Activity profile of two 5-nitroindazole derivatives over the moderately drug-resistant Trypanosoma cruzi Y strain (DTU TcII): in vitro and in vivo studies

AbstractIn previous studies, we have identified several families of 5-nitroindazole derivatives as promising antichagasic prototypes. Among them, 1-(2-aminoethyl)-2-benzyl-5-nitro-1,2-dihydro-3H-indazol-3-one, (hydrochloride) and 1-(2-acetoxyethyl)-2-benzyl-5-nitro-1,2-dihydro-3H-indazol-3-one (compounds 16 and 24, respectively) have recently shown outstanding activity in vitro over the drug-sensitive Trypanosoma cruzi CL strain (DTU TcVI). Here, we explored the activity of these derivatives against the moderately drug-resistant Y strain (DTU TcII), in vitro and in vivo. The outcomes confirmed their activity over replicative forms, showing IC50 values of 0.49 (16) and 5.75 μm (24) towards epimastigotes, 0.41 (16) and 1.17 μm (24) against intracellular amastigotes. These results, supported by the lack of toxicity on cardiac cells, led to better selectivities than benznidazole (BZ). Otherwise, they were not as active as BZ in vitro against the non-replicative form of the parasite, i.e. bloodstream trypomastigotes. In vivo, acute toxicity assays revealed the absence of toxic events when administered to mice. Moreover, different therapeutic schemes pointed to their capability for decreasing the parasitaemia of T. cruzi Y acute infected mice, reaching up to 60% of reduction at the peak day as monotherapy (16), 79.24 and 91.11% when 16 and 24 were co-administered with BZ. These combined therapies had also a positive impact over the mortality, yielding survivals of 83.33 and 66.67%, respectively, while untreated animals reached a cumulative mortality of 100%. These findings confirm the 5-nitroindazole scaffold as a putative prototype for developing novel drugs potentially applicable to the treatment of Chagas disease and introduce their suitability to act in combination with the reference drug.

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In Vitro and In Vivo Activities of E5700 and ER-119884, Two Novel Orally Active Squalene Synthase Inhibitors, against Trypanosoma cruzi

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.7.2379-2387.2004 ◽

2004 ◽

Vol 48 (7) ◽

pp. 2379-2387 ◽

Cited By ~ 62

Author(s):

Julio A. Urbina ◽

Juan Luis Concepcion ◽

Aura Caldera ◽

Gilberto Payares ◽

Cristina Sanoja ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Public Health Problem ◽

Squalene Synthase ◽

Host Cells ◽

In Vivo Studies ◽

Inorganic Pyrophosphate ◽

Orally Active

ABSTRACT Chagas' disease is a serious public health problem in Latin America, and no treatment is available for the prevalent chronic stage. Its causative agent, Trypanosoma cruzi, requires specific endogenous sterols for survival, and we have recently demonstrated that squalene synthase (SQS) is a promising target for antiparasitic chemotherapy. E5700 and ER-119884 are quinuclidine-based inhibitors of mammalian SQS that are currently in development as cholesterol- and triglyceride-lowering agents in humans. These compounds were found to be potent noncompetitive or mixed-type inhibitors of T. cruzi SQS with K i values in the low nanomolar to subnanomolar range in the absence or presence of 20 μM inorganic pyrophosphate. The antiproliferative 50% inhibitory concentrations of the compounds against extracellular epimastigotes and intracellular amastigotes were ca. 10 nM and 0.4 to 1.6 nM, respectively, with no effects on host cells. When treated with these compounds at the MIC, all of the parasite's sterols disappeared from the parasite cells. In vivo studies indicated that E5700 was able to provide full protection against death and completely arrested the development of parasitemia when given at a concentration of 50 mg/kg of body weight/day for 30 days, while ER-119884 provided only partial protection. This is the first report of an orally active SQS inhibitor that is capable of providing complete protection against fulminant, acute Chagas' disease.

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Prosopis Plant Chemical Composition and Pharmacological Attributes: Targeting Clinical Studies from Preclinical Evidence

Biomolecules ◽

10.3390/biom9120777 ◽

2019 ◽

Vol 9 (12) ◽

pp. 777 ◽

Cited By ~ 1

Author(s):

Javad Sharifi-Rad ◽

Farzad Kobarfard ◽

Athar Ata ◽

Seyed Abdulmajid Ayatollahi ◽

Nafiseh Khosravi-Dehaghi ◽

...

Keyword(s):

Chemical Composition ◽

Clinical Studies ◽

Positive Impact ◽

Biological Effects ◽

Food Supplement ◽

In Vivo Studies ◽

Plant Chemical ◽

Food Applications

Members of the Prosopis genus are native to America, Africa and Asia, and have long been used in traditional medicine. The Prosopis species most commonly used for medicinal purposes are P. africana, P. alba, P. cineraria, P. farcta, P. glandulosa, P. juliflora, P. nigra, P. ruscifolia and P. spicigera, which are highly effective in asthma, birth/postpartum pains, callouses, conjunctivitis, diabetes, diarrhea, expectorant, fever, flu, lactation, liver infection, malaria, otitis, pains, pediculosis, rheumatism, scabies, skin inflammations, spasm, stomach ache, bladder and pancreas stone removal. Flour, syrup, and beverages from Prosopis pods have also been potentially used for foods and food supplement formulation in many regions of the world. In addition, various in vitro and in vivo studies have revealed interesting antiplasmodial, antipyretic, anti-inflammatory, antimicrobial, anticancer, antidiabetic and wound healing effects. The phytochemical composition of Prosopis plants, namely their content of C-glycosyl flavones (such as schaftoside, isoschaftoside, vicenin II, vitexin and isovitexin) has been increasingly correlated with the observed biological effects. Thus, given the literature reports, Prosopis plants have positive impact on the human diet and general health. In this sense, the present review provides an in-depth overview of the literature data regarding Prosopis plants’ chemical composition, pharmacological and food applications, covering from pre-clinical data to upcoming clinical studies.

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Arsenic Trioxide Shows Synergistic Anti-Myeloma Effects When Combined with Bortezomib and Melphalan In Vitro and Helps Overcome Resistance of Multiple Myeloma Cells to These Treatments in Vivo.

Blood ◽

10.1182/blood.v104.11.2467.2467 ◽

2004 ◽

Vol 104 (11) ◽

pp. 2467-2467

Author(s):

Richard A. Campbell ◽

Haiming Chen ◽

Daocheng Zhu ◽

Janice C. Santos ◽

Benjamin Bonavida ◽

...

Keyword(s):

Arsenic Trioxide ◽

Cell Lines ◽

Combined Therapy ◽

In Vivo Studies ◽

Low Doses ◽

Drug Resistant ◽

Early Results ◽

Post Implantation

Abstract Arsenic trioxide (ATO) induces apoptosis of plasma cells through a number of mechanisms including inhibiting DNA binding by NF-κB. These results suggest that this agent may be synergistic when combined with other active anti-myeloma drugs. To evaluate this we examined the effect of ATO alone and in combination with anti-myeloma treatments evaluated in vitro with MTT assays and using our severe combined immunodeficient (SCID)-hu murine myeloma models. First, we determined the effects of combining ATO with bortezomib or melphalan on the myeloma cell lines RPMI8226 and U266. Cell proliferation assays demonstrated marked synergistic anti-proliferative effects of ATO at concentrations ranging from 5x10−5M – 5x10−9M and melphalan concentrations ranging from 3x10−5M – 3x10−9M. Similar effects were observed when these cell lines were treated with bortezomib and varying concentrations of ATO (5x10−5 M – 5x10−10 M). We also investigated the potential of ATO to increase the efficacy of anti-myeloma therapies in our SCID-hu murine model LAGλ–1 (Yang H et al. Blood 2002). Each SCID mouse was implanted with a 0.5 cm3 LAGλ–1 tumor fragment into the left hind limb muscle. Mice were treated with ATO alone at 6.0 mg/kg, 1.25 mg/kg, 0.25 mg/kg, and 0.05 mg/kg intraperitoneally (IP) daily x5/week starting 19 days post-implantation. Mice receiving the highest dose of ATO (6.0 mg/kg) showed marked inhibition of tumor growth and reduction of paraprotein levels while there was no effect observed in all other treatment groups. Next, 27 days following implantation of our LAGλ–1 intramuscular (IM) tumor, LAGλ–1 mice were treated with ATO (1.25 mg/kg) IP, bortezomib (0.25 mg/kg), or the combination of both drugs at these doses in the schedules outlined above. ATO or bortezomib treatment alone had no anti-myeloma effects at these low doses consistent with our previous results whereas there was a marked decrease in both tumor volume (57%) and paraprotein levels (53%) in mice receiving the combined therapy. The combination of melphalan and ATO was also evaluated in this model. LAGλ–1 bearing mice received therapy with melphalan IP x1/weekly at 12.0 mg/kg, 6.0 mg/kg, 0.6 mg/kg, and 0.06 mg/kg starting 22 days post-implantation and showed no anti-myeloma effects. Twenty-eight days following implantation of LAGλ–1 tumor, mice received ATO (1.25 mg/kg) or melphalan (0.6 mg/kg) alone at doses without anti-myeloma effects, or the combination of these agents at these doses. The animals treated with these drugs alone showed a similar growth and increase in paraprotein levels to control mice whereas the combination of ATO and melphalan at these low doses markedly suppressed the growth of the tumor by >50% and significantly reduced serum paraprotein levels. These in vitro and in vivo studies suggest that the addition of ATO to other anti-myeloma agents is likely to result in improved outcomes for patients with drug resistant myeloma. Based on these results, these combinations are now in clinical trials with promising early results for patients with drug resistant myeloma.

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Repositioning FDA Drugs as Potential Cruzain Inhibitors from Trypanosoma cruzi: Virtual Screening, In Vitro and In Vivo Studies

Molecules ◽

10.3390/molecules22061015 ◽

2017 ◽

Vol 22 (6) ◽

pp. 1015 ◽

Cited By ~ 14

Author(s):

Isidro Palos ◽

Edgar E. Lara-Ramirez ◽

Julio Cesar Lopez-Cedillo ◽

Carlos Garcia-Perez ◽

Muhammad Kashif ◽

...

Keyword(s):

Virtual Screening ◽

Trypanosoma Cruzi ◽

In Vivo Studies ◽

Screening In Vitro ◽

Cruzain Inhibitors

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Developing an antibiotic effective against multi-drug resistant bacteria.

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314092857 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C714-C714

Author(s):

Calvin Steussy ◽

Cynthia Stauffacher ◽

Mark Lipton ◽

Mohamed Seleem

Keyword(s):

Pathogenic Bacteria ◽

Modern Medicine ◽

In Vivo Studies ◽

Resistant Bacteria ◽

Drug Resistant ◽

Lead Compound ◽

Drug Resistant Bacteria ◽

Coa Reductase

The emergence of multi-drug resistant pathogenic bacteria is one of the great challenges to modern medicine. The gram positive cocci Methicillin Resistant Staphylococcus aureus (MRSA) and Vancomycin Resistant Enterococcus faecalis (VRE) are two particularly virulent examples. In vivo studies have shown that the eukaryotic like 'mevalonate' isoprenoid pathway used by these pathogenic cocci is essential to their growth and virulence [1]. Our structures of HMG-CoA reductase (HMGR) from P. mevalonii demonstrated that the bacterial enzymes are structurally distinct from the human enzymes allowing for specific antibacterial activity [2]. High throughput in vitro screening against bacterial HMGR at the Southern Research Center, Birmingham, AL uncovered a lead compound with an IC50 of 80 µM with a competitive mode of action. Our x-ray crystal structures of HMGR from E. faecalis complexed with the lead compound and its variations have informed the synthesis of new inhibitors that have improved the IC50 to 5 µM [3]. Studies of this compound show it to be active against both MRSA and VRE in culture, effective against these bacteria in biofilms, and efficacious in a model system of eukaryotic infection. Structures and kinetics of these compounds will be presented and future directions discussed.

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Coumarins and Quinolones as Effective Multiple Targeted Agents Versus Covid-19: An in Silico Study

Medicinal Chemistry ◽

10.2174/1573406417666210208223924 ◽

2021 ◽

Vol 17 ◽

Author(s):

Mojgan Nejabat ◽

Razieh Ghodsi ◽

Farzin Hadizadeh

Keyword(s):

Binding Affinity ◽

In Silico ◽

Oral Absorption ◽

Antiviral Agent ◽

In Vivo Studies ◽

Reference Drug ◽

Viral Proteases ◽

In Silico Study

Background: The Covid-19 virus emerged a few months ago in China and infections rapidly escalated into a pandemic. Objective: To date, there is no selective antiviral agent for the management of pathologies associated with covid-19 and the need for an effective agent against it is essential. Method: In this work two home-made databases from synthetic quinolines and coumarins were virtually docked against viral proteases (3CL and PL), human cell surface proteases (TMPRSS2 and furin) and spike proteins (S1 and S2). Chloroquine, a reference drug without a clear mechanism against coronavirus was also docked on mentioned targets and the binding affinities compared with title compounds. Result: The best compounds of synthetic coumarins and quinolines for each target were determined. All compounds against all targets showed binding affinity between -5.80 to -8.99 kcal/mol in comparison with the FDA-approved drug, Chloroquine, with binding affinity of -5.7 to -7.98 kcal/mol. Two compounds, quinoline-1 and coumarin-24, were found to be effective on three targets – S2, TMPRSS2 and furin – simultaneously, with good predicted affinity between -7.54 to -8.85 kcal/mol. In silico ADME studies also confirmed good oral absorption for them. Furthermore, PASS prediction was calculated and coumarin-24 had higher probable activity (Pa) than probable inactivity (Pi) with acceptable protease inhibitory as well as good antiviral activity against Hepatitis C virus (HCV), Human immunodeficiency virus (HIV) and influenza. Conclusion: Quinoline-1 and Coumarin-24 have the potential to be used against Covid-19. Hence these agents could be useful in combating covid-19 infection after further in vitro and in vivo studies.

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In Vitro and In Vivo Studies of the Trypanocidal Effect of Novel Quinolines

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01936-17 ◽

2017 ◽

Vol 62 (2) ◽

Cited By ~ 5

Author(s):

A. S. G. Nefertiti ◽

M. M. Batista ◽

P. B. Da Silva ◽

D. G. J. Batista ◽

C. F. Da Silva ◽

...

Keyword(s):

Parasite Species ◽

Oral Absorption ◽

In Vivo Studies ◽

Cure Rate ◽

Reference Drug ◽

Content Type ◽

African Trypanosomes ◽

Highly Active

ABSTRACT Therapies for human African trypanosomiasis and Chagas disease, caused by Trypanosoma brucei and Trypanosoma cruzi, respectively, are limited, providing minimal therapeutic options for the millions of individuals living in very poor communities. Here the effects of 10 novel quinolines are evaluated in silico and by phenotypic studies using in vitro and in vivo models. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties revealed that most molecules did not infringe on Lipinski's rules, which is a prediction of good oral absorption. These quinolines showed high probabilities of Caco2 permeability and human intestinal absorption and low probabilities of mutagenicity and of hERG1 inhibition. In vitro screens against bloodstream forms of T. cruzi demonstrated that all quinolines were more active than the reference drug (benznidazole [Bz]), except for DB2171 and DB2192, with five (DB2187, DB2131, DB2186, DB2191, and DB2217) displaying 50% effective concentrations (EC50s) of <3 μM (4-fold lower than that of Bz). Nine quinolines were more effective than Bz (2.7 μM) against amastigotes, showing EC50s ranging from 0.6 to 0.1 μM. All quinolines were also highly active in vitro against African trypanosomes, showing EC50s of ≤0.25 μM. The most potent and highly selective candidates for each parasite species were tested in in vivo models. Results for DB2186 were promising in mice with T. cruzi and T. brucei infections, reaching a 70% reduction of the parasitemia load for T. cruzi, and it cured 2 out of 4 mice infected with T. brucei. DB2217 was also active in vivo and cured all 4 mice (100% cure rate) with T. brucei infection.

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