scholarly journals Investigating In Vitro Antibacterial Activities of Medicinal Plants Having Folkloric Repute in Ethiopian Traditional Medicine

2019 ◽  
Vol 24 ◽  
pp. 2515690X1988627 ◽  
Author(s):  
Mekonnen Sisay ◽  
Negussie Bussa ◽  
Tigist Gashaw ◽  
Getnet Mengistu

Medicinal plants are targeted in the search for new antimicrobial agents. Nowadays, there is an alarmingly increasing antimicrobial resistance to available agents with a very slow development of new antimicrobials. It is, therefore, necessary to extensively search for new agents based on the traditional use of herbal medicines as potential source. The antibacterial activity of 80% methanol extracts of the leaves of Verbena officinalis (Vo-80ME), Myrtus communis (Mc-80ME), and Melilotus elegans (Me-80ME) was tested against 6 bacterial isolates using agar well diffusion technique. In each extract, 3 concentrations of 10, 20, and 40 mg/well were tested for each bacterium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined. Vo-80ME and Mc-80ME exhibited promising antibacterial activity against Staphylococcus aureus with the highest zone of inhibition being 18.67 and 26.16 mm, respectively at concentration of 40 mg/well. Regarding gram-negative bacteria, Vo-80ME exhibited an appreciable activity against Escherichia coli and Salmonella typhi. Mc-80ME displayed remarkable activity against all isolates including Pseudomonas aeruginosa with the maximum zone of inhibition being 22.83 mm. Me-80ME exhibited better antibacterial activity against E coli, but its secondary metabolites had little or no activity against other gram-negative isolates. The MIC values of Vo-80ME ranged from 0.16 to 4.00 mg/mL. The lowest MIC was observed in Mc-80ME, with the value being 0.032 mg/mL. Mc-80ME had bactericidal activity against all tested bacterial isolates. Mc-80ME showed remarkable zone of inhibitions in all tested bacterial isolates. Besides, Vo-80ME showed good antibacterial activity against S aureus, E coli, and S typhi. Conversely, Me-80ME has shown good activity against E coli only. Generally, M communis L and V officinalis have good MIC and MBC results.

2008 ◽  
Vol 5 (s1) ◽  
pp. S1008-S1014
Author(s):  
Jyoti Sharma ◽  
Sabir Hussain ◽  
Mohammad Amir

New series of 4-(substituted phenyl)-5-[(quinolin-8-yloxy) methyl]-4H-1,2,4-triazole-3-thiol(4a-c),N³-(4-substituted phenyl)-5-[(quinolin-8-yloxy) methyl]-4H-1,2,4-triazole-3,4-diamine(5a-c)andN-(4-substituted phenyl)-5-[(quinolin-8-yloxy) methyl]-1,3,4-thiadiazol-2-amine(6a-g)have been synthesized and the structures of the new compounds were established on the basis of IR,1H NMR spectral data.In vitroantimicrobial activity (MIC activity) was evaluated and compared with standard drugs of loxacin and ketoconazole. Compounds5aand6ein the series have shown interesting antibacterial activity against bothS. aureus(gram-positive) andE. coli(gram-negative) organisms. In this paper, we also describe studies leading to identification of antifungal agents. In the gratifying result, most of the compounds were found to have moderate antimicrobial activity.


2018 ◽  
Vol 10 (5) ◽  
pp. 209
Author(s):  
Shyla M. Haqq ◽  
Himanshu Pandey ◽  
Manju Gerard ◽  
Amit Chattree

Objective: In the present research work silver nanoparticles were synthesized using the flower extract of Chrysanthemum coronarium and their in-vitro antibacterial activity was evaluated against both the gram-positive S. aureus and gram-negative bacteria E. coli. The flower extract acted both as a reducing as well as a capping agent.Methods: Silver nanoparticles were verified using various spectroanalytical techniques such as visible ultraviolet spectroscopy, zeta potential, fourier transform infrared spectroscopy and particle size analyser. The antibacterial activity was evaluated against both the gram-positive bacteria S. aureus and gram-negative bacteria E. coli using the agar well diffusion method.Results: The silver nanoparticles synthesized were confirmed by the visual colour change. The ultraviolet, visible spectroscopy showed a surface plasmon resonance at 430 nm. Zetapotential was found to be around-15.6mV where the negative value indicated that the synthesized silver nanoparticles are stable. Fourier transform infrared spectroscopy showed the functional groups responsible for the stabilization of the nanoparticles. Particle size analyser showed that the size of the nanoparticles ranged from 5-50 nm. The antibacterial activity of the silver nanoparticles which was performed against S. aureus and E. coli showed good inhibition against both the bacteria. Better antibacterial activity was found for E. coli in comparison to S. aureus as the zone of inhibition for E. coli was found to be at 12 mm at 50ug/ml whereas the zone of inhibition against S. aureus was found to be at 10 mm.Conclusion: The silver nanoparticles were successfully synthesized using a green approach and can be used as a potential resource for therapeutic purpose.


Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 75 ◽  
Author(s):  
Wadha Alfouzan ◽  
Rita Dhar ◽  
David Nicolau

Limited data are available on susceptibilities of these organisms to some of the recently made accessible antimicrobial agents. The in vitro activities of newer antibiotics, such as, ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) along with some “older” antibiotics, for example fosfomycin (FOS) and colistin (CL) were determined against selected strains (resistant to ≥ 3 antimicrobial agents) of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined by Clinical and Laboratory Standards Institute microbroth dilution. 133 isolates: 46 E. coli, 39 K. pneumoniae, and 48 P. aeruginosa were tested. Results showed that E. coli isolates with MIC50/90, 0.5/1 μ g / mL for CL; 4/32 μ g / mL for FOS; 0.25/32 μ g / mL for C/T; 0.25/8 μ g / mL for CZA, exhibited susceptibility rates of 95.7%, 97.8%, 76.1%, and 89.1%, respectively. On the other hand, K. pneumoniae strains with MIC50/90, 0.5/1 μ g / mL for CL; 256/512 μ g / mL for FOS; 2/128 μ g / mL for C/T; 0.5/128 μ g / mL for CZA showed susceptibility rates of 92.3%, 7.7%, 51.3%, and 64.1%, respectively. P. aeruginosa isolates with MIC50/90, 1/1 μ g / mL for CL; 128/128 μ g / mL for C/T; 32/64 μ g / mL for CZA presented susceptibility rates of 97.9%, 33.3%, and 39.6%, respectively. Higher MICs were demonstrated against most of the antibiotics. However, CL retained efficacy at low MICs against most of the isolates tested.


2020 ◽  
Vol 14 (3) ◽  
pp. 1855-1861
Author(s):  
Isra Tayseer ◽  
Hanan Azzam ◽  
Nehaya Al-Karablieh ◽  
Amal Mayyas ◽  
Talal Aburjai

The present study was conducted to assess the in vitro activities of folk medicinal plants in combination with levofloxacin against TG1 and mutant KAM3-1(∆acrB-∆tolC) Escherichia coli strains. Plants were chosen based on their traditional use in combination with antibiotics among laymen. Standard protocols were followed to examine the antimicrobial activity of plant extracts and levofloxacin against E. coli in term of their minimum inhibitory concentrations (MICs) and to evaluate the plant extracts-levofloxacin interaction using checkerboard method. Among the twelve plants investigated, Thymus vulgaris, Zingiber officinale, Teucrium polium, Matricaria chamomilla and Curcuma longa had the best antimicrobial activities against E. coli strains with MIC values at 250 μg/ml. It is noteworthy to mention that other folk plants extracts reveled no effects against E coli strains. Furthermore, additive interactions were observed between levofloxacin and T. polium or T. vulgaris against E. coli wild-type TG1 strain. There was no antagonism being observed in this study. The detection of additive interaction between the extracts and levofloxacin demonstrates the prospective of these folk medicinal plants as a source of compounds to modulate antibiotic resistance.


2021 ◽  
Vol 33 (7) ◽  
pp. 1525-1529
Author(s):  
Parmesh Kumar Dwivedi ◽  
Devdutt Chaturvedi

A new series of fluorinated sulfur inserted benzimidazole analogues Za-i were synthesized and characterized. The new compounds were screened for their antimicrobial and antioxidant potential. The synthesized compounds were obtained by multiple step synthesis, initiating from the synthesis of 5-(difluoromethoxy)-1H-benzimidazole-2-thiol X. The compounds Ya-i prepared by reacting differently substituted anilines with chloroacetylchloride and triethylamine in DMF. Finally, the compound X was reacted with different derivatives of 2-chloro-N-phenylacetamide resulting in formation of titled compounds Za-i. The synthesized compounds (Za-Zi) were characterized by spectral analysis viz.1H & 13C NMR, mass spectra, elemental analysis and IR. The in vitro antimicrobial potential against Gram-positive (S. aureus and E. faecalis) and Gram-negative bacterial (E. coli and P.aeruginosa) strains as well as fungi (A. niger and C. albicans) was recorded for the obtained compounds. Some of the compounds exhibited encouraging results (in MIC) against Gram-positive and Gram-negative bacterial strains. These studies thus suggest that the designed sulfur inserted fluoro-benzimidazoles scaffold may serve as new promising template for further amplification as antimicrobial agents.


2021 ◽  
Vol 6 (3) ◽  
pp. 189-195
Author(s):  
Hary Widjajanti ◽  
Christina Vivid Handayani ◽  
Elisa Nurnawati

The antibiotic resistance of phatogenic bacteria has become a serious health problem and has encouraged the search for novel and effective antimicrobial metabolites. Meanwhile, endophytic fungi have great potential as a natural source for antimicrobial agents. The endophytic fungi that live in plant tissue produces secondary metabolites which potentially act as an antibacterial compound. The isolation of fungi for antibacterial sources reduces the large amount of plant as a source of antibacterial agents. Hence, this study aims to obtain endophytic fungi isolates from Paederia foetida L. that are capable of producing secondary metabolites as antibacterial, carry out in vitro tests to verify the antibacterial properties of secondary metabolites of the Paederia foetida L. endophytic fungi, and identify the potential of Paederia foetida L. endophytic fungi in producing antibacterial compounds. The antibacterial activity was tested against Escherichia coli ATCC8739 and Staphylococcus aureus ATCC6538 while seven isolates of endophytic fungi that potentially produced antibacterial were obtained from Sembukan (P. foetida L.). The results showed that antibacterial activities of SL1, SL4 and SL6 secondary metabolites against S. aureus ATCC6538 and E. coli ATCC8739 were moderate to strong activities. Furthermore, the Minimum Inhibition Concentration (MIC) of secondary metabolites extract of SL1 against S. aureus ATCC6538 value was 250 ????g/mL while the values of MIC extract of SL4 against S. aureus ATCC6538 and E. coli ATCC8739 were 125 ????g/mL and 250 ????g/mL respectively and MIC extract of SL6 against E. coli ATCC8739 value was 125 ????g/mL. The secondary metabolites extract of SL1 isolate were alkaloid and tannin, SL4 were phenolic and alkaloid while SL6 isolate were alkaloid and terpenoid. Hence, endophytic fungi SL1 isolate was identified as Fusarium sp., SL4 as Dematophora sp., and SL6 isolate as Acremonium sp.


2019 ◽  
Vol 16 (3) ◽  
pp. 284-290
Author(s):  
Nayan M. Panchani ◽  
Hitendra S. Joshi

Background:Several strategies have been reported for the synthesis of thiazole derivatives.Methods:However, many of these methods suffer from several drawbacks. Several modifications have been made to counter these problems. Here, we have synthesized a new series of 2-(2-((1HImidazol- 4-yl)methylene)hydrazinyl)-4-(4-substitutedphenyl)thiazoles without using the catalyst at room temperature.Results:The structures of synthesized compounds have been confirmed by spectral analysis, such as Mass, IR, 1H NMR and 13C NMR. All synthesized compounds were screened for in vitro antibacterial activity against some gram-positive and gram-negative bacteria.Conclusion:The thiazole derivatives, with a pharmacologically potent group, discussed in this article may provide valued therapeutic important in the treatment of microbial diseases, especially against bacterial and fungal infections.


2020 ◽  
Vol 83 (2) ◽  
pp. 331-337
Author(s):  
WENYUE WANG ◽  
RUI WANG ◽  
GUIJU ZHANG ◽  
FANGLI CHEN ◽  
BAOCAI XU

ABSTRACT Naturally occurring monoglyceride esters of fatty acids have been associated with a broad spectrum of antimicrobial activities. We used an automated turbidimetric method to measure the MIC and assess the antimicrobial activity of five monoglycerides (monocaprin, monolaurin, monomyristin, monopalmitin, and monostearin) against pathogenic strains of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. The antibacterial activity of monocaprin was highest because its carbon chain is shorter than those of other monoglycerides. The MICs of monocaprin against S. aureus, B. subtilis, P. aeruginosa, and E. coli were 0.32, 0.32, 2.5, and 2.5 mg/mL, respectively. Monocaprin had antibacterial activity under neutral and alkaline conditions (pH 7.0 to 9.0) but had no inhibitory effect on S. aureus, B. subtilis, and E. coli under weakly acidic conditions (pH 6.0). The antibacterial mechanism of monocaprin against gram-positive strains (S. aureus and B. subtilis) resulted from destruction of the cell membrane. In contrast, the antibacterial activity of monocaprin against gram-negative strains (P. aeruginosa and E. coli) was attributed to damage to lipopolysaccharides in the cell walls. Because of its inhibitory effect on both gram-positive and gram-negative bacteria, monocaprin could be used as an antibacterial additive in the food industry. HIGHLIGHTS


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bahar Mummed ◽  
Ashebr Abraha ◽  
Teka Feyera ◽  
Adugna Nigusse ◽  
Solomon Assefa

Background. External infections involving the skin and wound are the most frequent complications affecting humans and animals. Medicinal plants play great roles in the treatment of skin and wound infections. This study was aimed to evaluate thein vitroantibacterial activity of crude methanolic extracts of nine medicinal plants.Methods. Agar well diffusion and broth dilution methods were used to determine the antibacterial activity of nine Ethiopian plants against four bacterial species includingStaphylococcus aureus,Pseudomonas aeruginosa,Escherichia coli, andKlebsiella pneumoniae.Results. Among the tested plants, seven (Cissus quadrangularis,Commelina benghalensis,Euphorbia heterophylla,Euphorbia prostrate,Momordica schimperiana,Trianthemaspp., andSolanum incanum) were found to exhibit considerable antibacterial activity against at least one of the test bacteria. The extracts ofC. quadrangularis,E. heterophylla, andE. prostratahad a wide spectrum of antibacterial activities against test bacterial strains while the extracts ofGrewia villosaandSchinus molledid not show any inhibitory activity. Clinical isolate and laboratory strain of S.aureusshowed the highest susceptibility to highest concentration (780 mg/mL) ofE. prostratawith a zone of inhibition of 21.0mm and 22.3mm, respectively.Conclusion. This study indicates clear evidence supporting the traditional use of seven plants in treating skin and wound infections related to bacteria.


Chemotherapy ◽  
2017 ◽  
Vol 62 (3) ◽  
pp. 194-198 ◽  
Author(s):  
Socorro Leyva-Ramos ◽  
Denisse de Loera ◽  
Jaime Cardoso-Ortiz

Background: Fluoroquinolones are widely prescribed synthetic antimicrobial agents. Quinolones act by converting their targets, gyrase and topoisomerase IV, into toxic enzymes that fragment the bacterial chromosome; the irreversible DNA damage eventually causes the killing of bacteria. Thorough knowledge of the structure-activity relationship of quinolones is essential for the development of new drugs with improved activity against resistant strains. Methods: The compounds were screened for their antibacterial activity against 4 representing strains using the Kirby-Bauer disk diffusion method. Minimal inhibitory concentration (MIC) was determined by measuring the diameter of the inhibition zone using concentrations between 250 and 0.004 μg/mL. Results: MIC of derivatives 2, 3, and 4 showed potent antimicrobial activity against gram-positive and gram-negative bacteria. The effective concentrations were 0.860 μg/mL or lower. MIC for compounds 5-11 were between 120 and 515 μg/mL against Escherichia coli and Staphylococcus aureus, and substituted hydrazinoquinolones 7-10 showed poor antibacterial activity against gram-positive and gram-negative bacteria compared with other quinolones. Conclusion: Compounds obtained by modifications on C-7 of norfloxacin with the acetylated piperazinyl, halogen atoms, and substituted hydrazinyl showed good in vitro activity - some even better than the original compound.


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