A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol

BACKGROUND Drug resistance and failure of antibiotics to treat bacterial infections is the most challenging clinical and public health problem. There is ongoing research for new, safe and effective alternatives to antibiotics for the therapeutic management of bacterial infections. Essential oils are one of the outcomes of such type of research. This study was conducted to evaluate the effect of Artemisia judaica essential oil against the bacterial & the biofilm activity and to study its mode of action. METHODS Minimum biofilm inhibitory concentration (MBIC) susceptibility assays were performed using a biofilm inoculator with a 96-well plate with peg lid. Minimum inhibitory concentration (MIC) was performed in normal microtiter plates using a twofold dilution series. RESULTS The values of the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC) and the minimum biofilm eradication concentration (MBEC) were in the range of 0.25 - 1 mg / mL, 1.0 - 4 mg / mL, 0.50 - 2 mg / mL and 1.0 - 8 mg / mL, respectively. There was increase in the leakage of K+ and cellular components through the membrane of the tested bacteria under the effect of essential oil of Artemisia judaica proving that the cell membrane was the site of action of Artemisia judaica. This was shown by its inhibitory effect on the Staphylococcus epidermidis (ATCC 35984) during initial adherence at sub-inhibitory concentrations. CONCLUSIONS The essential oil of Artemisia judaica had the ability to overcome all tested bacterial resistance and also prevents the formation of biofilm. The site of action of Artemisia judaica essential oil was the cell membrane and cell wall. KEY WORDS Antibacterial, Antibiofilm, Artemisia judaica, Mode of Action, Essential Oil

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Antifungal Effects of Zataria multiflora Essential Oil on the Inhibitory Growth of some Postharvest Pathogenic Fungi

Notulae Scientia Biologicae ◽

10.15835/nsb749650 ◽

2015 ◽

Vol 7 (4) ◽

pp. 412-416

Author(s):

Mahboobeh NASSERI ◽

Hossein AROUIEE ◽

Shiva GOLMOHAMMADZADEH ◽

Mahmoud Reza JAAFARI ◽

Hossein NEAMATI

Keyword(s):

Minimum Inhibitory Concentration ◽

Essential Oil ◽

Inhibitory Concentration ◽

Alternaria Solani ◽

Pathogenic Fungi ◽

Aspergillus Ochraceus ◽

Malt Extract ◽

Zataria Multiflora ◽

Minimum Fungicidal Concentration

The present study aimed to determine minimum inhibitory concentration and minimum fungicidal concentration of the essential oil of Zataria multiflora to control Alternaria solani, Rhizoctonia solani, Rhizopus stolonifer, Aspergillus flavus, Aspergillus ochraceus and Aspergillus niger. The essential oil of Zataria multiflora was tested in vitro on PDA (malt extract agar medium) with eight concentrations: 0, 10, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 ppm. This investigation followed the completely randomized design (CRD) with three replications. GC-MS evaluations of the essential oil revealed that thymol (35%), carvacrol (34%), cymene-p (9.89%), gamma-terpinene (5.88%) and alpha-pinene (4.22%) were the main compounds of Zataria multiflora oil. The results showed that the essential oil of Zataria multiflora has antifungal activity; the lowest inhibition (75%) was observed in the A. niger, while the highest inhibition (95.3%) was observed in A. solani. Minimum inhibitory concentration for A. solani, R. solani, R. stolonifer, A. flavus, A. ochraceus and A. niger was 200, 200, 200, 300, 300 and 200 ppm respectively. In addition, the present results showed that minimum fungicidal concentration (MFC) for A. solani, R. solani, R .stolonifer, A. niger and A.ochraceus was 600, 400, 300, 900 and 700 ppm respectively and none of the tested concentrations were fatal for A. flavus. A. solani and R. solani showed a strong sensitivity to Zataria multiflora essential oil at all concentrations. Findings of the current study suggest that essential oils of Zataria multiflora could be used for control of postharvest phytopathogenic fungi on fruits or vegetables.

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Chemical Composition and Antifungal Activity of the Essential Oils of Schinus weinmannifolius Collected in the Spring and Winter

Natural Product Communications ◽

10.1177/1934578x1400900940 ◽

2014 ◽

Vol 9 (9) ◽

pp. 1934578X1400900

Author(s):

Camila Hernandes ◽

Silvia H. Taleb-Contini ◽

Ana Carolina D. Bartolomeu ◽

Bianca W. Bertoni ◽

Suzelei C. França ◽

...

Keyword(s):

Antimicrobial Activity ◽

Chemical Composition ◽

Minimum Inhibitory Concentration ◽

Antifungal Activity ◽

Essential Oil ◽

Essential Oils ◽

Inhibitory Concentration ◽

Biological Activities ◽

Antimicrobial Action ◽

Pharmacological Profile

Reports on the chemical and pharmacological profile of the essential oil of Schinus weinmannifolius do not exist, although other Schinus species have been widely investigated for their biological activities. This work aimed to evaluate the chemical composition and antimicrobial activity of the essential oil of S. weinmannifolius collected in the spring and winter. The essential oils were extracted by hydrodistillation, analyzed by GC/MS and submitted to microdilution tests, to determine the minimum inhibitory concentration. The oils displayed different chemical composition and antimicrobial action. Bicyclogermacrene and limonene predominated in the oils extracted in the winter and spring, respectively, whereas only the latter oil exhibited antifungal activity.

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Screening of antimicrobial activity of essential oil and methanol extract of Satureja hortensis on foodborne bacteria and fungi

Czech Journal of Food Sciences ◽

10.17221/753-cjfs ◽

2008 ◽

Vol 25 (No. 2) ◽

pp. 81-89 ◽

Cited By ~ 43

Author(s):

A. Adiguzel ◽

H. Ozer ◽

H. Kilic ◽

B. Cetin

Keyword(s):

Antimicrobial Activity ◽

Chemical Composition ◽

Minimum Inhibitory Concentration ◽

Essential Oil ◽

Inhibitory Concentration ◽

Methanol Extract ◽

Antimicrobial Activities ◽

Satureja Hortensis ◽

Bacteria And Fungi

The present work reports the in vitro antimicrobial activities of the essential oil and methanol extract from Satureja hortensis as well as the content of its essential oil. The chemical composition of hydrodistilled essential oil of Satureja hortensis was analysed by means of GC-MS. Thirty constituents were identified. The main constituents of the oil were thymol (40.54%), γ-terpinene (18.56%), carvacrol (13.98%), and p-cymene (8.97). The essential oil of Satureja hortensis exhibited the activity against 25 bacteria, 8 fungi, and a yeast, C. albicans; exerting the Minimum Inhibitory Concentration values (MIC) ranging from 15.62 to 250 µl/ml. Similarly, methanol extract of the plant also showed antimicrobial activity.

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The Chemical Composition and Anti-mycobacterial Activities of Trachyspermum copticum and Pelargonium graveolens Essential Oils

Recent Patents on Anti-Infective Drug Discovery ◽

10.2174/1574891x14666191028113321 ◽

2020 ◽

Vol 15 (1) ◽

pp. 68-74 ◽

Cited By ~ 1

Author(s):

Jalil Kardan-Yamchi ◽

Mohaddese Mahboubi ◽

Hossein Kazemian ◽

Gholamreza Hamzelou ◽

Mohammad M. Feizabadi

Keyword(s):

Mycobacterium Tuberculosis ◽

Chemical Composition ◽

Minimum Inhibitory Concentration ◽

Essential Oil ◽

Essential Oils ◽

Inhibitory Concentration ◽

Mycobacterium Fortuitum ◽

Drug Resistant ◽

Pelargonium Graveolens ◽

Trachyspermum Copticum

Background: Microbial resistance to antibiotics and their adverse effects related to these antibiotics are a matter of global public health in the 21th century. The emergence of drug-resistant strains, has gained the interest of the scientists to discover new antimicrobial agents from the essential oil of medicinal plants. Methods: Anti-mycobacterial effects of Trachyspermum copticum and Pelargonium graveolens essential oils were determined against multi-drug resistant clinical strains of Mycobacterium tuberculosis, Mycobacterium kansasii, Mycobacterium fortuitum and standard strain of Mycobacterium tuberculosis H37Rv by a Broth micro-dilution method. Pelargonium graveolens plant named Narmada was discovered by Kulkarni R.N et al. (Patent ID, USPP12425P2) and a formulation comprising thymol obtained from Trachyspermum is useful in the treatment of drug-resistant bacterial infections (Patent ID, US6824795B2). The chemical composition of hydro-distilled essential oils was determined by GC and GC-MS. Results: Minimum Inhibitory Concentration (MIC) values for T. copticum essential oil against tested isolates were ranged from 19.5 µg/mL to 78 µg/mL. The least minimum inhibitory concentration of P. graveolens extract against M. Kansasii and MDR-TB was 78 µg/ml. Conclusion: The results of the present research introduced T. copticum and P. graveolens essential oils as a remarkable natural anti-mycobacterial agent, but more pharmacological studies are required to evaluate their efficacy in animal models.

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In VitroAntimicrobial Activity of Essential Oil ofThymus schimperi,Matricaria chamomilla,Eucalyptus globulus, andRosmarinus officinalis

International Journal of Microbiology ◽

10.1155/2016/9545693 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 30

Author(s):

Awol Mekonnen ◽

Berhanu Yitayew ◽

Alemnesh Tesema ◽

Solomon Taddese

Keyword(s):

Antimicrobial Activity ◽

Minimum Inhibitory Concentration ◽

Essential Oil ◽

Essential Oils ◽

Inhibitory Concentration ◽

Antimicrobial Activities ◽

Diffusion Method ◽

Drug Preparation ◽

Bacteria And Fungi

In this study, thein vitroantimicrobial activities of four plant essential oils (T. schimperi,E. globulus,R. officinalis, andM. Chamomilla) were evaluated against bacteria and fungi. The studies were carried out using agar diffusion method for screening the most effective essential oils and agar dilution to determine minimum inhibitory concentration of the essential oils. Results of this study revealed that essential oils ofT. schimperi,E. globulus, andR. officinaliswere active against bacteria and some fungi. The antimicrobial effect ofM. chamomillawas found to be weaker and did not show any antimicrobial activity. The minimum inhibitory concentration values ofT. schimperiwere<15.75 mg/mL for most of the bacteria and fungi used in this study. The minimum inhibitory concentration values of the other essential oils were in the range of 15.75–36.33 mg/mL against tested bacteria. This study highlighted the antimicrobial activity of the essential oil ofE. globulus,M. chamomilla,T. Schimperi, andR. officinalis. The results indicated thatT. schimperihave shown strong antimicrobial activity which could be potential candidates for preparation of antimicrobial drug preparation.

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Antifungal Activity of Essential Oil ofEucalyptus camaldulensisDehnh. against SelectedFusariumspp.

International Journal of Microbiology ◽

10.1155/2017/8761610 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 22

Author(s):

Martin Muthee Gakuubi ◽

Angeline W. Maina ◽

John M. Wagacha

Keyword(s):

Minimum Inhibitory Concentration ◽

Antifungal Activity ◽

Essential Oil ◽

Mycelial Growth ◽

Inhibitory Concentration ◽

Eucalyptus Camaldulensis ◽

Gas Chromatography Mass Spectrometry ◽

Diffusion Method ◽

Minimum Fungicidal Concentration ◽

Potential Use

The objective of this study was to evaluate the antifungal activity of essential oil (EO) ofEucalyptus camaldulensisDehnh. against fiveFusariumspp. commonly associated with maize.The essential oil had been extracted by steam distillation in a modified Clevenger-type apparatus from leaves ofE. camaldulensisand their chemical composition characterized by gas chromatography mass spectrometry. Poisoned food technique was used to determine the percentage inhibition of mycelial growth, minimum inhibitory concentration, and minimum fungicidal concentration of the EO on the test pathogens. Antifungal activity of different concentrations of the EO was evaluated using disc diffusion method. The most abundant compounds identified in the EO were 1,8-cineole (16.2%),α-pinene (15.6%),α-phellandrene (10.0%), and p-cymene (8.1%). The EO produced complete mycelial growth inhibition in all the test pathogens at a concentration of 7-8 μL/mL after five days of incubation. The minimum inhibitory concentration and minimum fungicidal concentration of the EO on the test fungi were in the range of 7-8 μL/mL and 8–10 μL/mL, respectively. These findings confirm the fungicidal properties ofE. camaldulensisessential oils and their potential use in the management of economically importantFusariumspp. and as possible alternatives to synthetic fungicides.

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Effects of oregano, carvacrol and thymol on Staphylococcus aureus and Staphylococcus epidermidis biofilms

Journal of Medical Microbiology ◽

10.1099/jmm.0.46804-0 ◽

2007 ◽

Vol 56 (4) ◽

pp. 519-523 ◽

Cited By ~ 284

Author(s):

Antonia Nostro ◽

Andrea Sudano Roccaro ◽

Giuseppe Bisignano ◽

Andreana Marino ◽

Maria A. Cannatelli ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Essential Oil ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Inhibitory Concentration ◽

Oregano Essential Oil ◽

Planktonic Growth ◽

Subinhibitory Concentrations

The aim of this study was to evaluate the effect of oregano essential oil, carvacrol and thymol on biofilm-grown Staphylococcus aureus and Staphylococcus epidermidis strains, as well as the effects of the oils on biofilm formation. For most of the S. aureus (n=6) and S. epidermidis (n=6) strains tested, the biofilm inhibitory concentration (0.125–0.500 %, v/v, for oregano, and 0.031–0.125 %, v/v, for carvacrol and thymol) and biofilm eradication concentration (0.25–1.0 %, v/v, for oregano and 0.125–0.500 %, v/v, for carvacrol and thymol) values were twofold or fourfold greater than the concentration required to inhibit planktonic growth. Subinhibitory concentrations of the oils attenuated biofilm formation of S. aureus and S. epidermidis strains on polystyrene microtitre plates.

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Synthesis and anti-tubercular activity of 3-substituted benzothiophene-1,1-dioxides

10.7287/peerj.preprints.502v1 ◽

2014 ◽

Author(s):

N. Susantha Chandrasekera ◽

Mai A Bailey ◽

Megan Files ◽

Torey Alling ◽

Stephanie K Florio ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Minimum Inhibitory Concentration ◽

Mode Of Action ◽

Drug Targets ◽

Inhibitory Concentration ◽

Eukaryotic Cells ◽

Structure Activity ◽

Novel Drug ◽

Further Development ◽

Novel Drug Targets

We demonstrated that the 3-substituted benzothiophene-1,1-dioxide class of compounds are effective inhibitors of Mycobacterium tuberculosis growth under aerobic conditions. We examined substitution at the C-3 position of the benzothiophene-1,1-dioxide series systematically to delineate structure-activity relationships influencing potency and cytotoxicity. Compounds were tested for inhibitory activity against virulent M. tuberculosis and eukaryotic cells. The tetrazole substituent was most potent, with a minimum inhibitory concentration (MIC) of 2.6 µM. However, cytotoxicity was noted with even more potency (Vero cell TC50 = 0.1 µM). Oxadiazoles had good anti-tubercular activity (MICs of 3–8 µM), but imidazoles, thiadiazoles and thiazoles had little activity. Cytotoxicity did not track with anti-tubercular activity, suggesting different targets or mode of action between bacterial and eukaryotic cells. However, we were unable to derive analogs without cytotoxicity; all compounds synthesized were cytotoxic (TC50 of 0.1–5 µM). We conclude that cytotoxicity is a liability in this series precluding it from further development. However, the series has potent anti-tubercular activity and future efforts towards identifying the mode of action could result in the identification of novel drug targets.

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Antifungal activity of Cymbopogon citratus essential oil against Aspergillus flavus

Ciência e Natura ◽

10.5902/2179460x36055 ◽

2019 ◽

Vol 41 ◽

pp. 20

Author(s):

Ana Paula Martinazzo ◽

Filipe Da Silva de Oliveira ◽

Carlos Eduardo de Souza Teodoro

Keyword(s):

Minimum Inhibitory Concentration ◽

Essential Oil ◽

Aspergillus Flavus ◽

Inhibitory Concentration ◽

Fungal Growth ◽

In Vitro Tests ◽

Cymbopogon Citratus ◽

Object Of Study ◽

Corn Kernels

The search for alternatives for the control of microbiological contamination in foods has been the object of study in different scientific areas. This study aimed to evaluate the efficiency of lemon grass (Cymbopogon citratus) essential oil in controlling the growth of the fungus Aspergillus flavus in three types of analysis: first, by in vitro tests, in essential oil doses between 0.2 and 1.0 μL/ml; second, by serial microdilution to determine the minimum inhibitory concentration, in doses between 0.1 and 1.2 μL/mL; and third, by inhibition of fungal growth in corn kernels contaminated using essential oil doses of 0.4, 0.7, and 1.0 μL/mL, in the incubation times of 14, 28, and 42 days. The in vitro tests showed that the essential oil controlled the fungus from doses of 0.6 μL/mL, but the dose of 1.0 μL/mL controlled 100% growth until day eight of incubation, from which it decreased. The minimum inhibitory concentration for the microdilution analysis was 0.9 μL/mL. The evaluation of the corn kernels for all doses of essential oil and times tested showed 100% inhibition of the fungal growth.

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