Antibacterial Activity Of Essential Oils Research Articles

Chemical constituents and antibacterial activity of essential oils in <i>Amomum longiligulare</i> from Vietnam

This paper reports the chemical constituents and the antibacterial activity of essential oils from the leaves, rhizomes, and fruits of Amomum longiligulare T.L. Wu (Zingiberaceae) obtained by microwave-assisted hydrodistillation. The essential oils were analyzed by gas chromatography–mass spectrometry techniques. The minimum inhibitory concentration (MIC) values were measured by the broth microdilution assay. The oil yields of leaves, rhizomes and fruits from A. longiligulare were 0.23%, 0.27% and 1.93% (v/w), respectively, calculated on a dry weight basis. The leaf essential oil comprised mainly α-humulene (28.4%), α-pinene (24.9%), β-caryophyllene (17.3%), humulene epoxide II (7.3%), and β-pinene (4.7%). The major compounds of the rhizome essential oil were β-caryophyllene (28.7%), bicyclogermacrene (17.1%), humulene epoxide II (10.5%), camphene (7.9%), and α-pinene (5.7%). Camphor (40.7%) and bornyl acetate (34.2%) were the main constituents of the fruit oil. The essential oils demonstrated antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa with the MIC values ranging from 200 to 400 μg/mL. In summary, the A. longiligulare essential oils are a source of promising antibacterial agents. This is the first report on the chemical composition and antibacterial activity of A. longiligulare essential oil obtained by microwave-assisted hydrodistillation.

Antibacterial activity of essential oils for combating colistin-resistant bacteria

ABSTRACT Objectives Colistin (polymyxin E) is a bactericidal antibiotic used to treat severe infections caused by multidrug-resistant Gram-negative bacteria. The product of the mcr1 gene generates transferable plasmid-mediated colistin resistance, which has arisen as a worldwide health-care problem. This study aimed to isolate and identify colistin-resistant bacteria, and evaluate the ability of essential oils in its fights. Methods Twenty-seven bacterial isolates were collected from patients who were admitted to the National Cancer Institute, Cairo, Egypt, and processed using standard microbiological methods. Essential oils were purchased from AB Chem Company, Egypt, screened for antibacterial, cytotoxic activity, and (GC-MS) analysis. Results A total of 5 bacterial isolates were resistant to colistin with minimum inhibitory concentration (MIC) ranging from 6.25->200 µg/ml. Cinnamon oil exhibited the highest activity against colistin-resistant strains followed by thyme and eucalyptus oil. The (MIC) of cinnamon oils against resistant strains ranged from 4.88 to 312.5 µg/ml. Moreover, mcr-1 gene expression was extremely down-regulated after the treatment of bacterial strains with cinnamon oil and decreased to 20–35-fold. Examination of treated bacterial cells with sub-inhibitory concentrations under transmission electron microscopy showed various abnormalities occurred in most of these cells. Conclusions Cinnamon oil exhibits antibacterial activity against colistin-resistant strains, showing it as a promising natural alternative in clinical therapy.

Chemical Composition and Antibacterial Activity of the Leutea elbursensis Mozaff. Essential Oil from Dried Aerial Parts and Rhizome

Natural products are among the safe sources to produce and survey new bioactive compounds. Leutea elbursensis Mozaff. (Apiaceae) is an endemic and wild plant in Iran which grows on the foothills of Alborz Mountains. In this study, the essential oils (EOs) of dried samples of aerial parts and rhizome of L. elbursensis were extracted using Clevenger apparatus. Furthermore, the antibacterial activity of EOs was evaluated against Escherichia coli and Staphylococcus aureus standard strains as the models of Gram-negative and Gram-positive bacteria, respectively. The results of GC/MS spectrums indicated that β-pinene (24.7%), α-pinene (23.1%), and myrtenol (11.9%) were the most dominant products of aerial parts of the plant. Moreover, EO from the rhizome of L. elbursensis contained β-pinene (26.7%), α-pinene (19.3%), myrtenol (13.1%), and n-octanal (10.5%) as significant compounds. The findings showed that essential oils from aerial portions had more antibacterial action than rhizomes did against a number of different microbes. The MIC value of the EO from aerial parts was 8 mg/mL against E. coli, whereas this value was 16 mg/mL for the EO of the rhizome.

Chromatography analysis, in vitro antioxidant and antibacterial activities of essential oil of Artemisia herba-alba Asso of Boussaâda, Algeria

Abstract. Kadri M, Yahia A, Goubi S, Mekhedmi NE, Selmane M, Chemsa AE. 2022. Chromatography analysis, in vitro antioxidant and antibacterial activities of essential oil of Artemisia herba-alba Asso of Boussaâda, Algeria. Biodiversitas 23: 4424-4431. Artemisia herba-alba Asso (Asteraceae family) is widespread in the semi-arid and arid steppes of North Africa. This plant is used for traditional treatment. The present study aims to investigate the chemical composition, antioxidant and antimicrobial activities of A. herba-alba essential oil found in southwest Algeria (Boussaâda region). Artemisia herba-alba essential oil was obtained by hydrodistillation method, and its chemical composition was identified by using GC/MS analysis. In addition, the antioxidant activity of the extracted essential oil was determined using the DPPH assay. The antimicrobial activity of the essential oil was determined by the agar disc diffusion method. The essential oil extracted from the aboveground portions by hydrodistillation was analyzed by GC/MS. 38 components were identified, making up 69.37% of the oil, the most important of which is thujone (9.875%), camphor (3.762%), cis-p-menthadien-1-of (3.572%), and isoborneol (2.334%). The observed IC50 values of the DPPH assay were 7.31 ± 0.088 mg/mL. On the other hand, this oil was active against all strains tested, this activity varied from 12.77 ± 0.510 mm on Listeria innocua CIP 74915. These results demonstrate that the plant tested could be a potential source of natural antioxidants and antimicrobial agents.

EVALUATION OF THE ANTIBACTERIAL ACTIVITY OF ESSENTIAL OILS AGAINST E. COLI ISOLATED FROM RABBITS

The antibacterial activity of essential oils extracted from Origanum compactum, Thymus capitatus, Foeniculum vulgare, and Rosmarinus officinalis was assessed with the well diffusion method and a microbroth dilution assay against E. coli isolated from the carcasses of rabbits. The chemical composition of these essential oils was also determined by gas chromatography coupled with mass spectrometry (GC/MS). The results of this study indicate that essential oils with high phenol content exert a strong antibacterial activity against E. coli. Essential oils of Origanum compactum and Thymus capitatus containing high amounts of the monoterpenoid phenols thymol and carvacrol (68.99% and 95.25% carvacrol composition, respectively) were particularly effective against E. coli with low values of MIC = 0.3125% v/v and MBC = 0.625% v/v to report. The essential oil of Foeniculum vulgare also possessed moderate antibacterial activity (MIC = 50 % v/v) with a non-bactericidal effect, while the essential oil of Rosmarinus officinalis was ineffective at the concentrations tested.

Isolation and Analysis of Chemical Components of Garlic (Allium sativum L.) Tuber Essential Oil As Well As Antibacterial and Antioxidant Activity Tests

The essential oil from garlic tubers (Allium sativum L) was isolated by hydrodistillation method using the Stahl apparatus. Garlic tubers were distilled for 4 to 5 hours to produce as much oil as 0.05% (w/ w). The chemical components of essential oil of garlic tubers were analyzed using GC-MS spectroscopy. The GC-MS results showed that there were 11 components with 5 main components, namely diallyl disulfide (44.98%), 1,3-diallyl tri sulfane (13.63%), allyl sulfide (13.06%), methyl allyl disulfide (11.87%), and methyl allyl trisulfide (4.84%). The antibacterial activity of essential oil of garlic tubers with diffusion method to use concentration variation of 5%, 10%, and 15% have strong antibacterial activity against Gram-positive bacteria like Staphylococcus aureus and have a medium to strong antibacterial activity against Gram-negative bacteria like Escherichia coli. The antioxidant activity of the essential oil of garlic tubers with DPPH (2,2-diphenyl-1-picrylhydrazil) showed an IC50 value was 22.863 mg/L and a very strong antioxidant group.

An Efficient Approach for Separating Essential Oil and Polysaccharides Simultaneously from Fresh Leaves of Guajava by Microwave-Mediated Hydrodistillation with Lithium Salts and Antibacterial Activity of Essential Oil

The essential oils and polysaccharides from guava leaves have important functions. In the process of microwave extraction of plant essential oils and polysaccharides, pretreatment with lithium salts solution is helpful to increase the extraction rate. The experiment was conducted using a single factor method. Results were optimized by principal component analysis and response surface optimization. The optimal conditions were: LiCl dosage 45 μmol, microwave time 40 min, liquid-solid ratio 10, homogenization time 4.2 min, liquid-material ratio 10, and microwave irradiation power 700 W. The highest yield of essential oil and polysaccharide were 10.27 ± 0.58 mL/kg dry weight (DW) and 50.31 ± 1.88 g/kg·DW, respectively. Three verification experiments showed that the extraction rate of the microwave method was higher than that of the traditional heating method. In addition, the bacteriostatic zones reached the maximum 23.7 ± 0.11 mm when the concentration was 40 μL/mL, and the above results have practical significance.

Chemical Composition and Antibacterial Activity of Liquid and Volatile Phase of Essential Oils against Planktonic and Biofilm-Forming Cells of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen causing life-threatening, hard-to-heal infections associated with the presence of a biofilm. Essential oils (EOs) are promising agents to combat pseudomonal infections because of the alleged antimicrobial activity of their volatile fractions and liquid forms. Therefore, the purpose of this paper was to evaluate the antibacterial efficacy of both volatile and liquid phases of seven EOs (thyme, tea tree, basil, rosemary, eucalyptus, menthol mint, lavender) against P. aeruginosa biofilm and planktonic cells with the use of a broad spectrum of analytical in vitro methods. According to the study results, the antibacterial activity of EOs in their liquid forms varied from that of the volatile fractions. Overall, liquid and volatile forms of rosemary EO and tea tree EO displayed significant antibiofilm effectiveness. The outcomes indicate that these particular EOs possess the potential to be used in the therapy of P. aeruginosa infections.

Evaluation of Chemical Compounds and Comparison of Antibacterial Activity of Essential Oil and Nanoemulsion Containing Essential Oil of Ziziphora clinopodioides L

Introduction: Medicinal plants have played a major role in the treatment of multiple diseases for centuries. Ziziphora clinopodioides is one of these plants with well-known antibacterial properties. The present study aimed to investigate the antibacterial effects of Z. Clinopodioides essential oil and nanoemulsion. Method: After preparing and collecting the plant in spring, the samples were dried in the shade and transferred to the laboratory. Thereafter, the essential oil was extracted by Clevenger. Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were used to determine antibacterial properties. Results: Pulegone had the highest composition (44.49%) of essential oil. Particle size in 5% nanoemulsion of Z. Clinopodioides essential oil was 13.0 nm. The results demonstrated that considering the diameter zone of the no-growth, there was no significant difference between 5% nanoemulsion and 5% Z. Clinopodioides essential oil in both gram-positive and gram-negative bacteria. Conclusion: Nanoemulsion containing essential oil showed no significant difference in antibacterial activity compared to essential oil

Antimicrobial, Multidrug Resistance Reversal and Biofilm Formation Inhibitory Effect of Origanum majorana Extracts, Essential Oil and Monoterpenes.

Origanum majorana L. is a widely used medicinal plant; its distilled oil and preparations are extensively utilised in the phytotherapy and food industries. The objective of this study is to evaluate the extracts and the essential oil (EO) of Origanum majorana L, and its monoterpenes for antimicrobial, bacterial multidrug resistance reversing, and biofilm formation inhibitory potency. The composition of EO and n-hexane extract was characterized by GC-MS. In the essential oil terpinen-4-ol (24.92%), trans-sabinene hydrate (25.18%), γ-terpinene (6.48%), cis-sabinene hydrate (5.44%), p-cymene (4.72%), sabinene (4.53%), α-terpineol (4.43%), and α-terpinene (3.00%) were found as the main constituents while trans-sabinene hydrate (1.43%), and terpinen-4-ol (0.19%) were detected in the n-hexane extract besides a series of hydrocarbons. The antibacterial activity of EO and terpinen-4-ol, α-terpinene, and linalool was also assessed against sensitive and drug-resistant S. aureus, and E. coli strains with MIC values of 0.125–0.250% and 30–61 µM, respectively. In the efflux pump (EP) inhibitory assay, made by the ethidium bromide accumulation method in E. coli ATCC 25922, and AG100 and S. aureus ATCC 25923, and MRSA ATCC 43300 strains, EO exhibited substantial activity, especially in the E. coli ATCC 25922 strain. Among the EO constituents, only sabinene was an EP inhibitor in sensitive Escherichia strain. In the case of S. aureus strains, EO and sabinene hydrate exhibited moderate potency on the drug-resistant phenotype. The antibiofilm effects of the samples were tested by crystal violet staining at sub-MIC concentration. γ-Terpinene, terpinen-4-ol, sabinene, sabinene hydrate and linalool were found to be effective inhibitors of biofilm formation (inhibition 36–86%) on E. coli ATCC 25922 and S. aureus MRSA ATCC 43300, while EO was ineffective on these strains. In contrast to this, biofilms formed by E. coli AG100 and S. aureus ATCC 25923 were significantly inhibited by the EO; however, it was not affected by any of the monoterpenes. This observation suggests that the antibiofilm effect might be altered by the synergism between the components of the essential oil.

Parsley (Petroselinum crispum): chemical composition and antibacterial activity of essential oil from organic against foodborne pathogens

Microbial contamination is a serious problem for food industries, potentially leading to foodborne diseases that affect human health. Petroselinum crispum, popularly known as parsley, can be used for the production of biologically active essential oil. Considering the demand for novel natural products to control microorganisms, this study aimed to analyze the chemical composition and antibacterial activity of P. crispum essential oil from organic cultivation. Essential oil was extracted by hydrodistillation from the aerial part of P. crispum cv. plain (plain leaf type) at 70 days of age and analyzed for chemical composition by gas chromatography–mass spectrometry (GC-MS). Antibacterial activity was evaluated against five bacterial pathogens by the broth microdilution method. The essential oil yield was 0.02% and the major compounds were apiol (61.94%) and myristicin (9.33%). The minimum inhibitory concentration (MIC) of essential oil ranged from 1.70 to 10.00 mg mL−1, with the best activities against Staphylococcus epidermidis and Staphylococcus aureus. These results demonstrate that apiol-rich essential oil from organic P. crispum shows promise as an antibacterial agent in food and pharmaceutical industries

Chemical Profiles and Antibacterial Activity of Essential Oils from Rhizomes of Aspidistra phanluongii

Chemical Profiles and Antibacterial Activity of Essential Oils from Rhizomes of Aspidistra phanluongii

The Effect of Some Wild Grown Plant Extracts and Essential Oils on Pectobacterium betavasculorum: The Causative Agent of Bacterial Soft Rot and Vascular Wilt of Sugar Beet.

The bacterial soft rot and vascular wilt of sugar beet are the major diseases of sugar crops globally induced by Pectobacterium betavasculorum and P. carotovorum subsp. carotovorum (Pcc). The control of this bacterial disease is a severe problem, and only a few copper-based chemical bactericides are available for this disease. Because of the limitations of chemicals to control plant bacterial pathogens, the essential oils and extracts have been considered one of the best alternative strategies for their control. In this study, twenty-seven essential oils and twenty-nine plant extracts were extracted and evaluated for their antibacterial activities against Pectobacterium betavasculorum isolate C3, using the agar diffusion method at 0.01%, 0.1%, and 100% (v/v). Pure Pimpinella anisum L. oil exhibited the most anti-bacterial activity among three different concentrations of essential oils and extracts, followed by Thymus vulgaris L. oil and Rosa multiflora Thunb. extract. The efficacy of effective essential oils and extracts on Ic1 cultivar of sugar beet seeds germination and seedling growth in vivo also were tested. The seed germination of the Ic1 cultivar was inhibited at all the concentrations of essential oils used. Only extracts of Rosa multiflora Thunb., Brassica oleracea L., Lactuca serriola L., Salvia rosmarinus Spenn., Syzygium aromaticum (L.) Merr. and L.M.Perry, Eucalyptus globulus Labill., and essential oils of Ocmium basilicum L., Pimpinella anisum L., and Mentha× piperita L.L. in 0.1% concentration had no inhibition on seed germination and could improve seedling growth. This is the first report of the antibacterial activity of essential oils and extracts on Pectobacterium betavasculorum.

Potent Anti-Cutibacterium acnes Activity of the Essential Oils Derived from Allium sativum, Gerdenia jasminoides, and Hedychium coronarium Cultivated in Thailand

Plant oils derived from medicinal herbs have furnished bioactive synergistics, as well as antibacterial and antifungal properties. The study was to evaluate the antibacterial activity of essential oils (EOs) against Cutibacterium acnes and to analyze the chemical compositions of the effective oils. The experiment was conducted using a completely randomized design with duplications. Three EOs obtained from Allium sativum (garlic), Gardenia jasminoides (gardenia), and Hedychium coronarium (hydechium) cultivated in Thailand were tested for antibacterial activity using an agar well diffusion assay and the macro-dilution method. The chemical compositions of the selected oil were determined by gas chromatography and mass spectrometry (GC-MS). To compare the data, Duncan’s multiple range test (DMRT) was performed, and significance was determined at the p < 0.05 level. The results showed that garlic oil had the highest potent inhibitory zone on C. acnes, according to the findings. As a bactericidal, garlic oil had MIC and MBC values of 0.39 and 0.78 mg/mL, and even a MIC index (MBC/MIC) of 4. Diallyl thiosulfinate (allicin) (20.53%), 1,3-dithiane (12.53%), cyclic octaatomic sulfur (5.02%), 1,4-dihydro-2,3-benzoxathiin-3-oxide (4.73%), and carvone (3.40%) were the major components of garlic oil. The results suggest that garlic oil might be used to develop topical anti-acne treatments.

Study of Antibacterial and Synergistic Activities of Cinnamomum verum, Eucalyptus camaldulensis and Zataria multiflora Boiss. in Persian Medicine Against Some Gram-Negative and Gram-positive Pathogenic Bacteria

Antibacterial activities of essential oils (EOs) of three widely used herbal elements of cinnamon (Cinnamomum verum J.Presl), eucalyptus (Eucalyptus camaldulensis Dehnh.), and thyme (Zataria multiflora Boiss.), whose antimicrobial effects are indirectly described in the old literature of Persian medicine as antiseptic agents and treatments of diseases caused by Havaye Vabaee (e.g., air-borne infectious diseases), were investigated. Antibacterial activities of the EOs were evaluated against some important Zoonosis and medicine pathogenic gram-negative (Escherichia coli, Klebsiella pneumonia, Listeria monocytogenes, and Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus, S. epidermidis, and Streptococcus pyogenes) bacteria. These pathogens cause disease in animals and humans.To this end, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and double-diffusion assay (DDA) tests were utilized using a microdilution method. While MIC values for cinnamon, eucalyptus, and thyme ranged between 0.25-1, 8-64, and 0.5-16 μg mL-1, respectively, the range of MBC values were 1-4, 32-256, and 2-64 μg mL-1. In DDA tests, a concentration of 0.5 μg mL-1 of the three EOs induced inhibition zones ranging between 20-35, 9-25, and 0-35 mm in diameter in the culture media of the above bacteria. Antibacterial effects of double combinations of the EOs against E. coli and S. aureus were also investigated by checkerboard test and fractional inhibitory concentration (FIC) index. Combinations of the EOs resulted in FIC index values of 1.06-2, indicating no interaction between most of the compounds combined. Our study also suggested the use of thyme oil with caution in combination with cinnamon or eucalyptus oils against E. coli because of their possible antagonistic effects (FIC index = 4).

In Vitro Antibacterial Activity of Essential Oils From Tithonia Diversifolia Leaves and Flowers Against Ralstonia Solanacearum

Bacterial wilt disease caused by Ralstonia solanacearum is a major constraining factor in the production of tomatoes in Kenya, leading to an overreliance on synthetic pesticides. As a result, there is increased research on bio-pesticides as safer alternatives.  The present study, therefore,  characterized and evaluated in vitro antibacterial activity of essential oils from Tithonia diversifolia leaves and flowers against R. solanacearum. Hydrodistilled essential oils were characterized through  Gas Chromatography-Mass spectrometry (GC-MS) while functional groups were confirmed using Fourier Transform Infrared Spectroscopy (FT-IR). Antibacterial activity was performed using the disc diffusion method and minimum inhibitory concentration evaluated using broth dilution. Hydrodistilled leaves of T. diversifolia yielded  0.18 + 0.08 % (v/w); 0.10 + 0.07 % w/w as compared to 0.15 + 0.09 % (v/w); 0.08 + 0.03 % w/w in the leaves . GC-MS profiling revealed  the major compounds were (Z,Z,Z)-9,12,15- Octadecatrienoic acid ethyl ester(18%), palmitic acid (16%), spathulenol (12%), Cis- 9,12,15- Octadecatrienoic acid (8.14%), tetrateracontane (6%) and 1-Octen-3yl-acetate (5.22%) in the leaves ad α-linolenic acid trimethylester(33%), Z,Z Hexadecadienoic acid(26%), octadecanoic acid trimethylester (9%), palmitelaidic acid (8.49%), Germacrene D(5.45%), azelaic acid (5.02%) and caryophyllene oxide (5.00%) in the flowers. Antibacterial activity showed that T. diversifolia essential oils had mean inhibition zones of 12.61+ 0.22 mm and 11.82 + 0.76 mm from the leaves and flowers respectively, in comparison to metham sodium which gave inhibition zone of 25.78 ±0.29 mm (p = 0.001). Based on the results, this study gives credence to  T. diversifolia essential oils as viable antibacterial agents.

Antibacterial Properties of Essential Oil Extracted from Kaffir Lime (Citrus Hystrix) Peel

Background: Citrus hystrix (C. hystrix), locally known as ‘limau purut,’ is Malaysia’s major commercial fruit harvest. Besides being a common ingredient in Asian cuisines, the extracted essential oil has diverse applications. The essential oil can be extracted from peels or leaves, which could give strong aromatic properties. Objective: The main purpose of this study is to evaluate the antibacterial activity of C. hystrix essential oil by using disc diffusion method. Materials and Methods: C. hystrix essential oil was extracted from the peels using the Clevenger apparatus of hydro-distillation method. The antibacterial activity of essential oil was evaluated by agar disc diffusion method against four strains of bacteria: two Gram-positive bacteria (Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis ATCC 12228) and two Gram-negative bacteria (Escherichia coli ATCC 25922 and Shigella dysenteriae ATCC 13313). Each assay was done in triplicates. In this research, positive controls gentamicin and streptomycin were used as indicators to prove the research’s validity. Results: The Gram-positive bacteria were more susceptible to the essential oil (average zone of inhibition diameter; S. aureus = 19.3 ± 1.5 mm and S. epidermidis = 19.3.0 ± 0.6 mm) as compared to the Gram-negative bacteria (average zone of inhibition diameter; E. coli = 8.3 ± 0.6 mm and S. dysenteriae = 11.7 ± 0.6 mm). Gentamicin was recorded to be most effective against all tested bacteria (more than 15 mm zone of inhibition diameter). However, only S. epidermidis showed resistance to streptomycin. Conclusion: C. hystrix essential oil was found to possess antibacterial activity. Thus, these findings indicated that C. hystrix essential oil could be developed as an antibacterial agent in various applications.

Antibacterial Activity of Essential Oils against Oral Pathogens

AbstractThis updated review article covers the literature between 2011 and 2021 on the antibacterial activity of EOs against the main bacteria that cause caries and periodontal diseases. The criteria to classify the in vitro antibacterial activity of EOs is updated and the most promising results are addressed.

Antibacterial Activity of Essential Oil from Ripe Berries of Juniperus oxycedrus L. Against Multi-drug Resistant Pathogens Responsible for Skin Infections in Burn Patients

This study aimed to investigate the phytochemical composition and antibacterial activity of essential oil of ripe berries of Juniperus oxycedrus L. against multi-drug resistant (MDR) strains, which were isolated from wound infections among burn patients. The isolation of essential oil was carried out by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). In vitro antibacterial activity was determined by the disc diffusion method against the bacterial isolates. The chromatographic analysis revealed that the chemical composition of the essential oil is dominated by monoterpenes (75.40%), among which α-pinene was detected at 56.39%. The predominant strains of bacteria isolated from the infected wounds included Staphyloccocus aureus (35.29%), followed by Pseudomonas aeruginosa (17.64%), Proteus mirabilis (14.70%), Klebsiella pneumoniae and Staphylococcus epidermidis at the same level (11.76%), while Acinetobacter baumannii was found to be the least with only at 6.67%. These isolates showed high resistance to at least three different classes of the challenged antibiotics. J. oxycedrus L. essential oil has strong antibacterial activity against all the tested strains. The lowest minimal inhibitory concentration (MIC) was observed for Staphylococcus epidermidis (1.25 μL/mL), while the highest MIC was observed for Pseudomonas aeruginosa and Acinetobacter baumanii (5 μL/mL). These findings confirm that essential oil isolated from J. oxycedrus could be used to treat or prevent infections in patients suffering from burns.

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.