Dextran-immobilized curcumin: An efficient agent against food pathogens and cancer cells

2019 ◽  
Vol 34 (4-5) ◽  
pp. 309-320 ◽  
Author(s):  
Mahboobeh Zare ◽  
Malihe Norouzi Sarkati ◽  
Hamed Tashakkorian ◽  
Razieh Partovi ◽  
Somayeh Rahaiee

Curcumin–dextran conjugate was synthesized by free radical grafting reaction between curcumin and dextran. The chemical characterization of the conjugate was obtained by Fourier-transform infrared and 1H-NMR (proton nuclear magnetic resonance) spectroscopy analysis, while the functionalization degree was determined by the Folin–Ciocalteu assay, finding a 22.93 mg of curcumin/g of dextran conjugate. Antioxidant activity of curcumin and curcumin–dextran conjugate was investigated employing DPPH• radical method, and IC50 (the half maximal inhibitory concentration) values of curcumin and the curcumin–dextran conjugate (Cur equivalents) were 86.6 ± 0.1 and 17.4 ± 1 µM, respectively. The presence of dextran into the curcumin–dextran conjugate improved radical scavenging activities of the curcumin. In addition, antimicrobial effect of curcumin and curcumin–dextran conjugate was evaluated against gram-positive ( Listeria monocytogenes and Staphylococcus aureus) and gram-negative ( Escherichia coli O157:H7 and Salmonella typhimurium) bacteria. According to our experiments, gram-positive microorganisms are more sensitive to these compounds than gram-negative ones. Curcumin–dextran is a more potent bacteriostat ( S. aureus (minimum inhibitory concentration = 0.008 µg/mL), E. coli O157:H7 (minimum inhibitory concentration = 250 µg/mL), and S. typhimurium (minimum inhibitory concentration = 500 µg/mL)) and also a more potent bacteriosid against S. aureus and S. typhimurium than curcumin. The cytotoxic effects of the curcumin–dextran conjugate toward AGS, MCF-7, and normal fibroblast cell lines were determined at 48 and 72 h using an MTT assay. The results revealed the considerable antiproliferative effects of the curcumin–dextran conjugate in both AGS and MCF-7 cancer cells in comparison with fibroblast cells. This study shows that dextran as a versatile scaffold develops the biological activities of curcumin by covalent grafting and can be regarded in further bioapplications.

Author(s):  
Mohammad Hassan Moshafi ◽  
Ali Peymani ◽  
Alireza Foroumadi ◽  
Mohammad Reza Zabihi ◽  
Farzad Doostishoar

Introduction: Nitrofurans and nitroimidazoles are broad-spectrum antimicrobial agents, which affect the microbial DNA. The aim of the present study was to evaluate the new derivatives of these two groups of antimicrobials against certain Gram-positive and Gram-negative bacterial strains. Materials and Methods: Seven new derivatives of nitrofurans and nitroimidazoles were synthesized, and 6.4 mg of each derivative was dissolved in dimethyl sulfoxide. Then, 8 serial dilutions (0.5, 1, 2, 4, 8, 16, 32, and 64 μg/ml) of each derivative was prepared using Muller-Hinton broth, and the minimum inhibitory concentration for each derivative was measured and compared to ciprofloxacin (standard). Results: All the derivatives had no antibacterial effects against Gram-negative bacteria (minimum inhibitory concentration > 64 μg/ml); only 2-(5-nitro-2-furyl)-5-(n-pentylsulfunyl)-1,3,4-thiadiazole exhibited mild antibacterial effects against Klebsiella pneumonia (minimum inhibitory concentration of 16-32 μg/ml). The antibacterial effects of the derivatives against Gram-positive bacteria also showed variations from complete inhibition of the growth of Staphylococcus epidermidis and Bacillus subtilis (minimum inhibitory concentration < 0.5 μg/ml) by 2-(5-nitro-2-furyl)-5-(n-buthylthio)-1,3,4-thiadiazole to no inhibition of S. epidermidis and streptococcus pyogenes. Conclusion: These compounds have weak antibacterial effects; only two derivatives showed antibacterial effects similar to that of the positive control.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Biswanath Chakraborty ◽  
Suchandra Chakraborty ◽  
Chandan Saha

The antibacterial activity of Murrayaquinone A (10), a naturally occurring carbazoloquinone alkaloid, and 6-methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione (11), a synthetic carbazoloquinone, both obtained during the development of the synthesis of Carbazomycin G, having unique quinone moiety, was studied against Gram-positive (Bacillus subtilisandStaphylococcus aureus) and Gram-negative (Escherichia coliandPseudomonassp.) bacteria. Compound10showed antibacterial activities against both ofEscherichia coliandStaphylococcus aureuswhereas compound11indicated the activity againstStaphylococcus aureusonly. Both compounds10and11exhibited minimum inhibitory concentration (MIC) of 50 μg mL−1againstStaphylococcus aureus.


2016 ◽  
Author(s):  
◽  
Reshme Govender

Pharmacological research is essential for the advancement of treatment therapies to combat diseases that plague mankind. Pyrimidines have been a subject under investigation by medicinal chemists for many years due to their interesting pharmacological properties. In previous studies, pyrimidines and their derivatives have been reported to have antimicrobial, anti-inflammatory, antimalarial, analgesic, and antitumour activities amongst other biological activities. Although there has been a significant amount of research carried out on these heterocycles, there will always be a continuous need for the discovery of novel synthetic drugs which have a higher degree of potency and fewer side effects. Hence, this study was undertaken to determine the pharmacological activities of eight novel 1, 4 dihydropyrimidine analogues (DHPM 1 – 8), that have been synthesized in our laboratory. The dihydropyrimidines were synthesized and characterized and thereafter evaluated for in vitro antimicrobial, antioxidant, anti-inflammatory, cytotoxicity and apoptotic activities. The compounds also underwent a safety study. Antimicrobial activity was evaluated using the disk diffusion assay; compounds displaying superior activity were subjected to further analysis to establish the minimum inhibitory concentration. Overall compounds DHPM 7 and 8 showed the best antibacterial activity against Gram positive bacteria. The minimum inhibitory concentration (MIC) for DHPM 7 against the Gram positive organisms (B.cereus, S.aureus and B.coagulans) was 0.75 µg/mL; however DHPM 7 had a MIC of 0.37 µg/mL against M. luteus. DHPM 8 displayed an MIC of 0.75 µg/mL against B.cereus, S.aureus, M.luteus, S.faecalis and B.coagulans. Antioxidant activity was assessed using the DPPH method. DHPM 2 showed outstanding free radical scavenging capacity of 90.63% at a concentration of 1 mg/mL. The DHPM 1 - 8 were analysed for their lipoxygenase inhibitory activity. Excellent inhibition ranging from 59.37 ± 0.6 to 81.19 ± 0.94% was demonstrated. The inhibitory activity was elucidated by a molecular docking study against the lipoxygenase enzyme (PDB code = 3V99) using the MOE 2013.08 and Leadit 2.1.2 software and high affinities were demonstrated. DHPM 1 - 8 were tested for cytotoxic activity against two human cancer cell lines, MCF-7 and UACC-62 by means of the MTT assay. It was observed for the MCF-7 cell line, DHPM 1, 4, 6, 7 and 8 displayed cytotoxicity above 89% at 50 µg/mL. The DHPMs at 50 µg/mL were noted to be very effective against the Melanoma cell line with DHPM 2 having a cytotoxicity value of 82.62% and DHPM 1, 4, 5, 6, 7 and 8 exhibiting cytotoxicity greater than 96%. Only slight inhibition of the proliferation of PBMC’s was noted. IC50 values of DHPM 1-8 were determined and the best activity overall was displayed by DHPM 8. The IC50 of DHPM 8 was 0.92 ± 0.09 and 1.97 ± 0.08 µM against MCF - 7 and UACC - 62 cell lines, respectively. The compounds that displayed toxicity towards the UACC - 62 cell line were investigated for their apoptotic inducing potential. The apoptotic studies were performed by flow cytometry using the following assays; Annexin V, JC-1 and Caspase -3 assays. The effect of these compounds was compared to a known anti-cancer drug, Camptothecin. On evaluation of the mechanism of action of the compounds, it was found that most compounds are using apoptotic pathways for cell death. Our studies have identified antimicrobial activity (DHPM 1-8) against Gram positive organisms, high antioxidant activity (DHPM 2), anti-inflammatory activity (DHPM 1-8) and anticancer activity (DHPM 1-8) against UACC-62 and MCF-7 cells. DHPM 1-8 were found to have no toxicity at 100 µg/mL in the brine shrimp assay and hence are probably safe as therapeutic agents. Furthermore molecular docking studies confirmed the activity of DHPM 1-8 as potential lipoxygenase inhibitors. DHPM 1-8 are novel compounds with great potential to be developed into chemotherapeutic agents.


2019 ◽  
Vol 12 (04) ◽  
pp. 1835-1847
Author(s):  
Kamatchi Chandrasekar ◽  
Bhawani Kumar ◽  
Arunkumar Saravanan ◽  
Ayush Victor ◽  
Saranya Sivaraj ◽  
...  

The study was performed to identify a potent antibacterial benzimidazole derivative using in vitro and in silico techniques. Benzimidazole and its derivatives were synthesized by reflux process. The derivatives were screened for antibiotic susceptibility test (AST) and minimum inhibitory concentration (MIC) against Gram-negative and Gram-positive clinical isolates and compared with the positive control Norfloxacin. Insilico molecular docking was performed to screen the binding potential of the derivatives with target enzymes topoisomerase II /DNA gyraseof Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus) along with the control Norfloxacin.Totally fifty-four isolates were screened for antimicrobial supectibility test (AST) and minimum inhibitory concentration (MIC) and 35 clinical isolates of Gram-negative showed 86% resistance to Norfloxacin and 19 isolates of Gram-positive showed 90% resistance to Norfloxacin. However, these isolates were found to be sensitive to 1-(4-((1H–benzimidazol-1-yl) methylamino) phenyl) ethanone (3) (C2), and 2-methyl-1H-benzimidazole (C4) compounds, with MIC ranges from 6.25- 12.5 µg/ml. Molecular docking analysis revealed that the compound C2 exhibited better binding affinity towards topoisomerase II / DNA gyrase of E.coli and S.aureus when compared with C4 and control Norfloxacin. The antibacterial activity of these may due to the inactivation of these enzymes which is supported by the MIC results.The obtained in vitro and in silico results suggested that C2 showed better antimicrobial activity.


2017 ◽  
Vol 5 (02) ◽  
pp. 12-17
Author(s):  
Prachi Agrawal ◽  
G. Jeyabalan

On the basis of literature review Semicarbazones have been potent in activities such as antifungal, antibacterial, antituberculosis, anticancerous etc. Till date various works has been done however still there is tremendous opportunities which can be explored. So, we planned for the synthesis of Semicarbazone derivaties and checking their antimicrobial activities. Biological activity was determined for all 19 synthesized compounds against bacteria (gram positive and gram negative) by MIC(Minimum Inhibitory Concentration) method.


2020 ◽  
Vol 15 (2) ◽  
pp. 87-94

In this work, various concentrations of ZnO nano particles, prepared by the coprecipitation method with a size range of 47-68 nm, have been investigated as antimicrobial agents. Dilution antimicrobial susceptibility tests were carried out on two kinds of microbes (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) according to the standard method recommended by Clinical and Laboratory Standards Institute, CLSI-2015-M07-A10. The results showed that the antimicrobial effect is larger, the higher the concentration of ZnO nano particles in solution. It was also found that Gram-positive microbes are more sensitive to ZnO nano particles when compared with the Gram-negative ones. The minimum inhibitory concentration (MIC) for E. coli was found to be 50 mg/mL while that for S. aureus was 25 mg/mL. The minimum bactericidal concentration (MBC) was 1600 mg/mL for E. coli and 800 mg/mL for S. aureus.


Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 189 ◽  
Author(s):  
Stephanie C. Shealy ◽  
Matthew M. Brigmon ◽  
Julie Ann Justo ◽  
P. Brandon Bookstaver ◽  
Joseph Kohn ◽  
...  

The Clinical Laboratory Standards Institute lowered the fluoroquinolone minimum inhibitory concentration (MIC) susceptibility breakpoints for Enterobacteriaceae and glucose non-fermenting Gram-negative bacilli in January 2019. This retrospective cohort study describes the impact of this reappraisal on ciprofloxacin susceptibility overall and in patients with risk factors for antimicrobial resistance. Gram-negative bloodstream isolates collected from hospitalized adults at Prisma Health-Midlands hospitals in South Carolina, USA, from January 2010 to December 2014 were included. Matched pairs mean difference (MD) with 95% confidence intervals (CI) were calculated to examine the change in ciprofloxacin susceptibility after MIC breakpoint reappraisal. Susceptibility of Enterobacteriaceae to ciprofloxacin declined by 5.2% (95% CI: −6.6, −3.8; p < 0.001) after reappraisal. The largest impact was demonstrated among Pseudomonas aeruginosa bloodstream isolates (MD −7.8, 95% CI: −14.6, −1.1; p = 0.02) despite more conservative revision in ciprofloxacin MIC breakpoints. Among antimicrobial resistance risk factors, fluoroquinolone exposure within the previous 90 days was associated with the largest change in ciprofloxacin susceptibility (MD −9.3, 95% CI: −16.1, −2.6; p = 0.007). Reappraisal of fluoroquinolone MIC breakpoints has a variable impact on the susceptibility of bloodstream isolates by microbiology and patient population. Healthcare systems should be vigilant to systematically adopt this updated recommendation in order to optimize antimicrobial therapy in patients with bloodstream and other serious infections.


2020 ◽  
Vol 49 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Hatem E. Gaffer ◽  
Ismail I. Althagafi

Purpose The purpose of this paper is to synthesize some new azobenzene dyestuffs clubbed with thiazolidinone moiety and their solicitation in dyeing polyester fabrics representing their antibacterial evaluation. Design/methodology/approach Herein, the authors report the synthesis of new thiazolidinone moiety after the coupling of diazotized 4-aminoacetophenone with resorcinol. The newly synthesized dyes were characterized by IR, elemental analysis, mass spectroscopy and proton nuclear magnetic resonance (1H NMR) spectral studies. The characteristics of dyeing of these dyestuffs were evaluated at optimum conditions. Concurrent with dyeing of polyester fabric for synthesized dyes with their antibacterial activity was estimated. Antimicrobial activity of the dyed fabrics at different concentrations was evaluated against gram-positive and gram-negative bacteria. Findings Synthesized azobenzene dyestuffs clubbed with thiazolidinone dyes were applied on polyester fabrics. It was remarked that the modified dyes exhibited better colourfastness properties. Furthermore, the synthesized dyes revealed antimicrobial activity against gram-positive and gram-negative bacteria. Research limitations/implications The synthesized azobenzene dyes for polyester dyeing were not bore earlier. Practical implications The azobenzene dyes were accountable for giving improved colourfastness properties on polyester fabrics. Social implications The synthesized azobenzene derivatives are sensibly expensive and applicable dyes accompanied with good antimicrobial and anticancer activities. Originality/value A common process could be affording textiles of colour and antibacterial assets. The newly synthesized dyes containing thiazolidinone moieties with azobenzene coupler showed interesting disperse colourant for polyester with good antibacterial activity.


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