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1.
Bol. latinoam. Caribe plantas med. aromát ; 18(4): 411-424, jul. 2019. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1008180

RESUMO

Thymol (2-isopropyl-5-methylphenol) is an aromatic monoterpene found in essential oils extracted from plants belonging to the Lamiaceae family, such as Thymus, Ocimum, Origanum, Satureja, Thymbra and Monarda genera. Growth and biofilm formation by Listeria monocytogenes CLIP 74902 were evaluate using three carbon sources in the presence of thymol. Specific growth rate (h-1) values at 37o with glucose, trehalose and cellobiose with the addition of thymol (µg/mL) 0 (control) and 750, were respectively: 0.22, 0.07; 0.14, 0.04; 0.11, 0.04. Lag periods obtained under the same conditions were (h): 8.19, 13.2; 22.5, 27.5; 23.1, 28.1. A marked antibiofilm activity was observed against the exposure with 750 µg/mL of thymol, showing a high percentage of inhibition: glucose (99 %), trehalose (97 %) and cellobiose (98%), compared to the control. The results suggest that thymol could be used to inhibit the growth and production of biofilms by L. monocytogenes in the food industry.


Timol (2-isopropil-5-metilfenol) es un monoterpeno aromático presente en los aceites esenciales extraídos de plantas pertenecientes a la familia Lamiaceae, como los géneros Thymus, Ocimum, Origanum, Satureja, Thymbra y Monarda. El crecimiento y formación de biopelícula por Listeria monocytogenes CLIP 74902 fueron evaluados utilizando tres fuentes de carbono en presencia de timol. La velocidad específica de crecimiento (h-1) a 37o con glucosa, trehalosa y celobiosa con la adición de timol (µg/mL) 0 (control) y 750, fueron respectivamente: 0.22, 0.07; 0.14, 0.04, 0.11, 0,04. Los períodos lag obtenidos en las mismas condiciones fueron (h): 8.19, 13.2; 22.5, 27.5; 23.1, 28.1. Una marcada actividad antibiofilm fue obtenida con 750 µg/mL de timol, mostrando un alto porcentaje de inhibición con glucosa (99%), trehalosa (97%) y celobiosa (98%), respecto al control. Los resultados sugieren que timol podría ser usado para inhibir el crecimiento y producción de biopelículas por L. monocytogenes en la industria alimentaria.


Assuntos
Timol/farmacologia , Biofilmes/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Terpenos/farmacologia , Cinética , Biofilmes/crescimento & desenvolvimento , Meio Ambiente , Fermentação , Microbiologia de Alimentos , Listeria monocytogenes/crescimento & desenvolvimento
2.
J Agric Food Chem ; 67(30): 8382-8392, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31271032

RESUMO

Staphylococcus aureus is a common pathogen that can cause life-threatening infections. Treatment of antibiotic-resistant S. aureus infection needs effective antibacterial agents. Thymol, a generally recognized safe natural compound, has potential as an alternative to treat S. aureus infections. However, the targets and mechanisms of action of thymol were not fully understood. Bioinformatics analysis showed that IolS, a predicted aldo-keto reductase (AKR) in S. aureus, could be a potential target of thymol. Isothermal titration calorimetry (ITC) analysis demonstrated that thymol directly binds IolS and amino acid residues (Y30 and L33) are essential for such binding. Deletion of IolS or mutation of Y30A and L33A reduced the bactericidal activity of thymol at the concentration of 200 µg/mL, suggesting that thymol mediates bactericidal activity via binding with IolS. Biochemical analysis showed that addition of thymol significantly increased AKR activity of IolS from 1.6 ± 0.1 to 2.4 ± 0.2 U (p < 0.05). The content of NADPH within S. aureus cells decreased significantly from 105 ± 5 to 72 ± 3 pmol/108 cells (p < 0.05) following thymol treatment at the concentration of 200 µg/mL. Importantly, addition of NADPH could alleviate the bactericidal effect of thymol on S. aureus, indicating that the depletion of NADPH is responsible for thymol-mediated bactericidal activity. Overall, these results demonstrated that thymol could directly bind IolS and increase its AKR activity, leading to the depletion of NADPH and bactericidal effect. AKR activity of IolS could be a promising target for the development of new antimicrobials.


Assuntos
Aldo-Ceto Redutases/antagonistas & inibidores , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , NADP/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/enzimologia , Timol/farmacologia , Aldo-Ceto Redutases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética
3.
Cell Physiol Biochem ; 53(2): 285-300, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31334617

RESUMO

BACKGROUND/AIMS: Although naturally-derived antifungals have been investigated for their ability to inactivate Candida albicans, which is a major cause of candidiasis, they have shown a less than 3 log reduction in C. albicans or required treatment times of longer than 3 h. Thus, the naturally-derived antifungals used in previous studies could not substantially eradicate C. albicans within a short period of time. METHODS: To improve the fungicidal effects of naturallyderived antifungals against C. albicans within short time periods, we developed composites showing antifungal synergism using caprylic acid (CA), carvacrol (CAR) and thymol (THM) for 1-10 min at 22/37°C. Using flow cytometry, we examined the mode of action for the synergism of these compounds on membrane integrity and efflux pump activity. RESULTS: Whereas the maximum reduction by individual treatments was 0.6 log CFU/ml, CA + CAR/THM (all 1.5 mM) eliminated all pathogens (> 6.8 log reduction) after 1 min at 37°C and after 10 min at 22°C. The flow cytometry results showed that exposure to CA damaged the membranes in 15.7-36.5% of cells and inhibited efflux pumps in 15.4-31.3% of cells. Treatments with CAR/THM slightly affected cell membranes (in 1.8-6.9% of cells) but damaged efflux pumps in 14.4-29.6% of cells. However, the combined treatments clearly disrupted membranes (> 83.1% of cells) and pumps (> 95.0% of cells). The mechanism of this synergism may involve membrane damage by CA, which facilitates the entry of antifungals into the cytoplasm, and the inhibition of efflux pumps by CA, CAR or THM, causing their accumulation within cells and, leading to cell death. CONCLUSION: Antifungal composites (CA + CAR/THM) showing synergism (i.e., an additional 6 log reduction) within minutes at room/body temperature can be used to treat candidiasis and improve the microbiological safety of facilities contaminated with fungi as a novel alternative to synthetic antifungals.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Caprilatos/farmacologia , Proteínas Fúngicas/metabolismo , Monoterpenos/farmacologia , Timol/farmacologia , Candida albicans/metabolismo , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Sinergismo Farmacológico , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Temperatura Ambiente
4.
Int J Food Microbiol ; 305: 108246, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31238193

RESUMO

Cellulosic pads, amended with emulsions containing essential oils of thyme and oregano, exhibited antimicrobial activity against the psychrophilic microbiota of minced beef. In addition, the pads were active against specific meat bacterial species (Pseudomonas putida, Pseudomonas fragi, Pseudomonas fluorescens, Enterococcus faecalis and Lactococcus lactis) and some common foodborne pathogens (Salmonella enterica, Campylobacter jejuni and Staphylococcus aureus). Three emulsions, IT131017, Mediterranean and Etnic, containing different percentages of carvacrol, thymol, linalool, and ɑ and ß-pinene, significantly reduced the growth of S. enterica and P. putida. Pads derived from emulsions Mediterranean and Etnic induced slight (0.3-0.8 Log10 CFUs/g) but reproducible reduction of the psychrophilic microbiota in minced meat and hamburger stored for 12 and 15 days at 4 °C.


Assuntos
Antibacterianos/farmacologia , Cinnamomum zeylanicum/química , Óleos Voláteis/farmacologia , Origanum/química , Extratos Vegetais/farmacologia , Carne Vermelha/microbiologia , Thymus (Planta)/química , Animais , Antibacterianos/química , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Compostos Bicíclicos com Pontes , Bovinos , Celulose/química , Emulsões/química , Emulsões/farmacologia , Microbiologia de Alimentos , Carne/microbiologia , Monoterpenos/química , Monoterpenos/farmacologia , Óleos Voláteis/química , Extratos Vegetais/química , Carne Vermelha/análise , Timol/química , Timol/farmacologia
5.
J Food Sci ; 84(7): 1979-1985, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31206673

RESUMO

Essential oils (EO) are widely used in foods as flavoring and preservative agents. Many of the biological activities of EO have been attributed to major essential oil compounds (EOC) but their direct interaction with colonic epithelial cells and their genotoxic and genoprotective effects are not well established. In this study, the cytotoxicity and genotoxicity of EOC including nerolidol, thymol, geraniol, methylisoeugenol, eugenol, linalool, and a commercial blend (Agolin) were determined. Furthermore, the genoprotective effects of EOC against oxidative and methylating damage were assessed using the comet assay in HT-29 colorectal adenocarcinoma cells. The majority of EOC were cytotoxic to HT-29 cells at or above 250 ppm after 24 hr exposure. At noncytotoxic doses, none of the EOC was genotoxic in the comet assay. Genoprotection against oxidative DNA damage was observed for nerolidol (at 62.5 ppm), thymol (at 12.5 ppm), geraniol, and methylisoeugenol (both at 125 ppm), as well as linalool and Agolin (both at 250 ppm). Thymol was the most protective compound against oxidative DNA damage and geraniol (at 125 ppm) also protected cells against methylating DNA damage. This study highlights the potential of EOC such as thymol to protect the colonic epithelium against oxidative DNA damage and geraniol against methylating DNA damage. Further in vivo studies are needed to confirm these findings for safety and efficacy to exploit their potential pharmaceutical or nutraceutical uses for colonic health.


Assuntos
Dano ao DNA/efeitos dos fármacos , Óleos Voláteis/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Ensaio Cometa , Metilação de DNA/efeitos dos fármacos , Eugenol/análise , Eugenol/farmacologia , Humanos , Monoterpenos/análise , Monoterpenos/farmacologia , Óleos Voláteis/análise , Substâncias Protetoras/análise , Terpenos/análise , Terpenos/farmacologia , Timol/análise , Timol/farmacologia
6.
Planta Med ; 85(11-12): 941-946, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31163460

RESUMO

Targeted isolation based on a combination of NMR and HPLC-PDA-MS of a dichloromethane extract of Thymus vulgaris Varico 3 aerial parts afforded one new p-cymene dimer, 6,3',4'-trihydroxy-5,5'-diisopropyl-2,2'-dimethylbiphenyl (1: ), together with two known p-cymene derivatives (2: and 3: ), as well as five known compounds, namely, thymol (4: ), oleanolic acid (5: ), ursolic acid (6: ), cirsimaritin (7: ), and xanthomicrol (8: ). The structural elucidation of all compounds was performed by spectroscopic analyses, including 1D and 2D NMR, and HRESIMS experiments. The biphenyls were assayed for their inhibitory activity on tyrosinase. Compounds 2: and 3: showed negligible activity on tyrosinase, while compound 1: effectively inhibited the enzyme with 35% (± 0.3) inhibitory activity, higher than the inhibition of the reference compound kojic acid (18.6 ± 0.02).


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectroscopia de Ressonância Magnética/métodos , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monoterpenos/isolamento & purificação , Extratos Vegetais/química , Thymus (Planta)/química , Flavonas/farmacologia , Monoterpenos/farmacologia , Ácido Oleanólico/farmacologia , Timol/farmacologia , Triterpenos/farmacologia
7.
Biofouling ; 35(3): 361-375, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31088182

RESUMO

The aim of the present study was to determine the bioactive compounds in four essential oils (EO's) from Origanum heracleoticum, Origanum vulgare, Thymus vulgaris and Thymus serpyllum and to assess their antimicrobial and anti-biofilm activity against Salmonella Enteritidis. Strains were previously characterized depending on the expression of the extracellular matrix components cellulose and curli fimbriae as rdar (red, dry and rough) and bdar morphotype (brown, dry and rough). This study revealed that the EO's and EOC's (carvacrol and thymol) investigated showed inhibition of biofilm formation at sub-minimum inhibitory concentration. Comparing the efficacy of EO's and EOC's in the inhibition of biofilm formation between the strains with different morphotype (rdar and bdar) did not show a statistically significant difference. Results related to the effectiveness of EO's and EOC's (the essential oil components, carvacrol and thymol) on eradication of preformed 48 h old biofilms indicated that biofilm reduction occurred in a dose-dependent manner over time.


Assuntos
Biofilmes/efeitos dos fármacos , Monoterpenos/farmacologia , Óleos Voláteis/farmacologia , Salmonella enteritidis/efeitos dos fármacos , Timol/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Salmonella enteritidis/fisiologia
8.
J Food Sci ; 84(6): 1513-1521, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31120593

RESUMO

Geotrichum citri-aurantii causes sour rot in citrus fruits and is responsible for important economic losses during storage. However, the availability of chemical fungicides for the control of this pathogen is limited. Thus, the aim of this research was to evaluate the antifungal efficacy of thymol and carvacrol encapsulated in 2-hydroxylpropyl-beta-cyclodextrin (HP-ß-CD) (prepared by the microwave irradiation method [MW] and solubility method [S]) for inhibition of G. citri-aurantii using in vitro bioassays broth (micro and macrodilutions methods) and inoculated food testing. Both encapsulated thymol and carvacrol were shown to be effective for inhibiting G. citri-aurantii growth in in vitro assays. Thymol was more effective in inhibiting G. citri-aurantii, while better encapsulation was provided by MW. HP-ß-CD-thymol encapsulated by MW (HP-ß-CD-thymol-MW) showed the lowest 50% effective dose (ED50 = 1.16 mM), minimum inhibitory concentration (MIC = 5.06 mM), and minimum fungicide concentration (MFC = 52.6 mM). HP-ß-CD-thymol-MW was found highly effective in reducing the growth rate and mycelial growth inhibition. Finally, HP-ß-CD-thymol-MW and HP-ß-CD-carvacrol-MW showed a higher persistent effect than thymol and carvacrol in their natural form in inhibiting this fungus. Therefore, HP-ß-CD-thymol-MW could be a promising alternative to synthetic fungicides for controlling G. citri-aurantii, the causal agent of citrus sour rot. PRACTICAL APPLICATION: Encapsulated thymol and carvacrol in HP-ß-Cyclodextrins are effective for controlling G. citri-aurantii in in vitro experiments. Encapsulation of thymol and carvacrol by microwave irradiation method (MW) was more effective than the solubility (S) method. Thymol was more effective than carvacrol, and the best results on G. citri-auriantii inhibition were achieved using the HP-ß-CD-thymol-MW method (which gave the lowest ED50 , MIC, and MFC).


Assuntos
Citrus/microbiologia , Composição de Medicamentos/métodos , Fungicidas Industriais/farmacologia , Geotrichum/efeitos dos fármacos , Monoterpenos/farmacologia , Timol/farmacologia , beta-Ciclodextrinas/química , Fungicidas Industriais/química , Geotrichum/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Monoterpenos/química , Doenças das Plantas/microbiologia , Timol/química
9.
Meat Sci ; 155: 27-35, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31059939

RESUMO

The objective of the present experiment was to evaluate the effects of encapsuled active principles (eugenol, thymol and vanillin blend), and clove and rosemary essential oils inclusion into the finishing diets of Nellore heifers on chemical composition, collagen content, fatty acid profile and structural traits (fibers types, type I and III collagen and sarcomere length) of longissimus muscle. Treatments had no effect (P > .05) on type of fiber, the meat chemical composition or in the muscle fatty acid profile. However, the diet with clove and rosemary essential oil and the active principle blend led to an increase in sarcomere length, higher soluble collagen content and a lower amount of type III collagen (P < .05). The mixture of both active principles and essential oils clove and cinnamon essential oil, have a potential use in animal feed, favoring a greater sarcomere length, that is directly related to the increase of the meat tenderness, without altering the meat chemical composition or fatty acid profile.


Assuntos
Ração Animal/análise , Colágeno/análise , Ácidos Graxos/análise , Óleos Voláteis/farmacologia , Carne Vermelha/análise , Animais , Benzaldeídos/farmacologia , Bovinos , Dieta/veterinária , Eugenol/farmacologia , Feminino , Fibras Musculares Esqueléticas/efeitos dos fármacos , Sarcômeros/efeitos dos fármacos , Syzygium , Timol/farmacologia
10.
Int J Mol Sci ; 20(7)2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30934738

RESUMO

Parkinson's disease (PD), a multifactorial movement disorder that involves progressive degeneration of the nigrostriatal system affecting the movement ability of the patient. Oxidative stress and neuroinflammation both are shown to be involved in the etiopathogenesis of PD. The aim of this study was to evaluate the therapeutic potential of thymol, a dietary monoterpene phenol in rotenone (ROT)-induced neurodegeneration in rats that precisely mimics PD in humans. Male Wistar rats were injected ROT at a dose of 2.5 mg/kg body weight for 4 weeks, to induce PD. Thymol was co-administered for 4 weeks at a dose of 50 mg/kg body weight, 30 min prior to ROT injection. The markers of dopaminergic neurodegeneration, oxidative stress and inflammation were estimated using biochemical assays, enzyme-linked immunosorbent assay, western blotting and immunocytochemistry. ROT challenge increased the oxidative stress markers, inflammatory enzymes and cytokines as well as caused significant damage to nigrostriatal dopaminergic system of the brain. Thymol treatment in ROT challenged rats appears to significantly attenuate dopaminergic neuronal loss, oxidative stress and inflammation. The present study showed protective effects of thymol in ROT-induced neurotoxicity and neurodegeneration mediated by preservation of endogenous antioxidant defense networks and attenuation of inflammatory mediators including cytokines and enzymes.


Assuntos
Dieta , Neurônios Dopaminérgicos/patologia , Degeneração Neural/prevenção & controle , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/patologia , Timol/uso terapêutico , Animais , Catalase/metabolismo , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Glutationa/metabolismo , Mediadores da Inflamação/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Neostriado/efeitos dos fármacos , Neostriado/patologia , Degeneração Neural/patologia , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico Sintase Tipo II/metabolismo , Ratos Wistar , Rotenona , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Superóxido Dismutase/metabolismo , Timol/química , Timol/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo
11.
Food Chem ; 287: 139-150, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30857683

RESUMO

A novel synergistic formulation (TML) based on the combination of thymol (T), methyl cinnamate (M), and linalool (L) has been prepared using the mixture design assay. Nanoencapsulation of developed formulation TML (Ne-TML) was prepared and characterised by SEM, XRD and FTIR. The Ne-TML was assessed for its antifungal and anti-aflatoxin B1 potential in vitro and in the food systems (Pennisetum glaucum L.), and also examined its effects on organoleptic properties. The Ne-TML cause complete inhibition of growth and AFB1 production at 0.3 µl/ml and 0.2 µl/ml. In-situ results revealed that Ne-TML exhibited maximum protection from fungal (75.40%) and aflatoxin B1 contamination (100%) at 0.3 µl/ml during six months of storage. The speculated antifungal mode of action of Ne-TML was related to the decrease in ergosterol content, membrane ions leakage, impairment in carbon-source utilization, mitochondrial functioning, anti-oxidative defence system (SOD, CAT, and GR) and Ver-1 gene of aflatoxin B1 biosynthesis.


Assuntos
Aflatoxina B1/antagonistas & inibidores , Antifúngicos , Aspergillus flavus/efeitos dos fármacos , Nanocápsulas/química , Extratos Vegetais , Antifúngicos/química , Antifúngicos/farmacologia , Composição de Medicamentos , Estabilidade de Medicamentos , Microbiologia de Alimentos , Monoterpenos/química , Monoterpenos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Timol/química , Timol/farmacologia
12.
Mater Sci Eng C Mater Biol Appl ; 99: 394-404, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889714

RESUMO

Amorphous, medical grade poly(d,l-lactic acid) (PLA) and poly(d,l-lactic-co-glycolic acid) (PLGA) were used to develop systems for controlled release of a natural bioactive substance - thymol. Supercritical carbon dioxide (scCO2) was successfully used both as an impregnation medium for thymol incorporation into the polymer matrix and a foaming agent in a single-step batch process. Impregnation of samples using low to moderate scCO2 densities (273 kg/m3 and 630 kg/m3) and short processing times (2 h and 4 h) enabled thymol loading of 0.92%-6.62% and formation of microcellular foams upon system depressurization. Thymol effect on structural and thermal properties on foamed samples was proven by FTIR and DSC. The effect of CO2 under elevated pressure on the neat polymers was analysed by high pressure DSC. Foaming of polymers with lower molecular weight by CO2 of higher density yielded foams with smaller pores. All tested foams released thymol in a controlled manner in phosphate buffered saline (PBS) at 37 °C within 3 to 6 weeks. Higher loading and lower cell density favoured thymol release rate, while its concentration in PBS for the tested period depended on foam interaction with the medium. Representative PLGA foam sample with the highest thymol loading (6.62%) showed controlled thymol release within 72 h in mediums having pH values from 1.1 to 7.4.


Assuntos
Dióxido de Carbono/química , Liberação Controlada de Fármacos , Poliésteres/síntese química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/síntese química , Timol/farmacologia , Cinética , Poliésteres/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Porosidade , Pressão , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Temperatura de Transição
13.
Indian J Dent Res ; 30(1): 67-72, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30900660

RESUMO

Background: Streptococcus mutans is considered as the main pathogenic factor for initiation and progression of dental caries. Fluoride is one of the most effective agents used to control caries. Chlorhexidine (CHX) is the most antimicrobial agent against S. mutans and dental caries. Aims: The study aimed to compare the effectiveness of antimicrobial activity of CHX-thymol (CHX/T) and fluoride varnishes on S. mutans levels in children's saliva aged from 6 to 8 years old. Materials and Methods: The total number of children involved in this study is sixty, ages 6 and 8 years old. The participants were divided into three groups by block randomization: Group 1 CHX/T varnish, Group 2 fluoride varnish (f varnish, and Group 3 control group. Varnish was applied onto all tooth surfaces of the participants. At the baseline conditions, saliva samples were collected from the participants for bacterial examination test. This procedure was repeated in week 1, 4, and 12. Bacterial quantitative test was performed, and the number of S. mutans was estimated. Results: The results revealed the significant efficacy of the two groups (fluoride and CHX/T varnishes) in reducing salivary S. mutans numbers when compared to the control group (P < 0.05). In terms of salivary colony-forming unit counts reduction of S. mutans, no significant difference was observed between the fluoride and CHX/T varnish groups (P > 0.05). Conclusion: The outcomes showed that there was a significant reduction in S. mutans counts in children's saliva following the application of fluoride and CHX/T varnishes.


Assuntos
Anti-Infecciosos Locais/administração & dosagem , Anti-Infecciosos Locais/farmacologia , Cariostáticos/administração & dosagem , Cariostáticos/farmacologia , Clorexidina/administração & dosagem , Clorexidina/farmacologia , Fluoretos Tópicos/administração & dosagem , Fluoretos Tópicos/farmacologia , Saliva/microbiologia , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/isolamento & purificação , Timol/administração & dosagem , Timol/farmacologia , Criança , Cárie Dentária/etiologia , Cárie Dentária/microbiologia , Combinação de Medicamentos , Farmacorresistência Bacteriana , Feminino , Humanos , Masculino
14.
Lett Appl Microbiol ; 68(6): 562-572, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30861569

RESUMO

Streptococcus suis is a major swine pathogen. Different strategies to reduce the antimicrobial resistance to conventional antimicrobials (AMBs) have been proposed, including the combined use with essential oils (EOs). The objective of this work was to evaluate the effectiveness of the combination of cinnamon, oregano, common thyme and red thyme EOs and their main components (cinnamaldehyde, carvacrol and thymol) with conventional AMBs (oxytetracycline, trimethoprim-sulfamethoxazole, gentamicin and penicillin) against field resistant S. suis strains. The checkerboard method was used to assess the interaction, by the fractional inhibitory concentration index (FICindex ) determination. All the AMBs showed synergistic (FICindex  ≤ 0·5) or additive (0·5 < FICindex  ≤ 1) effect with at least one of the four essential oils. In general, the combination of the AMBs with the EOs showed better results than combination the AMBs with the main components, although no antagonist effects were detected in any case. The results obtained would support the combined use of AMBs agents with EOs for the treatment of S. suis. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptococcus suis is an important pig pathogen and a zoonosis. Control is based on antimicrobials; however, there is pressure to reduce the use of antimicrobials and new products or combination therapies are of considerable interest. We have evaluated the combined interaction of four essential oils or their main components with conventional antimicrobials against resistant S. suis strains. A positive interaction between gentamicin and oxytetracycline with cinnamon, oregano or thyme was observed, suggesting that a combination of conventional antimicrobials with EOs is a promising alternative for the control of S. suis infections.


Assuntos
Acroleína/análogos & derivados , Antibacterianos/farmacologia , Monoterpenos/farmacologia , Óleos Voláteis/farmacologia , Streptococcus suis/efeitos dos fármacos , Doenças dos Suínos/tratamento farmacológico , Timol/farmacologia , Acroleína/farmacologia , Animais , Cinnamomum zeylanicum/química , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Origanum/química , Streptococcus suis/crescimento & desenvolvimento , Suínos , Doenças dos Suínos/microbiologia , Thymus (Planta)/química
15.
Lett Appl Microbiol ; 68(4): 321-328, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30801748

RESUMO

Urinary tract infections (UTI), one of the most common diseases in humans, are caused primarily by uropathogenic Escherichia coli (UPEC). Cranberry juice (CB) is a widely known prophylaxis for UTI, but the treatment of CB alone could not effectively eradicate preformed UPEC biofilms. The aim of this study was to develop enforced CB composites within a short time by adding a small quantity of natural borne antimicrobials. UPEC biofilms (initial: 6·0 log CFU per cm2 ), formed on silicone coupons in artificial urine medium, were exposed to CB (4-8%), caprylic acid (CAR; 0·025-0·05%) and thymol (TM; 0·025-0·05%) at 37°C for 1 min. Individual treatment of each compound did not show the significant antibacterial effect on UPEC biofilms (P > 0·05). Otherwise, the survivor counts of biofilms were synergistically reduced with CB containing any of the antimicrobials. For example combined treatment with CB (8%) + CAR (0·05%) + TM (0·05%) resulted in a 6 log reduction in UPEC populations in the biofilm (no detectable bacteria remained) with 4·6 log of synergistic bactericidal effect. The confocal laser scanning microscope images indicated that any composites including TM might result in biofilm detachment from the surface. The present method is cost-effective and more acceptable to consumers as it is based on the synergistic interaction of natural borne antimicrobials. The results of this study could be widely applicable in the functional food, medical and healthcare field. SIGNIFICANCE AND IMPACT OF THE STUDY: Anti-biofilm effect of cranberry juice (CB) has been focused mainly on inhibiting biofilm formation of uropathogenic Escherichia coli (UPEC); however, combined treatment with natural borne antimicrobials derived from coconut oil (caprylic acid) and oregano essential oil (thymol) could synergistically enhance its eradicating activity against biofilms. This study developed novel CB composites showing marked anti-biofilm effects (complete eradication of UPEC biofilms within just 1 min).


Assuntos
Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Caprilatos/farmacologia , Preparações de Plantas/farmacologia , Timol/farmacologia , Escherichia coli Uropatogênica/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Sucos de Frutas e Vegetais , Humanos , Microscopia Confocal , Óleos Voláteis/farmacologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia , Vaccinium macrocarpon/química
16.
Food Chem ; 285: 380-388, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30797360

RESUMO

This study investigated effects of the simultaneous application of thymol and salicylic acid (SIMTSA) on the target sites of Rhizopus stolonifer, as well as the defenceenzymes of postharvest tomato, when applied as edible coating. SIMTSA induced the changes of ultrastructure and membrane integrity of R. stolonifer. When the concentrations of the fungistat increased, cells stained with propidium iodide and leakage of 260/280 nm-absorbing materials increased while ergosterol synthesis decreased, suggesting damage of cell membrane. Furthermore, SIMTSA treatment significantly reduced the citric acid content and the activities of enzymes related to the tricarboxylic acid cycle, and increased the mitochondrial membrane potential and the reactive oxygen species, indicating damage of mitochondrial-related functions. Moreover, SIMTSA edible coating increased the defence enzyme activities in tomato. Based on the results, SIMTSA can be used as a potential preservation method for tomato as it showed a targeted effect on the cell membrane and mitochondria of R. stolonifer.


Assuntos
Antifúngicos/farmacologia , Lycopersicon esculentum/microbiologia , Rhizopus/efeitos dos fármacos , Ácido Salicílico/farmacologia , Timol/farmacologia , Membrana Celular/efeitos dos fármacos , Ácido Cítrico/metabolismo , Enzimas/metabolismo , Ergosterol/metabolismo , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Rhizopus/citologia , Rhizopus/ultraestrutura
17.
J Agric Food Chem ; 67(6): 1736-1741, 2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30676718

RESUMO

The application of the nanofiber film in the field of food preservation was an emerging research direction in recent years. With the functionalization of nanofibers, the quality and safety of food can be better guaranteed. In the present work, thymol as an antibacterial agent was encapsulated into poly(lactide- co-glycolide) to form core-shell nanofibers by coaxial electrospinning. With such a core-shell nanofiber film, thymol can be slowly released to headspace between food and the nanofiber film, inhibiting the growth of bacteria on the surface of food. The morphology and core-shell structure of nanofibers were confirmed by scanning electron microscopy and transmission electron microscopy. The antibacterial and fruit preservation abilities of the nanofiber film were tested on strawberries. Studies have shown that it can effectively inhibit the growth of bacteria, fungi, and yeast and extend the shelf life of fruit. This novel antibacterial packaging material with excellent biocompatibility, biodegradability, and good sustained release performance would have a broad application prospect in the field of food preservation.


Assuntos
Antibacterianos/química , Conservação de Alimentos/métodos , Fragaria/química , Frutas/química , Nanofibras/química , Timol/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Composição de Medicamentos , Técnicas Eletroquímicas , Embalagem de Alimentos/instrumentação , Conservação de Alimentos/instrumentação , Armazenamento de Alimentos , Fragaria/microbiologia , Frutas/microbiologia , Poliglactina 910/química , Timol/farmacologia
18.
Int J Food Microbiol ; 292: 150-158, 2019 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-30599455

RESUMO

Strawberry has a limiting postharvest shelf life, especially because of soft rot. The antifungal activity of the essential oils (EOs) of Eucalyptus staigeriana, Lippia sidoides and Pimenta pseudocaryophyllus was tested in vitro against plant pathogen Rhizopus stolonifer. The chemical composition of the EO with the highest activity and its effects on pathogen morphology were verified. The in vivo antifungal activity of this EO associated with carboxymethylcellulose (CMC) coating, in preventive and curative applications, was also evaluated. L. sidoides EO presented the highest in vitro antifungal activity. The analysis of the chemical composition of this EO showed a prevalence of the compound thymol and the scanning and transmission electron microscopy showed that L. sidoides EO was able to cause damage to the cell wall and the intracellular components of the pathogen. Strawberries treated with L. sidoides EO associated with CMC presented a reduction in disease severity, especially when treated in a curative way.


Assuntos
Carboximetilcelulose Sódica/farmacologia , Fragaria/microbiologia , Fungicidas Industriais/farmacologia , Óleos Voláteis/farmacologia , Rhizopus/efeitos dos fármacos , Eucalyptus/química , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Lippia/química , Pimenta/química , Timol/farmacologia , Compostos Orgânicos Voláteis/farmacologia
19.
Carbohydr Polym ; 205: 533-539, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30446137

RESUMO

Bacterial biofilms are widely associated with persistent infections and food contamination. High resistance to conventional antimicrobial agents resulted in an urgent need for novel formulation to eliminate these bacterial communities. Herein we fabricated light controllable chitosan micelles loading with thymol (T-TCP) for elimination of biofilm. Due to the exterior chitosan, T-TCP micelles easily bind to negative biofilm through electrostatic interaction and efficiently deliver the essential oil payloads. Under irradiation, T-TCP micelles generated ROS, which triggered simultaneous thymol release and also resulted in additional ROS-inducing bactericidal effects, both effectively eradicating biofilms of Listeria monocytogenes and Staphylococcus aureus. This formulation provided a platform for other water-insoluble antimicrobials and might be used as a potent and controllable solution to biofilm fighting.


Assuntos
Biofilmes/efeitos dos fármacos , Quitosana/análogos & derivados , Quitosana/química , Portadores de Fármacos/química , Micelas , Timol/farmacologia , Quitosana/síntese química , Quitosana/efeitos da radiação , Portadores de Fármacos/síntese química , Portadores de Fármacos/efeitos da radiação , Liberação Controlada de Fármacos/efeitos da radiação , Interações Hidrofóbicas e Hidrofílicas , Luz , Listeria monocytogenes/fisiologia , Óleos Voláteis/farmacologia , Polímeros/síntese química , Polímeros/química , Polímeros/efeitos da radiação , Espécies Reativas de Oxigênio , Staphylococcus aureus/fisiologia , Sulfetos/síntese química , Sulfetos/química , Sulfetos/efeitos da radiação , Cloreto de Tolônio/síntese química , Cloreto de Tolônio/química , Cloreto de Tolônio/efeitos da radiação
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 208: 339-348, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30343222

RESUMO

Cyclodextrins have a wide range of applications in different areas of drug delivery and pharmaceutical industry due to their complexation ability and other versatile characteristics. Here we have studied the binding interactions of a small biologically important phenolic molecule, Thymol (Th), with both α and ß cyclodextrins (CDs), which are well known drug delivery vehicles. Extent of encapsulation has been determined using several spectroscopic techniques. In fluorescence experiments, significant increase in fluorescence intensities have been discerned for both the CDs but there had been a much early saturation for αCD. Anisotropy experiments have been performed too and very surprisingly no appreciable increase in anisotropy value was observed in either case. Isothermal titration calorimetry (ITC) data, however, show signature of binding of Th with the ßCD. These intriguing results were explained with the help of molecular docking and dynamics simulation studies. The docking calculations have shown that Th goes inside both α and ßCD. In keeping with the final NMR data and molecular dynamics we have ultimately concluded that solvated Th molecules are the main participants in the interaction with CDs which is responsible for these intriguing behaviors. Finally we have also performed an antioxidant assay to reveal the practical application of such encapsulation. It has been found that on encapsulation there is an enhancement of the antioxidant behavior of Th. Then we have also performed an antibacterial assay to show the unchanged antibacterial properties of Th on encapsulation. Hence it can be deduced that Th can be safely delivered through CDs in living system without hampering its beneficial properties.


Assuntos
Modelos Teóricos , Análise Espectral , Timol/farmacologia , beta-Ciclodextrinas/química , Anisotropia , Anti-Infecciosos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Compostos de Bifenilo/química , Calorimetria , Depuradores de Radicais Livres/química , Ligações de Hidrogênio , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Picratos/química , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Fluorescência , Timol/química
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