Antimicrobial Properties Of Essential Oils Research Articles

Chemical Profiles and Antimicrobial Properties of Essential Oils from Orange, Pummelo, and Tangelo Cultivated in Greece

Chemical Profiles and Antimicrobial Properties of Essential Oils from Orange, Pummelo, and Tangelo Cultivated in Greece

An approach to combat multidrug-resistant K. pneumoniae strain using synergistic effects of Ocotea diospyrifolia essential oil in combination with amikacin

The natural antimicrobial properties of essential oils (EOs) have contributed to the battle against multidrug-resistant microorganisms by providing new ways to develop more effective antibiotic agents. In this study, we investigated the chemical composition of Ocotea diospyrifolia essential oil (OdOE) and its antimicrobial properties combined with amikacin (AMK). Through gas chromatography-mass spectrometry (GCMS) analysis, the primary constituents of OdOE were identified as α-bisabolol (45.8 %), β-bisabolene (9.4 %), γ-elemene (7.6 %), (Z)- β-farnesene (5.2 %), spathulenol (3.5 %), (Z)-caryophyllene (3.3 %), and (E)-caryophyllene (3.1 %). In vitro assessments showed that the combined administration of OdOE and AMK exerted a synergistic antibacterial effect on the multidrug-resistant K. pneumoniae strain. This synergistic effect demonstrated bacteriostatic action. OdEO combined with amikacin showed protein extravasation within 2 h of treatment, leading to bacterial death, which was determined by a reduction in viable cell count. The effective concentrations showed hemocompatibility. In vivo assessments using Caenorhabditis elegans as a model showed the survival of 85 % of infected nematodes. Therefore, the combination OdEO combined with amikacin exhibited antimicrobial activity against a multidrug-resistant K. pneumoniae strain. Thus, OdOE is a promising agent that may be considered for development of antimicrobial treatment.

Phytochemical Analysis and Evaluation of Antioxidant and Antimicrobial Properties of Essential Oils and Seed Extracts of Anethum graveolens from Southern Morocco: In Vitro and In Silico Approach for a Natural Alternative to Synthetic Preservatives.

Anethum graveolens is an aromatic plant traditionally used as an antispasmodic and carminative. The objective of this study is to analyze the chemical composition of the essential oils and extracts obtained from seeds gathered in Errachidia, southern Morocco. Additionally, the antioxidant and antimicrobial properties of these oils and extracts will be evaluated. GC-MS analysis of the EO isolated by hydrodistillation revealed that its main compounds were E-anethole (38.13%), estragole (29.32%), fenchone (17.21%), and α-pinene (7.37%). The phenolic components were extracted using the methods of decoction and Soxhlet. The assay of the phenolic compounds showed that A. graveolens seeds contained considerable amounts of polyphenols, flavonoids, and condensed tannins, with variable levels depending on the extract analyzed. HPLC/UV-ESI-MS analyses performed on the decoction revealed a structural diversity of the molecules present in this extract, the most important of which were umbelliferone (12.35%), 3-hydroxyflavone (11.23%), rosmanol (8.95%), biotin (8.36%), emmotin H (4.91%), and coumarin (4.21%). The antioxidant activity, as determined by three techniques (DPPH•, FRAP, and CAT), demonstrated that the essential oils (EOs) and extracts had a potent capacity to counteract detrimental free radicals, control the generation of reactive oxygen species, and mitigate oxidative damages. The antimicrobial activity of the Eos and extracts was carried out in a liquid medium against five strains (E. cloacae, K. pneumoniae, E. coli, S. aureus, and S. epidermidis) and four candidiasis (C. albicans, C. dubliniensis, C. tropicalis, and C. parapsilosis) and Aspergillus niger. The results showed the effectiveness of the EOs compared to the aqueous, ethanolic, and decoction extracts against most of the microorganisms tested. In addition, the ethanolic extract showed antifungal activity that was distinguished from that of the other extracts. The antimicrobial efficacy of the essential oils under study can primarily be attributed to the synergistic interactions among its three principal constituents (E-anethole, estragole, and fenchone). Furthermore, molecular docking and molecular dynamics simulation results reveal significant interactions and stability between the selected bioactive compounds and different target proteins involved in antimicrobial and antioxidant activities. Compounds like 3-hydroxyflavone, emmotin H, trans-caftaric acid, methyl rosmarinate, 1-caffeoyl-beta-D-glucose, and kaempferol exhibited better binding energies with the explored proteins, indicating their potential as antimicrobial and antioxidant agents. Finally, our findings emphasize the significance of A. graveolens seeds as a promising reservoir of advantageous health compounds that can serve as organic substitutes for the presently employed synthetic preservatives.

Chemical composition, anticancer, antimicrobial activity of Aloysia citriodora Palau essential oils from four different locations in Palestine

The primary aim of this investigation was to determine the anticancer and antimicrobial properties of essential oils (EOs) extracted from the leaves of Aloysia citriodora Palau, which were procured from four separate locations in Palestine, in addition to analyzing their chemical composition. These areas include Jericho, which has the distinction of being the lowest location on Earth, at 260 m below sea level. The EOs were acquired by hydrodistillation, and their chemical composition was examined utilizing gas chromatography-mass spectrometry (GC-MS). The minimum inhibitory concentration (MIC) of EOs was assessed against six bacterial strains and one fungal species using 96-well microtiter plates. The primary components found in these oils are geranial (26.32–37.22%), neral (18.38–29.00%), and α-curcumene (7.76–16.91%) in three regions. α-Curcumene (26.94%), spathulenol (13.69%), geranial (10.79%), caryophyllene oxide (8.66%), and neral (7.59%) were found to be the most common of the 32 chemical components in the EO from Jericho. The EOs exhibited bactericidal properties, particularly against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and showed highly effective fungicidal activity. Nevertheless, the antifungal efficacy of the EO was found to surpass its antibacterial activity when administered at lower dosages. The EOs exhibited anticancer activities against melanoma cancer cells, as indicated by their IC50 values, which ranged from 4.65 to 7.96 μg/mL. A. citriodora EO possesses substantial antifungal and anticancer characteristics, rendering it appropriate for utilization in food-related contexts, hence potentially enhancing the sustainability of the food sector.

Antimicrobial activity of essential oil fractions of Siberian fir and Scotch pine

Introduction. Plants of the pine family, growing mainly in the Northern Hemisphere, are of interest both from an economic and medical point of view. The antimicrobial properties of essential oils of coniferous plants are being actively studied. Objective: to study the antimicrobial activity of the essential oil fractions of Siberian fir and Scotch pine growing in the Krasnoyarsk Territory. Material and methods. Essential oils were isolated by hydrosteam distillation on an all-metal installation with a Clevenger nozzle. The component composition of the essential oil fractions was determined by gas chromatography-mass spectrometry. The disc diffusion method was chosen to detect the antimicrobial activity of essential oil fractions. The following test cultures were used: Staphylococcus aureus (MSSA), Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa, Candida albicans. Results. In all fractions of the essential oil of Siberian fir and Scotch pine, monoterpenoids predominate, the dominant components are bornylacetate and pinene, respectively. All fractions of both oils showed antimicrobial activity against Staphylococcus aureus (MRSA), Staphylococcus aureus (MSSA) and Candida albicans. Isolated individually dominant compounds bornylacetate (Siberian fir) and pinene (Scots pine) also showed antimicrobial activity. Conclusion. The antimicrobial activity of individual fractions of essential oils of Siberian fir and Scotch pine and the dominant components of the fractions against Staphylococcus aureus (MSSA and MRSA), Escherichia coli, Pseudomonas aeruginosa, Candida albicans was studied. The activity of the fractions is largely due to the dominant components. The fractions enriched in monoterpenoids showed the highest activity. The strain of Staphylococcus aureus (MRSA) turned out to be the most sensitive to the fractions of essential oils.

Origanum dictamnus Essential Oil in Vapour or Aqueous Solution Application for Pepper Fruit Preservation against Botrytis cinerea

The use of synthetic sanitizers for fresh commodities preservation is of concern, with eco-friendly alternatives, including essential oils (EOs), attracting research and industry interest. Dittany (Origanum dictamnus—DIT) oil was applied, either through vapour or dipping, on pepper fruit or in vitro against Botrytis cinerea, and compared to untreated (control) or chlorine (CHL)-treated fruits stored at 11 °C. Direct DIT vapours (up to 6 d) suppressed lesion growth, spore germination, and spore production compared to the untreated fruits. The antimicrobial properties of EOs were evidenced in pre-exposed-to-DIT oil vapours (residual effect), resulting in fruit lesion suppression. However, DIT-pretreated fruits had the same spore production and spore germination as the control and CHL applications. In in vitro tests, DIT vapours decreased colony growth and spore production when fungi were grown on Potato Dextrose Agar (PDA) or PDA pre-exposed to DIT following B. cinerea inoculation. This evidenced that the disease suppression after DIT vapour application primarily affected the interaction of the fruit–pathogen and/or residual responses on fruit tissue and/or PDA media. Fungal biomass in Potato Dextrose Broth (PDB) was evaluated after DIT and CHL applications (10–50–100–500–5000 μL L−1) and decreased with the DIT oil. Additionally, DIT or CHL sanitary dipping on pepper was ineffective against B. cinerea compared to vapour application. Therefore, DIT vapours revealed antimicrobial properties and could be an alternative postharvest sanitiser. DIT oil application should also be evaluated at semi-commercial scale for further optimizations, prior to commercialisation.

A Mini-Review of the Main Effects of Essential Oils from Citrus aurantifolia, Ocimum basilicum, and Allium sativum as Safe Antimicrobial Activity in Poultry

Poultry production is accompanied by the use of antimicrobial agents because no production step is free of microorganisms. In the absence of antimicrobial treatments with synthetic drugs, essential oils are among the most cited natural alternatives used to prevent and treat microbial contamination in poultry. Although there are several studies on the antimicrobial properties of essential oils, there is still no review that simultaneously compiles information on the leading antimicrobial role of essential oils from Citrus aurantifolia (CAEO), Ocimum basilicum (OBEO), and Allium sativum (ASEO) in poultry. Awareness of the antimicrobial role of these substances opens the door to encouraging their use in natural antimicrobial protocols and discouraging harmful synthetics in poultry. This review aimed to compile information on applying CAEO, OBEO, and ASEO as antimicrobials in poultry farming. The available literature suggests that these essential oils can proportionately align with the poultry industry’s demands for microbiologically safe food products.

Chemical Composition and Antimicrobial Activity of Essential Oils from Horse Chestnut Flowers

Essential oil of brown color was obtained by hydro-distillation from fresh flowers of horse chestnut. All major components of the corresponding oils were identified by gas chromatography-mass spectrometry. The microorganisms most sensitive to the studied essential oil of flowers were revealed: Staphylococcus aureus, Serratia marcescens, and Bacillus subtilis. Extensive documentation on the antimicrobial properties of essential oils and their constituents has been carried out by several workers. Although the mechanism of action of a few essential oil components has been elucidated in many pioneering works in the past, detailed knowledge of most of the compounds and their mechanism of action is still lacking. This knowledge is particularly important for the determination of the effect of essential oils on different microorganisms, how they work in combination with other antimicrobial compounds, and their interaction with food matrix components. Also, recent studies have demonstrated that nanoparticles (NPs) functionalized with essential oils have significant antimicrobial potential against multidrug-resistant pathogens due to an increase in chemical stability and solubility, decreased rapid evaporation and minimized degradation of active essential oil components.

Essential Oils: A “Potential Green” Alternative in Pharmaceutical, Nutritional and Agricultural Sectors

In the era of modern medicine, the therapeutic use of plant-derived essential oils has been one of the fascinating fields of study for researchers around the globe. The plant-derived essential oils, which are a combination of volatile organic compounds may be used as a substitute for the treatment of pathogenic microbes. The antimicrobial properties of essential oils are extremely diverse. In microbial infections, essential oils create an electrochemical gradient across the cell wall which intervenes with ATP synthesis and can also disrupt the electron transport system (ETS) by rupturing the mitochondrial membrane. Many essential oils have antiviral properties that can effectively treat COVID-19. The purpose of the current review is to shed light on the antimicrobial efficacy of essential oils. A survey of the methods used for the determination of the interaction and mechanisms involved in the antimicrobial activities of essential oils are also reported as well and the applications of essential oils could be interesting COVID-19 therapeutic options because of their pharmacological actions. This review will attract the attention of researchers to optimize and elucidate the use of essential oils as green alternatives to treat the deadliest infectious diseases in living organisms.

Antibacterial Activity of Mentha piperita (Peppermint) Oil against Wound Infections Caused by Carbapenem-Resistant Klebsiella in Rats

Drug resistant Klebsiella pneumoniae causes nosocomial infections, pneumonia, wound sepsis and infections of newborns and intensive care patients. In many cases antibiotics are no longer very effective in patients treated for K. pneumoniae infections. Various studies have shown antimicrobial properties of essential oils and different compounds that are part of them. This study aimed to determine the antibacterial efficacy and minimum inhibitory concentration of the Mentha piperita essential oil against resistant strain of K. pneumoniae. Efficiency of peppermint oil when used with antibiotics in wound management as well as controlling K. pneumoniae infection was also investigated in this study. Well diffusion method was used to determine the antibacterial activity of peppermint oil, where its inhibitory capacity was observed along with antibiotics and compared with control. Bacterial load of K. pneumonia OXA48 resistant strain on wound in rat models was also studied and compared. Klebsiella pneumoniae OXA48 and K. pneumoniae ATCC 700603 were inhibited by effectively by 40 µl/ml of peppermint oil in well diffusion assays. In rat models the wounds were healed, and epithelization was quicker in 10% peppermint oil treated wounds. Wounds applied with a combination of peppermint oil and Imipenem were more effectively protected from infection and showed better healing as well. Peppermint oil depicted both inhibitory capacities against K. pneumonia OXA48 and promoted wound healing as well. Further studies regarding PMO and its efficacy in wound management as well as its associated molecular mechanism would provide better understanding regarding its potential.

Chemical Composition and Antimicrobial Properties of Essential Oil from Viburnum lutescens

Chemical Composition and Antimicrobial Properties of Essential Oil from Viburnum lutescens

Foeniculum vulgare Mill. ve Pimpinella anisum L. (Apiaceae) Türlerinin Uçucu Yağlarının Antimikrobiyal Aktivitesi

Today, essential oils are considered safe substances and can be used as antibacterial additives. Pimpinella anisum L. (Aniseed) and Foeniculum vulgare Mill. var. dulce (fennel) species are of great economic importance. It is among the medicinal and aromatic plants cultivated in wide areas in our country. In this study, it was aimed to determine the antimicrobial properties of essential oils obtained from Foeniculum vulgare Mill. and Pimpinella anisum L plants. The essential oils of the species were obtained by using the distillation method. The antimicrobial activities of essential oils by hand were studied using the hollow agar method. Known to be medically important in food, cosmetics and pharmaceutical products Enterobacter aerogenes (ATCC 13048), Enterococcus faecalis (ATCC 29212), Salmonella enteritidis (ATCC 13075), Staphylococcus aureus subsp. aureus (ATCC 25923), Escherichia coli (ATCC 25922) and Serratia marcescens (ATCC 13880) evaluated against pathogen and microbial contaminants. While Foeniculum vulgare showed results parallel to the antibiotic used as standard, no antibacterial activity was observed in Pimpinella anisum L.

Comprehensive Study of Components and Antimicrobial Properties of Essential Oil Extracted from Carum carvi L. Seeds.

Carum carvi L. belongs to the Apiaceae family and is widely used as a vegetable, food spice, preservative, and herbal medicine. This study investigated the impact of essential oil extracted from Carum carvi L. seeds (CEO) on methicillin-resistant Staphylococcus aureus (MRSA) and its possible action mechanism. The dominant chemical components of CEO determined by GC-MS were carvone and limonene. It was observed that CEO had a considerable inhibitory effect against the growth of planktonic bacteria and biofilm in MRSA cells. Untargeted metabolomics based on GC-Q-TOF-MS was used to analyze the possible mechanism of the interaction of MRSA with CEO. It was determined that there were 63 different metabolites based on fold change values greater than 1.5 or less than 1.5, p < 0.05, VIP > 1, which demonstrated amino acid metabolism in MRSA was significantly affected by CEO. In conclusion, CEO has a potent antimicrobial property and has promising potential for use in food and drugs.

Chemical composition, antioxidant and antibacterial properties of Juniperus excelsa M. Bieb. leaves from Türkiye

Juniper species are especially used in traditional medicine due to their analgesic, diuretic, antibacterial, antimicrobial, anti-inflammatory, and liver-protective effects. The goal of the present study was to investigate the chemical compounds, antioxidant, and antimicrobial properties of essential oil of Juniperus excelsa M. Bieb., a species of juniper with a large spread area in Turkey. Essential oils were extracted by the hydro-distillation method. The components of the hydro distilled oil samples were analyzed by gas chromatography-mass spectrometry (GC-MS). In the study, the essential oil was evaluated for its antibacterial activity against six bacterial strains consisting of two Gram (+) and four Gram (–) by the agar disc diffusion method. Additionally, the antioxidant properties of the oil were determined by TEAC/ABTS+ free radical scavenging assay. As a result, there were 27 compounds in the essential oil of J. excelsa. Of the 27 essential oil components identified, α-pinene (40.59%), α-cedrol (18.15%), β-myrcene (4.53%), and limonene (3.84%) were determined as the main components in total 91.54% of the essential oil. As a result, it was observed that the examined juniper essential oil showed a weak but effective antibacterial activity against all bacterial strains compared to the control agents, and also, the examined oil had low but valuable antioxidant activity.

Antimicrobial Properties of Essential Oils Obtained from Autochthonous Aromatic Plants.

The aim of this work was to determine the antimicrobial activity of the essential oils of six plants widely distributed in the Dehesa of Extremadura, such as Calendula officinalis, Cistus ladanifer, Cistus salviifolius, Cistus multiflorus, Lavandula stoechas, and Rosmarinus officinalis. The content of total phenolic compounds (TPC) and the antimicrobial activity of the essential oils against pathogenic and spoilage bacteria and yeasts as well as aflatoxin-producing molds were determined. A great variability was observed in the composition of the essential oils obtained from the six aromatic plants. The Cistus ladanifer essential oil had the highest content of total phenols (287.32 ppm), followed by the Cistus salviifolius essential oil; and the Rosmarinus officinalis essential oil showed the lowest amount of these compounds. The essential oils showed inhibitory effects on the tested bacteria and also yeasts, showing a maximum inhibition diameter of 11.50 mm for Salmonella choleraesuis and Kregervanrija fluxuum in the case of Cistus ladanifer and a maximum diameter of 9 mm for Bacillus cereus and 9.50 mm for Priceomyces carsonii in the case of Cistus salviifolius. The results stated that antibacterial and antiyeast activity is influenced by the concentration and the plant material used for essential oil preparation. In molds, aflatoxin production was inhibited by all the essential oils, especially the essential oils of Cistus ladanifer and Cistus salviifolius. Therefore, it can be concluded that the essential oils of native plants have significant antimicrobial properties against pathogenic and spoilage microorganisms, so they could be studied for their use in the industry as they are cheap, available, and non-toxic plants that favor the sustainability of the environment of the Dehesa of Extremeña.

Chemical Composition and in Vitro Antioxidant, Anti-Alzheimer, Anti-Diabetic, Anti-Tyrosinase, and Antimicrobial Properties of Essential Oils and Extracts Derived from Various Parts of the Algerian Calendula Suffruticosa Vahlsubsp. boissieri Lanza.

Calendula suffruticosa Vahl subsp. boissieri Lanza is well-known for its medicinal properties in northeastern Algeria. As far as literature has been able to prove, no study has attempted to make a phytochemical or biological activity evaluation (antioxidants, enzyme inhibitors and antimicrobial potential). This work intends to evaluate, for the first time, the chemical constituents and study the previously mentioned biological activities of C. suffruticosa boissieri essential oil and different sections (flowers, leaves, roots) as well as the effect of changing the solvent (ethanol 70 %) and (methanol 70 %) on these activities. The essential oil of aerial parts of this plant was investigated using GC/MS, and 45 compounds were discovered, accounting for 98.01 % of the essential oil, including 23 monoterpenes, 6 sesquiterpenes, 12 diterpenes, 1 coumarin, 3 alkanes, methyl-cyclohexane (23.73 %), limonene (25.02 %), and o-cymene (13.20 %). Five methods were used to study the antioxidant activity (ABTS, DPPH, CUPRAC, reducing power, and β-carotene bleaching assay), where the results were impressive, especially for the essential oil. In addition, the hydroethanolic solvent (70 %) was found to be the most effective solvent for extraction in general compared to the hydromethanolic solvent (70 %). The extracts and essential oils of C. suffruticosa boissieri also showed a strong inhibiting ability against cholinesterase, tyrosinase, anti-α-amylase, α-glucosidase, and antimicrobials, a very valuable antioxidant, which is a real discovery. Based on these results, it can be said that this plant has important biological activities, so it can be used in the phytotherapy, food, or pharmaceutical sectors.

In vitro antibacterial activities of essential oils and extracts of six herbals against gram-positive and gram-negative bacteria

Considering the development of bacterial resistance to chemical antibiotics and their adverse effects on the environment and public health, there is a growing demand to replace them with plant-based derivatives or combine these green agents with antibiotics to give synergistic effects. In this study, the antimicrobial properties of essential oils and extracts of six medicinal plants from Ahvaz region, Iran, against 12 gram-positive and gram-negative bacteria were evaluated. The EOs and extracts were extracted using water distillation with Clevenger apparatus. We analyzed the chemical composition of essential oils obtained. The antimicrobial properties and determination of the minimum concentration of growth inhibition of herbals were investigated by the broth dilution technique. All analyzed extracts and EOs showed antibacterial effects. The antimicrobial activity of Oliveria decumbens was strongest herbals with the least MIC ranges (0.008–0.1 mg/ml for EO, 0.9–20 mg/ml for extract), while the antibacterial effects of Artemisia vulgaris extract and Glycyrrhiza glabra EO with the highest MIC were weaker than the others. According to the effectiveness of plant extracts on bacteria, Pseudomonas aeruginosa was resistant to all extracts except Oliveria decumbens. In contrast, Bacillus cereus was more sensitive than other strains against analyzed EOs and extracts. In Oliveria decumbens, EO detected 18 components by GC/MS with accessible genuine standards, accounting for 98% of the oil content. It seems that due to the antimicrobial properties of the extracts and essential oils observed in this study, they can be used as an alternative to antimicrobial drugs after more extensive studies.

Antimicrobial Properties of Essential Oils of the Monarda Genus Plants Cultivated in Belarus

Antimicrobial Properties of Essential Oils of the Monarda Genus Plants Cultivated in Belarus

Variation in the Antimicrobial Activity of Essential Oils from Cultivars of Lavandula angustifolia and L. × intermedia

The antimicrobial properties of essential oil from Lavandula sp. raise hopes related to its use in phytotherapy. This study aimed to evaluate the antimicrobial activity of essential oils from cultivars of L. angustifolia (‘Hidcote Blue Strain’, ‘Hidcote Blue’) and L. × intermedia (‘Phenomenal’, ‘Grosso’) grown in central-eastern Poland, that is, at the border of the northern lavender cultivation range. The chemical composition of the essential oils was determined by GC/MS. Essential oil concentrations (20, 10, 5, 2.5, 1.25, 0.6, 0.3, 0.16, 0.08, and 0.04 mg/mL) were tested to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) towards ten strains of Gram-positive bacteria, five Gram-negative bacteria, and eight yeasts in vitro culture. Essential oils from the Lavendula cultivars showed antimicrobial activity against all microorganisms analysed. The yeasts were characterised by higher sensitivity to lavender oil compared to bacteria, while Gram-positive bacteria were more sensitive than Gram-negative bacteria. The lowest MIC values for bacteria and fungi were obtained for ‘Grosso’. Furthermore, the ‘Grosso’ oil showed the highest fungicidal activity, while the highest bactericidal activity was found in ‘Hidcote Blue’ and ‘Grosso’. Using Staphylococcus aureus as an example, it was shown that different bacterial strains of the same species show varying sensitivity to the essential oil. A higher oil content was noted for the cultivars L. × intermedia, especially for the ‘Phenomenal’. Linalyl acetate and linalool were the main components of the essential oil in all cultivars. However, in the ‘Grosso’ oil, a high content of terpinen-4-ol (18.08%) was also recorded. An analysis of the relationships between the content of the main components in the analysed essential oils and the antimicrobial activity of essential oils suggested that linalool and terpinen-4-ol were compounds potentially responsible for antimicrobial activity. The obtained results allow us to conclude that essential oil with significant antimicrobial activity can be obtained from Lavandula sp. plants harvested in the northern part of the cultivation range.

Antimicrobial action of Oregano, Thyme, Clove, Cinnamon and Black pepper essential oils free and encapsulated against foodborne pathogens

The antimicrobial properties of essential oils from spice and medicinal plants have aroused interest for their potential as an alternative to the use of chemical preservatives in foods. In this work, we studied the bacteriostatic and bactericidal effects of Oregano, Thyme, Clove, Cinnamon and Black-pepper essential oils (EOs) against strains of Staphylococcus aureus, Listeria sp, Escherichia coli and Salmonella sp. that contaminate food and cause Foodborne Diseases (FBD). The study was carried out with free EOs and in blends, to study the potential synergistic effect between them. Moreover, microcapsules containing oregano, thyme and clove EO were developed with different wall materials obtained by complex coacervation between three different polymers (chitosan, gelatin, and Arabic gum). Among the free EOs, cinnamon EO stood out in inhibiting the growth of all bacteria tested. The best combination was Oregano + Thyme, presenting a synergistic effect against the bacteria tested with a considerable reduction in the initial Minimum Inhibitory Concentration (MIC). Encapsulation positively influenced the inhibitory power of the oils by resulting in MICs lower or close to those of the oil in the free form. Given the above, we can conclude that the tested EOs perform well in inhibiting these pathogens and that their effect is potentiated when tested in combination.