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1.
Int J Food Microbiol ; 328: 108664, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32474229

RESUMO

To control Pseudomonas and Shewanella as important psychrotrophic spoilage bacteria in fish meat, we used ethanolic extracts of oregano (Origanum vulgare subsp. vulgare) and nettle (Urtica dioica), with phytochemical characterisation of the extracts and their bioactive compounds. Liquid chromatography coupled with photodiode array detection and electrospray ionisation-mass spectrometry was used for qualitative compositional determination of the extracts. Four main compounds were identified in the oregano extract, with rosmarinic acid the most abundant, followed by three glycosylated phenolics, one of which is reported for the first time in O. vulgare: 4'-O-ß-d-glucopyranosyl-3',4'-dihydroxybenzyl-4-hydroxybenzoate. Six main compounds were identified in the nettle extract, as caffeoylmalic acid and five flavonoid glycosides. These oregano and nettle ethanolic extracts showed in-vitro antimicrobial activities against selected Pseudomonas and Shewanella strains in broth and fish meat homogenate when evaluated at two inoculum concentrations. The antimicrobial activities were more pronounced for the nettle extract at the lower inoculum concentration, and for both the Shewanella strains. Growth inhibition in the fish meat homogenate was evaluated at 3.13 mg/mL and 1.56 mg/mL at 5 °C. Again, the nettle extract showed greater antimicrobial activity, which was seen as the lowest maximum growth rate, followed by the oregano extract, which was inhibitory only at 3.13 mg/mL. Finally, the extracts were applied to fish meat that was then stored at 5 °C for 9 days. Evaluation here was for the counts of the mesophilic, psychrotrophic, Pseudomonas and H2S producers. These confirmed the better antimicrobial effects of the nettle extract, especially against the H2S-producing bacteria, which included Shewanella. Both of the extracts were rich in glycosides of flavonoids and phenolic acids. The enzymatic activities of the Pseudomonas and Shewanella spoilage bacteria and their actions on the phenolic glycosides from natural sources will be further investigated.


Assuntos
Doenças dos Peixes/tratamento farmacológico , Origanum/química , Extratos Vegetais/farmacologia , Pseudomonas/efeitos dos fármacos , Shewanella/efeitos dos fármacos , Urtica dioica/química , Animais , Ácidos Cafeicos/farmacologia , Cinamatos/farmacologia , Depsídeos/farmacologia , Peixes/microbiologia , Flavonoides , Microbiologia de Alimentos , Hidroxibenzoatos/farmacologia , Malatos/farmacologia , Fenóis/química , Alimentos Marinhos/microbiologia , Espectrometria de Massas por Ionização por Electrospray
2.
Food Chem ; 317: 126448, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32114274

RESUMO

The chemometric issues related to the application of non-targeted analysis for the detection of food frauds were analyzed employing discriminant analysis and a one-class classifier. The similarities and differences between the two methods were investigated. The results of classification are characterized by a set of indices called figures of merit. They comprehensively characterized the quality and reliability of classification. The principle is illustrated using an actual example of Oregano herbs adulteration. The informative region 9000-4000 cm-1 of near-Infrared spectroscopy is used as analytical means. The results of the application of each method for Oregano data collection are presented. It is shown that the discriminant method is only partially appropriate for solving the authentication problem. One class classifier is a powerful and devoted for non-targeted analysis. The step by step analysis introduced in the paper can also be successfully utilized in apply for revealing of forgeries of various food products.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Fraude , Origanum/química , Análise Discriminante , Análise de Alimentos/estatística & dados numéricos , Contaminação de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectroscopia de Luz Próxima ao Infravermelho/métodos
3.
J Dairy Sci ; 103(3): 2303-2314, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954586

RESUMO

Different inclusion rates of oregano essential oil (OEO) were investigated for their effects on ruminal in vitro fermentation parameters, total gas, methane production, and bacterial communities. Treatments were (1) control, 0 mg/L of OEO (CON); 13 mg/L (OEO1); 52 mg/L (OEO2); 91 mg/L (OEO3); and 130 mg/L (OEO4), each incubated with 150 mL of buffered rumen fluid and 1,200 mg of substrate for 24 h using the Ankom in vitro gas production system (Ankom Technology Corp., Fairport, NY). Treatment responses were statistically analyzed using polynomial contrasts. Digestibility of DM, NDF, and ADF increased quadratically with increasing OEO inclusion rates. Digestibility of DM and NDF were highest for OEO2, whereas ADF digestibility was highest for OEO3, compared with CON, with the remaining treatments being intermediate and similar. Ammonia nitrogen concentrations decreased from CON at a quadratic rate with increasing OEO inclusion rates, and OEO2 had the lowest concentration compared with the other groups. Total VFA, acetate, propionate, butyrate, valerate, and isovalerate concentrations linearly decreased with increasing OEO inclusion rates. Total gas production levels by CON and OEO4 were greater than those of OEO1, OEO2, and OEO3 in a quadratic response, and methane production linearly decreased from CON, compared with OEO4, at a decreasing rate with OEO inclusion rates. As determined by 16S rRNA sequencing, the α biodiversity of ruminal bacteria was similar among OEO inclusion rates. Increasing OEO inclusion rates linearly increased the relative abundance of Prevotella and Dialister bacteria. Several bacteria demonstrated different polynomial responses, whereas several bacteria were similar among increasing OEO inclusion rates. These results suggested that OEO supplementation can modify ruminal fermentation to alter VFA concentrations and reduce methane emissions by extensively altering the ruminal bacterial community, suggesting an optimal feeding rate for future animal studies of approximately 52 mg/L for mature ruminants.


Assuntos
Bactérias/classificação , Bovinos/fisiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Metano/metabolismo , Óleos Voláteis/administração & dosagem , Origanum/química , Ovinos/fisiologia , Amônia/metabolismo , Ração Animal/análise , Animais , Bactérias/genética , Dieta/veterinária , Digestão/efeitos dos fármacos , Feminino , Fermentação/efeitos dos fármacos , Masculino , Nitrogênio/metabolismo , Óleos Vegetais/administração & dosagem , RNA Ribossômico 16S/genética , Rúmen/metabolismo
4.
Nat Prod Res ; 34(1): 87-92, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30905174

RESUMO

This research is carried out in order to characterize the actual contamination by two ubiquitous environmental pollutants, plasticizers and Bisphenol A, in spices (black pepper, caraway and coriander) and aromatic herbs (fennel, laurel, mint, oregano, rosemary, thyme and verbena) from Algeria (n = 26), Tunisia (n = 65) and Italy (n = 53). Algerian samples seem to contain fewer residues than Italian and Tunisian samples. Among the Italian samples, only aromatic herbs, precisely mint, oregano, and laurel, were contaminated. In general, all Tunisian samples showed five plasticizers residues: the caraway, among the spices, and the rosemary, among the aromatic herbs, are found to contain more residues. Also, dietary intake of these contaminants by spices and aromatic herbs under analysis seems not to constitute a risk to the consumers.


Assuntos
Compostos Benzidrílicos/análise , Contaminação de Alimentos/análise , Fenóis/análise , Plastificantes/análise , Especiarias/análise , Argélia , Carum/química , Foeniculum/química , Humanos , Itália , Origanum/química , Piper nigrum/química , Rosmarinus/química , Especiarias/normas , Thymus (Planta)/química , Tunísia
5.
J Appl Microbiol ; 128(2): 376-386, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31448524

RESUMO

AIMS: This study evaluated the efficacy of essential oil from Origanum vulgare L. (oregano; OVEO) and Rosmarinus officinalis L. (rosemary; ROEO) to inactivate sessile cells of Salmonella enterica serovar Enteritidis 86 (SE86) in young and mature biofilms formed on stainless steel. METHODS AND RESULTS: Ultrastructural alterations and damage in different physiological functions caused by OVEO and ROEO in noncultivable sessile cells of SE86 were investigated using scanning electron microscopy and flow cytometry. OVEO (2·5 µl ml-1 ) and ROEO (40 µl ml-1 ) were effective to eradicate young and mature biofilms formed by SE86 sessile cells on stainless steel surfaces; however, the efficacy varied with exposure time. OVEO and ROEO caused alterations in morphology of SE86 sessile cells, inducing the occurrence of bubbles or spots on cell surface. OVEO and ROEO compromised membrane polarization, permeability and efflux activity in noncultivable SE86 sessile cells. These findings show that OVEO and ROEO act by a multitarget mechanism on SE86 membrane functions. CONCLUSIONS: ROEO and OVEO showed efficacy to eradicate SE86 sessile cells in preformed biofilms on stainless steel, displaying a time-dependent effect and multitarget action mode on bacterial cell membrane. SIGNIFICANCE AND IMPACT OF THE STUDY: The study provides for the first time the effects of OVEO and ROEO on morphology and physiological functions of noncultivable sessile cells of S. Enteritidis biofilms preformed on stainless steel surfaces.


Assuntos
Biofilmes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Origanum/química , Óleos Vegetais/farmacologia , Rosmarinus/química , Salmonella enteritidis/efeitos dos fármacos , Salmonella enteritidis/crescimento & desenvolvimento , Salmonella enteritidis/fisiologia , Aço Inoxidável/análise
6.
J Dairy Sci ; 103(2): 1516-1527, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31759586

RESUMO

Because of their antimicrobial properties, essential oils and their components have been suggested as alternatives to other antimicrobials (e.g., monensin) that are commonly fed to ruminants to improve nutrient utilization and enhance feed efficiency and milk performance. In this study, we evaluated the potential of oregano oil and its main component (carvacrol) as rumen modifiers. For this purpose, 8 ruminally cannulated lactating dairy cows (92 ± 11 d in milk, 36.5 ± 7.6 kg of milk yield, and 703 ± 74 kg of body weight) were used in a double 4 × 4 Latin square (28-d periods). Cows were fed 1 of the 4 following treatments: (1) control (CTL, no additive); (2) monensin [MON, 24 mg/kg of dry matter (DM)]; (3) oregano oil (ORE, 50 mg/kg of DM); and (4) carvacrol (CAR, 50 mg/kg of DM). Cows were fed (ad libitum intake) a total mixed ration consisting of 60% forages (corn silage and alfalfa silage) and 40% concentrates, on a DM basis. Feeding ORE and CAR had no effect on nutrient total-tract apparent digestibility, N utilization, rumen fermentation (i.e., pH, ammonia, volatile fatty acids), protozoa counts, or milk performance. Feeding MON increased the molar proportion of propionate and tended to increase total-tract apparent digestibility of crude protein. None of the feed additives evaluated affected enteric methane production (491 g/d, 21.1 g/kg of DM intake, 6.14% of gross energy intake on average). Milk fatty acid composition was not changed by ORE or CAR, but MON increased the proportion of trans-10 18:1, an intermediate of ruminal biohydrogenation. Thus, when included at 50 mg/kg of dietary dry matter, neither oregano oil nor carvacrol favorably altered rumen fermentation, improved nutrient utilization or milk performance, or mitigated enteric methane emissions in dairy cows.


Assuntos
Bovinos/fisiologia , Cimenos/administração & dosagem , Metano/metabolismo , Leite/metabolismo , Óleos Voláteis/administração & dosagem , Origanum/química , Animais , Dieta/veterinária , Ingestão de Energia , Ácidos Graxos/análise , Feminino , Fermentação , Lactação , Medicago sativa , Leite/química , Nutrientes/metabolismo , Rúmen/metabolismo , Silagem/análise , Zea mays
7.
Food Chem ; 309: 125678, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31670125

RESUMO

Significant quantities of several important herbs are processed and consumed from Norwegian commercial kitchens annually although surprisingly the contents of polyphenols have been scarcely characterized. We here report on the qualitative and quantitative content of polyphenolic compounds from ten of the most utilized herbs. From parsley (Petroselinum crispum) var. Darki, isorhamnetin 3-(6″-malonylglucoside)-7-glucoside (2) and diosmetin 7-(2″-apiosyl-6″-malonylglucoside) (8) are reported for the first time, in addition to seven known flavonoids, some of which are reported for the first time from this plant species. Oregano, rosemary and thyme contained the highest amounts of total phenolics with maximum levels of 23.8, 24.2 and 23.4 mg GAE g-1 dry matter, respectively. Fresh herbs contained significantly higher quantities of phenolics than processed, dried herbs. Parsley, coriander, dill and thyme were the richest sources of flavonoids among the investigated herbs.


Assuntos
Flavonoides/análise , Extratos Vegetais/química , Polifenóis/análise , Anethum graveolens/química , Coriandrum/química , Origanum/química , Petroselinum/química , Rosmarinus/química , Thymus (Planta)/química
8.
Plant Biol (Stuttg) ; 22(1): 81-89, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31539455

RESUMO

Potato common scab is a worldwide disease mainly caused by Streptomyces scabiei. It seriously affects potato crops by decreasing tuber quality. Essential oils (EO) are natural products with recognised antimicrobial properties. In this research, the antibacterial activities of thyme, oregano, suico and mint EO against S. scabiei were analysed. Infected tubers and soil samples were used for bacterial isolation; the obtained isolates were genetically identified. The chemical composition of the EO was determined by GC-MS. The broth microdilution method was used to analyse antibacterial properties of EO. Thirty-one bacterial isolates were obtained. The isolate chosen for antibacterial assays was morpho-physiologically and genetically identified as S. scabiei. Thyme EO was mainly composed of thymol and o-cymene; suico EO of dihydrotagetone, trans-tagetone and verbenone; oregano EO of trans-sabinene hydrate, thymol and É£-terpinene; and mint EO of menthone and menthol. All the EO tested were effective against S. scabiei, but thyme and suico EO were the most successful, with a minimum inhibitory concentration of 0.068 g·l-1 and 0.147 g·l-1 , respectively, and a minimum bactericidal concentration of 0.137 g·l-1 and 0.147 g·l-1 , respectively. Scanning electron microscopy showed similar damage caused by both thyme and suico EO to the bacterial envelope. Total phenolic content of EO was not related to their antibacterial activity. Thyme and suico EO are effective antibacterial agents against S. scabiei, impeding bacterial viability and disturbing the bacterial cell envelope. These EO are promising tools for control of potato common scab.


Assuntos
Óleos Voláteis , Solanum tuberosum , Streptomyces , Anti-Infecciosos/farmacologia , Mentha/química , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Origanum/química , Doenças das Plantas/prevenção & controle , Solanum tuberosum/microbiologia , Streptomyces/efeitos dos fármacos , Thymus (Planta)/química
9.
Food Microbiol ; 86: 103357, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703857

RESUMO

We investigated combinations of gaseous essential oils (EO gases) for their synergistic inhibitory activities against Listeria monocytogenes on a laboratory medium and radish sprouts. The minimum inhibitory concentrations and minimum lethal concentrations of oregano, thyme thymol, and cinnamon bark EO gases against L. monocytogenes were 0.0781 µL/mL on nutrient agar supplemented with glucose and bromocresol purple (NGBA). A checkerboard assay showed that combinations of oregano and thyme thymol EO gases and of oregano and cinnamon bark EO gases exert the strongest synergistic antilisterial activity (fractional inhibitory concentration index [FICI] = 0.3750). A combination of thyme thymol and cinnamon bark EO gases also had a synergistic effect (FICI = 0.5000) on L. monocytogenes on NGBA. Combinations of oregano and thyme thymol EO gases were tested for synergistic antimicrobial activity against L. monocytogenes on radish sprouts. A combination of these gases, each at 0.313 µL/mL, caused a significant (P ≤ 0.05) reduction in the number of L. monocytogenes on radish sprouts compared with reductions caused by treatment with oregano or thyme thymol EO gas alone at the same concentration. Our findings provide information that will be useful when developing antimicrobial applications using EO gases to control L. monocytogenes in the food industry.


Assuntos
Antibacterianos/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Origanum/química , Raphanus/microbiologia , Timol/farmacologia , Thymus (Planta)/química , Antibacterianos/química , Cinnamomum zeylanicum/química , Meios de Cultura/química , Meios de Cultura/metabolismo , Sinergismo Farmacológico , Gases/farmacologia , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Raphanus/crescimento & desenvolvimento , Timol/química
10.
Food Microbiol ; 86: 103348, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703879

RESUMO

The effects of the incorporation of the essential oils from Origanum vulgare L. (OVEO; 0.07 µL/g) and Rosmarinus officinalis L. (ROEO; 2.65 µL/g) in combination in Minas Frescal cheese on the counts of the probiotic Lactobacillus acidophilus LA-5 and Escherichia coli O157:H7 were evaluated during refrigerated storage (7 ±â€¯0.5 °C). The terpenes of OVEO and ROEO, survival of the probiotic strain during in vitro digestion, as well as the physicochemical and sensory aspects were also monitored in Minas Frescal cheese. All terpenes decreased in cheese when the storage time increased. The incorporation of OVEO and ROEO delayed the increase in L. acidophilus LA-5 counts in cheese, but did not affect its ability to survive in cheese under simulated gastrointestinal conditions. The decreases in counts of E. coli O157:H7 observed in the first 15 days of refrigerated storage were strongly correlated (r ≥ 0.82) with the terpenes detected in cheese. Scores attributed for aroma, flavor, overall impression and purchase intention of cheese with OVEO and ROEO increased with the increase of the storage time. The incorporation of OVEO and ROEO in combination could be a strategy to control E. coli O157:H7 in probiotic Minas cheese during storage; however, the amounts of these substances should be cautiously selected considering possible negative sensory impacts in this product.


Assuntos
Queijo/microbiologia , Escherichia coli O157/crescimento & desenvolvimento , Aditivos Alimentares/análise , Lactobacillus acidophilus/crescimento & desenvolvimento , Óleos Voláteis/análise , Origanum/química , Óleos Vegetais/análise , Rosmarinus/química , Queijo/análise , Escherichia coli O157/efeitos dos fármacos , Aditivos Alimentares/farmacologia , Humanos , Lactobacillus acidophilus/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Paladar
11.
Pak J Pharm Sci ; 32(5): 2117-2122, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31813878

RESUMO

The methanolic extract of the leaves of Origanum majorana L., was screened for its antioxidant potential and chemical composition. Apart from high total phenolic, flavonoid and antioxidant contents, significant free radical scavenging ability was observed as assessed by the free radical scavenging assays viz., 2,2-Diphenyl-1-picryl hydrazyl, Ferric thiocyanate, Thiobarbituric acid, Ferric reducing antioxidant power and ABTS assays. The GC-MS analysis of the methanolic extract detected the presence of seven compounds - 5H-Cyclopropa[3,4]benz[1,2-e]azulen-5-one, 3,9,9a-tris (acetyloxy)-3-[(acetyloxy)methyl]-2-chloro-1,1a,1b,2,3,4,4a,7a,7b,8,9,9a-dodecahydro-4a,7b-dihydroxy-1,1,6,8-tetrame-thyl-,[1aR-(1aa,1ba,2a,3a,4aa,7aa,7ba,8a,9a,9aa)]-; Pentacosanoic acid, methyl ester; 10-Octadecenoic acid, methyl ester; 1,2,4-Trioxolane-2-octanoic acid, 5-Octyl-, methyl ester; Oleoyl chloride; Docosanedioic acid, dimethyl ester and Ethyl iso-allocholate.


Assuntos
Antioxidantes/química , Origanum/química , Flavonoides/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Óleos Voláteis/química , Fenóis/química , Extratos Vegetais/química , Folhas de Planta/química
12.
PLoS One ; 14(12): e0216853, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31821320

RESUMO

Food borne illnesses have a world-wide economic impact and industries are continuously developing technologies to reduce the spread of disease caused by microorganisms. Antimicrobial growth promoters (AGPs) have been used to decrease microbiological infections in animals and their potential transfer to humans. In recent years there has been a global trend to remove AGPs from animal feed in an attempt to reduce the spread of antimicrobial resistant genes into the human population. Phytobiotics, such as oregano powder, are one of the potential replacements for AGPs due to their well-established antimicrobial components. 16S rRNA gene amplicons were used to determine the effect of oregano powder (1% w/v) on the microbiota of mixed bacterial cell cultures, which were obtained from the ceca of traditionally grown meat chickens (broilers). Oregano powder had a mild effect on the microbial cell cultures increasing Enterococcus faecium, rearranging ratios of members in the genus Lactobacillus and significantly reducing the genus Streptococcus (p = 1.6e-3). Beneficial short chain fatty acids (SCFA), acetic and butyric acid, were also significantly increased in oregano powder supplemented cultures. These results suggest that oregano powder at a concentration of 1% (w/v) may have beneficial influences on mixed microbial communities and SCFA production.


Assuntos
Antibacterianos/farmacologia , Galinhas/crescimento & desenvolvimento , Ácidos Graxos Voláteis/metabolismo , Origanum/química , Pós/farmacologia , Streptococcus/efeitos dos fármacos , Animais , Células Cultivadas , Galinhas/microbiologia , Meios de Cultura , Testes de Sensibilidade Microbiana , Streptococcus/metabolismo
13.
Molecules ; 24(23)2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31817023

RESUMO

Essential oil of Origanum species is well known for antimicrobial activity, but only a few have been evaluated in narrow spectrum antiprotozoal assays. Herein, we assessed the antiprotozoal potential of Turkish Origanum onites L. oil and its major constituents against a panel of parasitic protozoa. The essential oil was obtained by hydrodistillation from the dried herbal parts of O. onites and analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography coupled with Mass Spectrometry (GC-MS). The in vitro activity of the oil and its major components were evaluated against Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, and Plasmodium falciparum. The main component of the oil was identified as carvacrol (70.6%), followed by linalool (9.7%), p-cymene (7%), γ-terpinene (2.1%), and thymol (1.8%). The oil showed significant in vitro activity against T. b. rhodesiense (IC50 180 ng/mL), and moderate antileishmanial and antiplasmodial effects, without toxicity to mammalian cells. Carvacrol, thymol, and 10 additional abundant oil constituents were tested against the same panel; carvacrol and thymol retained the oil's in vitro antiparasitic potency. In the T. b. brucei mouse model, thymol, but not carvacrol, extended the mean survival of animals. This study indicates the potential of the essential oil of O. onites and its constituents in the treatment of protozoal infections.


Assuntos
Antiprotozoários/administração & dosagem , Antiprotozoários/química , Óleos Voláteis/administração & dosagem , Óleos Voláteis/química , Origanum/química , Tripanossomíase Africana/tratamento farmacológico , Animais , Antiprotozoários/farmacologia , Cimenos/administração & dosagem , Cimenos/farmacologia , Modelos Animais de Doenças , Cromatografia Gasosa-Espectrometria de Massas , Concentração Inibidora 50 , Camundongos , Estrutura Molecular , Óleos Voláteis/farmacologia , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Timol/administração & dosagem , Timol/farmacologia , Trypanosoma brucei rhodesiense/efeitos dos fármacos
14.
Molecules ; 24(24)2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31847159

RESUMO

In this study, we determined the antimicrobial activity of ten essential oils (EOs)-oregano, thyme, clove, arborvitae, cassia, lemongrass, melaleuca, eucalyptus, lavender, and clary sage-against drug-resistant microorganisms previously isolated from patients with skin infections. The essential oil compositions were determined using gas chromatography coupled to mass spectrometry (GC/MS). The assayed bacteria included Pseudomonas aeruginosa, Proteus vulgaris, Citrobacter koseri, and Klebsiella pneumoniae. Two drug-resistant yeasts (Candida albicans and Candida parapsilosis) were also involved in our survey. Oregano, thyme, cassia, lemongrass and arborvitae showed very strong antibacterial and antifungal activity against all tested strains. These results show that these essential oils may be effective in preventing the growth of the drug-resistant microorganisms responsible for wound infections. In this study, the genotoxic effects of tested essential oils on healthy human keratinocytes HaCaT were evaluated using the comet assay for the first time. These results revealed that none of the essential oils induced significant DNA damage in vitro after 24 h. Moreover, the treatment of HaCaT cells with essential oils increased the total antioxidant status (TAS) level. The obtained results indicate that EOs could be used as a potential source of safe and potent natural antimicrobial and antioxidant agents in the pharmaceutical and food industries.


Assuntos
Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Óleos Voláteis/química , Óleos Vegetais/química , Dermatopatias Infecciosas/microbiologia , Candida albicans/efeitos dos fármacos , Candida parapsilosis/efeitos dos fármacos , Cassia/química , Linhagem Celular , Citrobacter koseri/efeitos dos fármacos , Cymbopogon/química , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Origanum/química , Óleos Vegetais/farmacologia , Proteus vulgaris/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Thuja/química , Thymus (Planta)/química
15.
Molecules ; 24(22)2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31698834

RESUMO

Essential oils (EOs) are one of the most important groups of plant metabolites responsible for their biological activities. This study was carried out to study the chemical composition and the antimicrobial effects of Artemisia herba-alba and Origanum majorana essential oils against some Gram-positive and Gram-negative bacteria, and a fungal strain isolated from spoiled butter. The plants were collected in the region Azzemour of South West Morocco and the EOs, extracted by hydrodistillation, were analyzed by GC-MS. The antimicrobial activity was determined using the agar paper disc method. The main components of A. herba-alba EO were cis-thujone, trans-thujone and vanillyl alcohol; in O. majorana EO terpinen-4-ol, isopulegol and ß-phellandrene predominated. Both essential oils exhibited growth inhibiting activities in a concentration-dependent manner on several microorganism species. Our results demonstrated that O. majorana and A. herba-alba EOs could be effective natural antibacterial agents in foods.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Artemisia/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Origanum/química , Compostos Fitoquímicos/química , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Testes de Sensibilidade Microbiana , Marrocos , Análise Espectral
16.
Vet Dermatol ; 30(6): 524-e159, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31566822

RESUMO

BACKGROUND: Multidrug-resistant pathogens present a major global challenge in antimicrobial therapy and frequently complicate otitis externa in dogs. HYPOTHESIS/OBJECTIVES: In vitro efficacy of oregano oil, thyme oil and their main phenolic constituents against bacterial and fungal isolates associated with canine otitis externa were investigated. It was hypothesized that the main phenolic components would have greater antimicrobial activity compared to the relative essential oil. METHODS AND MATERIALS: Antimicrobial susceptibility testing was performed using broth microdilution with spot-plating technique to determine minimum inhibitory and bactericidal/fungicidal concentrations (MICs, MBCs and MFCs). A time-kill kinetics assay was performed to confirm the bactericidal and fungicidal activity of the oils and their phenolic constituents. One hundred bacterial and fungal isolates, including meticillin-susceptible Staphylococcus pseudintermedius (n = 10), meticillin-resistant S. pseudintermedius (n = 10), ß-haemolytic Streptococcus spp. (n = 20), Pseudomonas aeruginosa (n = 20; including 10 isolates resistant to one or two antimicrobials), Proteus mirabilis (n = 20) and Malassezia pachydermatis (n = 20) from dogs with otitis externa were used. RESULTS: Oregano oil, thyme oil, carvacrol and thymol exhibited antibacterial activity against all bacterial and fungal isolates tested. MIC90 values ranged from 0.015 to 0.03% (146-292 µg/mL) for the Gram-positive bacteria and P. mirabilis. For P. aeruginosa and M. pachydermatis, MIC90 values ranged from 0.09 to 0.25% (800-2,292 µg/mL). CONCLUSIONS AND CLINICAL SIGNIFICANCE: Oregano oil, thyme oil, carvacrol and thymol showed good in vitro bactericidal and fungicidal activity against 100 isolates from dogs with otitis externa, including some highly drug-resistant isolates. These essential oils and their main phenolic constituents have the potential to be further investigated in vivo for the treatment of canine otitis externa.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Óleos Voláteis/farmacologia , Otite Externa/veterinária , Óleos Vegetais/farmacologia , Animais , Cimenos/farmacologia , Doenças do Cão/microbiologia , Cães , Testes de Sensibilidade Microbiana , Origanum/química , Otite Externa/microbiologia , Timol/farmacologia , Thymus (Planta)/química
17.
Exp Appl Acarol ; 79(2): 209-219, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31578646

RESUMO

Essential oils show promise as natural alternatives to synthetic tick repellents, but few studies have investigated their repellent efficacy in vivo or under field conditions. Here, blanket-drags and standardised walks were employed to evaluate tick acquisition by 1 m2 cotton blankets or cotton trousers, respectively, in woodland edge habitats of known high tick abundance. Blankets and trousers had been treated with one of 5% oregano, rosemary, spearmint or thyme oils, 20% DEET (N,N-diethyl-3-methylbenzamide) (positive control) or ethanol excipient-only (negative control). The number of ticks present on the blankets or trousers differed significantly between treatments: spearmint oil treatments resulted in significantly fewer ticks than the negative controls for both blankets and trousers and significantly fewer ticks were present on the oregano oil treated blankets. For ticks that did attach to the trousers, the rate of drop off within 3 min was significantly higher for trousers treated with spearmint oil or thyme oil than ethanol, oregano oil and rosemary oil. No reduction in repellence was detected over a 24 h period between treatment and testing. The results suggest that 5% oregano and spearmint oils exhibit potential as natural clothing repellents, with an effective equivalence to 20% DEET.


Assuntos
Óleos Voláteis , Substâncias Protetoras , Controle de Ácaros e Carrapatos , Carrapatos , Animais , Inglaterra , Mentha spicata/química , Origanum/química , Rosmarinus/química , Thymus (Planta)/química
18.
Food Funct ; 10(11): 7037-7041, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31625548

RESUMO

The aim of this study was to determine dietary salicylate content in selected culinary herbs and spices, using the RP-HPLC method with fluorescence detection. The highest concentrations of salicylates were found in dried basil and cumin, followed by dried oregano and cloves. Our research contributes to the global database of salicylate content in food products.


Assuntos
Extratos Vegetais/química , Salicilatos/química , Especiarias/análise , Cuminum/química , Ocimum basilicum/química , Origanum/química , Syzygium/química
19.
PLoS One ; 14(9): e0222854, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31560730

RESUMO

The reduction of synthetic fungicides in agriculture is necessary to guarantee a sustainable production that protects the environment and consumers' health. Downy mildew caused by the oomycete Plasmopara viticola is the major pathogen in viticulture worldwide and responsible for up to 60% of pesticide treatments. Alternatives to reduce fungicides are thus utterly needed to ensure sustainable vineyard-ecosystems, consumer health and public acceptance. Essential oils (EOs) are amongst the most promising natural plant protection alternatives and have shown their antibacterial, antiviral and antifungal properties on several agricultural crops. However, the efficiency of EOs highly depends on timing, application method and the molecular interactions between the host, the pathogen and EO. Despite proven EO efficiency, the underlying processes are still not understood and remain a black box. The objectives of the present study were: a) to evaluate whether a continuous fumigation of a particular EO can control downy mildew in order to circumvent the drawbacks of direct application, b) to decipher molecular mechanisms that could be triggered in the host and the pathogen by EO application and c) to try to differentiate whether essential oils directly repress the oomycete or act as plant resistance primers. To achieve this a custom-made climatic chamber was constructed that enabled a continuous fumigation of potted vines with different EOs during long-term experiments. The grapevine (Vitis vinifera) cv Chasselas was chosen in reason of its high susceptibility to Plasmopara viticola. Grapevine cuttings were infected with P. viticola and subsequently exposed to continuous fumigation of different EOs at different concentrations, during 2 application time spans (24 hours and 10 days). Experiments were stopped when infection symptoms were clearly observed on the leaves of the control plants. Plant physiology (photosynthesis and growth rate parameters) were recorded and leaves were sampled at different time points for subsequent RNA extraction and transcriptomics analysis. Strikingly, the Oregano vulgare EO vapour treatment during 24h post-infection proved to be sufficient to reduce downy mildew development by 95%. Total RNA was extracted from leaves of 24h and 10d treatments and used for whole transcriptome shotgun sequencing (RNA-seq). Sequenced reads were then mapped onto the V. vinifera and P. viticola genomes. Less than 1% of reads could be mapped onto the P. viticola genome from treated samples, whereas up to 30% reads from the controls mapped onto the P. viticola genome, thereby confirming the visual observation of P. viticola absence in the treated plants. On average, 80% of reads could be mapped onto the V. vinifera genome for differential expression analysis, which yielded 4800 modulated genes. Transcriptomic data clearly showed that the treatment triggered the plant's innate immune system with genes involved in salicylic, jasmonic acid and ethylene synthesis and signaling, activating Pathogenesis-Related-proteins as well as phytoalexin synthesis. These results elucidate EO-host-pathogen interactions for the first time and indicate that the antifungal efficiency of EO is mainly due to the triggering of resistance pathways inside the host plants. This is of major importance for the production and research on biopesticides, plant stimulation products and for resistance-breeding strategies.


Assuntos
Fungicidas Industriais/administração & dosagem , Óleos Voláteis/administração & dosagem , Oomicetos/patogenicidade , Origanum/química , Doenças das Plantas/prevenção & controle , Óleos Vegetais/administração & dosagem , Vitis/imunologia , Ciclopentanos/metabolismo , Resistência à Doença/efeitos dos fármacos , Resistência à Doença/imunologia , Fumigação , Fungicidas Industriais/toxicidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/imunologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/efeitos dos fármacos , Óleos Voláteis/toxicidade , Oxilipinas/metabolismo , Fotossíntese/efeitos dos fármacos , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/microbiologia , Óleos Vegetais/toxicidade , Sesquiterpenos/metabolismo , Vitis/efeitos dos fármacos , Vitis/microbiologia
20.
Food Microbiol ; 84: 103240, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421790

RESUMO

This study evaluated whether the pre-exposure (24, 48 and 72 h) to sublethal conditions caused by acetic acid (AA), lactic acid (LA), sodium chloride (NaCl) or potassium chloride (KCl) could induce increased cross-tolerance to the essential oils from Origanum vulgare L. (OVEO) and Rosmarinus officinalis L. (ROEO) in different Listeria monocytogenes strains. Damage to membrane integrity, membrane potential, enzymatic activity and efflux activity in L. monocytogenes cells pre-exposed (24 h) to AA or NaCl and further treated with OVEO or ROEO (8 and 24 h) were investigated using flow cytometry (FC). Results of minimum inhibitory concentration (MIC) modulation test showed that pre-exposure to sublethal conditions caused by organic acids or salts increased cross-tolerance only to ROEO, since MIC of ROEO increased up to 4.8-fold against pre-exposed cells. Otherwise, MIC of OVEO against these pre-exposed cells was up to ten-fold lower than that observed against not pre-exposed cells, indicating no increase in cross-tolerance. Bacterial survival assays showed that ROEO only decreased the counts over time of cells not pre-exposed to organic acids or salts, while OVEO decreased similarly or more the counts of pre-exposed cells compared to not pre-exposed cells. Results of FC analysis showed that all measured functions in L. monocytogenes cells pre-exposed to AA or NaCl and treated with OVEO or ROEO were affected, although with different intensities. These data indicate that exposure to sublethal conditions imposed by organic acids or salts could result in a phenotype of increased cross-tolerance to ROEO but not to OVEO in L. monocytogenes.


Assuntos
Listeria monocytogenes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Origanum/química , Rosmarinus/química , Sais/farmacologia , Ácido Acético/farmacologia , Cicloexanóis/farmacologia , Microbiologia de Alimentos , Conservantes de Alimentos/farmacologia , Listeria monocytogenes/fisiologia , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Cloreto de Potássio/farmacologia , Cloreto de Sódio/farmacologia , Estresse Fisiológico
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