scholarly journals Leishmanicidal activity of racemic ± 8-[(4-Amino-1-methylbutyl)amino]-6-methoxy-4-methyl-5-[3,4-dichlorophenoxy]quinoline

2010 ◽  
Vol 5 (3) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Angélica P. Isaac-Márquez ◽  
James D. McChesney ◽  
N.P. Dammika Nanayakara ◽  
Abhay R. Satoskar ◽  
Claudio M. Lezama-Dávila
Keyword(s):  
Stationary Phase ◽  
Hela Cells ◽  
Parasite Growth ◽  
In Vitro Toxicity ◽  
Reference Drug ◽  
Leishmanicidal Activity ◽  
First Report ◽  
Cells Cultured

In this work we studied the in vitro toxicity of ± 8-[(4-Amino-1-Methylbutyl)Amino]-6-Methoxy-4-Methyl-5-[3,4-dichlorophenoxy]quinoline (DN3-27-1) against stationary phase promastigotes Leishmania (L.) mexicana. Our results indicate that this drug induces an important reduction in parasite growth and killing compared to the reference drug N-methyl meglumine (Glucantime™). DN3-27-1 was not toxic to Hela cells cultured in vitro. This is the first report describing the promising potential of DN3-27-1 in treatment of L. ( L.) m exicana infections.

scholarly journals Leishmanicidal Activity of Artemisinin, Deoxoartemisinin, Artemether and Arteether

2007 ◽  
Vol 2 (1) ◽  
pp. 1934578X0700200 ◽  
Author(s):  
Claudio M. Lezama-Dávila ◽  
Abhay R. Satoskar ◽  
Mirna Úc-Encalada ◽  
Ricardo Isaac-Márquez ◽  
Angélica P. Isaac-Márquez
Keyword(s):  
Hela Cells ◽  
Parasite Growth ◽  
In Vitro Toxicity ◽  
Reference Drug ◽  
Chemical Derivatives ◽  
Synthetic Derivatives ◽  
Eventual Death ◽  
Potential Use ◽  
Cells Cultured

In this work we studied the in vitro toxicity of artemisinin and its chemical derivatives deoxoartemisinin, artemether and arteether against stationary phase promastigotes of Leishmania (L) mexicana. Results presented in this work include dramatic changes in parasite morphology when they were cultured in the presence of these chemicals. These changes were accompanied by the parasite's lost of mobility and eventual death after four days of culturing. We also observed that parasite growth was much more effectively reduced in cultures carried out in the presence of either artemisinin or its semi-synthetic derivatives than the reference drug N-methyl meglumine (Glucantime™, Rhone Poulenc, France). The compounds tested in this work were not toxic to Hela cells cultured in vitro. This is the first report describing the promising potential use of Qinghaosu (artemisinin) and related chemical analogues to treat L (L) mexicana infections.

scholarly journals Leishmanicidal Activity of Isoselenocyanate Derivatives

2018 ◽  
Vol 63 (2) ◽  
pp. e00904-18 ◽  
Author(s):  
Celia Fernández-Rubio ◽  
Esther Larrea ◽  
José Peña Guerrero ◽  
Eduardo Sesma Herrero ◽  
Iñigo Gamboa ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Amphotericin B ◽  
Cell Cycle Progression ◽  
Leishmania Major ◽  
Antitumor Agents ◽  
Peritoneal Macrophages ◽  
Reference Drug ◽  
Content Type ◽  
Leishmanicidal Activity

ABSTRACTConventional chemotherapy against leishmaniasis includes agents exhibiting considerable toxicity. In addition, reports of drug resistance are not uncommon. Thus, safe and effective therapies are urgently needed. Isoselenocyanate compounds have recently been identified with potential antitumor activity. It is well known that some antitumor agents demonstrate effects againstLeishmania. In this study, thein vitroleishmanicidal activities of several organo-selenium and organo-sulfur compounds were tested againstLeishmania majorandLeishmania amazonensisparasites, using promastigotes and intracellular amastigote forms. The cytotoxicity of these agents was measured in murine peritoneal macrophages and their selectivity indexes were calculated. One of the tested compounds, the isoselenocyanate derivative NISC-6, showed selectivity indexes 2- and 10-fold higher than those of the reference drug amphotericin B when evaluated inL. amazonensisandL. major, respectively. The American strain (L. amazonensis) was less sensitive to NISC-6 thanL. major, showing a trend similar to that observed previously for amphotericin B. In addition, we also observed that NISC-6 significantly reduced the number of amastigotes per infected macrophage. On the other hand, we showed that NISC-6 decreases expression levels ofLeishmaniagenes involved in the cell cycle, such astopoisomerase-2(TOP-2),PCNA, andMCM4, therefore contributing to its leishmanicidal activity. The effect of this compound on cell cycle progression was confirmed by flow cytometry. We observed a significant increase of cells in the G1phase and a dramatic reduction of cells in the S phase compared to untreated cells. Altogether, our data suggest that the isoselenocyanate NISC-6 may be a promising candidate for new drug development against leishmaniasis.

Manipulation of the phenotype of immortalised rat hepatocytes by different culture configurations and by dimethyl sulphoxide

2000 ◽  
Vol 19 (5) ◽  
pp. 309-317 ◽  
Author(s):  
M I Grant ◽  
K Anderson ◽  
G McKay ◽  
M Wills ◽  
C Henderson ◽  
...  
Keyword(s):  
Primary Cultures ◽  
Toxicity Testing ◽  
Normal Liver ◽  
Rat Hepatocytes ◽  
In Vitro Toxicity ◽  
Collagen Gels ◽  
Testosterone Metabolism ◽  
Glutathione S Transferases ◽  
Cells Cultured

The liver-specific phenotype of immortalised rat hepato-cytes is not irretrievably lost as they age in culture but can be manipulated by modifying the culture environment. Testosterone metabolism was used to investigate the profile of cytochrome P450 isoenzymes present in two immortalised cell lines, P9 and LQC, and in primary cultures of rat hepatocytes, cultured on collagen films, gels and double gel cultures (sandwich configuration). The extent of testosterone metabolism, and the range of metabolites produced, was increased in immortalised cells by the presence of collagen as a substratum film or gel but survival was poorer and the range of metabolites was reduced in sandwich culture. In contrast, testosterone metabolism was retained in primary hepatocytes in sandwich cultures at a higher level than in collagen film or gel cultures. Expression of alpha class glutathione-S-transferases (GSTs) increased and that of GSTP1 decreased (changes which indicate a recovery of normal liver GST phenotype) when the medium of immortalised cell cultures was supplemented with dimethyl sulph-oxide (DMSO). DMSO also improved ethoxyresorufin 0-deethylation (EROD) and testosterone metabolism in immortalised cells. It also markedly inhibited prolifera-tion, DNA, RNA and protein synthesis. Maximal testosterone metabolism was observed in immortalised cells cultured on collagen gels in the presence of l1o (v/v) DMSO. Development of a protocol for treating immortalised liver cells cultured on collagen gels with DMSO to switch between proliferation and differentiation may provide a convenient system expres-sing the xenobiotic metabolising enzymes required for in vitro toxicity testing.

scholarly journals Leishmanicidal Activity of Nine Novel Flavonoids fromDelphinium staphisagria

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Inmaculada Ramírez-Macías ◽  
Clotilde Marín ◽  
Jesús G. Díaz ◽  
María José Rosales ◽  
Ramón Gutiérrez-Sánchez ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Mammalian Cells ◽  
Mechanisms Of Action ◽  
Reference Drug ◽  
Ultrastructural Alteration ◽  
Leishmanicidal Activity ◽  
Design And Methods ◽  
Electronic Microscope ◽  
Intracellular Amastigote

Objectives. To evaluate thein vitroleishmanicidal activity of nine flavonoid derivatives fromDelphinium staphisagriaagainstL. infantumandL. braziliensis.Design and Methods. Thein vitroactivity of compounds1–9was assayed on extracellular promastigote and axenic amastigote forms and on intracellular amastigote forms of the parasites. Infectivity and cytotoxicity tests were carried on J774.2 macrophage cells using Glucantime as the reference drug. The mechanisms of action were analysed performing metabolite excretion and transmission electronic microscope ultrastructural alteration studies.Results. Nine flavonoids showed leishmanicidal activity against promastigote as well as amastigote forms ofLeishmania infantumandL. braziliensis. These compounds were nontoxic to mammalian cells and were effective at similar concentrations up to or lower than that of the reference drug (Glucantime). The results showed that2″-acetylpetiolaroside (compound8) was clearly the most active.Conclusion. This study has demonstrated that flavonoid derivatives are active againstL. infantumandL. braziliensis.

scholarly journals Intracellular Growth of Legionella pneumophila Gives Rise to a Differentiated Form Dissimilar to Stationary-Phase Forms

2002 ◽  
Vol 70 (11) ◽  
pp. 6273-6283 ◽  
Author(s):  
Rafael A. Garduño ◽  
Elizabeth Garduño ◽  
Margot Hiltz ◽  
Paul S. Hoffman
Keyword(s):  
Stationary Phase ◽  
Hela Cells ◽  
Legionella Pneumophila ◽  
Protein A ◽  
Plaque Assay ◽  
Growth Cycle ◽  
Potential Marker ◽  
Legionnaires Disease

ABSTRACT When Legionella pneumophila grows in HeLa cells, it alternates between a replicative form and a morphologically distinct “cyst-like” form termed MIF (mature intracellular form). MIFs are also formed in natural amoebic hosts and to a lesser extent in macrophages, but they do not develop in vitro. Since MIFs accumulate at the end of each growth cycle, we investigated the possibility that they are in vivo equivalents of stationary-phase (SP) bacteria, which are enriched for virulence traits. By electron microscopy, MIFs appeared as short, stubby rods with an electron-dense, laminar outer membrane layer and a cytoplasm largely occupied by inclusions of poly-β-hydroxybutyrate and laminations of internal membranes originating from the cytoplasmic membrane. These features may be responsible for the bright red appearance of MIFs by light microscopy following staining with the phenolic Giménez stain. In contrast, SP bacteria appeared as dull red rods after Giménez staining and displayed a typical gram-negative cell wall ultrastructure. Outer membranes from MIFs and SP bacteria were equivalent in terms of the content of the peptidoglycan-bound and disulfide bond cross-linked OmpS porin, although additional proteins, including Hsp60 (which acts as an invasin for HeLa cells), were detected only in preparations from MIFs. Proteomic analysis revealed differences between MIFs and SP forms; in particular, MIFs were enriched for an ∼20-kDa protein, a potential marker of development. Compared with SP bacteria, MIFs were 10-fold more infectious by plaque assay, displayed increased resistance to rifampin (3- to 5-fold) and gentamicin (10- to 1,000-fold), resisted detergent-mediated lysis, and tolerated high pH. Finally, MIFs had a very low respiration rate, consistent with a decreased metabolic activity. Collectively, these results suggest that intracellular L. pneumophila differentiates into a cyst-like, environmentally resilient, highly infectious, post-SP form that is distinct from in vitro SP bacteria. Therefore, MIFs may represent the transmissible environmental forms associated with Legionnaires' disease.

scholarly journals Synthesis and Leishmanicidal Activity of Novel Urea, Thiourea, and Selenourea Derivatives of Diselenides

2019 ◽  
Vol 63 (5) ◽  
Author(s):  
Marta Díaz ◽  
Héctor de Lucio ◽  
Esther Moreno ◽  
Socorro Espuelas ◽  
Carlos Aydillo ◽  
...  
Keyword(s):  
Trypanothione Reductase ◽  
Standard Drug ◽  
Reference Drug ◽  
Content Type ◽  
Leishmanicidal Activity ◽  
Intracellular Amastigotes ◽  
Axenic Amastigotes ◽  
Structure Activity ◽  
Derivatives Of

ABSTRACT A novel series of thirty-one N-substituted urea, thiourea, and selenourea derivatives containing diphenyldiselenide entities were synthesized, fully characterized by spectroscopic and analytical methods, and screened for their in vitro leishmanicidal activities. The cytotoxic activity of these derivatives was tested against Leishmania infantum axenic amastigotes, and selectivity was assessed in human THP-1 cells. Thirteen of the synthesized compounds showed a significant antileishmanial activity, with 50% effective concentration (EC50) values lower than that for the reference drug miltefosine (EC50, 2.84 μM). In addition, the derivatives 9, 11, 42, and 47, with EC50 between 1.1 and 1.95 μM, also displayed excellent selectivity (selectivity index ranged from 12.4 to 22.7) and were tested against infected macrophages. Compound 11, a derivative with a cyclohexyl chain, exhibited the highest activity against intracellular amastigotes, with EC50 values similar to those observed for the standard drug edelfosine. Structure-activity relationship analyses revealed that N-aliphatic substitution in urea and selenourea is recommended for the leishmanicidal activity of these analogs. Preliminary studies of the mechanism of action for the hit compounds was carried out by measuring their ability to inhibit trypanothione reductase. Even though the obtained results suggest that this enzyme is not the target for most of these derivatives, their activity comparable to that of the standards and lack of toxicity in THP-1 cells highlight the potential of these compounds to be optimized for leishmaniasis treatment.

The Use of Human Lymphocytes for the In Vitro Estimation of Acute Toxicity of Ten Chemicals from the MEIC List

1991 ◽  
Vol 19 (2) ◽  
pp. 187-190
Author(s):  
Mette Tingleff Skaanild ◽  
Jørgen Clausen
Keyword(s):  
Hela Cells ◽  
Cultured Cells ◽  
Human Lymphocytes ◽  
Primary Cultures ◽  
Biological Significance ◽  
In Vitro Cytotoxicity ◽  
In Vitro Toxicity ◽  
Human Hepatoma Cells ◽  
Response Curves

The acute cytotoxicity of ten chemicals included in the MEIC (multicentre evaluation of in vitro cytotoxicity) list has already been estimated in various cell lines, e.g. primary rat hepatocytes, HeLa cells, human hepatoma cells, and 3T3 and mouse fibroma cells. In the present study, primary cultures of human lymphocytes, with or without an S9-mix (microsomes), were used to assay for in vitro toxicity. The cultured cells were initially treated with different concentrations of the respective drugs for 24 hours. Then cellular enzymatic activity was estimated using two assay systems, namely, measurement of cytosolic LDH activity and the mitochondrial (diaphorase) MTT test. Since the biological significance of the assay of LC50 values is dependent upon the slope of the dose-response curves, the results are expressed as LC20, LC50 and LC80 values in μM for the ten drugs. A Spearman rank correlation analysis revealed a significant correlation between the results from the two assays in both cell culture systems (r=1.00 and r=0.99). The LC50 values found in the lymphocyte cultures, both with and without an S9-mix, correlated well with the results previously found using primary cultures of hepatocytes and HeLa cells.

scholarly journals Synthesis and Biological Profiles of Some Benzimidazolyl-chalcones as Anti-leishmanial and Trypanocidal Agents

2021 ◽  
pp. 47-56
Author(s):  
D. U. J-P. N'Guessan ◽  
L. A. C. Kablan ◽  
A. Kacou ◽  
C. Bories ◽  
S. Coulibaly ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Leishmania Donovani ◽  
Parasite Growth ◽  
Drug Candidate ◽  
Trypanosoma Brucei Brucei ◽  
Reference Drug ◽  
Starting Point ◽  
Ic50 Values ◽  
Chlorine Derivative

Background: Benzimidazole constitutes a starting point for the development of new antiprotozoal agents since this nucleus exists in several pharmacologically significant molecules, in particular possessing antifungal, antiviral, antibacterial, and antiparasitic properties. Objective: The present study aimed to identify a molecular hit likely to be developed as an anti-leishmanial and antitrypanosomal drug candidate. Methods: Thus, 12 hybrids of chalcone or benzimidazolyl-arylpropenones were synthesized and screened in vitro for anti-leishmanial activity against promastigotes of Leishmania donovani. The microculture tetrazolium assay was used to determine their potential to inhibit 50% of a parasite growth (IC50). Results: Two compounds among 5-chlorobenzimidazole-chalcones (4a and 4c), which exhibited potent activity (IC50<1 μM) against L. donovani and one derivative (4d) poorly effective against L. donovani (IC50>50 μM) were selected to check their trypanocidal activity. Lethal concentration (LC100) values of these compounds were estimated by using observations on the viability of trypomastigotes of Trypanosoma brucei brucei in MEM medium with Earle’s salts and L-glutamine. Seven of the tested compounds (4a, 4b, 4c, 4e, 4g, 4h, and 4j) showed particularly higher inhibitory activity than pentamidine (IC50= 7.6 μM) against L. donovani promastigotes with IC50 values in a range from 0.5 to 1.8 μM. In addition, the 2’-chlorine derivative (4c), displayed potent anti-trypanosomal activity comparable to those of melarsoprol, used as reference drug. Conclusion: These results support this series of benzimidazole holding arylpropenone group in position 2 as a starting point for future optimization to get novel agents active against leishmaniasis and trypanosomiasis.

Human liver cell cultivation for long-term in vitro toxicity studies in a miniaturized multi-compartment 3D bioreactor system

2011 ◽  
Vol 49 (01) ◽  
Author(s):  
SA Hoffmann ◽  
M Lübberstedt ◽  
U Müller-Vieira ◽  
D Knobeloch ◽  
A Nüssler ◽  
...  
Keyword(s):  
Liver Cell ◽  
Human Liver ◽  
In Vitro Toxicity ◽  
Cell Cultivation ◽  
Toxicity Studies ◽  
Human Liver Cell ◽  
Bioreactor System
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