scholarly journals Efficacy of essential oils in the management of soft rot caused by Pectobacterium aroidearum in lettuce

2021 ◽  
Vol 37 ◽  
pp. e37095
Author(s):  
Karol Alves Barroso ◽  
Xênia Bastos de Oliveira ◽  
Márcia Ferreira Queiroz ◽  
Camila De Oliveira Almeida ◽  
Vitor Prates Lorenzo ◽  
...  
Keyword(s):  
Essential Oils ◽  
Preventive Treatment ◽  
Soft Rot ◽  
Susceptible Variety ◽  
Bacterial Suspension ◽  
Tea Tree ◽  
Chromatographic Characterization ◽  
Severity Of The Disease

Lettuce is susceptible to several diseases, especially soft rot caused by bacteria of the genus Pectobacterium. Due to the adaptability of this pathogen and the lack of disease control registered for the crop, the objective of this work was to evaluate the effects of essential oils in the management of soft rot caused by P. aroidearum in lettuce. The study was developed at the Universidade do Estado da Bahia, Juazeiro, BA, Brazil, and the essential oils (EOs) of orange, bergamot, lemongrass, palmarosa, citronella, cloves, tea tree, rosemary, sage, and ginger were used in concentrations of 0.25; 0.5; 0.75 and 1.0% to assess the in vitro growth inhibition of the bacterium. Subsequently, the curative effects of the disease were evaluated by applying the EOs that obtained the best results in vitro in lettuce plants of the susceptible variety “Mônica”. The treatments were applied, via spraying, 12 hours after inoculation using the bite method with bacterial suspension. The best in vivo treatment was selected to assess its preventive and curative activity, as well as to find the ideal concentration for reducing epidemiological variables and chromatographic characterization. The EOs of palmarosa, sage, citronella, lemongrass, and cloves (0.25%), and that of sage (0.75%), inhibited bacterial growth in vitro. The EO of salvia showed the best results in vivo, inhibiting the growth of the disease in concentrations of 0.50 and 0.75%, so it was selected for the preventive and curative control tests alone. The preventive treatment was not efficient for the management of soft rot in lettuce, however, from the regression analysis, a concentration of 0.64% of the salvia EO was found as a potential for curative control of this bacteriosis, as it reduces the incidence and severity of the disease. Linalyl acetate and linalool were found in higher concentrations in the chromatographic analysis. These components, probably, conferred the bactericidal capacity of the EO of sage, being potential for the use in the control of P. aroidearum in lettuce.  

scholarly journals THE EFFECT OF ESSENTIAL OILS ON MICROORGANISMS CAUSING CARIES AND PERIODONTITIS

2020 ◽  
Vol 20 (2) ◽  
pp. 253-259
Author(s):  
N.M. Devyatkina ◽  
N.O. Bobrova ◽  
E.M. Vazhnichaya
Keyword(s):  
Essential Oils ◽  
Dental Treatment ◽  
Therapeutic Potential ◽  
Oral Care ◽  
Antibacterial Properties ◽  
Herbal Medicines ◽  
Oral Streptococci ◽  
Tea Tree

The oral cavity contains a large number of bacteria, some of which are involved in the development of caries and periodontitis (S. mutans, S. sobrinus, Lactobacilli spp, P. intermedia, P. gingivalis, and T. forythus). The disadvantages of existing antiseptics used in dentistry necessitate the study of antibacterial properties of herbal medicines, and, in particular, of essential oils. The aim of this review is to provide the analysis of literature sources from PubMed and Google Scholar databases related to the effects of essential oils of cloves, mint, thyme, eucalyptus, tea tree and their components on cariogenic and periodontopathic microflora. It was found out that the most in vitro studies evaluated the effects of essential oils or isolated compounds (eugenol, menthol, thymol, carvacrol, eucalyptol, and terpinene-4-ol) on S. mutans, which is considered to be the most cariogenic of oral streptococci, and the researchers limited to defining the susceptibility of the microorganism and effects on biofilm formation. Only in a few studies, the effects of essential oils on the virulence factors of oral pathogens, in particular glycosyl transferase, are represented. Clinical trials of essential oils, their components and combinations confirm the therapeutic potential of these agents in vivo, but raise the question of their effectiveness, taking into account the short-term action, which does not exceed the potency of chlorhexidine. Essential oils of cloves, mint, thyme, eucalyptus, tea tree and their components should be used for treating caries and periodontitis. They are also promising when used as agents of the oral care products, preservatives of the dental medicinal forms, and as remedies for halitosis. With a rational prescription, essential oils can be useful in improving the quality of dental treatment and preventive procedures.

scholarly journals Essential Oils as Natural Fungicides to Control Rhizopus stolonifer-Induced Spoiled of Strawberries

2021 ◽  
Vol 11 (5) ◽  
pp. 13244-13251
Author(s):  
Josemar Gonçalves Oliveira Filho ◽  
Guilherme da Cruz Silva ◽  
Mariana Buranelo Egea ◽  
Henriette Monteiro Cordeiro de Azeredo ◽  
Marcos David Ferreira
Keyword(s):  
Essential Oils ◽  
Spore Germination ◽  
Soft Rot ◽  
Mentha Piperita ◽  
In Vitro Tests ◽  
Rhizopus Stolonifer ◽  
Mentha Spicata ◽  
Minimum Fungicidal Concentration

Strawberry is a highly desirable fruit with a unique taste and a good source of bioactive compounds beneficial to human health. However, it has a short post-harvest shelf life, mainly due to the soft rot caused by Rhizopus stolonifer. This study aimed to evaluate the antimicrobial properties of essential oils (EOs) of Mentha piperita, Cymbopogon martinii, Cinnamomum camphora, and Mentha spicata using spore germination and micro-well dilution assays, and to test the effects of the vapor-phase application of M. spicata and C. martini on the incidence and severity of soft rot in strawberry artificially inoculated with R. stolonifer. In in vitro tests, C. martinii and M. spicata EOs were the most effective, inhibiting more than 95% of the spore germination. Additionally, in the microwell dilution test, these EOs had the lowest minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) (5 and 10 μg/mL, respectively), and for the microwell dilution test, the lowest MIC (5 μg/mL and 10 μg/mL, respectively) and MFC (10 μg/mL for both). High in vivo inhibitory effects of M. spicata and C. martinii EOs were observed at 10% concentration, with 100 and 78% reduction, respectively, in the R. stolonifer-induced spoilage. Our results suggest that C. martinii and M. spicata EOs can be used as efficient natural fungicides and can be an alternative to synthetic fungicides for preserving fresh strawberries from soft rot.

scholarly journals Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

2012 ◽  
Vol 47 (3) ◽  
pp. 351-359 ◽  
Author(s):  
Gilvaine Ciavareli Lucas ◽  
Eduardo Alves ◽  
Ricardo Borges Pereira ◽  
Fabiano José Perina ◽  
Ricardo Magela de Souza
Keyword(s):  
Essential Oils ◽  
Bacterial Spot ◽  
Powdered Milk ◽  
Tea Tree ◽  
Plant Essential Oils ◽  
Bacterial Morphology ◽  
Severity Of The Disease ◽  
And Control ◽  
Xanthomonas Vesicatoria

The objective of this work was to evaluate the effects of plant essential oils (EOs) on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings under greenhouse conditions. The effects of citronella, lemongrass, clove, and tea tree EOs, at 0.1%, on X. vesicatoria cells were evaluated by transmission electron microscopy. All EOs showed direct toxic effect on the bacteria at a 10%-concentration in vitro. Under greenhouse conditions, the EOs of clove, citronella, tea tree, and lemongrass reduced disease severity. EOs of clove and tea tree, and streptomycin sulfate promoted loss of electron-dense material and alterations in the cytoplasm, whereas EO of tea tree promoted cytoplasm vacuolation, and those of citronella, lemongrass, clove, and tea tree caused damage to the bacterial cell wall. The EOs at a concentration of 0.1% reduce the severity of the disease.

scholarly journals In-vitro Antibacterial Activity of Carbopol-Essential Oils hydrogels

2020 ◽  
Vol 7 (2) ◽  
pp. 564-571
Author(s):  
Esam Yahya ◽  
Muhanad Abdullah Abdulsamad
Keyword(s):  
Antibacterial Activity ◽  
Essential Oils ◽  
Skin Irritation ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Tea Tree ◽  
Entire Duration ◽  
Animal Skin

Background and Objectives: The main purpose of the drug therapy of any disease is to maintain the desired therapeutic concen-tration of the drug for the entire duration of the treatment. The aim of this study is to formulate mixed essential oils loaded hydrogel, and evaluate its antibacterial activity against some pathogens. Materials and Methods: Different hydrogels were formulated by using different concentration of essential oils. Antibacterial evaluation was done using disk diffusion method. Screening for antibacterial activity of essential oils were studied prior to hydrogel formulation to compare the changes in activity after incorporation in the hydrogel. Results: Clove oil exhibited the strongest activity towards all the tested pathogens, compared to other tested essential oils (clove > cinnamon > tea tree > rosemary). The formulation containing mixed essential oils showed the best results, with synergistic effect against all tested pathogens. Hydrogels were further subjected to evaluation of physical properties like color, clarity, pH, viscosity and animal skin irritation study. The zone of inhibition of the final formulation containing only 3% from the selected three essential oils was between 18‐23 mm for S. aureus, 17‐20mm for E. coli, and 14‐18mm for P. aeruginosa. The hydrogels were non-irritant, stable, and free of any microbes at room temperature. Conclusion: Activity of essential oils was much affected by incorporation in hydrogel. The loaded hydrogel showed better antimicrobial activity against all the microorganisms used in the study, despite the need for clinical studies to determine of the effectiveness and potential toxic effects in-vivo.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

scholarly journals Polymorphisms in Plasmodium falciparum dihydropteroate synthetase and dihydrofolate reductase genes in Nigerian children with uncomplicated malaria using high-resolution melting technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adeyemi T. Kayode ◽  
Fehintola V. Ajogbasile ◽  
Kazeem Akano ◽  
Jessica N. Uwanibe ◽  
Paul E. Oluniyi ◽  
...  
Keyword(s):  
High Resolution ◽  
Dihydrofolate Reductase ◽  
Uncomplicated Malaria ◽  
High Resolution Melting ◽  
Intermittent Preventive Treatment ◽  
Preventive Treatment ◽  
Triple Mutant ◽  
Seasonal Malaria Chemoprevention

AbstractIn 2005, the Nigerian Federal Ministry of Health revised the treatment policy for uncomplicated malaria with the introduction of artemisinin-based combination therapies (ACTs). This policy change discouraged the use of Sulphadoxine-pyrimethamine (SP) as the second-line treatment of uncomplicated falciparum malaria. However, SP is used as an intermittent preventive treatment of malaria in pregnancy (IPTp) and seasonal malaria chemoprevention (SMC) in children aged 3–59 months. There have been increasing reports of SP resistance especially in the non-pregnant population in Nigeria, thus, the need to continually monitor the efficacy of SP as IPTp and SMC by estimating polymorphisms in dihydropteroate synthetase (dhps) and dihydrofolate reductase (dhfr) genes associated with SP resistance. The high resolution-melting (HRM) assay was used to investigate polymorphisms in codons 51, 59, 108 and 164 of the dhfr gene and codons 437, 540, 581 and 613 of the dhps gene. DNA was extracted from 271 dried bloodspot filter paper samples obtained from children (< 5 years old) with uncomplicated malaria. The dhfr triple mutant I51R59N108, dhps double mutant G437G581 and quadruple dhfr I51R59N108 + dhps G437 mutant haplotypes were observed in 80.8%, 13.7% and 52.8% parasites, respectively. Although the quintuple dhfr I51R59N108 + dhps G437E540 and sextuple dhfr I51R59N108 + dhps G437E540G581 mutant haplotypes linked with in-vivo and in-vitro SP resistance were not detected, constant surveillance of these haplotypes should be done in the country to detect any change in prevalence.

67 Current Status and Future Prospective of the Use of Plant Bioactive Compounds in Dairy and Beef Cattle

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 132-132
Author(s):  
Sergio Calsamiglia ◽  
Maria Rodriguez-Prado ◽  
Gonzalo Fernandez-Turren ◽  
Lorena Castillejos
Keyword(s):  
Beef Cattle ◽  
Essential Oils ◽  
Average Daily Gain ◽  
Rumen Fermentation ◽  
Production Performance ◽  
In Vivo Studies ◽  
Current Status ◽  
The Impact

Abstract In the last 20 years there has been extensive in vitro research on the effects of plant extracts and essential oils on rumen microbial fermentation. The main objectives have been to improve energy metabolism through a reduction in methane emissions and an increase in propionate production; and to improve protein metabolism by reducing proteolysis and deamination. While the positive results from in vitro studies has stimulated the release of commercial products based on blends of essential oils, there is limited in vivo evidence on the rumen fermentation and production performance effects. A literature search was conducted to select in vivo studies where information on rumen fermentation and animal performance was reported. For dairy cattle, we identified 37 studies of which 21 were adequate to test production performance. Ten studies reported increases and 3 decreases in milk yield. For beef cattle, we identified 20 studies with rumen fermentation profile and 22 with performance data. Average daily gain improved in 7 and decreased in 1 study. Only 1 out of 16 studies reported an improvement in feed efficiency. Data indicate that out of more than 500 products tested in vitro, only around 20 have been tested in vivo in different mixtures and doses. The use of statistical approaches will allow to describe the conditions, doses and responses in dairy and beef cattle performance. The search for postruminal effects offers another alternative use. Evidence for effects on the intestinal and systemic effects on the immune system and antioxidant status (i.e., capsicum, garlic, eugenol, cinnamaldehyde curcuma, catechins, anethol or pinene), and in the modulation of metabolic regulation (capsicum, cinnamaldehyde, curcuma or garlic) may open the opportunity for future applications. However, stability of the product in the GI tract, description of the mechanisms of action and the impact of these changes on performance needs to be further demonstrated.

scholarly journals Phytotoxicity of Essential Oils on Selected Weeds: Potential Hazard on Food Crops

Plants ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 79 ◽  
Author(s):  
María Ibáñez ◽  
María Blázquez
Keyword(s):  
Seed Germination ◽  
Essential Oil ◽  
Essential Oils ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Food Crops ◽  
Potential Hazard ◽  
Spectrometry Analysis

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

scholarly journals Emprego do óleo de Melaleuca alternifolia Cheel (Myrtaceae) na odontologia: perspectivas quanto à utilização como antimicrobiano alternativo às doenças infecciosas de origem bucal

2011 ◽  
Vol 13 (4) ◽  
pp. 492-499 ◽  
Author(s):  
A.C.M. Oliveira ◽  
A. Fontana ◽  
T.C. Negrini ◽  
M.N.M. Nogueira ◽  
T.B.L. Bedran ◽  
...  
Keyword(s):  
Tea Tree Oil ◽  
Melaleuca Alternifolia ◽  
Tea Tree

O interesse por medicamentos alternativos, principalmente daqueles provenientes de extratos naturais, tem aumentado nas últimas décadas. A Melaleuca alternifolia é um arbusto pertencente ao gênero Melaleuca, popularmente conhecida como "árvore de chá", cujo principal produto é o óleo essencial (TTO - tea tree oil), de grande importância medicinal por possuir comprovada ação bactericida e antifúngica contra diversos patógenos humanos. Em virtude da atividade terapêutica em diversas especialidades médicas, o TTO passou a ser empregado na área odontológica. Esta revisão de literatura foi realizada com o objetivo de discutir os ensaios já realizados com o TTO contra microrganismos relacionados à doença cárie, doença periodontal e problemas pulpares. O óleo de Melaleuca tem demonstrado boa ação antibacteriana in vitro contra microrganismos bucais, porém, pesquisas envolvendo o estudo do mecanismo de ação sobre as células microbianas ou estudos in vivo ainda são escassos e precisam ser realizados, já que esse produto pode ser útil na odontologia, seja na manutenção química da higiene ou prevenção de doenças bucais.

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