scholarly journals Antimicrobial potential of eucalyptus oil and lemongrass oil alone and in combination against clinical bacteria in planktonic and biofilm mode

2021 ◽  
Vol 6 (2) ◽  
pp. 21
Author(s):  
Iram Liaqat ◽  
Amna Asgar

The use of natural substances has been trending from past few years. In recent years, the synthetic products obtained from plants have gained immense importance. Essential oils and volatile products obtained from plants are the source of food flavoring, aroma products and fragrance industries. Their use is also common to cure different ailments such as cancer, skin problems and nosocomial infections. Vast research has shown the antimicrobial properties of essential oils obtained from plants. Essential oils of lemongrass and eucalyptus have antiviral, antibacterial, antioxidant and insecticidal characteristics. Lemongrass and eucalyptus oils shows their antibacterial activity towards Gram positive bacteria such as Staphylococcus aureus, Bacillus subtilis and Gram-negative bacteria such as Escherichia coli and Klebsiella pneumonia. Combination of these oils also depicts high antimicrobial activity against different strains of bacteria. This review highlights the use of essential oils of lemongrass and eucalyptus for their in vitro antimicrobial properties against different bacteria in planktonic and biofilm mode. Mode of action by which the oil shows its inhibitory activity will be discussed. Susceptibility shown by different bacteria towards these essential oils and their components will be described

2019 ◽  
Vol 17 (72) ◽  
pp. 129-138
Author(s):  
Yasmine Kadom. Al-Majedy

Novel Quinozolins were synthesized in a good yield through convert lacton to lactam and study the biological activity of the synthesized compounds. Quinozolins were characterized by elemental analysis, FT-IR and UV/visible spectra. The novel Quinozolins have been tested in vitro against (gram positive bacteria Staphylococcus aureus and against other gram negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus vulgaris; in order to assess their antimicrobial properties. Moreover, charge, bond length, bond angle, twist angle, heat of formation and steric energy were calculated by using of the ChemOffice program. The study indicates that these Quinozolins have high activity against tested bacteria. Based on the reported results, it may be concluded that the coumarin act as synthons for synthesis of new Quinozolins derivatives through the replacement of oxygen atom by nitrogen atom.


2000 ◽  
Vol 44 (10) ◽  
pp. 2701-2705 ◽  
Author(s):  
Hong Zhang ◽  
Shigenobu Yoshida ◽  
Tomoyasu Aizawa ◽  
Ritsuko Murakami ◽  
Masato Suzuki ◽  
...  

ABSTRACT ASABF is a CSαβ-type antimicrobial peptide that contains four intramolecular disulfide bridges (Y. Kato and S. Komatsu, J. Biol. Chem. 271:30493–30498, 1996). In the present study, a recombinant ASABF was produced by using a yeast expression system, and its antimicrobial activity was characterized in detail. The recombinant ASABF was active against all gram-positive bacteria tested (7 of 7; minimum bactericidal concentration [MBC], 0.03 to 1 μg/ml) exceptLeuconostoc mesenteroides, some gram-negative bacteria (8 of 14; MBC, >0.5 μg/ml), and some yeasts (3 of 9; MBC >3 μg/ml). Slight hemolytic activity (4.2% at 100 μg/ml) against human erythrocytes was observed only under low-ionic-strength conditions. Less than 1 min of contact was enough to kill Staphylococcus aureus ATCC 6538P. The bactericidal activity against S. aureus was inhibited by salts.


2021 ◽  
Author(s):  
Mansour Amin ◽  
Sousan Akrami ◽  
Farkhondeh Haghparasty ◽  
Atiyeh Hakimi

Abstract Background: Today, due to the increasing use of chemical drugs and the spread of microbial resistance to synthetic antibiotics, as well as side effects of drugs, the identification and introduction of plant species with medicinal and antimicrobial properties is very important. In this study, the antimicrobial properties of essential oils and extracts of 6 medicinal plants from Ahvaz region, Iran against 12 Gram-positive and Gram-Negative Bacteria were evaluated. Methods: The EOs and extracts were extracted using water distillation with Clevenger apparatus. The antimicrobial properties and determination of the minimum concentration of growth inhibition of herbals were investigated by the modified E-test method. Results: All analyzed extracts and EOs showed antibacterial effects. The antimicrobial activity of Oliveria decumbens was strongest herbals with the least MIC ranges (0.008-0.1 mg/ml for EO, 0.9-20 mg/ml for extract), while the antibacterial effects of Artemisia vulgaris extract and Glycyrrhiza glabra EO with the highest MIC were weaker than the others. According to the effectiveness of plant extracts on bacteria, Pseudomonas aeruginosa was resistant to all extracts except Oliveria decumbens. In contrast, Bacillus cereus was more sensitive than other strains against analyzed EOs and extracts.Conclusions: It seems that due to the antimicrobial properties of the extracts and essential oils observed in this study, they can be used as an alternative to antimicrobial drugs after more extensive studies.


2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.


Author(s):  
Mohammed Al-Amery1 ◽  
Ashraf Saad Rasheed ◽  
Dina A. Najeeb

Five new mixed ligand metal complexes have been synthesized by the reaction of divalent transition metal ions (Hg, Ni, Zn, Cu and Cd) with 2-(naphthalen-l-ylamino)-2-phenylacetonitrile (L1 ) and 1,10-phenanthroline (L2). The coordination likelihood of the two ligands toward metal ions has been suggested in the light of elemental analysis, UV-Vis spectra, FTIR, 1H-NMR, flam atomic absorption, molar conductance and magnetic studies. Results data suggest that the octahedral geometry for all the prepared complexes. Antibacterial examination of synthesized complexes in vitro was performed against four bacterias. Firstly, Gram-negative bacteria namely, Pseudomonas aerugin and Escherichia. Secondly, Gram-positive bacteria namely, Bacillus subtilis, Staphylococcuaurouss. Results data exhibit that the synthesized complexes exhibited more biological activity than tetracycline pharmaceutical.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2124
Author(s):  
Giulia Vanti ◽  
Ekaterina-Michaela Tomou ◽  
Dejan Stojković ◽  
Ana Ćirić ◽  
Anna Rita Bilia ◽  
...  

Food poisoning is a common cause of illness and death in developing countries. Essential oils (EOs) could be effective and safe natural preservatives to prevent and control bacterial contamination of foods. However, their high sensitivity and strong flavor limit their application and biological effectiveness. The aim of this study was firstly the chemical analysis and the antimicrobial evaluation of the EOs of Origanum onites L. and Satureja thymbra L. obtained from Symi island (Greece), and, secondly, the formulation of propylene glycol-nanovesicles loaded with these EOs to improve their antimicrobial properties. The EOs were analyzed by GC-MS and their chemical contents are presented herein. Different nanovesicles were formulated with small average sizes, high homogeneity, and optimal ζ-potential. Microscopic observation confirmed their small and spherical shape. Antibacterial and antifungal activities of the formulated EOs were evaluated against food-borne pathogens and spoilage microorganisms compared to pure EOs. Propylene glycol-nanovesicles loaded with O. onites EO were found to be the most active formulation against all tested strains. Additionally, in vitro studies on the HaCaT cell line showed that nanovesicles encapsulated with EOs had no toxic effect. The present study revealed that both EOs can be used as alternative sanitizers and preservatives in the food industry, and that their formulation in nanovesicles can provide a suitable approach as food-grade delivery system.


2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.


2012 ◽  
Vol 57 (1) ◽  
pp. 333-342 ◽  
Author(s):  
Justyna Nowakowska ◽  
Hans J. Griesser ◽  
Marcus Textor ◽  
Regine Landmann ◽  
Nina Khanna

ABSTRACTTreatment options are limited for implant-associated infections (IAI) that are mainly caused by biofilm-forming staphylococci. We report here on the activity of the serrulatane compound 8-hydroxyserrulat-14-en-19-oic acid (EN4), a diterpene isolated from the Australian plantEremophila neglecta. EN4 elicited antimicrobial activity toward various Gram-positive bacteria but not to Gram-negative bacteria. It showed a similar bactericidal effect against logarithmic-phase, stationary-phase, and adherentStaphylococcus epidermidis, as well as against methicillin-susceptible and methicillin-resistantS. aureuswith MICs of 25 to 50 μg/ml and MBCs of 50 to 100 μg/ml. The bactericidal activity of EN4 was similar againstS. epidermidisand its Δicamutant, which is unable to produce polysaccharide intercellular adhesin-mediated biofilm. In time-kill studies, EN4 exhibited a rapid and concentration-dependent killing of staphylococci, reducing bacterial counts by >3 log10CFU/ml within 5 min at concentrations of >50 μg/ml. Investigation of the mode of action of EN4 revealed membranolytic properties and a general inhibition of macromolecular biosynthesis, suggesting a multitarget activity.In vitro-tested cytotoxicity on eukaryotic cells was time and concentration dependent in the range of the MBCs. EN4 was then tested in a mouse tissue cage model, where it showed neither bactericidal nor cytotoxic effects, indicating an inhibition of its activity. Inhibition assays revealed that this was caused by interactions with albumin. Overall, these findings suggest that, upon structural changes, EN4 might be a promising pharmacophore for the development of new antimicrobials to treat IAI.


2010 ◽  
Vol 4 (2) ◽  
pp. 37-45
Author(s):  
Matheel D. Al-Sabti ◽  
Ahmed A. H. Al-Amiery ◽  
Thorria R. Marzoog ◽  
Yasmien K. Al-Majedy

This study involves the chemical synthesis of the novel ligand 5-(2-diphenylphosphino) phenyl-1,2-dihydro-1,2,4-triazole-3-thione (DPDTT) by the reaction of 2-diphenylphosphino benzoic acid with absolute ethanol that yield ethyl 2-diphenylphosphino benzoate and by cyclization of this compound with thiosemicarbazide, DPDTT will be produced. The chelating complexes of this ligand with Cr(III), Co(II), Ni(II), Cu(II) and Cd(II) were also prepared and studied. The new complexes were characterized by FT-IR, UV/visible spectra, and room temperature magnetic susceptibility. The stability for the prepared complexes was also measured using the density function theory and it was found that the cadmium complex is the most stable and the chromium complex is the least stable. Free ligand and its metal complexes have been tested in vitro against a number of microorganisms, like gram positive bacteria Staphylococcus aureus and gram negative bacteria E. coli, Proteus vulgaris, Pseudomonas and Klebsiella in order to assess their antimicrobial properties. All complexes showed considerable activity against all the studied bacteria.


Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3462
Author(s):  
Magdalena Woźniczka ◽  
Manas Sutradhar ◽  
Armando J. L. Pombeiro ◽  
Mirosława Świątek ◽  
Marek Pająk ◽  
...  

The present study describes the coordination properties of a reduced Schiff base, N-(2-hydroxybenzyl)alanine, towards cobalt(II) using potentiometric as well as spectroscopic (UV-Vis and ESI-MS) methods. The results indicate the formation of six mononuclear complexes showing high stability in aqueous solution. Coordination occurs in the {O−phenolic,N,O−carboxyl} and {N,O−carboxyl} chelation modes, depending on the degree of ligand deprotonation. Examination of the complexation equilibria at pH ca 7, which is important from a biological point of view, allowed to identify two species: [CoL] and [CoL2H]−. The kinetic analysis showed a structural change of those cobalt(II) complexes from octahedral to tetrahedral in accordance with a first-order time relationship. The antimicrobial properties of N-(2-hydroxybenzyl)alanine, cobalt(II) nitrate and of the Co(II) – ligand complexes were determined against Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis), Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Helicobacter pylori) and a fungal strain (Candida). The results indicate that the complexes are more active for more strains than the ligand alone. Nevertheless, the complexes induce a higher decrease in the metabolic activity of cells but without damage to nuclei. Tetrahedral structures show stronger anti-cellular toxicity than octahedral complexes, which is most likely due to the higher accessibility of the cobalt(II) center.


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