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1.
Curr Microbiol ; 80(12): 398, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910319

RESUMO

The present study aimed to evaluate the antibacterial activity of the essential oil (EO) of Moroccan endemic Thymus broussonnetii alone, and in combination with EOs obtained from selected medicinal plants, namely Myrtus communis, Artemisia herba alba, Thymus pallidus, Thymus satureioides, Teucrium polium, and Rosmarinus officinalis. The synergistic interactions between the most effective combinations based on T. broussonnetii EO with two conventional antibiotics (streptomycin and ciprofloxacin) were also investigated. T. broussonnetii EO possessed a higher inhibitory activity against tested pathogenic bacteria with inhibition zone diameter (IZ) ranging from 21.61 ± 0.03 to 40.09 ± 0.02 mm, and MIC values between 0.140 mg/mL and 0.280 mg/mL. M. communis, A. herba alba, T. pallidus, T. satureioides, T. polium, and R. officinalis EOs showed moderate to weak antibacterial activity. Among tested EO mixtures, the highest synergistic antibacterial effect was recorded with the EO combination of T. broussonnetii and T. pallidus against S. aureus, E. coli, and S. enterica (FICI = 0.258). This EO combination was also the most effective mixture to synergistically enhance the antibacterial activity of the two antibiotics with up to a 128-fold increase, particularly against the gram-negative E. coli. These findings suggest that T. broussonnetii EO may be an interesting source of natural antimicrobials, for use in combination therapies with other plant EOs, and with conventional antimicrobial drugs to tackle the emergence of multidrug-resistant bacteria.


Assuntos
Anti-Infecciosos , Óleos Voláteis , Plantas Medicinais , Thymus (Planta) , Antibacterianos/farmacologia , Óleos Voláteis/farmacologia , Escherichia coli , Staphylococcus aureus , Testes de Sensibilidade Microbiana , Anti-Infecciosos/farmacologia
2.
BioTech (Basel) ; 11(3)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35892927

RESUMO

Traditional antimicrobial antibiotics are increasingly suffering from the emergence of multidrug resistance among pathogenic microorganisms. The antibiotic era is threatened by the ruthless rise of resistance in bacterial infections. A significant role in these resistance profiles is attributed to multidrug efflux pumps. Hence, much effort is being directed towards developing new compounds to overcome this problem. During our screening program of efflux pumps inhibitors (EPI) produced by bioactive Moroccan Actinobacteria, 210 isolates were screened for their antibacterial activities against Escherichia coli strains containing a system of efflux pump AcrAB-TolC, fully functional, and its mutant, inactivated due to the insertion of transposon Tn903 in AcrAB operon, using the method of agar disc diffusion. The results showed that 14 isolates were able to produce EPI as they were active against the wild type strain but not against the mutant in comparison with the synthetic inhibitor L-Phe-L-Arg-ß-naphthylamide (PaßN). We focused on the highest EPI activity produced by four strains (Z332, Z35/G, Z385/b and 136). Taxonomic studies and the 16S rDNA sequence indicated that these strains belonged to the Streptomyces species. This work could contribute to the discovery of a new class of antibacterial agents that could expand the therapeutic arsenal.

3.
Mar Drugs ; 20(3)2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35323468

RESUMO

Volatile compounds from the marine cyanolichen Lichina pygmaea, collected from the Moroccan Atlantic coast, were extracted by hydrodistillation and their putative chemical composition was investigated by gas chromatography coupled to mass spectrometry (GC/MS). Based on the obtained results, Lichina pygmaea volatile compounds (LPVCs) were mainly dominated by sesquiterpenes compounds, where γ-himachalene, ß-himachalene, (2E,4E)-2,4 decadienal and α-himachalene were assumed to be the most abundant constituents, with percentage of 37.51%, 11.71%, 8.59% and 7.62%, respectively. LPVCs depicted significant antimicrobial activity against all tested strains (Staphylococcus aureus CCMM B3, Pseudomonas aeruginosa DSM 50090, Escherichia coli ATCC 8739 and Candida albicans CCMM-L4) with minimum inhibitory concentration (MIC) values within the range of 1.69-13.5 mg/mL. Moreover, this LPVC showed interesting scavenging effects on the 2,2-diphenyl-1-picrylhydrazyl radical with an IC50 of 0.21 mg/mL. LPVCs could be an approving resource with moderate antimicrobial potential and interesting antioxidant activity for cosmetics and pharmaceutical applications.


Assuntos
Anti-Infecciosos , Antioxidantes , Ascomicetos/química , Sesquiterpenos , Compostos Orgânicos Voláteis , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Compostos de Bifenilo/química , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Picratos/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Sesquiterpenos/análise , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/farmacologia
4.
Molecules ; 26(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34641393

RESUMO

This study reported the volatile profile, the antimicrobial activity and the synergistic potential of essential oil (EO) from the Moroccan endemic Thymus atlanticus (Ball) Roussine, in combination with the antibiotics ciprofloxacin and fluconazole for the first time, to the best of our knowledge. The EO chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS) analysis and the antimicrobial activity assessed by the disc diffusion method against three Gram positive (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and one clinical isolate, Klebsiella pneumonia). The antifungal activity was evaluated in four pathogenic yeasts (Candida albicans, C. glabrata, C. krusei and C. parapsilosis). The minimum inhibition concentration (MIC) and the synergistic effect with ciprofloxacin and fluconazole were determined by the two-fold dilution technique and checkerboard test, respectively. Twenty-one constituents were identified by GC-MS in the EO, including carvacrol (21.62%) and borneol (21.13%) as the major components. The EO exhibited a significant antimicrobial activity with inhibition zones ranging from 0.7 mm to 22 mm for P. aeruginosa and B. subtilis, respectively, and MIC values varying from 0.56 mg/mL to 4.47 mg/mL. The fractional inhibitory concentration index (FICI) values ranged from 0.25 to 0.50 for bacteria and from 0.25 to 0.28 for yeasts. The maximum synergistic effect was observed for K. pneumonia with a 256-fold gain of antibiotic MIC. Our results have suggested that EO from T. atlanticus may be used alone or in association with antibiotics as a new potential alternative to prevent and control the emergence of resistant microbial strains both in the medical field and in the food industry.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Sinergismo Farmacológico , Óleos Voláteis/farmacologia , Thymus (Planta)/química , Marrocos
5.
Antibiotics (Basel) ; 10(9)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34572630

RESUMO

The development of opportunistic pathogenic Candida strains insensitive to several classes of antifungals has emerged as a major health care problem during the last years. Combinational therapy of natural products (e.g., essential oils, EOs) with conventional antifungals has been suggested as a promising alternative to overcome this medical problem. The present study investigates the potential antifungal activity of EOs extracted from some selected medicinal plants, alone and in combination with two common conventional antifungals (fluconazole and amphotericin B) against four clinical Candida isolates. MIC assays indicated that EOs induced strong anticandidal activities with MIC values ranging from 0.162 to 4.950 mg/mL. The combination of amphotericin B with Thymus leptobotrys, Origanum compactum and Artemisia herba alba EOs provided a synergistic effect against C. krusei only, with MIC gain of four-fold, and additive effect against remaining strains (MIC gain = two-fold). Interesting synergistic interactions were observed by combining all studied EOs with fluconazole, with reduction rates of their MICs ranging from 16 to 512-fold. This synergistic effect was very pronounced with the combination of T. leptobotrys EO and fluconazole. These findings indicate that studied EOs can be used as anti-candidals in combination with antifungals, particularly fluconazole, to counteract the emergence of resistant Candida spp.

6.
Arch Microbiol ; 203(7): 4361-4366, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34115157

RESUMO

The purpose of the present study was to determine for the first time the volatile constituents, the antioxidant and antimicrobial activities of the essential oil (EO) of the endemic Moroccan Linaria ventricosa, alone or in combination with four known antibiotics. The major constituents were 2-methoxy-4-vinylphenol (17.4%), α-terpinene (13.64%) and 3,5-dimethylphenyl isocyanate (12.21%). The EO had moderate antioxidant potency, as measured by DPPH free radical scavenging (1.233 ± 0.031 mg/mL), ferric reducing antioxidant power assay (0.373 ± 0.019 mg/mL) and ß-carotene/linoleic acid (0.922 ± 0.026 mg/mL). EO showed microbicidal activity against all microorganisms tested. The highest effectiveness was recorded against Candida albicans (IZ = 24 mm, MIC = 4.87 mg/mL and MMC = 9.75 mg/mL) and Candida glabrata (IZ = 22 mm, MIC = MMC = 4.87 mg/mL). Gram negative bacteria were the most resistant (MIC = MMC = 39 mg/mL). The combination of EO at sub-inhibitory concentrations with antibiotics showed a significant decrease in their individual MICs from 2 to 128 fold, being the best for ciprofloxacin and fluconazole against E. coli and C. albicans and C. glabrata, respectively.


Assuntos
Antioxidantes , Candida albicans , Candida glabrata , Escherichia coli , Linaria , Óleos Voláteis , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Candida albicans/efeitos dos fármacos , Candida glabrata/efeitos dos fármacos , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Linaria/química , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia
7.
J Microbiol Methods ; 181: 106128, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33347918

RESUMO

The NorA efflux pump is one of the most studied efflux systems in Staphylococcus aureus and confers multidrug resistance to a variety of dyes and antimicrobial compounds. Hence, inhibition of the NorA efflux pump might be a viable option for restoring susceptibility to antibiotics like fluoroquinolones. Fluorescent real-time efflux assays are important tools to identify putative efflux pump inhibitors. Nevertheless, the number of available compounds for usage in Staphylococcus aureus is limited. Previously, a 3-dipropyloxacarbocyanine iodide (DiOC3) efflux assay was published that circumvented problems associated with the usage of ethidium bromide, namely slow efflux and suggested mutagenicity. However, the DiOC3 assay protocol was cuvette - based and therefore needs to be adapted to the 96-well plate format. Hence, we optimized this assay for usage with 96-well plates. The new assay allows for rapid high-throughput efflux pump inhibitor screening.


Assuntos
Antibacterianos/química , Proteínas de Bactérias/antagonistas & inibidores , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Infecções Estafilocócicas , Staphylococcus aureus/metabolismo , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia
8.
Nat Prod Res ; 35(24): 6078-6082, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32945194

RESUMO

In this study, the chemical composition and antimicrobial activity of the essential oil (EO) extracted from leaves of the Moroccan endemic plant Argania spinosa were investigated for the first time, to the best of our knowledge. In addition, the EO antimicrobial activity was evaluated in combination with two known antibiotics (ciprofloxacin and fluconazole), in order to ascertain possible synergistic effects. The chemical composition analyzed by GC/MS showed that A. spinosa EO was characterised by the abundance of geranyl acetate (19.18%), methyleugenol (10.98%), linalyl acetate (10.59%) and eucalyptol (8.49%), and monoterpene hydrocarbons was the major class. EO showed an antimicrobial potential against all tested microorganisms. The highest activity was recorded against Gram positive bacteria and yeasts with MICs ranging from 7.75 to 15.5 mg/mL and from 3.88 to 7.75 mg/mL, respectively. The Gram negative bacteria were the most resistant with MICs of 31 mg/mL. The mixture of EO at sub-inhibitory concentrations with conventional drugs exhibited a significant decrease in their individual MICs from 4 to 32 fold. The highest level of synergy was observed for ciprofloxacin against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Despite the antimicrobial activity of A. spinosa EO is weak, the results of the current study suggest a potential synergy between EO and antibiotics in the goal to modulate drug resistance.


Assuntos
Anti-Infecciosos , Óleos Voláteis , Sapotaceae , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia
9.
Antibiotics (Basel) ; 9(4)2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32218155

RESUMO

Laurus nobilis L. (laurel, Lauraceae) and Prunus armeniaca L. (apricot, Rosaceae) are important industrial crops and display significant biological properties, including antimicrobial activity. In this work, essential oils (EOs) prepared from the leaves of both species from Morocco were evaluated for the first time for possible synergistic in vitro antibacterial and antifungal effects with some conventional antimicrobial drugs, namely fluconazole, ciprofloxacin and vancomycin. Samples were further evaluated for chemical composition by gas chromatography-mass spectrometry (GC-MS). The main volatile compounds detected in L. nobilis were eucalyptol (40.85%), α-terpinyl acetate (12.64%) and methyl eugenol (8.72%), while P. armeniaca was dominated essentially by (Z)-phytol (27.18%), pentacosane (15.11%), nonacosane (8.76%) and benzaldehyde (7.25%). Regarding antimicrobial activity, both EOs inhibited significantly all the microorganisms tested. The EO from L. nobilis had the highest activity, with minimal inhibitory concentrations (MICs) ranging from 1.39 to 22.2 mg/mL for bacteria and between 2.77 and 5.55 mg/mL for yeasts. Conversely, the combination of the studied EOs with ciprofloxacin, vancomycin and fluconazol resulted in a noteworthy decrease in their individual MICs. In fact, of the 32 interactions tested, 23 (71.87%) demonstrated total synergism and 9 (28.12%) a partial synergistic interaction. The EO from L. nobilis exhibited the highest synergistic effect with all the antibiotics used, with fractional inhibitory concentration (FIC) index values in the range of 0.266 to 0.75 for bacteria, and between 0.258 and 0.266 for yeast. The synergistic interaction between the studied EOs and standard antibiotics may constitute promising anti-infective agents useful for treating diseases induced by antibiotic-resistant pathogens.

10.
Artigo em Inglês | MEDLINE | ID: mdl-30637404

RESUMO

Streptomyces sp. strain Z26 exhibited antifungal activity and turned out to be a producer of the secondary metabolites novonestmycin A and B. The 6.5-Mb draft genome gives insight into the complete secondary metabolite production capacity and builds the basis to find and locate the biosynthetic gene cluster encoding the novonestmycins.

11.
Int J Mol Cell Med ; 7(2): 133-145, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30276168

RESUMO

Fungal diseases are currently a serious public health problem, due to the limited number of fact-based effective principles, and the emergence of resistant strains to the polyenic antifungals. The aim of this study was to screen, for non-polyenic antifungals production by Actinobacteria, and to validate the screening program by characterizingthe produced compounds.Actinobacteria isolates were tested against four clinic human-pathogenic fungi isolated from Hospital Mohammed V Rabat, Morocco. The production of non-polyenic antifungal metabolites by active isolates was investigated based on the yeast cell specificity as challenging targets, antibacterial activity, activity against resistant Candida tropicalis R2 and Pythium irregular (resistant to polyenes), inhibition of antifungal activity by the addition of exogenous ergosterol, and the UV-visible light spectrophotometric analysis of the active crude extracts.The antifungal compound produced was purified using various chromatographic techniques and the selected producing strain was identified using the polyphasic approach.Among 480 Actinobacteria isolates, 55 showed antifungal activity against all tested clinically derived fungi. After performing the screening program, 4 Actinobacteria that hadall the desired criteriawere selected. Using the polyphasic approach, the taxonomic position of the selected Streptomyces AS25, isolated from rhizospheric soil of Alyssum spinosum, showed that it belongs to Streptomyces genus with 100% partial 16S similarity with Streptomyces albidoflavus NBRC13010. On the basis of HPLC and mass spectrometry, the purified compound produced by Streptomyces AS25 was identified as a non-polyenic lactone, antimycin A19, which has been found for the first time to be produced by Streptomyces albidoflavus strain. Following the obtained results, it is important to note that our screening criteria for non-polyenic antifungals have been validated and the rhizospheric soil represents an interesting source to isolate Actinobacteria.

12.
Nat Prod Commun ; 11(11): 1717-1720, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30475515

RESUMO

The chemical composition, antioxidant, antimicrobial and insecticidal properties of essential oil obtained by hydro-distillation from Bubonium imbricatum Cav. have been investigated. The essential oil of aerial parts was analyzed by GC-FID and GC-MS. A total of 63 compounds were identified representing more than 82% of the oil. The major components were cis-chrysanthenyl acetate (31.2%) and thymol isobutyrate (3.4%). The antioxidant activity was evaluated by the DPPH and reducing power test. The data showed moderate activity compared with the reference compounds. Our results showed strong activity of the investigated oil against all tested microorganisms. The highest antibacterial activity was observed against Bacillus subtilis (inhibition zone= 18 ± 0.21, MIC= 0.18 mg/mL). In general, Gram-positive bacteria were more susceptible than Gram-negative ones. Candida parapsilosis was the most sensitive among the Candida strains tested. LD50 and LD90 values were 33.1 and 53.1 ppm against 1-d-old larvae of Aedes aegypti L.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Asteraceae/química , Inseticidas/farmacologia , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Aedes/efeitos dos fármacos , Animais , Anti-Infecciosos/química , Antioxidantes/química , Bactérias/efeitos dos fármacos , Bioensaio , Candida/efeitos dos fármacos , Inseticidas/química , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Marrocos , Óleos Voláteis/química , Óleos de Plantas/química
13.
ScientificWorldJournal ; 2015: 761834, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25763383

RESUMO

Accumulation of high concentrations of heavy metals in environments can cause many human health risks and serious ecological problems. Nowadays, bioremediation using microorganisms is receiving much attention due to their good performance. The aim of this work is to investigate heavy metals resistance and bioaccumulation potential of actinobacteria strains isolated from some abandoned mining areas. Analysis of mining residues revealed that high concentration of zinc "Zn" was recorded in Sidi Bouatman, Arbar, and Bir Nhass mining residues. The highest concentration of lead "Pb" was found in Sidi Bouatman. Copper "Cu," cadmium "Cd," and chromium "Cr" were found with moderate and low concentrations. The resistance of 59 isolated actinobacteria to the five heavy metals was also determined. Using molecular identification 16S rRNA, these 27 isolates were found to belong to Streptomyces and Amycolatopsis genera. The results showed different levels of heavy metal resistance; the minimum inhibitory concentration (MIC) recorded was 0.55 for Pb, 0.15 for Cr, and 0.10 mg·mL(-1) for both Zn and Cu. Chemical precipitation assay of heavy metals using hydrogen sulfide technic (H2S) revealed that only 27 isolates have a strong ability to accumulate Pb (up to 600 mg of Pb per g of biomass for Streptomyces sp. BN3).


Assuntos
Actinobacteria/metabolismo , Metais Pesados/metabolismo , Mineração
14.
Chem Biodivers ; 9(3): 598-605, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22422527

RESUMO

The essential oils of leaves and flowers of the wild and cultivated Moroccan Achillea ageratum L., a rare and threatened medicinal species, were examined by GC/MS, and their chemical compositions were compared. At least nine components were identified in both wild and cultivated A. ageratum oils, representing more than 95% of the oils. Artemisyl acetate (62.34-78.79%), yomogi alcohol (4.89-12.40%), santolina alcohol (4.86-11.77%), and artemisia alcohol (3.36-7.04%) were the major compounds. Terpene-alcohol proportion was higher in wild A. ageratum than in cultivated A. ageratum. The antibacterial analysis showed that both oils presented high activity against all the studied Gram-positive strains in a range of MIC values from 2.55 to 7.02 mg/ml, but they appeared not effective against the tested Gram-negative ones (MIC values 20.40-41.10 mg/ml). They also exhibited remarkable antifungal activities against Candida species with MIC values ranging from 5.83 to 8.42 mg/ml. From these results, it was concluded that domestication of this threatened medicinal species using clonal propagation did not significantly affect its chemical composition and consequently its antimicrobial properties.


Assuntos
Achillea/química , Antibacterianos/química , Antifúngicos/química , Óleos Voláteis/análise , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Flores/química , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Marrocos , Folhas de Planta/química , Plantas Medicinais/química
15.
Phytomedicine ; 19(5): 464-71, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22257599

RESUMO

The aim of this study was to evaluate the antibacterial effect of the association between conventional antibiotics and essential oils (EOs) of endemic Moroccan thyme species, Thymus maroccanus and T. broussonetii, on antibiotic-resistant bacteria involved in nosocomial infections. Synergistic interactions between antibiotics (ciprofloxacin, gentamicin, pristinamycin, and cefixime) and EOs, and between T. maroccanus and T. Broussonetii EOs were determined by the checkerboard test. Serial dilutions of two antimicrobial agents were mixed together so that each row (and column) contained a fixed amount of the first agent and increasing amounts of the second one. The results indicate that the oils had a high inhibitory activity against tested bacteria, except for Pseudomonas aeruginosa. In parallel with the increase of cellular killing, the release of 260nm-absorbing materials from bacterial cells, treated with EOs, increased in response to oil concentration. Out of 80 combinations tested between EOs and antibiotics, 71% showed total synergism, 20% had partial synergistic interaction and 9% showed no effect. Combination with carvacrol, the major constituent of T. maroccanus and T. broussonetii, showed also an interesting synergistic effect in combination with ciprofloxacin. The effect on Gram-positive bacteria was more important than on Gram-negative bacteria. These findings are very promising since the use of these combinations for nosocomial infections treatment is likely to reduce the minimum effective dose of the antibiotics, thus minimizing their possible toxic side effects and treatment cost. However, further investigations are needed to assess the potential for therapeutic application.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Thymus (Planta)/química , Antibacterianos/química , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Ciprofloxacina/farmacologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Cimenos , Sinergismo Farmacológico , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Humanos , Testes de Sensibilidade Microbiana , Monoterpenos/farmacologia , Óleos Voláteis/química , Componentes Aéreos da Planta/química , Óleos de Plantas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento
16.
Nat Prod Commun ; 6(10): 1447-50, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22164779

RESUMO

In the present study, we report for the first time the antioxidant and antimicrobial activities of Withania frutescens (L.) Pauquy roots and leaves. Total phenolic content was determined using the Folin-Ciocalteu method and antioxidant activity was evaluated by the DPPH free radical scavenging and reducing power methods. Antimicrobial activity tests were carried out against ten bacterial species involved in nosocomial infections and two opportunistic clinical yeast isolates. The ethyl acetate and n-butanol leaf fractions exhibited the highest DPPH radical scavenging activity with IC50 = 4.53 +/- 0.12 and 8.49 +/- 0.46 microg/mL, respectively. The n-butanol root fraction showed the greatest reducing power comparable with that of quercetin at 0.4 mg/mL. The dichloromethane leaf fraction exhibited the highest antibacterial activity against both Gram-positive and Gram-negative bacteria with MIC values ranging between 50 and 400 microg/mL, depending on the tested bacteria. However, none of the examined extracts exhibited anticandidal activity. The polyphenol and glycowithanolide constituents appeared to be responsible for the antioxidant capacity of W. frutescens, whereas the observed antimicrobial activity may be due to the presence of withanolides.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Withania/química , Antibacterianos/química , Antioxidantes/química , Bactérias/efeitos dos fármacos , Compostos de Bifenilo/química , Farmacorresistência Bacteriana Múltipla , Picratos/química , Folhas de Planta/química , Raízes de Plantas/química
17.
Nat Prod Commun ; 6(10): 1491-4, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22164791

RESUMO

The chemical composition and anticandidal properties of the essential oil of Moroccan Cotula cinerea aerial parts have been examined. GC-MS data were used to identify 24 constituents. Oxygenated monoterpenes constituted the main fraction with trans-thujone (41.4%), cis-verbenyl acetate (24.7%), 1,8-cineole (8.2%) and camphor (5.5%) as the major components. The anticandidal activity of the essential oil was evaluated using a panel of human pathogenic fungi (Candida albicans CCMM L4 and CCMM L5, C. krusei CCMM L10, C. glabrata CCMM L7 and C. parapsilosis CCMM L18). The oil showed high anticandidal activity against all investigated strains with minimal inhibitory concentrations of 3.2 to 4.7 mg/mL depending on the tested yeast and 5.9 mg/mL as a minimal candidicidal concentration value. These findings add significant information to the pharmacological activity of Cotula cinerea essential oil, which may present a good alternative to antibiotics for the treatment of resistant strains of Candida.


Assuntos
Antifúngicos/farmacologia , Asteraceae/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Antifúngicos/química , Candida/efeitos dos fármacos , Espécies em Perigo de Extinção , Marrocos , Componentes Aéreos da Planta/química , Plantas Medicinais/química
18.
Int J Antimicrob Agents ; 38(4): 325-30, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21752605

RESUMO

Bacterial drug resistance is a worrying public health problem. Antibiotic efflux is a major non-specific resistance mechanism used by bacteria, and efflux pumps are involved in the low-level susceptibility of various important Gram-negative pathogens. Use of molecules that can block bacterial pumps is an attractive strategy, but several studies report only partial efficacy owing to limits of these molecules (stability, selectivity, bioavailability, toxicity, etc.). The objective of this study was to search for natural sources of molecules able to inhibit efflux pump systems of resistant Gram-negative bacteria (Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Salmonella enterica serotype Typhimurium and Pseudomonas aeruginosa). The results indicate that the studied essential oils exhibit interesting activity against the tested bacteria. This activity was significantly enhanced in the presence of an efflux pump inhibitor such as phenylalanine arginyl ß-naphthylamide (PAßN). The role of lipopolysaccharide (LPS) structure in the effect of essential oils was also reported in Salmonella LPS deep-rough mutants. In addition, essential oils of Thymus maroccanus and Thymus broussonetii, used at a low concentration (a fraction of the minimum inhibitory concentration), are able to significantly increase chloramphenicol susceptibility of several resistant isolates. These results demonstrate that these essential oils can alter efflux pump activity and may be attractive candidates to develop new drugs for chemosensitising multidrug-resistant strains to clinically used antibiotics.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Óleos Voláteis/farmacologia , Antibacterianos/metabolismo , Antibacterianos/uso terapêutico , Cloranfenicol/metabolismo , Cloranfenicol/farmacologia , Descoberta de Drogas , Farmacorresistência Bacteriana/fisiologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/fisiologia , Enterobacter aerogenes/efeitos dos fármacos , Enterobacter aerogenes/metabolismo , Escherichia coli/metabolismo , Bactérias Gram-Negativas/metabolismo , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/metabolismo , Lamiaceae , Lipopolissacarídeos/genética , Testes de Sensibilidade Microbiana , Marrocos , Naftalenos/farmacologia , Óleos Voláteis/metabolismo , Óleos Voláteis/uso terapêutico , Fitoterapia , Componentes Aéreos da Planta , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/metabolismo
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