scholarly journals Identification of New Antileishmanial Leads from Hits Obtained by High-Throughput Screening

2011 ◽  
Vol 56 (3) ◽  
pp. 1182-1189 ◽  
Author(s):  
Xiaohua Zhu ◽  
Trupti Pandharkar ◽  
Karl Werbovetz
Keyword(s):  
High Throughput Screening ◽  
Leishmania Major ◽  
Vero Cells ◽  
Cyanine Dye ◽  
Control Group ◽  
Content Type ◽  
Lead Compounds ◽  
Pubchem Database ◽  
Low Cytotoxicity

ABSTRACTA previous screen of ∼200,000 compounds from the PubChem database identified 70 compounds possessing 50% effective concentrations (EC50s) below 1 μM againstLeishmania majorpromastigotes that were not toxic to mammalian epithelial cancer cells at this concentration (E. Sharlow et al., PLoS Negl. Trop. Dis. 3:e540, 2009). Based on availability and chemical exclusion criteria, 31 of these compounds were purchased from commercial suppliers and evaluated forin vitroactivity against intracellularL. donovaniandL. amazonensisparasites. Benzothiazole cyanine compounds (PubChem 16196319 and 16196223) displayed potent activity against intracellular amastigotes, prompting a search for commercially available compounds that were structurally related. Pubchem 123859 (the cyanine dye thiazole orange) showed exceptionally potent activity against intracellularL. donovani in vitro(50% inhibitory concentration [IC50] = 21 ± 12 nM) and low cytotoxicity against Vero cells (IC50= 7,800 ± 200 nM). Administration of 123859 and 16196319 at a dose of 1 mg/kg of body weight intraperitoneally (i.p.) daily for 5 days resulted in 44% ± 4% and 42% ± 3% suppression of liver parasitemia inL. donovani-infected BALB/c mice, respectively, compared to the untreated control group (the reductions in liver parasitemia were 30% ± 5% and 27% ± 4%, respectively, compared to the (2-hydroxypropyl)-β-cyclodextrin solution (HPβCD) vehicle control, which itself displayed some antileishmanial activity). Benzothiazole-containing cyanine dyes are thus potential lead compounds for the discovery of novel antileishmanial agents.

scholarly journals Significant Reduction of Brain Cysts Caused by Toxoplasma gondii after Treatment with Spiramycin Coadministered with Metronidazole in a Mouse Model of Chronic Toxoplasmosis

2012 ◽  
Vol 56 (4) ◽  
pp. 1762-1768 ◽  
Author(s):  
Wai Kit Chew ◽  
Ignacio Segarra ◽  
Stephen Ambu ◽  
Joon Wah Mak
Keyword(s):  
Toxoplasma Gondii ◽  
Vero Cells ◽  
Toxoplasmic Encephalitis ◽  
Combination Group ◽  
Control Group ◽  
Time Curve ◽  
Content Type ◽  
Brain Cysts ◽  
The Brain

ABSTRACTToxoplasma gondiiis a parasite that generates latent cysts in the brain; reactivation of these cysts may lead to fatal toxoplasmic encephalitis, for which treatment remains unsuccessful. We assessed spiramycin pharmacokinetics coadministered with metronidazole, the eradication of brain cysts and thein vitroreactivation. Male BALB/c mice were fed 1,000 tachyzoites orally to develop chronic toxoplasmosis. Four weeks later, infected mice underwent different treatments: (i) infected untreated mice (n= 9), which received vehicle only; (ii) a spiramycin-only group (n= 9), 400 mg/kg daily for 7 days; (iii) a metronidazole-only group (n= 9), 500 mg/kg daily for 7 days; and (iv) a combination group (n= 9), which received both spiramycin (400 mg/kg) and metronidazole (500 mg/kg) daily for 7 days. An uninfected control group (n= 10) was administered vehicle only. After treatment, the brain cysts were counted, brain homogenates were cultured in confluent Vero cells, and cysts and tachyzoites were counted after 1 week. Separately, pharmacokinetic profiles (plasma and brain) were assessed after a single dose of spiramycin (400 mg/kg), metronidazole (500 mg/kg), or both. Metronidazole treatment increased the brain spiramycin area under the concentration-time curve from 0 h to ∞ (AUC0–∞) by 67% without affecting its plasma disposition. Metronidazole plasma and brain AUC0–∞values were reduced 9 and 62%, respectively, after spiramycin coadministration. Enhanced spiramycin brain exposure after coadministration reduced brain cysts 15-fold (79 ± 23 for the combination treatment versus 1,198 ± 153 for the untreated control group [P< 0.05]) and 10-fold versus the spiramycin-only group (768 ± 125). Metronidazole alone showed no effect (1,028 ± 149). Tachyzoites were absent in the brain. Spiramycin reducedin vitroreactivation. Metronidazole increased spiramycin brain penetration, causing a significant reduction ofT. gondiibrain cysts, with potential clinical translatability for chronic toxoplasmosis treatment.

Substituted Furanocoumarins as Novel Class of Antibacterial Translation Inhibitors

2019 ◽  
Vol 22 (6) ◽  
pp. 400-410
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Andrey A. Ayginin ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
High Throughput Screening ◽  
Luciferase Assay ◽  
Cytotoxicity Test ◽  
Reporter System ◽  
Lead Compounds ◽  
High Antibacterial Activity ◽  
Low Cytotoxicity ◽  
Screening Platform

Introduction: A variety of organic compounds has been reported to have antibacterial activity. However, antimicrobial resistance is one of the main problems of current anti-infective therapy, and the development of novel antibacterials is one of the main challenges of current drug discovery. Methods: Using our previously developed dual-reporter High-Throughput Screening (HTS) platform, we identified a series of furanocoumarins as having high antibacterial activity. The construction of the reporter system allows us to differentiate three mechanisms of action for the active compounds: inhibition of protein synthesis (induction of Katushka2S), DNA damaging (induction of RFP) or other (inhibition of bacterial growth without reporter induction). Results: Two primary hit-molecules of furanocoumarin series demonstrated relatively low MIC values comparable to that observed for Erythromycin (Ery) against E. coli and weakly induced both reporters. Dose-dependent translation inhibition was shown using in vitro luciferase assay, however it was not confirmed using C14-test. A series of close structure analogs of the identified hits was obtained and investigated using the same screening platform. Compound 19 was found to have slightly lower MIC value (15.18 µM) and higher induction of Katushka2S reporter in contrast to the parent structures. Moreover, translation blockage was clearly identified using both in vitro luciferase assay and C14 test. The standard cytotoxicity test revealed a relatively low cytotoxicity of the most active molecules. Conclusion: High antibacterial activity in combination with low cytotoxicity was demonstrated for a series of furanocoumarins. Further optimization of the described structures may result in novel and attractive lead compounds with promising antibacterial efficiency.

scholarly journals Gallic and Ellagic Acids Are Promising Adjuvants to Conventional Amphotericin B for the Treatment of Cutaneous Leishmaniasis

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Michel Muálem de Moraes Alves ◽  
Daniel Dias Rufino Arcanjo ◽  
Kayo Alves Figueiredo ◽  
Jéssica Sara de Sousa Macêdo Oliveira ◽  
Felipe José Costa Viana ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Amphotericin B ◽  
Leishmania Major ◽  
Negative Control ◽  
Control Group ◽  
Histopathological Analysis ◽  
Activated Macrophages ◽  
Content Type

ABSTRACT In this study, we demonstrated the potential associative effect of combining conventional amphotericin B (Amph B) with gallic acid (GA) and with ellagic acid (EA) in topical formulations for the treatment of cutaneous leishmaniasis in BALB/c mice. Preliminary stability tests of the formulations and in vitro drug release studies with Amph B, GA, Amph B plus GA, EA, and Amph B plus EA were carried out, as well as assessment of the in vivo treatment of BALB/c mice infected with Leishmania major. After 40 days of infection, the animals were divided into 6 groups and treated twice a day for 21 days with a gel containing Amph B, GA, Amph B plus GA, EA, or Amph B plus EA, and the negative-control group was treated with the vehicle. In the animals that received treatment, there was reduction of the lesion size and reduction of the parasitic load. Histopathological analysis of the treatments with GA, EA, and combinations with Amph B showed circumscribed lesions with the presence of fibroblasts, granulation tissue, and collagen deposition, as well as the presence of activated macrophages. The formulations containing GA and EA activated macrophages in all evaluated parameters, resulting in the activation of cells of the innate immune response, which can generate healing and protection. GA and EA produced an associative effect with Amph B, which makes them promising for use with conventional Amph B in the treatment of cutaneous leishmaniasis.

scholarly journals In Vitro and In Vivo Characterization of Potent Antileishmanial Methionine Aminopeptidase 1 Inhibitors

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Felipe Rodriguez ◽  
Sarah F. John ◽  
Eva Iniguez ◽  
Sebastian Montalvo ◽  
Karina Michael ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Treatment Options ◽  
Parasite Load ◽  
Host Cells ◽  
Control Group ◽  
Severe Toxicity ◽  
Methionine Aminopeptidase ◽  
Content Type

ABSTRACT Leishmania major is the causative agent of cutaneous leishmaniasis (CL). No human vaccine is available for CL, and current drug regimens present several drawbacks, such as emerging resistance, severe toxicity, medium effectiveness, and/or high cost. Thus, the need for better treatment options against CL is a priority. In the present study, we validate the enzyme methionine aminopeptidase 1 of L. major (MetAP1Lm), a metalloprotease that catalyzes the removal of N-terminal methionine from peptides and proteins, as a chemotherapeutic target against CL infection. The in vitro antileishmanial activities of eight novel MetAP1 inhibitors (OJT001 to OJT008) were investigated. Three compounds, OJT006, OJT007, and OJT008, demonstrated potent antiproliferative effects in macrophages infected with L. major amastigotes and promastigotes at submicromolar concentrations, with no cytotoxicity against host cells. Importantly, the leishmanicidal effect in transgenic L. major promastigotes overexpressing MetAP1Lm was diminished by almost 10-fold in comparison to the effect in wild-type promastigotes. Furthermore, the in vivo activities of OJT006, OJT007, and OJT008 were investigated in L. major-infected BALB/c mice. In comparison to the footpad parasite load in the control group, OJT008 decreased the footpad parasite load significantly, by 86%, and exhibited no toxicity in treated mice. We propose MetAP1 inhibitor OJT008 as a potential chemotherapeutic candidate against CL infection caused by L. major infection.

Evaluating the Effect of Cinnarizine on Promastigotes and Amastigotes forms of Leishmania major

2020 ◽  
Vol 20 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Lima Asgharpour Sarouey ◽  
Parvaneh Rahimi-Moghaddam ◽  
Fatemeh Tabatabaie ◽  
Khadijeh Khanaliha
Keyword(s):  
Flow Cytometry ◽  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Inhibitory Effect ◽  
Control Group ◽  
Secondary Infections ◽  
Ic50 Values ◽  
J774 Cells ◽  
Mtt Assays

: As an important global disease, cutaneous leishmaniasis is associated with complications such as secondary infections and atrophic scars. The first line treatment with antimonials is expensive and reported to have serious side effects and enhance resistance development. The main objective of this study was to evaluate the effect of Cinnarizine on standard strains of Leishmania major because of paucity of information on this subject. Methods: In this experimental study, four concentrations of the drug (5, 10, 15 and 20 μg/ml) were added to Leishmania major cultures at 24, 48 and 72 hours intervals. MTT assays were performed to determine parasite viability and drug toxicity. Leishmania major promastigotes were augmented to the in vitro cultured macrophages (J774 cells) and then incubated for 72 hours. Half maximal inhibitory concentration (IC50) was ascertained by counting parasites. The inhibitory effect of the drug was compared with that of Glucantime. Flow-cytometry was performed to investigate apoptosis. Each test was repeated thrice. Results: The IC50 values of Cinnarizine after 72 hours were calculated to be 34.76 μg/ml and 23.73 μg/ml for promastigotes and amastigotes, respectively. The results of MTT assays showed 48 % promastigote viability after 72 hour-exposure to Cinnarizine at 20 μg/ml concentration. Programmed cell death in promastigote- and amastigote-infected macrophages was quantified to be 13.66 % and 98.7 %, respectively. Flow- cytometry analysis indicated that Cinnarizine induced early and late apoptosis in parasites. All treatments produced results which differed significantly from control group (P<0.05). Conclusion: Cinnarizine showed low toxicity with anti-leishmanial and apoptosis effects on both promastigote and intracellular amastigote forms. Therefore, we may suggest further assessment on animal models of this drug as candidates for cutaneous leishmaniasis therapy.

scholarly journals Pharmacological Basis of CD101 Efficacy: Exposure Shape Matters

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Elizabeth A. Lakota ◽  
Justin C. Bader ◽  
Voon Ong ◽  
Ken Bartizal ◽  
Lynn Miesel ◽  
...  
Keyword(s):  
Time Course ◽  
Fungicidal Activity ◽  
Control Group ◽  
Time Curve ◽  
Content Type ◽  
Treatment Groups ◽  
Concentration Time ◽  
Treatment Control Group ◽  
Pharmacological Basis

ABSTRACT CD101 is a novel echinocandin with concentration-dependent fungicidal activity in vitro and a long half-life (∼133 h in humans, ∼70 to 80 h in mice). Given these characteristics, it is likely that the shape of the CD101 exposure (i.e., the time course of CD101 concentrations) influences efficacy. To test this hypothesis, doses which produce the same total area under the concentration-time curve (AUC) were administered to groups of neutropenic ICR mice infected with Candida albicans R303 using three different schedules. A total CD101 dose of 2 mg/kg was administered as a single intravenous (i.v.) dose or in equal divided doses of either 1 mg/kg twice weekly or 0.29 mg/kg/day over 7 days. The studies were performed using a murine disseminated candidiasis model. Animals were euthanized at 168 h following the start of treatment. Fungi grew well in the no-treatment control group and showed variable changes in fungal density in the treatment groups. When the CD101 AUC from 0 to 168 h (AUC0–168) was administered as a single dose, a >2 log10 CFU reduction from the baseline at 168 h was observed. When twice-weekly and daily regimens with similar AUC values were administered, net fungal stasis and a >1 log10 CFU increase from the baseline were observed, respectively. These data support the hypothesis that the shape of the CD101 AUC influences efficacy. Thus, CD101 administered once per week demonstrated a greater degree of fungal killing than the same dose divided into twice-weekly or daily regimens.

In vitro synergistic interactions of oleanolic acid in combination with isoniazid, rifampicin or ethambutol against Mycobacterium tuberculosis

2010 ◽  
Vol 59 (5) ◽  
pp. 567-572 ◽  
Author(s):  
Fa Ge ◽  
Fanli Zeng ◽  
Siguo Liu ◽  
Na Guo ◽  
Haiqing Ye ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Oleanolic Acid ◽  
Antimycobacterial Activity ◽  
Vero Cells ◽  
Drug Resistant ◽  
Synergistic Interactions ◽  
Combination Treatments ◽  
Low Cytotoxicity ◽  
Drug Resistant Strains

Reports have shown that oleanolic acid (OA), a triterpenoid, exists widely in food, medicinal herbs and other plants, and that it has antimycobacterial activity against the Mycobacterium tuberculosis strain H37Rv (ATCC 27294). In this study it was found that OA had antimycobacterial properties against eight clinical isolates of M. tuberculosis and that the MICs of OA against drug-sensitive and drug-resistant isolates were 50–100 and 100–200 μg ml−1, respectively. The combination of OA with isoniazid (INH), rifampicin (RMP) or ethambutol (EMB) showed favourable synergistic antimycobacterial effects against six drug-resistant strains, with fractional inhibitory concentration indices of 0.121–0.347, 0.113–0.168 and 0.093–0.266, respectively. The combination treatments of OA/INH, OA/RMP and OA/EMB displayed either a synergistic interaction or did not show any interaction against two drug-sensitive strains. No antagonism resulting from the OA/INH, OA/RMP or OA/EMB combination was observed for any of the strains tested. OA exhibited a relatively low cytotoxicity in Vero cells. These results indicate that OA may serve as a promising lead compound for future antimycobacterial drug development.

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.

scholarly journals In vitro comparison of the cytotoxicity of different endodontic sealers; AH Plus, AdSeal, Endoseal MTA, and GuttaFlow Bioseal

2021 ◽  
Author(s):  
Mehdi Dastorani ◽  
Muhammad javad Aliee ◽  
Raheleh Halabian ◽  
Mostafa Solati ◽  
Mohammadsadegh Alemrajabi
Keyword(s):  
Repeated Measures ◽  
Negative Control Group ◽  
Negative Control ◽  
Control Group ◽  
Gingival Fibroblasts ◽  
Periapical Lesions ◽  
Ah Plus ◽  
Low Cytotoxicity ◽  
Endodontic Sealers

Abstract Background: This study aimed to assess the cytotoxicity of four commonly used endodontic sealers namely AH Plus, AdSeal, Endoseal MTA, and GuttaFlow Bioseal against human gingival fibroblasts (HGFs). Methods: After culturing the HGFs, they were exposed to the respective sealers in set form and in five different weights, after sterilization. The cytotoxicity of the sealers was evaluated after 1, 3 and 7 days using the methyl thiazolyl tetrazolium (MTT) assay. Data were analyzed by repeated measures ANOVA. Results: After 24 h, all sealers showed low cytotoxicity. However, all sealers in 250 mg and 500 mg weights showed significantly higher cytotoxicity than the negative control group at 72 h, and 7 days (P<0.05) except for AdSeal in 80 mg weight (P>0.05). AH Plus was significantly more cytotoxic than other sealers at 3 and 7 days (P<0.05) while AdSeal had the closest results to the negative control group, and showed significantly higher biocompatibility than other sealers in 250 mg concentration. Conclusion: AdSeal showed the highest biocompatibility while AH Plus had the highest cytotoxicity among the tested sealers. Thus, its application may delay the healing of periapical lesions.

scholarly journals Effect of Topical Liposomes Containing Paromomycin Sulfate in the Course of Leishmania major Infection in Susceptible BALB/c Mice

2009 ◽  
Vol 53 (6) ◽  
pp. 2259-2265 ◽  
Author(s):  
Mahmoud R. Jaafari ◽  
Neda Bavarsad ◽  
Bibi Sedigheh Fazly Bazzaz ◽  
Afshin Samiei ◽  
Dina Soroush ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Mouse Skin ◽  
Parasite Burden ◽  
Lesion Size ◽  
Control Group ◽  
In Vitro Permeation ◽  
Significant Difference ◽  
Pm 10 ◽  
Franz Diffusion Cells

ABSTRACT The aim of this study was to evaluate the antileishmanial effects of topical liposomal paromomycin sulfate (PM) in Leishmania major-infected BALB/c mice. Liposomes containing 10 or 15% PM (Lip-PM-10 and Lip-PM-15, respectively) were prepared by the fusion method and were characterized for their size and encapsulation efficiency. The penetration of PM from the liposomal PM formulations (LPMFs) through and into skin was evaluated in vitro with Franz diffusion cells fitted with mouse skin at 37°C for 8 h. The in vitro permeation data showed that almost 15% of the LPMFs applied penetrated the mouse skin, and the amount retained in the skin was about 60% for both formulations. The 50% effective doses of Lip-PM-10 and Lip-PM-15 against L. major promastigotes in culture were 65.32 and 59.73 μg/ml, respectively, and those against L. major amastigotes in macrophages were 24.64 and 26.44 μg/ml, respectively. Lip-PM-10 or Lip-PM-15 was used topically twice a day for 4 weeks to treat L. major lesions on BALB/c mice, and the results showed a significantly (P < 0.001) smaller lesion size in the mice in the treated groups than in the mice in the control group, which received either empty liposomes or phosphate-buffered saline (PBS). Eight weeks after the beginning of the treatment, every mouse treated with LPMFs was completely cured. The spleen parasite burden was significantly (P < 0.001) lower in mice treated with Lip-PM-10 or Lip-PM-15 than in mice treated with PBS or control liposomes, but no significant difference was seen between the two groups treated with either Lip-PM-10 or Lip-PM-15. The results suggest that topical liposomal PM may be useful for the treatment of cutaneous leishmaniasis.

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