scholarly journals Original Contributions to the Chemical Composition, Microbicidal, Virulence-Arresting and Antibiotic-Enhancing Activity of Essential Oils from Four Coniferous Species

2021 ◽  
Vol 14 (11) ◽  
pp. 1159
Author(s):  
Diana-Carolina Visan ◽  
Eliza Oprea ◽  
Valeria Radulescu ◽  
Ion Voiculescu ◽  
Iovu-Adrian Biris ◽  
...  

This study aimed to establish the essential oil (EO) composition from young shoots of Picea abies, Larix decidua, Pseudotsuga menziesii, and Pinus nigra harvested from Romania and evaluate their antimicrobial and anti-virulence activity, as well as potential synergies with currently used antibiotics. The samples’ EO average content varied between 0.62% and 1.02% (mL/100 g plant). The mono- and sesquiterpene hydrocarbons were dominant in the composition of the studied EOs. The antimicrobial activity revealed that the minimum inhibitory concentration (MIC) values for the tested EOs and some pure compounds known for their antimicrobial activity ranged from 6.25 to 100 µL/mL. The most intensive antimicrobial effect was obtained for the Pinus nigra EO, which exhibited the best synergistic effect with some antibiotics against Staphylococcus aureus strains (i.e., oxacillin, tetracycline, erythromycin and gentamycin). The subinhibitory concentrations (sMIC) of the coniferous EOs inhibited the expression of soluble virulence factors (DN-ase, lipase, lecithinase, hemolysins, caseinase and siderophore-like), their efficiency being similar to that of the tested pure compounds, and inhibited the rhl gene expression in Pseudomonas aeruginosa, suggesting their virulence-arresting drug potential.

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1406
Author(s):  
Rita Cava-Roda ◽  
Amaury Taboada-Rodríguez ◽  
Antonio López-Gómez ◽  
Ginés Benito Martínez-Hernández ◽  
Fulgencio Marín-Iniesta

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.


2009 ◽  
Vol 64 (5-6) ◽  
pp. 339-342 ◽  
Author(s):  
Katarina Šavikin ◽  
Nebojša Menković ◽  
Gordana Zdunić ◽  
Tatjana Stević ◽  
Dragoja Radanović ◽  
...  

Methanolic extracts of flowers and leaves of Gentiana lutea L., together with the isolated compounds mangiferin, isogentisin and gentiopicrin, were used to investigate the antimicrobial activity of the plant. A variety of Gram-positive and Gram-negative bacteria as well as the yeast Candida albicans has been included in this study. Both extracts and isolated compounds showed antimicrobial activity with MIC values ranging from 0.12 - 0.31 mg/ml. Our study indicated that the synergistic activity of the pure compounds may be responsible for the good antimicrobial effect of the extracts. Quantification of the secondary metabolites was performed using HPLC


2011 ◽  
Vol 6 (7) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Márcia G. Martini ◽  
Humberto R. Bizzo ◽  
Davyson de L. Moreira ◽  
Paulo M. Neufeld ◽  
Simone N. Miranda ◽  
...  

Ocimum selloi, a traditional medicinal plant from Brazil, is sold in open-air markets at Rio de Janeiro State. Hesperozygis myrtoides is a very aromatic small bush found in the State of Minas Gerais, Brazil, growing at an altitude of 1800m. The chemical composition of both essential oils was analyzed as well as their antimicrobial activity against fungi and bacteria. For all specimens of Ocimum selloi obtained at open-air markets, methylchavicol was major compound found (93.6% to 97.6%) in their essential oils. The major compounds identified in the oil of H. myrtoides were pulegone (44.4%), isomenthone (32.7%), and limonene (3.5%). Both oils displayed antimicrobial activity against all tested microorganisms but Candida albicans was the most susceptible one. Combinations of the two oils in different proportions were tested to verify their antimicrobial effect against C. albicans, which, however, was not modified in any of the concentrations tested. The minimum inhibitory concentration (MIC) was determined to confirm the antimicrobial activity against C. albicans as well as other clinical isolates ( C. glabrata, C. krusei, C. parapsilosis and C. tropicalis).


2017 ◽  
Vol 28 (3) ◽  
pp. 372-379 ◽  
Author(s):  
Loiane Massunari ◽  
Renata Zoccal Novais ◽  
Márcio Teixeira Oliveira ◽  
Diego Valentim ◽  
Eloi Dezan Junior ◽  
...  

Abstract Psidium cattleianum (PC) has been displaying inhibitory effect against a variety of microorganisms, but this effect has not yet been tested against endodontic pathogens. The aim of this study was to evaluate the antimicrobial activity and biocompatibility of the aqueous (PCAE) and hydroethanolic (PCHE) extracts from Psidium cattleianum (PC) leaves. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the microdilution broth method in order to analyze the antimicrobial effect against Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii and Candida albicans in planktonic conditions. Biofilm assays were conducted only with the extracts that were able to determine the MLC for microorganisms in planktonic conditions. Immediate and late tissue reactions against PC extracts were evaluated using edemogenic test and histological analysis of subcutaneous implants in Wistar rats. The results showed that the MIC and MLC values ranged between 0.25 and 4 mg/mL. The MLC obtained for PCHE inhibited 100% growth of all the tested strains, except for C. albicans. PCAE had the same effect for E. faecalis and P. aeruginosa. Both PC extracts were able to eliminate E. faecalis biofilms and only the PCHE eliminated P. aeruginosa biofilms. The positive controls inhibited the growth of all tested strains in MIC and MLC essays, but no CHX tested concentrations were able to eliminate A. israelii biofilm. PCAE caused a discrete increase in the edema over time, while PCHE caused a higher initial edema, which decreased progressively. Both PCAE and PCHE extracts were biocompatible, but PCHE showed better results with slight levels of inflammation at 28 days. In conclusion, PCHE was biocompatible and presented better antimicrobial effect against important pathogens associated with persistent endodontic infections


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Stephanie de Rapper ◽  
Alvaro Viljoen ◽  
Sandy van Vuuren

The paper focuses on the in vitro antimicrobial activity of Lavandula angustifolia Mill. (lavender) essential oil in combination with four commercial antimicrobial agents. Stock solutions of chloramphenicol, ciprofloxacin, nystatin, and fusidic acid were tested in combination with L. angustifolia essential oil. The antimicrobial activities of the combinations were investigated against the Gram-positive bacterial strain Staphylococcus aureus (ATCC 6538) and Gram-negative Pseudomonas aeruginosa (ATCC 27858) and Candida albicans (ATCC 10231) was selected to represent the yeasts. The antimicrobial effect was performed using the minimum inhibitory concentration (MIC) microdilution assay. Isobolograms were constructed for varying ratios. The most prominent interaction was noted when L. angustifolia essential oil was combined with chloramphenicol and tested against the pathogen P. aeruginosa (ΣFIC of 0.29). Lavendula angustifolia essential oil was shown in most cases to interact synergistically with conventional antimicrobials when combined in ratios where higher volumes of L. angustifolia essential oil were incorporated into the combination.


2021 ◽  
Vol 50 (2) ◽  
pp. 383-393
Author(s):  
Anis Asmi Azman ◽  
Nurul Nadiah ◽  
Andi Rifki Rosandy ◽  
Afnani Alwi ◽  
Nurkhalida Kamal ◽  
...  

The research study regarding antimicrobial activity of pure compounds and LCMS data comparison from extract of lichen Parmotrema praesorediosum in Bangi, Selangor, Malaysia. Antimicrobial activity of acetone, ethanol, and methanol extracts as well as five compounds, namely methyl divaricatinate, methyl haematommate, methyl chlorohaematommate, methyl β-orsellinate, and vinapraesorediosic acid from methanol extract were identified for the microbial activity against four bacterial species, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Enterobacter aerogens, and Escerichia coli as well as two fungal species, Candida albicans and Candida parapsilosisbased on standards. The determination of IC50 using minimal inhibitory concentration (MIC) by broth microdilution method was carried out. For acetone extract, 201 μg/mL concentration was required to inhibit 50% (IC50) growth of positive gram bacteria, S. aureus while the concentrations of 430 and 480 μg/mL were able to inhibit 50% (IC50) growth of C. albicans and C. parapsilosis, respectively. Ethanol and methanol extract as well as five pure compounds did not inhibit 50% (IC50) of bacterial and yeast growths. Five pure compounds were first reported to determine IC50 of minimal inhibitory concentration (MIC) from lichen, Parmotrema praesorediosum in Malaysia. The comparison of LC-MS data between ethanol and acetone extracts showed that there was a peak of the main compound, atranorin in the acetone extract, but was invisible in the ethanol extract where the main bond broke down and produced other compounds. Result of pure compounds from antimicrobial activity and LCMS data comparison from extract of lichen Parmotrema praesorediosum were first reported in Bangi, Selangor, Malaysia. Data produced from this study will be used to show the comparison and latest result that will provide ongoing body of research into the issue of natural product.


2021 ◽  
Author(s):  
Edina Avdović ◽  
◽  
Žiko B. Milanović ◽  
Milanka Radulović ◽  
Dušan S. Dimić

In this manuscript, the in vitro antimicrobial activity of the previously synthesized coumarin derivative 3- (1- (3-hydroxyphenyl) amino) ethylidene) chroman-2,4-dione (L) and its corresponding palladium (II) complex (C) were examined. Their antimicrobial activity was screened against four strains of bacteria Bacillus cereus (ATCC 11778) G+; Staphylococcus aureus (ATCC 13709) G+; Klebsiella pneumoniae (ATCC 27736) G-; and Escherichia coli (ATCC 2592) G-) and three strains of fungi (Aspergillus flavus (ATCC15517); Candida albicans (ATCC 10231); Fusarium oxysporum (ATCC 695) using disc diffusion and microdilution method. The obtained minimum inhibitory concentration (MIC) values by microdilution method for ligand and complex are similar for all tested bacteria and fungi, which means that both compounds have a similar antimicrobial effect. On the other hand, analysis of zone of inhibition (ZI) values for the tested compounds shows that the complex is generally somewhat more active than the ligand.


2013 ◽  
Vol 49 (2) ◽  
pp. 241-250 ◽  
Author(s):  
Ania Ochoa Pacheco ◽  
Jorge Marín Morán ◽  
Zenia González Giro ◽  
Adrian Hidalgo Rodríguez ◽  
Rachel Juliet Mujawimana ◽  
...  

The antimicrobial activity of 13 total extracts was evaluated, 10 soft extracts (B) and 3 blended extracts (E) prepared from dry and fresh leaves of Petiveria alliacea L. Various solvents were used for their preparation: hydroalcoholic solution at 30%, 80% and isopropyl alcohol. The antimicrobial effect of the extracts was tested by means of the method of Kirby-Bauer, using four bacterial strains from the ATCC collection (Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa) and a leveduriform fungus (Candida albicans). The following quality control parameters were determined for most active extracts: physical, physical-chemical and chemical parameters. The results were: nine extracts showed antibacterial activity, being the most concentrated (B8 and E3), the ones with the highest activity in the presence of the bacteria tested; the effect of blended extracts (E1, E2 and E3) was greater in the presence of P. aeruginosa. Blended extracts are considered more potent and active than soft extracts. No antifungal activity was obtained for both types of extracts. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined for both extracts, with the following results: MIC-soft extracts (>100 mg/mL), blended extracts (>50 mg/mL); MBC-soft extracts (≥400 mg/mL), blended extracts (≥200 mg/mL) based on fresh leaves.


2016 ◽  
Vol 62 (2) ◽  
pp. 67-77 ◽  
Author(s):  
Małgorzata Kikowska ◽  
Jolanta Długaszewska ◽  
Marcelina Maria Kubicka ◽  
Izabela Kędziora ◽  
Jaromir Budzianowski ◽  
...  

SummaryIntroduction:Due to increasing resistance against antibiotics and antifungal agents, crude plant extracts, fractions, and isolated pure compounds became a new interest as antimicrobial agents.Objectives:The antimicrobial activity of methanolic extracts and fractions ofEryngium planumL.,E. campestreL., andE. maritimumL. was evaluated against selected bacteria, yeast and mould, and compared in testedEryngiumspecies and in their organs.Methods:The antimicrobial activity was studied with use of broth microdilution method. The antibacterial (Staphylococcus aureus,Pseudomonas aeruginosa) and antifungal (Candida albicans,Aspergillus niger) activity of selected extracts and fractions compared with the reference substance was expressed by Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal/Fungicidal Concentration (MBC/MFC). The extract and fraction compounds were identified on the basis of TLC examination.Results:The saponin-phenolic acid fractions ofE. maritimumandE. planumand a saponin fraction ofE. planumshowed the highest activity againstS. aureus(MIC = 1–2.5 mg·ml−1). The growth ofC. albicanswas inhibited by methanolic extract ofE. planumcell suspension culture (MIC = 7.8 mg·ml−1).Conclusion:The antimicrobial activity depends on theEryngiumspecies, tested biomass, and microorganism.


Author(s):  
Carlos Padilla ◽  
Olga Lobos ◽  
Patricia Poblete-Tapia ◽  
Verónica Carrasco-Sánchez

Background and Objectives: Haplopappus multifolius Phil. Ex Reiche and Haplopappus taeda Reiche are medicinal shrubs native to Chile and are popularly known as "Bailahuén". Regularly, this plant is used for liver, digestive and renal affections, as well as colds and the cleaning of infected wounds. The aim of the study was to identify the responsible compounds for the antimicrobial activity of H. multifolius and H. taeda. Materials and Methods: Infusions and ethanolic extracts of H. taeda and H. multifolius were analysed by thin-layer chromatography bioautography (TLC-B) to determine the compounds responsible for the antimicrobial activity against Gram-positive and Gram-negative bacterial strains and yeasts of Bailahuén. Finally, the minimum inhibitory concentration (MIC) of pure compounds isolated was determinate. Results: Extract of Bailahuén had activity only against Gram-positive bacterial strains and this activity was associated with aesculetin, 18-acetoxy-cis-cleroda-3,13E-dien-15-oic acid and aromadendrin-7-methyl ether compounds. Conclusion: H. multifolius and H. taeda have antibacterial capacity on different species of Gram-positive bacteria pathogenic for humans.


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