Screening of Antimicrobial Activity and Cytotoxic Effects of Two Cladonia Species

2013 ◽  
Vol 68 (5-6) ◽  
pp. 191-197 ◽  
Author(s):  
Birkan Açıkgöz ◽  
İskender Karaltı ◽  
Melike Ersöz ◽  
Zeynep M. Coşkun ◽  
Gülşah Çobanoğlu ◽  
...  

The present study explores the antimicrobial activity and cytotoxic effects in culture assays of two fruticose soil lichens, Cladonia rangiformis Hoffm. and Cladonia convoluta (Lamkey) Cout., to contribute to possible pharmacological uses of lichens. In vitro antimicrobial activities of methanol and chloroform extracts against two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus), and the yeast Candida albicans were examined using the paper disc method and through determination of minimal inhibitory concentrations (MICs). The data showed the presence of antibiotic substances in the chloroform and the methanol extracts of the lichen species. The chloroform extracts exhibited more signifi cant antimicrobial activity than the methanol extracts. However, a higher antifungal activity was noted in the methanol extract of C. rangiformis. The maximum antimicrobial activity was recorded for the chloroform extract of C. convoluta against E. coli. The cytotoxic effects of the lichen extracts on human breast cancer MCF-7 cells were evaluated by the trypan blue assay yielding IC50 values of ca. 173 and 167 μg/ml for the extracts from C. rangiformis and C. convoluta, respectively.

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 912
Author(s):  
Taeeun Kim ◽  
Seung Cheol Lee ◽  
Moonsuk Bae ◽  
Heungsup Sung ◽  
Mi-Na Kim ◽  
...  

Ceftazidime-avibactam (CAZ-AVI) and aztreonam-avibactam (AZT-AVI) are novel antibiotic combinations active against multidrug-resistant Gram-negative pathogens. This study aimed to evaluate their in vitro activities and inoculum effects in carbapenem-resistant Enterobacterales (CRE), including carbapenemase-producing (CP)-CRE and non-CP-CRE. A total of 81 independent clinical isolates of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae were collected. CAZ-AVI and AZT-AVI minimal inhibitory concentrations (MICs) were evaluated by broth microdilution using standard and high inocula. The inoculum effect was defined as an ≥8-fold increase in MIC with high inoculum. Phenotypic determination of β-lactam resistance mechanism and PCR for carbapenemase genes were performed. Of the 81 CRE isolates, 35 (43%) were CP-CRE. Overall, 73% of the isolates were susceptible to CAZ-AVI, and 95% had low AZT-AVI MICs (≤8 µg/mL). The MIC50/MIC90s of CAZ-AVI and AZT-AVI were 4/≥512 µg/mL and 0.5/4 µg/mL, respectively. CAZ-AVI was more active against non-CP-CRE than against CP-CRE (susceptibility 80% vs. 63%, p = 0.08; MIC50/MIC90, 2/16 μg/mL vs. 4/≥512 μg/mL), whereas AZT-AVI was more active against CP-CRE (MIC50/MIC90, 0.25/1 μg/mL vs. 0.5/8 μg/mL). All four isolates with high AZT-AVI MIC (≥16 μg/mL) were resistant to CAZ-AVI, but only 18% (4/22) of CAZ-AVI-resistant isolates had high AZT-AVI MIC. The rates of the inoculum effect for CAZ-AVI and AZT-AVI were 18% and 47%, respectively (p < 0.001). Interestingly, the frequency of the AZT-AVI inoculum effect was higher in K. pneumoniae than E. coli (64% vs. 8%, p < 0.001). AZT-AVI is more active against CRE than CAZ-AVI, even in CP-CRE and CAZ-AVI-resistant isolates. The presence of a substantial inoculum effect may contribute to clinical failure in high-inoculum infections treated with AZT-AVI.


2019 ◽  
Vol 1 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Aline Rossato ◽  
Larissa da Silva Silveira ◽  
Leonardo Quintana Soares Lopes ◽  
Walter Paixão De Sousa Filho ◽  
Larissa Finger Schaffer ◽  
...  

Hospital Infection is a major health problem and affects around 1.5 million people annually around the world. The Amazon region has a wide diversity of native palm trees that have fruits and oilseeds. Astrocaryum vulgare, commonly known as Tucumã in Brazil, belongs to the family Arecaceae. This palm has orange, fleshy, single-egg-shaped fruits that are used for therapeutic purposes in diseases of the eyes and skin due to the high content of carotenoids, oil is used in cooking, health treatment and massage. This study evaluated the antimicrobial activity of the Tucumã oil against 18 microorganisms. The antimicrobial activity of Tucumã was measured through the determination of the Minimum Inhibitory Concentration (MIC), as well as the determination of the Minimum Microbicidal Concentration (CMM) aiming to contribute to the discovery of new antimicrobials against pathogenic microorganisms’ human health and may contribute to the treatment of nosocomial infections. The results showed that the oil of Tucumã presented antimicrobial activity against five important bacteria, four Gram - positive bacteria (Enterococcus faecalis, Enterococcus faecium, Staphylococcus epidermidis and Streptococcus agalactiae) and one Gram - negative (Acinetobacter baumannii).


Author(s):  
Abu- Safieh Rana ◽  
Muhi- Eldeen Zuhair ◽  
Alsarahni Aseel ◽  
Al-Kaissi Elham

A new series of 7-methoxy-2-[4-(t-amino-1-yl)oxy]-naphthalene derivatives; 7-methoxy-2-{[4-(2-methylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ2), 7-methoxy-2-{[4-(2,6-dimethylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ3), 7-methoxy-2{[4-(piperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ4), 7-methoxy-2-{[4-(pyrrolidine)but-2-yn-1-yl]oxy}-naphthalene (RZ5), 7-methoxy-2-{[4-(N-methylpiperazine)but-2-yn-1-yl]oxy}-naphthalene (RZ6), 7-methoxy -2-{[4-(hexamethyleneimine)but-2-yn-1-yl]oxy}-naphthalene (RZ7) were synthesized and screened in vitro as potential antimicrobial agents. Antimicrobial activity were evaluated by measuring the minimum inhibitory and bactericidal/fungicidal concentration (MIC, MBC and MFC). RZ2, RZ5, RZ6 and RZ7 showed the highest antimicrobial activity against S. aureus with MIC value 62.5 µg/ml, compounds RZ2, RZ4, RZ5, and RZ7 have the highest antimicrobial activity against B. subtilis with MIC vale 62.5 µg/ml, RZ3, RZ6 have the same antimicrobial activity with MIC value 125µg/ml, compounds. RZ4, RZ5, RZ6 and RZ7 have the highest antimicrobial activity against E. coli with MIC value 125 µg/ml, all compounds have the same MIC value against P. aeruginosa (125 µg/ml). RZ2, RZ4, RZ5, RZ6, RZ7 showed the highest antifungal activity with MIC of 62.5 µg/ml. In conclusion, the synthesized compounds showed good antimicrobial activity and promising potency against gram positive bacteria, gram negative bacteria and fungi.


2012 ◽  
Vol 7 (12) ◽  
pp. 1934578X1200701 ◽  
Author(s):  
Niko S. Radulović ◽  
Milan B. Stojković ◽  
Snežana S. Mitić ◽  
Pavle J. Randjelović ◽  
Ivan R. Ilić ◽  
...  

In this study we evaluated in vitro (radical scavenging) and in vivo (hepatoprotective effect) antioxidant activities and antimicrobial properties of the extracts of the above- and underground parts of Geranium macrorrhizum L. (Geraniaceae), an ethnopharmacologically renowned plant species. The antioxidant activity and total phenol and flavonoid contents of four different solvent extracts were evaluated by seven different methods. The methanol extracts, administered i.p. to rats (120-480 mg/kg), were evaluated for hepatoprotective activity in a CCl4-induced hepatotoxicity model. The same extracts were tested for antimicrobial activity against seven bacterial and two fungal species. The administered methanol extracts with the highest antioxidant potential showed a significant dose-dependent hepatoprotective action against CCl4-induced liver damage in both decreasing the levels of liver transaminases and bilirubin and in reducing the extent of morphological malformations of the liver. The leaf methanol extract displayed a very strong antibacterial activity, especially against Staphylococcus aureus, with low minimal inhibitory and bactericidal concentrations. These results justify the frequent use of this plant species in folk medicine. Besides the known astringent effect, one can expect that the observed antimicrobial activity against several human pathogens contributes to the wound healing properties of this plant.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ramesh S. Yamgar ◽  
Y. Nivid ◽  
Satish Nalawade ◽  
Mustapha Mandewale ◽  
R. G. Atram ◽  
...  

The synthesis and antimicrobial activity of novel Zn(II) metal complexes derived from three novel heterocyclic Schiff base ligands 8-[(Z)-{[3-(N-methylamino)propyl]imino}methyl]-7-hydroxy-4-methyl-2H-chromen-2-one, 2-[(E)-{[4-(1H-1,2,4-triazol-1-ylmethyl)phenyl]imino}methyl]phenol, and (4S)-4-{4-[(E)-(2-hydroxybenzylidene)amino]benzyl}-1,3-oxazolidin-2-one have been described. These Schiff base ligands and metal complexes are characterised by spectroscopic techniques. According to these data, we propose an octahedral geometry to all the metal complexes. Antimicrobial activity of the Schiff base ligand and its metal complexes was studied against Gram negative bacteria:E. coliandPseudomonas fluorescens, Gram positive bacteria:Staphylococcus aureus,and also against fungi, that is,C. albicansandA. niger. Some of the metal complexes show significant antifungal activity (MIC < 0.2 μg/mL). The “in vitro” data has identified [Zn(NMAPIMHMC)2]·2H2O, [Zn(TMPIMP)2]·2H2O, and [Zn(HBABO)2]·2H2O as potential therapeutic antifungal agents againstC. albicansandA. niger.


Author(s):  
HOSUR NARAYANAPPA VENKATESH ◽  
DEVIHALLI CHIKKAIAH MOHANA

Objective: The continuous emergence of multidrug resistance bacteria and yeast, and the negative impact of synthetic preservatives have led to an increased interest in the use of plant extracts as alternative antimicrobial agents. In the present investigation, the antimicrobial activity of successive solvent extracts of Albizia lebbeck and Solanum seaforthianum has been evaluated against human pathogenic bacteria and yeast. Methods: The disc diffusion method was employed for determination of the zone of inhibitions (ZOIs) and twofold broth dilution technique was employed for determination of minimal inhibitory concentrations, and minimal bactericidal/fungicidal concentrations. Results: Among the successive solvent extracts tested, methanol extracts of both A. lebbeck and S. seaforthianum showed highest antibacterial activity with ZOIs ranged between 10.0 and 20.4 mm at 1 mg/disc followed by ethanol (ZOIs 8.1–17.6 mm). The petroleum ether, toluene, and chloroform extracts showed the least activity. The highest activity was observed against Streptococcus faecalis, whereas the least activity was observed against Pseudomonas aeruginosa. Conclusion: The broad-spectrum antimicrobial activity of methanol extract of A. lebbeck and S. seaforthianum could be explored as antimicrobial agents for the management of pathogenic bacteria and yeast.


2015 ◽  
Vol 45 ◽  
pp. 67-74 ◽  
Author(s):  
P. Vedhanarayanan ◽  
T. Vaithiyanathan ◽  
P. Sundaramoorthy

The antimicrobial activity of chloroform and methanol extracts of Lennea coromandelica were screened for their was studied against gram positive bacteria strains Staphylococcus aureus,Streptococcus pyogenes and Bacillus subtilis gram negative bacteria strains Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli and fungal strains such as Candida albicans, C. parapsilosis, C. krusei and C. glabrata using disc diffusion method, determination of Minimum Inhibitory Concentrations (MIC), Minimum Bacterial Concentrations (MBC) and Minimum Fungicidal Concentrations (MFC). The antimicrobial activity for different concentrations like 250 μg, 500 μg and 1000 μg of different solvent extracts of Lannea cormandelica. bacterial strains and recorded in highest mean zones of inhibition ranged from 19.6 mm and Candidal strains and the exhibited the highest mean zones of inhibition ranged from 10.6 mm. Methanol extracts showed the best results as inhibition zones against tested organisms. Results showed also that, the greatest effect was towards Staphylococcus aureus and the lowest was against Candida krusei. The present study reported the great effect of Lannea cormandelica extracts against some of most important pathogens.


2019 ◽  
Vol 15 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Rakesh Kumar ◽  
Shailendra Patil

Background:Diseases caused by microbial infections are very common worldwide. Although the search of innovative antimicrobial agents is the current focus for the researchers, the treatment of infectious diseases remains an important public health issue and a challenging problem in front of medicinal chemist.Methods:A series of 2-(4-hydroxyphenyl)-3-(4-(4-nitrophenyl) thiazol-2-yl)thiazolidin-4-one derivatives (T1-T10) was designed and synthesized. All the titled compounds were evaluated for their antimicrobial potential. Antimicrobial activity was performed by tube dilution methods against Gram negative Escherichia coli MTCC 443 (E. Coli), Gram positive bacteria: Staphylococcus aureus MTCC 3160 (S. aureus) and Bacillus subtilis MTCC 441 (B. Subtilis), and fungal strains: Aspergillus niger MTCC 281 (A. niger) and Candida albicans MTCC 227 (C. albicans).Results:Among the synthesized derivatives, compounds 2, 4 and 10 were found to be most active antimicrobial agents.Conclusion:In conclusion, a series of 2-(phenyl)-3-(4-(phenyl)thiazol-2-yl)thiazolidin-4-ones have been designed and synthesized. All the titled compounds were evaluated for their in vitro antimicrobial activity against five representative microorganisms. The results of antimicrobial study indicated that the presence of nitro and chloro groups in aromatic ring improved antibacterial activity, whereas the presence of hydroxy group improved antifungal activity of substituted 4-thiazolidinone derivatives.


2020 ◽  
Vol 16 (8) ◽  
pp. 1112-1123
Author(s):  
Othman Hamed ◽  
Oswa Fares ◽  
Shaima Taleeb ◽  
Ghaleb Adwan ◽  
Haythem Saadeh ◽  
...  

Background: Curcumin is a safe, versatile natural product with unlimited number of biological activities and a precursor for various heterocyclic compounds. Objective: The present study was aimed to the development of a curcumin based antimicrobial reagent with high potency against gram-positive and gram-negative bacteria. Methods: Herein we report a simple and convenient one step method for synthesizing a series of 1,4-benzodiazepines via condensation cyclization reaction between curcumin and various 1,2- phenylenediamine in refluxed ethanol. Results: A series of new 1,4-benzodiazepins were synthesized and their structures were supported by FT-IR, 1H NMR, 13C NMR, and mass spectral analysis. Synthesized 1,4-benzodiazepins were evaluated for their in vitro antimicrobial activity against gram positive (S. aureus and S. epidermidis) and gram negative (E. coli and P. aeruginosa) bacteria. They exhibited low to high potency against the tested organisms. In particular, dichlorinated 1,4-benzodiazepine 9 exhibited a remarkable potency against the gram-positive bacteria S. aureus (MIC: 3.125 μg mL-1, MBC: 12 μg mL-1). It showed a higher potency than most of the tested reference drugs. Compound 9 showed the medium activity against E. coli. Genotoxic study revealed that, benzodiazepines 9 attacked the DNA of E. coli strains and damaged it. The potency of compound 9, could be attributed to the multiple chlorine atoms present on the aromatic ring. Conclusion: Some of the synthesized curcumin based benzodiazepines showed excellent potency against gram positive bacteria. These benzodiazepines could be a great candidate as a future antimicrobial agent.


2014 ◽  
Vol 6 (2) ◽  
pp. 155-157
Author(s):  
Gandi Kishore NAIDU ◽  
B. SUJATHA ◽  
K. Chandra Sekhar NAIDU

The present study was carried out the antibacterial activity and phytochemical screening of the hexane, chloroform and methanol extracts of leaves of Limonia acidissima. The antibacterial activity was evaluated against four Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris) and five Gram-positive bacteria (Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Streptococcus pneumoniae) by agar well diffusion method. Methanol extract showed good antibacterial activity with the high inhibition zones while chloroform extract exhibited mild to moderate activity and hexane extract was found to be less active. Phytochemical screening revealed the presence of various secondary metabolites like steroids, alkaloids, phenols, flavonoids, coumarins, saponins, tannins and triterpenoids. The results of the present study suggest that leaves of Limonia acidissima can be used to treating infectious diseases caused by E. coli, P. vulgarisand S. pneumoniae.


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