scholarly journals The Variability of Thymol and Carvacrol Contents Reveals the Level of Antibacterial Activity of the Essential Oils from Different Accessions of Oliveria decumbens

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 409
Author(s):  
Tahereh Khoshbakht ◽  
Akbar Karami ◽  
Aminallah Tahmasebi ◽  
Filippo Maggi

Oliveria decumbens (Apiaceae) is an aromatic herb traditionally employed in the Persian medicine for the treatment of infectious and gastrointestinal disorders. In the present study, we analyzed the chemical composition of essential oils obtained from different Iranian populations and evaluated their efficacy on a panel of human pathogens (Staphylococcus aureus and Escherichia coli), probiotic (Bacillus subtilis), and phytopathogens (Clavibacter michiganensis, Curtobacterium flaccumfaciens, Xanthomonas citri, and Agrobacterium tumefaciens). The gas chromatographic-mass spectrometry analysis put in evidence four main volatile constituents such as thymol (20.3–36.4%), carvacrol (18.8–33.1%), γ-terpinene (10.6–25.9%), and p-cymene (9.5–17.3%), though with significant variability from an essential oil to another. Notably, the oils from the populations sited in Nourabad Mamasani and Dehdasht showed the highest amount of the phenolic monoterpenes thymol (36.4 and 35.2%, respectively) and carvacrol (33.1 and 30.6%, respectively). The antibacterial activity of O. decumbens essential oils was assessed by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods, showing high activity for the samples from Nourabad Mamasani and Dehdasht populations exhibiting high level of the above phenolics. The obtained MIC and MBC values (mg/ml) were in the ranges 0.0625–2 mg/ml and 1–16 mg/ml, respectively. Noteworthy, in some cases, the antibacterial activity of O. decumbens essential oils was higher than that of chloramphenicol used as positive control. The average MBCs displayed by the O. decumbens samples showed that C. flaccumfaciens had the highest sensitivity to the essential oils. Based on these results, our work shed light on selected O. decumbens populations deserving proper breeding and cultivation strategies in order to warrantee production of bioactive essential oils to be used at pharmaceutical and agricultural level to combat several pathogens.

Plants ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 79 ◽  
Author(s):  
María Ibáñez ◽  
María Blázquez

The chemical composition of winter savory, peppermint, and anise essential oils, and in vitro and in vivo phytotoxic activity against weeds (Portulaca oleracea, Lolium multiflorum, and Echinochloa crus-galli) and food crops (maize, rice, and tomato), have been studied. Sixty-four compounds accounting for between 97.67–99.66% of the total essential oils were identified by Gas Chromatography-Mass Spectrometry analysis. Winter savory with carvacrol (43.34%) and thymol (23.20%) as the main compounds produced a total inhibitory effect against the seed germination of tested weed. Menthol (48.23%), menthone (23.33%), and iso-menthone (16.33%) from peppermint only showed total seed germination inhibition on L. multiflorum, whereas no significant effects were observed with trans-anethole (99.46%) from anise at all concentrations (0.125–1 µL/mL). Low doses of peppermint essential oil could be used as a sustainable alternative to synthetic agrochemicals to control L. multiflorum. The results corroborate that in vivo assays with a commercial emulsifiable concentrate need higher doses of the essential oils to reproduce previous in vitro trials. The higher in vivo phytotoxicity of winter savory essential oil constitutes an eco-friendly and less pernicious alternative to weed control. It is possible to achieve a greater in vivo phytotoxicity if less active essential oil like peppermint is included with other active excipients.


Author(s):  
R. Cabrera-Contreras ◽  
R. Morelos-Ramírez ◽  
J. P. Quiróz-Ríos ◽  
D. Muñoz-Quiróz

Essential oils (EOs) are commonly used in food industry, due that they possess antioxidative and antimicrobial properties. There are few essential oils that have been used in medicine, due to its potent antibacterial activity against intrahospital pathogens. OEO has experimentally shown potent antibacterial effect on nosocomial Gram-positive bacteria, therefore it can be very useful in hospital environments, where there are many bacterial pathogens, which are the etiological agents of nosocomial infections and most of them are resistant to several antibiotics. Objective: The aim of this study was to determine antimicrobial effect of OEO on most frequent bacterial intrahospital pathogens: MRSA, MRSE comparatively to selected ATCC bacterial reference strains. Methods: This experimental study investigates the antibacterial action of oregano (Origanum vulgare) essential oil (OvEO) on two human pathogens: Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE) Here, we used OEO against one of the most prominent antibiotic-resistant bacterial strains: methicillin-resistant SA (MRSAmecA+ = Meticillin Resistant SA and mecA- = Meticillin Resistance SA ), methicillin-resistant SE (MRSEmecA+ = Meticillin Resistance Staphylococcus epidermidis mecA+) and reference strains: S. aureus ATCC 700699, S. epidermidis ATCC 359845 and E. coli ATCC 25922. Bactericidal effects of the OEO on these bacteria were mainly evaluated using undiluted and four serial dilutions in coconut oil (CCO) l: 1:10, 1:100, 1:200, 1:400. Results: OEO, undiluted and 4 serial dilutions showed potent antibacterial activity against all strains tested. In conclusion, this OEO could be used as an alternative in medicine. The ability of OEO to inhibit and kill clinical Multi-Drug-Resistant (MDR): MRSA and MRSE strains, highlights it´s potential for use in the management of drug-resistant MDR infections in hospitals wards.


Author(s):  
Fatima El Kamari ◽  
Amal Taroq ◽  
Yassine El Atki ◽  
Imane Aouam ◽  
Badiaa Lyoussi ◽  
...  

Objective: The aim of the current study is to determine the chemical composition and evaluate antibacterial activity of Vitex agnus-castus L. (VAC) essential oils against some bacteria causing nosocomial infections in the neonatal and intensive care rooms at the university hospital center of Fez Morocco. Methods: The phytochemical screening of essential oils was determined using gas chromatography (GC) and GC-mass spectrometry analysis. The antibacterial test was evaluated against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria species (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis) using disc diffusion method. Results: Twenty-nine components were identified in the fruits’ oil representing 93.1% of total oil. The major components in the fruits oil are 1,8-cineole (11.6%), α-thujene (9.3%), phyllocladene (8.2%), α-pinene (7.9%), caryophyllene (5.9%), and cubenol (5%). Furthermore, 28 components were identified in the leaf essential oil. The main component was caryophyllene (9.5%), followed by 1,8-cineole (8.7%), manoyl oxide (7.3%), eugenyl acetate (7.1%), phyllocladene (6.8%), and α-pinene (5.2%). Antibacterial activity of both oils showed a strong activity against nosocomial bacteria tested. Conclusion: Essential oils of Moroccan VAC could be exploited as natural drugs for bacteria, especially those who have acquired resistance to conventional antibiotics.


2018 ◽  
Vol 19 (10) ◽  
pp. 2946 ◽  
Author(s):  
Jingtao Li ◽  
Xianghui Zhang ◽  
Le Li ◽  
Jinliang Liu ◽  
Yanhua Zhang ◽  
...  

Sclerotinia sclerotiorum (Lib.) de Bary is a devastating necrotrophic fungal pathogen attacking a broad range of agricultural crops. In this study, although the transcript accumulation of SsNsd1, a GATA-type IVb transcription factor, was much lower during the vegetative hyphae stage, its mutants completely abolished the development of compound appressoria. To further elucidate how SsNsd1 influenced the appressorium formation, we conducted proteomics-based analysis of the wild-type and ΔSsNsd1 mutant by two-dimensional electrophoresis (2-DE). A total number of 43 differentially expressed proteins (≥3-fold change) were observed. Of them, 77% were downregulated, whereas 14% were upregulated. Four protein spots fully disappeared in the mutants. Further, we evaluated these protein sequences by mass spectrometry analysis of the peptide mass and obtained functionally annotated 40 proteins, among which only 17 proteins (38%) were identified to have known functions including energy production, metabolism, protein fate, stress response, cellular organization, and cell growth and division. However, the remaining 23 proteins (56%) were characterized as hypothetical proteins among which four proteins (17%) were predicted to contain the signal peptides. In conclusion, the differentially expressed proteins identified in this study shed light on the ΔSsNsd1 mutant-mediated appressorium deficiency and can be used in future investigations to better understand the signaling mechanisms of SsNsd1 in S. sclerotiorum.


2019 ◽  
Vol 74 (11-12) ◽  
pp. 289-293
Author(s):  
Modjinan Kayangar ◽  
Raymond Ngansop Nono ◽  
Jonas Kühlborn ◽  
Roland Tchuenguem ◽  
Beaudelaire K. Ponou ◽  
...  

Abstract A new saponin, 3-O-β-d-3-oxo-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (1), was isolated from the methanol extract of stem bark of Crossopteryx febrifuga together with the known 3β-d-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (2), shanzhiside methyl ester (3), shanzhiside (4), β-sitosterol (5), β-sitosterol-3-O-β-d-glucopyranoside (6), ursa-12,20(30)-diene-27,28-dioic acid (7), hederagenin (8), and oleanolic acid (9). The structures were established by comprehensive interpretation of their spectral data 1D- (1H and 13C), 2D-NMR (1H-1H COSY, HMQC, HMBC), spectroscopic, and electrospray ionisation time-of-flight mass spectrometry analysis. The isolated compounds and extracts were screened for their antibacterial properties. Although the EtOAc and n-BuOH extracts exhibited considerable antibacterial activity against Pseudomonas aeruginosa with minimum inhibitory concentration (MIC) value of 32 μg/mL, compounds 2 and 8 showed moderate activity against Enterococcus faecalis with MIC values of 256 and 128 μg/mL, respectively. The new compound (1) exhibited a moderate antibacterial activity against Staphylococcus aureus with an MIC value of 512 μg/mL.


2021 ◽  
Author(s):  
Mohamed Ahmed ◽  
Jared Stuart Mackenzie ◽  
Robert Krause ◽  
Barry Truebody ◽  
Liku Bekele Tezera ◽  
...  

Mycobacterium tuberculosis (Mtb) is one of the most successful human pathogens and remains a leading cause of death from infectious disease. Interferonγ (IFNγ) is a central regulator of the immune defense against Mtb. Several cytokines have been shown to increase virulence of other bacterial pathogens, leading us to investigate whether IFNγ has a direct effect on Mtb. We found that both recombinant and T cell derived IFNγ rapidly induced a dose dependent increase in the oxygen consumption rate (OCR) of Mtb, consistent with increased bacterial respiration. This was also observed in clinical strains, but not in the vaccine strain Bacillus Calmette Guerin (BCG), and did not occur for other cytokines tested, including TNFα. IFNγ binds to the cell surface of intact Mtb, but not BCG, whilst TNFα binds to neither. Mass spectrometry analysis identified mycobacterial membrane protein large 10 (MmpL10) as the transmembrane binding partner. Consistent with this, IFNγ binding and the OCR response was absent in a Mtb Δmmpl10 strain and restored by complementation of the mutant strain. RNA-sequencing of IFNγ exposed Mtb revealed a distinct transcriptional profile, including genes involved in virulence and cholesterol catabolism. Finally, exposure of Mtb cells to IFNγ resulted in sterilization of bacilli treated with isoniazid (INH), indicating clearance of phenotypically resistant bacteria that persist in the presence of INH alone. Our data suggest a novel mechanism allowing Mtb to respond to host immune activation that may be important in the immunopathogenesis of TB and have use in novel eradication strategies.


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