scholarly journals Differential in vitro activities of ionophore compounds against Plasmodium falciparum and mammalian cells.

1996 ◽  
Vol 40 (3) ◽  
pp. 602-608 ◽  
Author(s):  
C Gumila ◽  
M L Ancelin ◽  
G Jeminet ◽  
A M Delort ◽  
G Miquel ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Inhibitory Concentration ◽  
Antimalarial Activity ◽  
Monovalent Cations ◽  
Macrophage Cell ◽  
Mammalian Cell Lines ◽  
Gramicidin D

Twenty-two ionophore compounds were screened for their antimalarial activities. They consisted of true ionophores (mobile carriers) and channel-forming quasi-ionophores with different ionic specificities. Eleven of the compounds were found to be extremely efficient inhibitors of Plasmodium falciparum growth in vitro, with 50% inhibitory concentrations of less than 10 ng/ml. Gramicidin D was the most active compound tested, with 50% inhibitory concentration of 0.035 ng/ml. Compounds with identical ionic specificities generally had similar levels of antimalarial activity, and ionophores specific to monovalent cations were the most active. Compounds were further tested to determine their in vitro toxicities against mammalian lymphoblast and macrophage cell lines. Nine of the 22 compounds, i.e., alborixin, lonomycin, nigericin, narasin, monensin and its methylated derivative, lasalocid and its bromo derivative, and gramicidin D, most specific to monovalent cations, were at least 35-fold more active in vitro against P. falciparum than against the two other mammalian cell lines. The enhanced ability to penetrate the erythrocyte membrane after infection could be a factor that determines ionophore selectivity for infected erythrocytes.

Synthesis, Plasmodium falciparum Inhibitory Activity, Cytotoxicity and Solubility of N2 ,N4 -Disubstituted Quinazoline-2,4-diamines.

2019 ◽  
Vol 15 (6) ◽  
pp. 693-704 ◽  
Author(s):  
Nattakarn Pobsuk ◽  
Praphasri Suphakun ◽  
Supa Hannongbua ◽  
Chanin Nantasenamat ◽  
Kiattawee Choowongkomon ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Physical Properties ◽  
Vero Cell ◽  
Cell Lines ◽  
Inhibitory Activity ◽  
Antimalarial Activity ◽  
Control Strategies ◽  
Treatment Options ◽  
Mammalian Cell Lines ◽  
Vero Cell Lines

Background: Despite the development of extensive control strategies and treatment options, approximately 200 million malaria cases, leading to approximately 450,000 deaths, were reported in 2015. Due to issue of disease resistance, additional drug development efforts are needed to produce new, more effective treatments. Quinazoline-2,4-diamines were identified as antiparasitic compounds over three decades ago and have remained of interest to date in industry and academia. Objective: An anti-malarial SAR evaluation of previously unreported N2 ,N4 -disubstituted quinazoline- 2,4-diamines have been undertaken in this study. We have synthesized and evaluated new derivatives against P. falciparum in our attempt to better characterize their biological activity and overall physical properties. Methods: The synthesis of N2 ,N4 -disubstituted quinazoline-2,4-diamines inhibitors is reported along with activities in a radioactive labeled hypoxanthine incorporation assay against the f Plasmodium falciparum (Pf.) K1 strain. In addition, cytotoxicity was determined in the A549 and Vero cell lines using an MTT based. The aqueous solubility of key compounds was assessed at pH 7.4 using a shake flask-based approach. Results: We identified compounds 1 and 6p as sub µM inhibitors of P. falciparum, having equivalent anti-malarial activity to Chloroquine. Compounds 1 and 6m are low µM inhibitors of P. falciparum with improved cytotoxicity profiles. Compound 6m displayed the best balance between P. falciparum Inhibitory activity (2 µM) and cytotoxicity, displaying >49 fold selectivity over A549 and Vero cell lines. Conclusion: Twenty one N2 ,N4 -Disubstituted Quinazoline-2,4-diamines have been prepared in our group and characterized in terms of their antimalarial activity, cytotoxicity and physical properties. Compounds with good activity and reasonable selectivity over mammalian cell lines have been identified. SAR analyses suggest further exploration is are necessary to improve the balance of P. falciparum Inhibitory activity, cytotoxicity and solubility.

scholarly journals A Novel Series of [1,2,4]Triazolo[4,3-a]Pyridine Sulfonamides as Potential Antimalarial Agents: In Silico Studies, Synthesis and In Vitro Evaluation

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4485
Author(s):  
Veronika R. Karpina ◽  
Svitlana S. Kovalenko ◽  
Sergiy M. Kovalenko ◽  
Oleksandr G. Drushlyak ◽  
Natalya D. Bunyatyan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Molecular Docking ◽  
Virtual Screening ◽  
Inhibitory Concentration ◽  
Antimalarial Activity ◽  
Virtual Library ◽  
Antimalarial Agents ◽  
Starting Point ◽  
In Silico Studies

For the development of new and potent antimalarial drugs, we designed the virtual library with three points of randomization of novel [1,2,4]triazolo[4,3-a]pyridines bearing a sulfonamide fragment. The library of 1561 compounds has been investigated by both virtual screening and molecular docking methods using falcipain-2 as a target enzyme. 25 chosen hits were synthesized and evaluated for their antimalarial activity in vitro against Plasmodium falciparum. 3-Ethyl-N-(3-fluorobenzyl)-N-(4-methoxyphenyl)-[1,2,4]triazolo[4,3-a]pyridine-6-sulfonamide and 2-(3-chlorobenzyl)-8-(piperidin-1-ylsulfonyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one showed in vitro good antimalarial activity with inhibitory concentration IC50 = 2.24 and 4.98 μM, respectively. This new series of compounds may serve as a starting point for future antimalarial drug discovery programs.

scholarly journals Potent and Selective Activity of a Combination of Thymidine and 1843U89, a Folate-Based Thymidylate Synthase Inhibitor, against Plasmodium falciparum

2000 ◽  
Vol 44 (4) ◽  
pp. 1047-1050 ◽  
Author(s):  
Lei Jiang ◽  
Pei-Chieh Lee ◽  
John White ◽  
Pradipsinh K. Rathod
Keyword(s):  
Plasmodium Falciparum ◽  
Thymidylate Synthase ◽  
Mammalian Cells ◽  
De Novo ◽  
Antimalarial Activity ◽  
Malarial Parasite ◽  
Drug Resistant ◽  
Additional Tool ◽  
Synthase Inhibitor

ABSTRACT Unlike mammalian cells, malarial parasites are completely dependent on the de novo pyrimidine pathway and lack the enzymes to salvage preformed pyrimidines. In the present study, first, it is shown that 1843U89, even without polyglutamylation, is a potent folate-based inhibitor of purified malarial parasite thymidylate synthase. The binding was noncompetitive with respect to methylenetetrahydrofolate, and 1843U89 had a Ki of 1 nM. The compound also had potent antimalarial activity in vitro. Plasmodium falciparum cells in culture were inhibited by 1843U89, with a 50% inhibitory concentration of about 70 nM. The compound was effective against drug-sensitive as well as drug-resistant clones ofP. falciparum. As predicted by the biochemistry of the parasite, the potent inhibition of parasite proliferation by 1843U89 could not be reversed with 10 μM thymidine. In contrast, in the presence of 10 μM thymidine, mammalian cells were unaffected by 1843U89 even at concentrations as high as 0.1 mM, thus offering a selectivity window of more than 1,000-fold. On this basis, folate-based thymidylate synthase inhibitors may represent a powerful additional tool that can be used to combat drug-resistant malaria.

scholarly journals Inhibition of Plasmodium falciparum Growth In Vitro and Adhesion to Chondroitin-4-Sulfate by the Heparan Sulfate Mimetic PI-88 and Other Sulfated Oligosaccharides

2006 ◽  
Vol 50 (8) ◽  
pp. 2850-2852 ◽  
Author(s):  
Yvonne Adams ◽  
Craig Freeman ◽  
Reinhard Schwartz-Albiez ◽  
Vito Ferro ◽  
Christopher R. Parish ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Surface ◽  
Heparan Sulfate ◽  
Phase Ii ◽  
Inhibitory Concentration ◽  
Antimalarial Activity ◽  
Placental Malaria ◽  
Sulfated Oligosaccharides ◽  
Adhesion Inhibition

ABSTRACT A panel of sulfated oligosaccharides was tested for antimalarial activity and inhibition of adhesion to the placental malaria receptor chondroitin-4-sulfate (CSA). The heparan sulfate mimetic PI-88, currently undergoing phase II anticancer trials, displayed the greatest in vitro antimalarial activity against Plasmodium falciparum (50% inhibitory concentration of 7.4 μM) and demonstrated modest adhesion inhibition to cell surface CSA.

scholarly journals Antimalarial Activity of Simalikalactone E, a New Quassinoid from Quassia amara L. (Simaroubaceae)

2009 ◽  
Vol 53 (10) ◽  
pp. 4393-4398 ◽  
Author(s):  
N. Cachet ◽  
F. Hoakwie ◽  
S. Bertani ◽  
G. Bourdy ◽  
E. Deharo ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Inhibitory Concentration ◽  
Antimalarial Activity ◽  
Selectivity Index ◽  
Strain Sensitivity ◽  
Isolation And Identification ◽  
Quassia Amara ◽  
Plasmodium Vinckei

ABSTRACT We report the isolation and identification of a new quassinoid named simalikalactone E (SkE), extracted from a widely used Amazonian antimalarial remedy made out of Quassia amara L. (Simaroubaceae) leaves. This new molecule inhibited the growth of Plasmodium falciparum cultured in vitro by 50%, in the concentration range from 24 to 68 nM, independently of the strain sensitivity to chloroquine. We also showed that this compound was able to decrease gametocytemia with a 50% inhibitory concentration sevenfold lower than that of primaquine. SkE was found to be less toxic than simalikalactone D (SkD), another antimalarial quassinoid from Q. amara, and its cytotoxicity on mammalian cells was dependent on the cell line, displaying a good selectivity index when tested on nontumorogenic cells. In vivo, SkE inhibited murine malaria growth of Plasmodium vinckei petteri by 50% at 1 and 0.5 mg/kg of body weight/day, by the oral or intraperitoneal routes, respectively. The contribution of quassinoids as a source of antimalarial molecules needs therefore to be reconsidered.

scholarly journals In Vitro and In Vivo Toxicity Evaluation of Natural Products with Potential Applications as Biopesticides

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 805
Author(s):  
Felicia Sangermano ◽  
Marco Masi ◽  
Amrish Kumar ◽  
Ravindra Peravali ◽  
Angela Tuzi ◽  
...  
Keyword(s):  
Natural Products ◽  
Cell Lines ◽  
Mammalian Cell ◽  
Mammalian Cells ◽  
Toxic Effects ◽  
Mammalian Cell Lines ◽  
Dittrichia Viscosa ◽  
Potential Applications

The use of natural products in agriculture as pesticides has been strongly advocated. However, it is necessary to assess their toxicity to ensure their safe use. In the present study, mammalian cell lines and fish models of the zebrafish (Danio rerio) and medaka (Oryzias latipes) have been used to investigate the toxic effects of ten natural products which have potential applications as biopesticides. The fungal metabolites cavoxin, epi-epoformin, papyracillic acid, seiridin and sphaeropsidone, together with the plant compounds inuloxins A and C and ungeremine, showed no toxic effects in mammalian cells and zebrafish embryos. Conversely, cyclopaldic and α-costic acids, produced by Seiridium cupressi and Dittrichia viscosa, respectively, caused significant mortality in zebrafish and medaka embryos as a result of yolk coagulation. However, both compounds showed little effect in zebrafish or mammalian cell lines in culture, thus highlighting the importance of the fish embryotoxicity test in the assessment of environmental impact. Given the embryotoxicity of α-costic acid and cyclopaldic acid, their use as biopesticides is not recommended. Further ecotoxicological studies are needed to evaluate the potential applications of the other compounds.

scholarly journals Synthesis and Antiplasmodial Activity of 1,2,3-Triazole-Naphthoquinone Conjugates

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3917 ◽  
Author(s):  
Oramas-Royo ◽  
López-Rojas ◽  
Amesty ◽  
Gutiérrez ◽  
Flores ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Tumor Cell ◽  
Cell Lines ◽  
Antiproliferative Activity ◽  
Antimalarial Activity ◽  
Tumor Cell Lines ◽  
Dihydroorotate Dehydrogenase ◽  
Structure Activity ◽  
Mcf 7

A series of 34 1,2,3-triazole-naphthoquinone conjugates were synthesized via copper-catalyzed cycloaddition (CuAAC). They were evaluated for their in vitro antimalarial activity against chloroquine-sensitive strains of Plasmodium falciparum and against three different tumor cell lines (SKBr-3, MCF-7, HEL). The most active antimalarial compounds showed a low antiproliferative activity. Simplified analogues were also obtained and some structure–activity relationships were outlined. The best activity was obtained by compounds 3s and 3j, having IC50 of 0.8 and 1.2 μM, respectively. Molecular dockings were also carried on Plasmodium falciparum enzyme dihydroorotate dehydrogenase (PfDHODH) in order to rationalize the results.

scholarly journals A Novel Cell-Associated Protection Assay Demonstrates the Ability of Certain Antibiotics To Protect Ocular Surface Cell Lines from Subsequent ClinicalStaphylococcus aureusChallenge

2011 ◽  
Vol 55 (8) ◽  
pp. 3788-3794 ◽  
Author(s):  
J. B. Wingard ◽  
E. G. Romanowski ◽  
R. P. Kowalski ◽  
F. S. Mah ◽  
Y. Ling ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Lines ◽  
Antibiotic Susceptibility ◽  
Mammalian Cells ◽  
Cell Layer ◽  
Gentian Violet ◽  
Mammalian Cell Lines ◽  
Dosing Regimens

ABSTRACTIn vivoeffectiveness of topical antibiotics may depend on their ability to associate with epithelial cells to provide continued protection, but this contribution is not measured by standard antibiotic susceptibility tests. We report a newin vitromethod that measures the ability of test antibiotics azithromycin (AZM), erythromycin (ERY), tetracycline (TET), and bacitracin (BAC) to associate with mammalian cells and to protect these cells from destruction by bacteria. Mammalian cell lines were grown to confluence using antibiotic-free medium and then incubated in medium containing a single antibiotic (0 to 512 μg/ml). After incubation, the cells were challenged withStaphylococcus aureusocular isolates, without antibiotics added to the culture medium. Epithelial cell layer integrity was assessed by gentian violet staining, and the minimum cell layer protective concentration (MCPC) of an antibiotic sufficient to protect the mammalian cells fromS. aureuswas determined. Staining was also quantified and analyzed. Bacterial viability was determined by culture turbidity and growth on agar plates. Preincubation of Chang and human corneal limbal epithelial cells with AZM, ERY, and TET at ≥64 μg/ml provided protection against AZM-susceptibleS. aureusstrains, with increasing protection at higher concentrations. TET toxicity was demonstrated at >64 μg/ml, whereas AZM displayed toxicity to one cell line at 512 μg/ml. BAC failed to show consistent protection at any dose, despite bacterial susceptibility to BAC as determined by traditional antibiotic susceptibility testing. A range of antibiotic effectiveness was displayed in this cell association assay, providing data that may be considered in addition to traditional testing when determining therapeutic dosing regimens.

scholarly journals Optimization of Xanthones for Antimalarial Activity: the 3,6-Bis-ω-Diethylaminoalkoxyxanthone Series

2002 ◽  
Vol 46 (1) ◽  
pp. 144-150 ◽  
Author(s):  
Jane Xu Kelly ◽  
Rolf Winter ◽  
David H. Peyton ◽  
David J. Hinrichs ◽  
Michael Riscoe
Keyword(s):  
Plasmodium Falciparum ◽  
Inhibitory Concentration ◽  
Antimalarial Activity ◽  
Multidrug Resistant ◽  
Food Vacuole ◽  
Ionic Interactions ◽  
Side Chains ◽  
Antimalarial Agents ◽  
Unique Manner

ABSTRACT Hydroxyxanthones have been identified as novel antimalarial agents. The compounds are believed to exert their activity by complexation to heme and inhibition of hemozoin formation. Modification of the xanthone structure was pursued to improve their antimalarial activity. Attachment of R-groups bearing protonatable nitrogen atoms was conducted to enhance heme affinity through ionic interactions with the propionate side chains of the metalloporphyrin and to facilitate drug accumulation in the parasite food vacuole. A series of 3,6-bis-ω-diethylaminoalkoxyxanthones with side chains ranging from 2 to 8 carbon atoms were prepared and evaluated. Measurement of heme affinity for each of the derivatives revealed a strong correlation (R 2 = 0.97) between affinity and antimalarial potency. The two most active compounds in the series contained 5- and 6-carbon side chains and exhibited low nanomolar 50% inhibitory concentration (IC50) values against strains of chloroquine-susceptible and multidrug-resistant Plasmodium falciparum in vitro. Both of these xanthones exhibit stronger heme affinity (8.26 × 105 and 9.02 × 105 M−1, respectively) than either chloroquine or quinine under similar conditions and appear to complex heme in a unique manner.

scholarly journals Examining the relative activity of several dicistrovirus intergenic internal ribosome entry site elements in uninfected insect and mammalian cell lines

2008 ◽  
Vol 89 (12) ◽  
pp. 3150-3155 ◽  
Author(s):  
James R. Carter ◽  
Tresa S. Fraser ◽  
Malcolm J. Fraser
Keyword(s):  
Cell Lines ◽  
Internal Ribosome Entry Site ◽  
Mammalian Cells ◽  
Relative Activity ◽  
Luciferase Expression ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Mammalian Cell Lines ◽  
Insect Cell Lines

Comparisons of the relative activities of 11 intergenic region (IGR) internal ribosome entry site (IRES) elements of insect dicistrovirus with 5′ IRES elements of the hepatitis C and encephalomyocarditis viruses were performed in insect and mammalian cells. Dual luciferase assays were performed to determine the most effective dicistrovirus IGR IRES in the lepidopteran cell lines Sf9 (Spodoptera frugiperda) and BmN (Bombyx mori), and the dipteran cell lines S2 (Drosophila melanogaster) and ATC-10 (Aedes aegypti). Evaluation of dual luciferase expression from DNA plasmids and in vitro-transcribed RNA revealed apparent splicing with certain IRES elements. Though IRES activity depended upon the cell line examined, the black queen cell and Drosophila C dicistrovirus intergenic IRES elements were most effective for coupled gene expression in the diverse insect cell lines examined.

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