Identification of Pyrazolo[3,4-e][1,4]thiazepin based CYP51 inhibitors as potential Chagas disease therapeutic alternative: In vitro and in vivo evaluation, binding mode prediction and SAR exploration

American trypanosomiasis or Chagas disease (CD) is a vector borne pathology caused by the parasite Trypanosoma cruzi (T. cruzi), which remains a serious global health problem. The current available treatment for CD is limited to two nitroderivatives with limited efficacy and several side effects. The rational design of ergosterol synthetic route inhibitors (e.g. CYP51 inhibitors) represents a promising strategy for fungi and trypanosomatids, exhibiting excellent anti-T.cruzi activity in pre-clinical assays. In the present work, we evaluate through different approaches (molecular docking, structure activity relationships, CYP51 inhibitory assay, and phenotypic screenings in vitro and in vivo) the potency and selectivity of a novel CYP51 inhibitor (compound 1) and its analogues against T.cruzi infection. Regarding anti-parasitic effect, compound 1 was active in vitro with EC50 3.86 and 4.00 μM upon intracellular (Tulahuen strain) and bloodstream forms (Y strain), respectively. In vivo assays showed that compound 1 reduced in 43% the parasitemia peak but, unfortunately failed to promote animal survival. In order to promote an enhancement at the potency and pharmacological properties, 17 new analogues were purchased and screened in vitro. Our findings demonstrated that five compounds were active against intracellular forms, highlighting compounds 1e and 1f, with EC50 2.20 and 2.70 μM, respectively, and selectivity indices (SI) = 50 and 36, respectively. Against bloodstream trypomastigotes, compound 1f reached an EC50 value of 20.62 μM, in a similar range to Benznidazole, but with low SI (3). Although improved the solubility of compound 1, the analogue 1f did not enhance the potency in vitro neither promote better in vivo efficacy against mouse model of acute T.cruzi infection arguing for the synthesis of novel pyrazolo[3,4-e][1,4]thiazepin derivatives aiming to contribute for alternative therapies for CD

In Vitro and In Vivo Investigation of the Efficacy of Arylimidamide DB1831 and Its Mesylated Salt Form - DB1965 - against Trypanosoma cruzi Infection

Chagas disease is caused by infection with the intracellular protozoan parasite Trypanosoma cruzi. At present, nifurtimox and benznidazole, both compounds developed empirically over four decades ago, represent the chemotherapeutic arsenal for treating this highly neglected disease. However, both drugs present variable efficacy depending on the geographical area and the occurrence of natural resistance, and are poorly effective against the later chronic stage. As a part of a search for new therapeutic opportunities to treat chagasic patients, pre-clinical studies were performed to characterize the activity of a novel arylimidamide (AIA - DB1831 (hydrochloride salt) and DB1965 (mesylate salt)) against T.cruzi. These AIAs displayed a high trypanocidal effect in vitro against both relevant forms in mammalian hosts, exhibiting a high selectivity index and a very high efficacy (IC50 value/48 h of 5–40 nM) against intracellular parasites. DB1965 shows high activity in vivo in acute experimental models (mouse) of T.cruzi, showing a similar effect to benznidazole (Bz) when compared under a scheme of 10 daily consecutive doses with 12.5 mg/kg. Although no parasitological cure was observed after treating with 20 daily consecutive doses, a combined dosage of DB1965 (5 mg/kg) with Bz (50 mg/kg) resulted in parasitaemia clearance and 100% animal survival. In summary, our present data confirmed that aryimidamides represent promising new chemical entities against T.cruzi in therapeutic schemes using the AIA alone or in combination with other drugs, like benznidazole

Engolo and Capoeira. From Ethnic to Diasporic Combat Games in the Southern Atlantic

This article provides a re-examination of the main Afrocentric narrative of capoeira origins, the engolo or ‘Zebra Dance’, in light of historical primary sources and new ethnographic evidence gathered during fieldwork in south-west Angola. By examining engolo’s bodily techniques, its socio-historical context and cultural meanings, the piece emphasises its insertion into a pastoral lifestyle and highlights the relatively narrow ethnic character of the practice in Angola. This analysis and the comparison with capoeira helps us to develop certain hypotheses about the formation, migration, and re-invention of diasporic combat games between southern Angola and coastal Brazil, and more broadly, to increase our understanding of how African cultures spread across the southern Atlantic

Racial differences in systemic sclerosis disease presentation: a European Scleroderma Trials and Research group study

Objectives. Racial factors play a significant role in SSc. We evaluated differences in SSc presentations between white patients (WP), Asian patients (AP) and black patients (BP) and analysed the effects of geographical locations.Methods. SSc characteristics of patients from the EUSTAR cohort were cross-sectionally compared across racial groups using survival and multiple logistic regression analyses.Results. The study included 9162 WP, 341 AP and 181 BP. AP developed the first non-RP feature faster than WP but slower than BP. AP were less frequently anti-centromere (ACA; odds ratio (OR) = 0.4, P < 0.001) and more frequently anti-topoisomerase-I autoantibodies (ATA) positive (OR = 1.2, P = 0.068), while BP were less likely to be ACA and ATA positive than were WP [OR(ACA) = 0.3, P < 0.001; OR(ATA) = 0.5, P = 0.020]. AP had less often (OR = 0.7, P = 0.06) and BP more often (OR = 2.7, P < 0.001) diffuse skin involvement than had WP.AP and BP were more likely to have pulmonary hypertension [OR(AP) = 2.6, P < 0.001; OR(BP) = 2.7, P = 0.03 vs WP] and a reduced forced vital capacity [OR(AP) = 2.5, P < 0.001; OR(BP) = 2.4, P < 0.004] than were WP. AP more often had an impaired diffusing capacity of the lung than had BP and WP [OR(AP vs BP) = 1.9, P = 0.038; OR(AP vs WP) = 2.4, P < 0.001]. After RP onset, AP and BP had a higher hazard to die than had WP [hazard ratio (HR) (AP) = 1.6, P = 0.011; HR(BP) = 2.1, P < 0.001].Conclusion. Compared with WP, and mostly independent of geographical location, AP have a faster and earlier disease onset with high prevalences of ATA, pulmonary hypertension and forced vital capacity impairment and higher mortality. BP had the fastest disease onset, a high prevalence of diffuse skin involvement and nominally the highest mortality

Exploring the potential activity spectrum of two 5-nitroindazolinone prototypes on different Trypanosoma cruzi strains

Submitted by sandra infurna ([email protected]) on 2016-03-22T17:16:07Z No. of bitstreams: 1 mariane_vasconcelos_etal_IOC_2015.pdf: 462658 bytes, checksum: fb088563cf7c4096be045521175938bd (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-03-22T17:27:09Z (GMT) No. of bitstreams: 1 mariane_vasconcelos_etal_IOC_2015.pdf: 462658 bytes, checksum: fb088563cf7c4096be045521175938bd (MD5)Made available in DSpace on 2016-03-22T17:27:09Z (GMT). No. of bitstreams: 1 mariane_vasconcelos_etal_IOC_2015.pdf: 462658 bytes, checksum: fb088563cf7c4096be045521175938bd (MD5) Previous issue date: 2015UCM-UPM & CSIC. CEI Campus Moncloa. Madrid, Spain / Universidad Complutense de Madrid. Facultad de Farmacia. Departamento de Parasitologia. Madrid, Spain.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.UCM-UPM & CSIC. CEI Campus Moncloa. Madrid, Spain / Universidad Complutense de Madrid. Facultad de Farmacia. Departamento de Parasitologia. Madrid, Spain.UCM-UPM & CSIC. CEI Campus Moncloa. Madrid, Spain / Consejo Superior de Investigaciones Científicas (CSIC). Instituto de Química Médica (IQM),. Madrid, Spain.UCM-UPM & CSIC. CEI Campus Moncloa. Madrid, Spain / Universidad Complutense de Madrid. Facultad de Farmacia. Departamento de Parasitologia. Madrid, Spain.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.In the present study, the potential activity of two 5-nitroindazole derivatives previously proposed as suitable antichagasic prototypes was further evaluated on diverse Trypanosoma cruzistrains belonging to two discrete typing units (DTUs) frequently associated with human infection (i.e. DTUs TcII and TcVI). The trypanocidal profile that both 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives achieved on Tulahuen amastigotes (IC50 = 3·56 ± 0·99 and 6·31 ± 1·04 µM, respectively) correlates with that of formerly obtained on CL Brener, corroborating an outstanding activity on DTU TcVI parasites. Moreover, a sequential screening on extracellular and intracellular stages of T. cruzi Y (DTU TcII) demonstrated also the effectiveness of 22 and 24 over this strain on a similar range of activity (IC50 epimastigotes = 3·55 ± 0·47 and 7·92 ± 1·63 µM, IC50 amastigotes = 2·80 ± 0·46 and 9·02 ± 5·26 µM, respectively). These results, supported by a lack of toxicity registered over either L929 fibroblasts or primary cultures of cardiomyocytes, confirm that 5-nitroindazolinones 22 and 24 display great selectivity on both drug-sensitive (CL and Tulahuen) and drug-moderately resistant (Y) T. cruzi strains, and therefore, represent an important outcome in the research of Chagas disease chemotherapy

Activities of Psilostachyin A an Cynaropicrin against Trypanosoma cruzi In Vitro and In Vivo

Made available in DSpace on 2015-08-19T13:49:15Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) fabiana_rocha_etal_IOC-2013.pdf: 7997141 bytes, checksum: 4c775f9a5ca87f1b13332fbbeff45911 (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.University of Basel. Department of Pharmaceutical Sciences, Pharmaceutical Biology. Basel, Switzerland.University of Basel. Department of Pharmaceutical Sciences, Pharmaceutical Biology. Basel, Switzerland.University of Basel. Department of Pharmaceutical Sciences, Pharmaceutical Biology. Basel, Switzerland / Swiss Tropical and Public Health Institute. Department of Medical Parasitology and Infection Biology. Basel, Switzerland.University of Basel. Department of Pharmaceutical Sciences, Pharmaceutical Biology. Basel, Switzerland.Swiss Tropical and Public Health Institute. Department of Medical Parasitology and Infection Biology. Basel, Switzerland.University of Graz. Institute of Zoology. Graz, Austria.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.In vitro and in vivo activities against Trypanosoma cruzi were evaluated for two sesquiterpene lactones: psilostachyin A and cynaropicrin. Cynaropicrin had previously been shown to potently inhibit African trypanosomes in vivo, and psilostachyin A had been reported to show in vivo effects against T. cruzi, albeit in another test design. In vitro data showed that cynaropicrin was more effective than psilostachyin A. Ultrastructural alterations induced by cynaropicrin included shedding events, detachment of large portions of the plasma membrane, and vesicular bodies and large vacuoles containing membranous structures, suggestive of parasite autophagy. Acute toxicity studies showed that one of two mice died at a cynaropicrin dose of 400 mg/kg of body weight given intraperitoneally (i.p.). Although no major plasma biochemical alterations could be detected, histopathology demonstrated that the liver was the most affected organ in cynaropicrin-treated animals. Although cynaropicrin was as effective as benznidazole against trypomastigotes in vitro, the treatment (once or twice a day) of T. cruzi-infected mice (up to 50 mg/kg/day cynaropicrin) did not suppress parasitemia or protect against mortality induced by the Y and Colombiana strains. Psilostachyin A (0.5 to 50 mg/kg/day given once a day) was not effective in the acute model of T. cruzi infection (Y strain), reaching 100% animal mortality. Our data demonstrate that although it is very promising against African trypanosomes, cynaropicrin does not show efficacy compared to benznidazole in acute mouse models of T. cruzi infection

Cure assessment of DB1965 combined or not with benznidazole (Bz) in murine model of acute <i>T. cruzi</i>-infection¹.

1<p>Swiss male mice weight 20 to 24 g inoculated with 10⁴ blood trypomastigotes (Y strain).</p><p>Treatment was initiated at 5° dpi followed by different schemes of treatment (up to 20 consecutive daily doses). All assays were run at least twice.</p>2<p>Intraperitoneal – ip.</p>3<p>per oral – p.o.</p><p>Nd = not done.</p

Biochemical analysis of <i>T.cruz</i>i-infected mice treated or not by DB1965 and Benznidazole.

<p>All assays were run at least two times and the data represent Mean ±SD.</p><p>ALT = alanino Aminotransferase.</p><p>CK = creatine kinase.</p><p>Bz = Benznidazole.</p