scholarly journals Evaluation of the Antimicrobial Effect of the Extracts of the Pods of Piliostigma thonningii (Schumach.) Milne-Redh. (Fabaceae)

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Memory Makosa ◽  
Simbarashe Sithole ◽  
Stanley Mukanganyama
Keyword(s):  
Antimicrobial Agents ◽  
Membrane Integrity ◽  
Herbal Medicines ◽  
Antimicrobial Properties ◽  
Fine Powder ◽  
Ethanol Extract ◽  
Antimicrobial Effects ◽  
Cell Membrane Integrity ◽  
Successive Extraction ◽  
Piliostigma Thonningii

Plants have been used traditionally by people in treating and the management of diseases since time immemorial. Traditional medicines including the herbal medicines are used for primary healthcare in some domains in almost every country. Approximately 80% of the population in developing coutries depend on plants as their source of medicine for combating diseases. New and effective antimicrobial agents that have novel mechanism of actions are required. Piliostigma thonningii (Schumach.) Milne-Redh. is a species of flowering plants in the legume family, Fabaceae. Different parts of the P. thonningii plants such as the roots, leaves, seeds, and fruits have been used in treating wounds, heart pain, and gingivitis and as cough remedy. This study focused on determining the antimicrobial properties found in the pods of P. thonningii. The sample was prepared by grinding the dried pods into a fine powder. Successive extraction and extraction with 1 : 1 DCM: methanol was used. The antimicrobial assay was carried out using the broth microdilution and MTT assay. The microorganism used for the tests was Pseudomonas aeruginosa, Candida krusei and Mycobacterium smegmatis. The most potent extract was then used to determine its effect on microbial cell membrane integrity. The results showed that methanol extract had the highest percentage yield of 5%. The extract with the highest antimicrobial effects was ethanol extract with the 100 μg/mL concentration inhibiting the growth of cells to 26%, 87%, and 90% for P. aeruginosa, M. smegmatis, and C. krusei, respectively. The ethanol extracts caused significant leakage of proteins in these microorganisms. In conclusion, the pods of P. thonningii contain phytochemicals with antimicrobial properties. The pods of the plant can be a source of phytochemicals that can serve as sources of lead compounds with antimicrobial effects. One of the mechanisms of action of these phytochemicals is via membrane-damaging effects on microbes.

scholarly journals Effect of Farnesol on Staphylococcus aureus Biofilm Formation and Antimicrobial Susceptibility

2006 ◽  
Vol 50 (4) ◽  
pp. 1463-1469 ◽  
Author(s):  
M. A. Jabra-Rizk ◽  
T. F. Meiller ◽  
C. E. James ◽  
M. E. Shirtliff
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Membrane Integrity ◽  
Antimicrobial Properties ◽  
Bloodstream Infections ◽  
High Concentration ◽  
Bacterial Populations ◽  
Cell Membrane Integrity ◽  
Plate Counts

ABSTRACT Staphylococcus aureus is among the leading pathogens causing bloodstream infections able to form biofilms on host tissue and indwelling medical devices and to persist and cause disease. Infections caused by S. aureus are becoming more difficult to treat because of increasing resistance to antibiotics. In a biofilm environment particularly, microbes exhibit enhanced resistance to antimicrobial agents. Recently, farnesol was described as a quorum-sensing molecule with possible antimicrobial properties. In this study, the effect of farnesol on methicillin-resistant and -susceptible strains of S. aureus was investigated. With viability assays, biofilm formation assessment, and ethidium bromide uptake testing, farnesol was shown to inhibit biofilm formation and compromise cell membrane integrity. The ability of farnesol to sensitize S. aureus to antimicrobials was assessed by agar disk diffusion and broth microdilution methods. For both strains of staphylococci, farnesol was only able to reverse resistance at a high concentration (150 μM). However, it was very successful at enhancing the antimicrobial efficacy of all of the antibiotics to which the strains were somewhat susceptible. Therefore, synergy testing of farnesol and gentamicin was performed with static biofilms exposed to various concentrations of both agents. Plate counts of harvested biofilm cells at 0, 4, and 24 h posttreatment indicated that the combined effect of gentamicin at 2.5 times the MIC and farnesol at 100 μM (22 μg/ml) was able to reduce bacterial populations by more than 2 log units, demonstrating synergy between the two antimicrobial agents. This observed sensitization of resistant strains to antimicrobials and the observed synergistic effect with gentamicin indicate a potential application for farnesol as an adjuvant therapeutic agent for the prevention of biofilm-related infections and promotion of drug resistance reversal.

Antimicrobial Effects of 7,8-Dihydroxy-6-Methoxycoumarin and 7-Hydroxy-6-Methoxycoumarin Analogues against Foodborne Pathogens and the Antimicrobial Mechanisms Associated with Membrane Permeability

2017 ◽  
Vol 80 (11) ◽  
pp. 1784-1790 ◽  
Author(s):  
Ji-Yeon Yang ◽  
Jun-Hwan Park ◽  
Myung-Ji Lee ◽  
Ji-Hoon Lee ◽  
Hoi-Seon Lee
Keyword(s):  
Antimicrobial Activity ◽  
Cell Membrane ◽  
Membrane Permeability ◽  
Foodborne Pathogens ◽  
Antimicrobial Agents ◽  
Functional Group ◽  
Membrane Integrity ◽  
Cell Membrane Permeability ◽  
Antimicrobial Effects ◽  
Structural Analogues

ABSTRACT The antimicrobial effects of 7,8-dihydroxy-6-methoxycoumarin and 7-hydroxy-6-methoxycoumarin isolated from Fraxinus rhynchophylla bark and of their structural analogues were determined in an attempt to develop natural antimicrobial agents against the foodborne pathogens Escherichia coli, Bacillus cereus, Staphylococcus intermedius, and Listeria monocytogenes. To elucidate the relationship between structure and antimicrobial activity for the coumarin analogues, isolated constituents and their structural analogues were evaluated against foodborne pathogens. Based on the culture plate inhibition zones and MICs, 6,7-dimethoxycoumarin, 7,8-dihydroxy-6-methoxycoumarin, 7-hydroxy-6-methoxycoumarin, and 7-methoxycoumarin, containing a methoxy functional group on the coumarin skeleton, had the notable antimicrobial activity against foodborne pathogens. However, 7-hydroxycoumarin and 6,7-dihydroxycoumarin, which contained a hydroxyl functional group on the coumarin skeleton, had no antimicrobial activity against these pathogens. An increase in cell membrane permeability was confirmed by electron microscopy observations, and release of extracellular ATP and cell constituents followed treatment with the ethyl acetate fraction of F. rhynchophylla extract. These findings indicate that F. rhynchophylla extract and coumarin analogues have potential for use as antimicrobial agents against foodborne pathogens and that the antimicrobial mechanisms are associated with the loss of cell membrane integrity.

Plant-Derived Products as Antibacterial and Antifungal Agents in Human Health Care

2019 ◽  
Vol 26 (29) ◽  
pp. 5501-5541 ◽  
Author(s):  
Ladislav Kokoska ◽  
Pavel Kloucek ◽  
Olga Leuner ◽  
Pavel Novy
Keyword(s):  
Human Health ◽  
Clinical Efficacy ◽  
Antimicrobial Agents ◽  
Antifungal Agents ◽  
Higher Plants ◽  
Herbal Medicines ◽  
Antimicrobial Properties ◽  
Urinary Infections ◽  
Antibacterial And Antifungal

:A number of papers reporting antimicrobial properties of extracts, essential oils, resins and various classes of compounds isolated from higher plants have been published in recent years; however, a comprehensive analysis of plant-derived antimicrobial agents currently applied in practice for the improvement of human health is still lacking. This review summarizes data on clinical efficacy, antimicrobial effects and the chemistry of commercially available antibacterial and antifungal agents of plant origin currently used in the prevention and treatment of gastrointestinal, oral, respiratory, skin, and urinary infections. As a result of an analysis of the literature, more than 40 plant-derived over-the-counter pharmaceuticals, dietary supplements, cosmetics, herbal medicines, and functional foods containing complex mixtures (e.g. Glycyrrhiza glabra extract, Melaleuca alternifolia essential oil, and Pistacia lentiscus resin), pure compounds (e.g. benzoic acid, berberine, eucalyptol, salicylic acid and thymol) as well as their derivatives and complexes (e.g. bismuth subsalicylate and zinc pyrithione) have been identified. The effectiveness of many of these products is illustrated by results of clinical trials and supported by data on there in vitro antimicrobial activity. A broad spectrum of various commercial products currently available on the market and their welldocumented clinical efficacy suggests that plants are prospective sources for the identification of new types of antimicrobial agents in future. Innovative approaches and methodologies for effective proof-of-concept research and the development of new types of plant-derived products effective against recently emerging problems related to human microbial diseases (e.g. antimicrobial resistance) are also proposed in this review.

scholarly journals Biofilm Eradication Using Biogenic Silver Nanoparticles

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2023 ◽  
Author(s):  
María Belén Estevez ◽  
Sofía Raffaelli ◽  
Scott G. Mitchell ◽  
Ricardo Faccio ◽  
Silvana Alborés
Keyword(s):  
Silver Nanoparticles ◽  
Colloidal Stability ◽  
Fatty Acid Content ◽  
Membrane Integrity ◽  
Antimicrobial Properties ◽  
Value Added ◽  
Industrial Applications ◽  
Bioactive Substances ◽  
Cell Membrane Integrity ◽  
E Coli

Microorganisms offer an alternative green and scalable technology for the synthesis of value added products. Fungi secrete high quantities of bioactive substances, which play dual-functional roles as both reducing and stabilizing agents in the synthesis of colloidal metal nanoparticles such as silver nanoparticles, which display potent antimicrobial properties that can be harnessed for a number of industrial applications. The aim of this work was the production of silver nanoparticles using the extracellular cell free extracts of Phanerochaete chrysosporium, and to evaluate their activity as antimicrobial and antibiofilm agents. The 45–nm diameter silver nanoparticles synthesized using this methodology possessed a high negative surface charge close to −30 mV and showed colloidal stability from pH 3–9 and under conditions of high ionic strength ([NaCl] = 10–500 mM). A combination of environmental SEM, TEM, and confocal Raman microscopy was used to study the nanoparticle-E. coli interactions to gain a first insight into their antimicrobial mechanisms. Raman data demonstrate a significant decrease in the fatty acid content of E. coli cells, which suggests a loss of the cell membrane integrity after exposure to the PchNPs, which is also commensurate with ESEM and TEM images. Additionally, these biogenic PchNPs displayed biofilm disruption activity for the eradication of E. coli and C. albicans biofilms.

scholarly journals Effects of silver nanoparticles of different sizes on cytotoxicity and oxygen metabolism disorders in both reproductive and respiratory system cells

2016 ◽  
Vol 42 (4) ◽  
pp. 32-47 ◽  
Author(s):  
Lidia Zapór
Keyword(s):  
Silver Nanoparticles ◽  
Oxidative Dna Damage ◽  
Antimicrobial Agents ◽  
Membrane Integrity ◽  
Oxygen Metabolism ◽  
Protective Measures ◽  
Cytotoxic Effects ◽  
Cell Membrane Integrity ◽  
Antioxidative Status ◽  
Low Concentrations

Abstract Silver nanoparticles (AgNPs) are widely used in numerous industries and areas of daily life, mainly as antimicrobial agents. The particles size is very important, but still not suffi ciently recognized parameter infl uencing the toxicity of nanosilver. The aim of this study was to investigate the cytotoxic effects of AgNPs with different particle size (~ 10, 40 and 100 nm). The study was conducted on both reproductive and pulmonary cells (CHO-9, 15P-1 and RAW264.7). We tested the effects of AgNPs on cell viability, cell membrane integrity, mitochondrial metabolic activity, lipid peroxidation, total oxidative and antioxidative status of cells and oxidative DNA damage. All kinds of AgNPs showed strong cytotoxic activity at low concentrations (2÷13 μg/ml), and caused an overproduction of reactive oxygen species (ROS) at concentrations lower than cytotoxic ones. The ROS being formed in the cells induced oxidative damage of DNA in alkaline comet assay. The most toxic was AgNPs<10 nm. The results indicate that the silver nanoparticles, especially less than 10 nm, may be harmful to the organisms. Therefore, risk should be considered when using nanosilver preparations and provide appropriate protective measures when they are applied.

scholarly journals New Functionalized Macroparticles for Environmentally Sustainable Biofilm Control in Water Systems

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 399
Author(s):  
Ana C. Barros ◽  
Ana Pereira ◽  
Luis F. Melo ◽  
Juliana P. S. Sousa
Keyword(s):  
Cell Membrane ◽  
Antimicrobial Agents ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Membrane System ◽  
Bacterial Cells ◽  
Cell Membrane Integrity ◽  
Cell Membrane Damage ◽  
Environmentally Sustainable ◽  
Partial Blocking

Reverse osmosis (RO) depends on biocidal agents to control the operating costs associated to biofouling, although this implies the discharge of undesired chemicals into the aquatic environment. Therefore, a system providing pre-treated water free of biocides arises as an interesting solution to minimize the discharge of chemicals while enhancing RO filtration performance by inactivating bacteria that could form biofilms on the membrane system. This work proposes a pretreatment approach based on the immobilization of an industrially used antimicrobial agent (benzalkonium chloride—BAC) into millimetric aluminum oxide particles with prior surface activation with DA—dopamine. The antimicrobial efficacy of the functionalized particles was assessed against Escherichia coli planktonic cells through culturability and cell membrane integrity analysis. The results showed total inactivation of bacterial cells within five min for the highest particle concentration and 100% of cell membrane damage after 15 min for all concentrations. When reusing the same particles, a higher contact time was needed to reach the total inactivation, possibly due to partial blocking of immobilized biocide by dead bacteria adhering to the particles and to the residual leaching of biocide. The overall results support the use of Al2O3-DA-BAC particles as antimicrobial agents for sustainable biocidal applications in continuous water treatment systems.

scholarly journals Octominin: A Novel Synthetic Anticandidal Peptide Derived from Defense Protein of Octopus minor

Marine Drugs ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 56 ◽  
Author(s):  
Chamilani Nikapitiya ◽  
S.H.S. Dananjaya ◽  
H.P.S.U. Chandrarathna ◽  
Mahanama De Zoysa ◽  
Ilson Whang
Keyword(s):  
Cell Wall ◽  
Cell Membrane ◽  
Antimicrobial Agents ◽  
Membrane Integrity ◽  
Alpha Helix ◽  
Infection Model ◽  
Dependent Manner ◽  
Cell Membrane Integrity ◽  
Defense Protein ◽  
Octopus Minor

The rapid emergence of multidrug-resistant pathogens makes an urgent need for discovering novel antimicrobial agents as alternatives to conventional antibiotics. Towards this end, we designed and synthesized a synthetic peptide of 23 amino acids (AAs) (1GWLIRGAIHAGKAIHGLIHRRRH23) from a defense protein 3 cDNA sequence of Octopus minor. The sequence of the peptide, which was named Octominin, had characteristic features of known antimicrobial peptides (AMPs) such as a positive charge (+5), high hydrophobic residue ratio (43%), and 1.86 kcal/mol of Boman index. Octominin was predicted to have an alpha-helix secondary structure. The synthesized Octominin was 2625.2 Da with 92.5% purity. The peptide showed a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 50 and 200 μg/mL, respectively, against Candida albicans. Field emission scanning electron microscopy observation confirmed that Octominin caused ultrastructural cell wall deformities in C. albicans. In addition, propidium iodide penetrated the Octominin-treated C. albicans cells, further demonstrating loss of cell membrane integrity that caused cell death at both MIC and MFC. Octominin treatment increased the production of intracellular reactive oxygen species and decreased cell viability in a concentration dependent manner. Cytotoxicity assays revealed no significant influence of Octominin on the viability of human embryonic kidney 293T cell line, with over 95% live cells in the Octominin-treated group observed up to 100 µg/mL. Moreover, we confirmed the antifungal action of Octominin in vivo using a zebrafish experimental infection model. Overall, our results demonstrate the Octominin is a lead compound for further studies, which exerts its effects by inducing cell wall damage, causing loss of cell membrane integrity, and elevating oxidative stress.

scholarly journals Combination Therapy Involving Lavandula angustifolia and Its Derivatives in Exhibiting Antimicrobial Properties and Combatting Antimicrobial Resistance: Current Challenges and Future Prospects

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 609
Author(s):  
Wye-Hong Leong ◽  
Kok-Song Lai ◽  
Swee-Hua Erin Lim
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Essential Oil ◽  
Antimicrobial Agents ◽  
Synergistic Effects ◽  
Antimicrobial Properties ◽  
Multidrug Resistant ◽  
Antimicrobial Effects ◽  
Insight Into

Antimicrobial resistance (AMR) has been identified as one of the biggest health threats in the world. Current therapeutic options for common infections are markedly limited due to the emergence of multidrug resistant pathogens in the community and the hospitals. The role of different essential oils (EOs) and their derivatives in exhibiting antimicrobial properties has been widely elucidated with their respective mechanisms of action. Recently, there has been a heightened emphasis on lavender essential oil (LEO)’s antimicrobial properties and wound healing effects. However, to date, there has been no review published examining the antimicrobial benefits of lavender essential oil, specifically. Previous literature has shown that LEO and its constituents act synergistically with different antimicrobial agents to potentiate the antimicrobial activity. For the past decade, encapsulation of EOs with nanoparticles has been widely practiced due to increased antimicrobial effects and greater bioavailability as compared to non-encapsulated oils. Therefore, this review intends to provide an insight into the different aspects of antimicrobial activity exhibited by LEO and its constituents, discuss the synergistic effects displayed by combinatory therapy involving LEO, as well as to explore the significance of nano-encapsulation in boosting the antimicrobial effects of LEO; it is aimed that from the integration of these knowledge areas, combating AMR will be more than just a possibility.

Ethanol Extract Of Centella Asiatica (L.) Urban Leaves Effectively Inhibit Streptococcus pyogenes and Pseudomonas aeruginosa by Invitro Test

2020 ◽  
Vol 2 (2) ◽  
pp. 69-76
Author(s):  
Dini Aulia Azmi ◽  
Nurlailah Nurlailah ◽  
Ratih Dewi Dwiyanti
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Streptococcus Pyogenes ◽  
Bacterial Infections ◽  
Herbal Medicines ◽  
Centella Asiatica ◽  
Ethanol Extract ◽  
Dilution Method ◽  
Initial Stage ◽  
Independent Variable

Streptococcus pyogenes and Pseudomonas aeruginosa are some of the causes of infectious diseases. Centella asiatica (L.) Urban has many benefits for humans, including overcoming fever, anti-bacterial, and anti-inflammatory. This study aims to determine the inhibition of Centella asiatica (L.) Urban leaves ethanol extract on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. This research is the initial stage of the development of herbal medicines to treat Streptococcus pyogenes and Pseudomonas aeruginosa infections. The independent variable was the concentration of ethanol extract of Centella asiatica (L.) Urban leaves and the dependent variable was the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. The anti-bacterial activity test was carried out by the liquid dilution method. The concentrations used are 20%, 40%, 60%, 80%. 100% The results showed that the minimum inhibitory concentration (MIC) against Streptococcus pyogenes: 40% and Pseudomonas aeruginosa: 40%. Minimum bactericidal concentration (MBC) results for Streptococcus pyogenes: 60% and Pseudomonas aeruginosa: 60%. So it can be concluded that there is inhibition of the ethanol extract of Centella asiatica (L.) Urban leaves on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. Centella Asiatica (L.) Urban extract has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.

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