efficacy against certain strains. Consequently, these promising results could serve as a basis to confirm the efficacy of these natural products and their ability to serve as alternative antimicrobial agents. Keywords: Mentha, Essential oil, Hydrosol, Bacteria, Antibacterial activity.

Antibacterial activity of Myrtus communis L. and Melaleuca leucadendron var. cajaputi essential oils against antibiotic-resistant bacterial strains

Background: Antimicrobial resistance (AMR) is a global threat to public health. There is a dire need for new antibiotics as AMR threatens our last-resort antibiotics efficacy.1,2 Myrtle plants have been used in folk medicine for centuries. Essential oils from these plants demonstrated therapeutics effects. This study aims to examine the antibacterial activity of essential oils extracted from Myrtus communis L and Melaleuca leucadendron against clinically relevant bacterial pathogens.3Methods: Bacterial growth curves and bactericidal assays were performed on antibiotic-sensitive Staphylococcus aureus (SA) and antibiotic low and high resistant Methicillin-resistant Staphylococcus aureus (MRSA) strains; sensitive and resistant Klebsiella pneumoniae strains (KPS and KPR). Minimum bactericidal concentration (MBC) was performed on 4 strains of colistin sensitive E. coli and 4 colistin resistant E. coli strains. Results: Myrtle essential oils demonstrated a dose-dependent antibacterial activity against all tested strains and inhibited growth even after 24 hours. The tested oils dilutions ranged from 6.15 μl/ml up to 50 μl/ml and inhibited bacterial growth of both antibiotic sensitive and resistant strains of SA, MRSA (Figure 1), and Klebsiella. Further, the incubation of colistin sensitive and colistin-resistant E. coli strains with 50 μl/ml of Myrtle oil for one hour inhibited the growth of all tested strains. The viability of bacteria was tested by spotting on agar plates and further incubation overnight. The data suggest that Myrtle essential oils can effectively kill bacterial pathogens. Conclusion: Essential oils from Myrtus communis L. and Melaleuca leucadendron var. cajaputi possess potent antibacterial activity against antibiotic sensitive and resistant bacterial pathogens. There is a potential for utilizing these antibacterial oils as topical treatment of wound infections.

Chemical Composition and Antibacterial Activity of Essential Oil Derived from the Leaves of Argania spinosa (L.) Grown in Northwestern Algeria

The objective of this study was to analyse the chemical composition and antibacterial activity of essential oils derived from the leaves of A. spinosa (ASEO), found in the Stidia region on the western coast of northern Algeria. Among the 36 terpenic compounds identified, cubenol (31.02%) and 1,10-di-epi-cubenol (22.50%) were the most abundant, followed by camphor (8.22%), viridiflorol (7.10%), linalool (5.60%), and eucalyptol (5.40%). To the best knowledge of the authors, this is the first study to identify cubenol and 1,10-di-epi-cubenol as the major constituents of A. spinosa-derived essential oil, with oxygenated sesquiterpenes (63.60%) forming the main class of compounds. The antibacterial properties of ASEO were evaluated using the broth microdilution method to determine minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) against eight bacterial species and the results were compared to those Cefuroxime. The highest antimicrobial activity was recorded against Gram-positive bacteria with MICs ranging from 7.81 mg/mL to 15.62 mg/mL; additionally, the Gram-negative bacteria, except Pasteurella multocida and Klebsiella pneumoniae (7.81 mg/mL), were the most resistant with MICs of 31.24 mg/mL. The MBC/MIC ratio values for all bacterial strains indicated a bactericidal property of ASEO. Thus, ASEO could have potential applications in pharmaceutical and cosmetic industry.

Compositional characteristics and antibacterial activity of essential oils in citrus hybrid peels

Satsuma mandarin (Citrus unshiu Marc.), Hallabong [(C. unshiu Marc. × C. sinensis Osb.)×(C. reticulata Blanco)], Cheonhyehyang [((C. unshiu×C. sinensis)×C. reticulata)×(C. reticulate×C. sinensis)], and Redhyang (citrus hybrid 'Kanpei), which are citrus hybrids, are mostly consumed in Korea. The flavor of citrus peel depends on the composition and content of volatile essential oils. Limonene, γ-terpinene, β-myrcene, linalool, ocimene, octanal, and sabinene were found to be the main components in Satsuma mandarin, Hallabong, Cheonhyehyang, Redhyang, and orange (C. sinensis Osb.) peel essential oils. Limonene was the main component (82.05–91.84%) of all citrus peel essential oils. γ-Terpinene was present in a particularly high content (8.09%) in the essential oil of Satsuma mandarin peel. Linalool was found in the highest proportion (4.39%) in the essential oil of Cheonhyehyang peels. β-Ocymene had the highest concentration (6.50%) in Redhyang peel essential oil. Citrus peel essential oils showed slight antibacterial activity against Salmonella choleraesuis (S. choleraesuis), Bacillus cereus (B. cereus), Listeria monocytogenes (L. monocytogenes), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa). Cheonhyehyang peel essential oil showed the highest antibacterial activity against all foodborne pathogens. Additionally, B. cereus was the most sensitive, and S. aureus was the most resistant to the Cheonhyehyang peel essential oil.

Antibacterial Effect of Essential Oils (Clove Oil, Castor Oil and Ginger Oil) Against Human Pathogenic Bacteria

Essential oils are volatile, natural, complex compounds which are produced as secondary metabolites by plants for their protection against various microorganisms as well as pests. A wide range of plants have been explored for their essential oils in the past few decades. The study was conducted to determine the antibacterial activity of essential oils against human pathogenic bacteria which were gram positive (Staphylococcus aureus and Streptococcus pyogenes) as well as gram negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Shigella sonnei). Five ml of three different oils, i.e. clove oil, castor oil, and ginger oil, were taken in a test tube so that each oil had four different concentrations. Four concentrations of (0, 25, 50 and 75) μL of oils were mixed with 1000, 975, 950 and 925 μL of DMSO respectively to make it a volume of 1ml. It was observed that clove oil was effective against the entire gram positive as well as gram negative bacteria that were used. The inhibition zone was greatest in the case of clove oil at 75 μL against P. aeruginosa (23 mm) and the smallest zone of inhibition was shown by castor oil against K. pneumoniae (12 mm). Other oils were sensitive as well as resistant to the bacteria. Hence, it is found that different oils have shown inhibitory activity towards different pathogens to a variable extent. However, clove oil was inhibitory to all the bacteria in all concentrations. Int. J. Appl. Sci. Biotechnol. Vol 9(4): 250-255

Antioxidant and Antibacterial Activities of the Essential Oils of Synedrella nodiflora, Mikania cordata and Melanthera scandensthree Plants of the Ivorian Flora

Aims: The objective of this work is to contribute to the valorization of medicinal and aromatic plants of the Ivorian flora. We propose to evaluate the antioxidant and antibacterial activities of the essential oil (EO) of three species used in traditional medicine.
 Study Design: Valorization of aromatic and medicinal plants and essential oil.
 Methodology: The antioxidant potential of the extracts was evaluated using the Blois method. The antibacterial activity of the different oils at different concentrations was determined for each bacterial strain, by the technique of macro-dilution in solid medium (diffusion in wells).The minimum inhibitory concentration (MIC) and The Minimum Bactericidal Concentration (MBC) were determined. MBC / MIC ratios were calculated. When this ratio is less than 4, the extract is considered to be bactericidal. When it is 4, the extract is considered bacteriostatic.
 Results: The antioxidant activity has pointed out the poor antioxidant power of the essential oil(EO) extracted. The EC50 values vary from 15 µg/mL to 32 µg/mg. The antibacterial tests have shown that the samples exert an inhibitory effect on Gram (+) bacteria. The diameters of the inhibition zones vary between 14 and 25 mm for the extracts against 35 mm for the gentamycin. The MBC/MIC is 2 for the gentamycin and 4 for all the EO combined versus the resistant S. aureus methicillin. Therefore, the essential oil has shown a bacteriostatic effect on this strain. As far as S. aureus CIP 483 is concerned, the MBC/MIC has given 1 for the gentamycin, 2 for M. scandens. The EO extract of M. scandens has a bactericidal action against this bacteria strain.
 Conclusion: All the essential oils have less antioxidant activity than that of vitamin C.
 The antibacterial activity of EO has given satisfactory results on all Gram (+) bacteria. Melanthera scandens Essential Oil shows antibacterial potential against Staphylococcus aureus CIP 483.

Chemical Composition, Acetylcholine Esterase and Anti-bacterial Activities of Essential Oils of Elaeosilenum thapsioides (Desf.) Maire from Algeria.

Traditionally, the Algerian medicinal plant Elaeosilenum thapsioides (Desf.) Maire has been used for many diseases. The present research work aims to explore the chemical and biological characterization of its essential oil. The essential oils were obtained by hydrodistillation of different Elaeosilenum thapsioides (Apiaceae) aerial parts samples collected from two different regions (Mahouane and Megres) from Setif, Eastern Algeria. The chemical characterization of the obtained essential oils is reported here for the first time. Besides, they were evaluated for their in vitro Acetylcholinesterase (AChE) inhibitory activity involved in Alzheimer's disease using Ellman's spectrophotometric method. Additionally, their in vitro antimicrobial activity was assessed by the disc diffusion method. Both activities were performed at various oil concentrations. The GC/MS analysis of the essential oils from aerial parts (leaves, stems, flowers, and seeds) of E. thapsioides identified 47 constituents. Monoterpene hydrocarbons were the main components, ranging from 72.78 to 99.13%. Oxygenated monoterpenes and oxygenated sesquiterpenes ranged between 1.37 and 17.25% and 0.12 and 3.53% in essential oils from leaves and stems. Sesquiterpene hydrocarbons were present in small to large quantities in the essential oils of both populations, ranging from 0.69 to 13.44%. The presence of m-Methoxybenzyl isothiocyanate was recorded in stems essential oils from Mahouane and leaves essential oils from Merges, which was 9.73% and 3.72%, respectively. The stems essential oils obtained from plants collected in Mahouane showed the highest AChE inhibitory activity. The highest anti-bacterial activity was shown by the essential oil obtained from Megres leaves against Bacillus cereus ATCC 11778. The oils exhibited a moderate inhibitory activity in both tests.

Chemical composition and antibacterial activity of essential oils of Cinnamomum cassia and Syzygium aromaticum plants and their nanoparticles against Erwinia amylovora

This study aimed at evaluating the antibacterial activity of Cinnamomum cassia and Syzygium aromaticum essential oils and their nanoparticles (EOs-NPS) against Erwinia amylovora, the causal agent of fire blight disease. First, EOs of C. cassia and S. aromaticum were obtained by hydrodistillation and analysed using a GC–MS/FID. Results showed that the main components of C. cassia EOs are E-Cinnamaldehyde (73.23%), alpha-Copaene (6.44%), and Eugenol (4.23%) while the EOs of S. aromaticum showed the presence of Eugenol (58.64%), β-Caryophyllene (32.91%), and Humulene (3.25%). C. cassia EOs was the most effective with an inhibition zone of 37.7 mm and a minimum bactericidal concentration (MBC) of 1.04%. However, EOs-NPS of C. cassia had greater effects than S. aromaticum with an MBC of 0.75%, rather than the effect of EOs alone. Significant reduction of the disease incidence (86%) was observed in the in vivo pre-treatment using EOs-NPS of C. cassia. Therefore, C. cassia EOs-NPS is recommended against E. amylovora.

Chemical Characterisation and Biological Effects of Essential Oils of Four Gabonese Medicinal Plants

Aims: The objective of this work is to determine the chemical composition and in vitro evaluation of the antibacterial activities of essential oils of four species of aromatic plants of Gabonese origin obtained by hydrodistillation.
 Methods: All the samples were examined by chromatographic analyzes and by GC / MS coupling. Antimicrobial activity was assessed by diffusion and microdilution methods.
 Results: The most common compounds found in essential oils were terpene hydrocarbons and oxygenates. The major constituents are β-phellandrene (56.3%), β-pinene (11%) and myrcene (10.4%). The three bacterial strains used are sensitive to essential oils. However, some essential oils stood out with greater spectra of action compared to others, such as Maranthes gabunensis and Mammea africana which showed activity against all strains. The inhibition parameters (MIC and CMB) are between 0.78 and 25 mg / mL. Some oils have shown bacteriostatic and / or bactericidal activity on the targeted strains.
 Conclusion: The essential oils studied present a diversity of chemical compositions and good antibacterial activities.

Chemical Composition, Antibacterial Activity using Micro-broth Dilution Method and Antioxidant Activity of Essential Oil and Water Extract from Aerial Part of Tunisian Thymus algeriensis Boiss. & Reut.

In this study, we investigated the chemical composition, antioxidant and antibacterial activities of essential oil and aqueous extract from Thymus algeriensis Boiss. & Reut growing in Tunisia. GC/MS analysis of essential oil from the aerial part of the plant led to identifying 54 constituents representing 96.87 % of the total oil composition. Monoterpenes represented the major components of the essential oil. On the other hand, the aqueous extract and the essential oil were screened for their antioxidant and antibacterial activities. The latter was assessed against Gram-negative and Gram-positive bacterial strains using the broth dilution micro method for the determination of antibacterial activity. The antioxidant activity was evaluated using the DPPH scavenging activity and Ferric Reducing/Antioxidant Power (FRAP) assays. The essential oil was found to be more active in antibacterial screening (MIC = 0.54 μg/mL). Whereas the aqueous extract exhibited the most potent antioxidant activity with (IC50 = 0.04 μg/mL). UHPLC ESI(-)-HRMS/MS analysis of the aqueous extract allowed tentative identification of its constituents and showed that it is rich in phenolic compounds. Luteolin-glucuronide was found to be the most abundant compound followed by Vicenin-2 and Apigenin-diglucuronide.

Antifungal Activity of Essential Oils from Three Artemisia Species against Colletotrichum gloeosporioides of Mango.

Post-harvest diseases of mango reduce fruit quality and cause severe yield losses with completely unmarketable fruits. The most common diseases of mangos are anthracnose (Colletotrichum gloeosporioides). In this study, the antibacterial activities of essential oils from Artemisia scoparia, Artemisia lavandulaefolia, and Artemisia annua against C. gloeosporioides were tested. The results showed that the essential oil of A. scoparia was more effective by the agar diffusion method; the EC50 value was 9.32 µL/mL. The inhibition rate was 100%, at a concentration of 10 μL/mL, through the spore germination method. The morphological changes of the mycelium were observed by scanning electron microscopy (SEM), the mycelia treated with essential oils showed shrinking, deformity, fracture, and dryness through SEM. A. scoparia essential oil was inoculated in vivo and subjected to paroxysm testing under natural conditions. A. scoparia had significantly inhibitory activity, and the inhibition rate was 66.23% in vivo inoculation tests after 10 days. The inhibition rate was 92.06% in the paroxysm test under natural conditions after 15 days. Finally, A. acoparia essential oil was analyzed by gas chromatography-mass spectrometry. The main compounds were 2-ethenyl-Naphthalene (23.5%), 2,4-pentadiynyl-Benzene (11.8%), 1,2-dimethoxy-4-(2-propenyl)-Benzene (10.0%), β-Pinene (8.0%), and 1-methyl-4-(1-methylethyl)-1,4-Cyclohexadiene (6.3%). The results have revealed the potential use of A. scoparia essential oil against post-harvest fungal pathogens C. gloeosporioides.

Artemisia annua Growing Wild in Romania-A Metabolite Profile Approach to Target a Drug Delivery System Based on Magnetite Nanoparticles.

The metabolites profile of a plant is greatly influenced by geographical factors and the ecological environment. Various studies focused on artemisinin and its derivates for their antiparasitic and antitumoral effects. However, after the isolation and purification stage, their pharmaceutical potential is limited due to their low bioavailability, permeability and lifetime. The antibacterial activity of essential oils has been another topic of interest for many studies on this plant. Nevertheless, only a few studies investigate other metabolites in Artemisia annua. Considering that secondary metabolites act synergistically in a plant, the existence of other metabolites with antitumor and high immunomodulating activity is even more important. Novel nano-carrier systems obtained by loading herbs into magnetic nanoparticles ensures the increase in the antitumor effect, but also, overcoming the barriers related to permeability, localization. This study reported the first complete metabolic profile from wild grown Romanian Artemisia annua. A total of 103 metabolites were identified under mass spectra (MS) positive mode from 13 secondary metabolite categories: amino acids, terpenoids, steroids, coumarins, flavonoids, organic acids, fatty acids, phenolic acids, carbohydrates, glycosides, aldehydes, hydrocarbons, etc. In addition, the biological activity of each class of metabolites was discussed. We further developed a simple and inexpensive nano-carrier system with the intention to capitalize on the beneficial properties of both components. Evaluation of the nano-carrier system’s morpho-structural and magnetic properties was performed.

GC-MS/FID analysis, antibacterial activity and modes of action of essential oils from three Aframomum species found in Cameroon against foodborne pathogenic bacteria

Background: The current study examined the chemical profile and in vitro antibacterial activity of essential oils (EOs) extracted from Aframomum danielli (leaves and seeds), Aframomum chlamydentum (leaves), and Aframomum melegueta (leaves) against foodborne pathogenic bacteria.
 Methods: The hydro-distillation technique using a Clevenger-type apparatus was used to extract EOs, whereas the Gas Chromatography-Mass Spectrometry (GC-MS) and GC coupled to Flame Ionization Detector (GC-FID) allowed the chemical characterization of oil constituents. The broth micro-dilution method was applied for the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Besides, some modes of action were studied on the cell membrane integrity and biofilm formation of Salmonella typhi.
 Results: The major compounds identified from EOs of A. danielli seeds were eucalyptol (48.707%), limonene (11.368%), beta pinene (10.342-10.335%), and alpha terpineol (8.785-9.049%), whereas EOs from A. danielli leaves were dominated by sabinene (42.87%), beta pinene, (11.22%), caryophyllene (7.84%), terpinen-4-ol (5.68%), linalool (3.48%) and gamma terpinene (2.02%). Major volatile markers from EOs of A. chlamydentum leaves comprised beta pinene (49.72%), caryophyllene (10.62%), alpha pinene (6.21%) and linalool (2.96%), while those of EOs from A. melegueta included beta pinene (37.15%), caryophyllene (17.64%), caryophyllene oxide (8.72%) and alpha pinene (8.26%). This study is the first to report on the chemical constituents of EOs from A. chlamydentum. Test oils displayed significant antibacterial activity with the MIC ranging from 0.0625 to 0.5% (v/v). EOs from A. melegueta (leaves) appeared to be the most active, acting against all tested bacteria. All EOs identified displayed bactericidal effects against Citrobacter freundii, a bacterium known to cause a broad range of infections associated with a higher rate of in-hospital mortality. The EOs from A. melegueta may act through perturbation of cell membrane integrity and permeability as well as the inhibition of bacterial biofilm formation.
 Conclusion: Our findings suggest the possible application of essential oils in agricultural food products for the control of bacterial diseases.

Antibacterial activity of essential oils from twenty Curcuma aeruginosa genotypes

Curcuma aeruginosa is a rhizome-like medicinal plant with many pharmacological properties. This research aimed to evaluate the antibacterial activity in essential oils from C. aeruginosa genotypes. Using hydrodistillation process, essential oils were acquired from twenty genotypes of C. aeruginosa rhizomes. Antibacterial activity of the samples has been evaluated using agar disk diffusion against Escherichia coli, Staphylococcus aureus, and Streptococcus mutants. Using the broth dilution process, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured for the selected bacteria. Twenty C. aeruginosa genotypes (excluding the G4, G8, G14 and G20 genotypes) demonstrated antibacterial activity against S aureus with varying levels of inhibition. The genotype G15 showed inhibition against E. coli, while the genotype G1, G2, G4, G12 and G16 presented inhibition against S mutants. These findings revealed that, compared with E. coli and S mutants, the essential oils of C. aeruginosa exhibited good antibacterial activity in S aureus. The MIC and MBC of twenty essential oils of C. aeruginosa genotypes against S aureus ranged from 7.81 to 2000 |ag/ml and 250 to 2000 |ag/ml, respectively. These findings suggest that the essential oils of C. aeruginosa may be used as a natural antibiotic to treat many infectious diseases caused by gram-positive bacteria.

ANTIBACTERIAL ACTIVITY OF PEPPERMINT, BASIL AND ROSEMARY ESSENTIAL OILS OBTAINED BY STEAM DISTILLATION

The aim of this paper is to present the antibacterial activity of peppermint, basil and rosemary essential oils obtained by steam distillation after the preservation period using various methods. The processing methods used for the plant materials were natural drying, freezing and gamma ray irradiation. The oils were extracted after certain preservation periods from Mentha piperita, Ocimum basilicum and Rosmarinus officinalis aromatic plant materials. The antibacterial activity of the studied essential oils was assessed against 8 bacterial strains (Staphylococcus aureus, Streptococcus pyogenes, Streptococcus viridans, Enterococcus faecalis, Streptococcus pneumoniae, Escherichia coli, Klebsiella pneumoniae and Serratia marcescens). Antibacterial activity of the essential oils was investigated using disc diffusion method. The results showed that the antibacterial activity depends on the type of aromatic plant and the type of used preservation methods. The most active essential oils against the tested bacteria were, in descending order rosemary, peppermint and basil.

A Research Proposal of Antibacterial Activity of Some Volatile Oil Bearing Plants

The antibacterial activity of essential oil of two Ethiopia plants will be study. The essential oil produced from different parts of plants (coriander and fennel plants) will by measuring MIC (minimum inhibitory concentration), whereas some bacterial strains are used in this study such as follows: Staphylococcus aureus, and klebisela. The two samples used in this experiment have antibacterial activity against Gram-positive and Gram-negative bacteria. Extract by different solvents and then examined by GCMS preliminary phytochemical screening. The antibacterial activities of the essential oils will determine.

Antioxidant and antibacterial activities of essential oils and aromatic waters of some plants grown in the highlands

The essential oils from twenty-two plants grown in the highlands were isolated by hydrodistillation. The plants with an essential oil yield above one percent, including Achillea millefolium, Asparagus plumosus, Matricaria chamomilla, Mentha piperita, Mentha pulegium, and Thymus vulgaris, were tested for the antibacterial activity and total antioxidant capacity. Their antibacterial activities against three most common foodborne pathogens and an opportunistic pathogen were evaluated. Results indicated that T. vulgaris essential oil had the highest total antioxidant capacity with 11.78 ± 0.01 mmol/L TE. The essential oils of plants inhibited the growth of pathogen bacteria tested, while their aromatic waters showed no inhibition. T. vulgaris oil was most powerful antibacterial essential oil with the inhibition zones of 49.27±7.26 mm against S. aureus, 44.13±4.16 mm against L. monocytogenes, 39.55 ± 0.52 mm against E. coli, and 38.09 ± 4.15 mm against M. luteus. Furthermore, the volatile compounds of T. vulgaris essential oil were detected using GC-MS. Thymol, carvacrol, caryophyllene, 1,8-cineole, 2 acetyl-4,5-dimethylphenol, and γ-terpinene were determined as major compounds in T. vulgaris essential oil. The obtained results suggest that the essential oils of tested plants with high antimicrobial activity and antioxidant capacity might be used as natural antioxidant and antimicrobial agents.