Screening of Potential anti-Trypanosoma cruzi Candidates: In Vitro and In Vivo Studies

Chagas disease (CD), caused by the intracellular protozoan Trypanosoma cruzi, is a parasitic illness endemic in Latin America. In the centennial after CD discovery by Carlos Chagas (1909), although it still represents an important public health problem in these affected areas, the existing chemotherapy, based on benznidazole and nifurtimox (both introduced more than four decades ago), is far from being considered ideal due to substantial toxicity, variable effect on different parasite stocks and well-known poor activity on the chronic phase. CD is considered one of the major “neglected” diseases of the world, as commercial incentives are very limited to guarantee investments for developing and discovering novel drugs. In this context, our group has been pursuing, over the last years, the efficacy, selectivity, toxicity, cellular targets and mechanisms of action of new potential anti-T. cruzi candidates screened from an in-house compound library of different research groups in the area of medicinal chemistry. A brief review regarding these studies will be discussed, mainly related to the effect on T. cruzi of (i) diamidines and related compounds, (ii) natural naphthoquinone derivatives, and (iii) megazol derivatives

Glomerular filtration rate change during chronic hepatitis C treatment with Sofosbuvir/Ledipasvir in HCV/HIV Coinfected patients treated with Tenofovir and a boosted protease inhibitor: an observational prospective study

INTRODUCTION: Concomitant use of ledipasvir and boosted protease inhibitors (PIs) may increase the risk of tenofovir (TDF) nephrotoxicity, since both these drugs increase TDF levels. Our aim was to evaluate glomerular filtration rate (eGFR) evolution during HCV treatment with sofosbuvir/ledipasvir (SOF/LDV) in HCV/HIV coinfected patients, according to their antiretroviral treatment (ARV). METHODS: Observational prospective study of HCV/HIV coinfected patients treated with SOF/LDV. eGFR evolution was evaluated during and 12 weeks after HCV treatment. Patients were categorized in three groups based on ARV regimen: non TDF, non-boosted TDF and TDF + boosted PI. RESULTS: We included 273 patients: 145 were receiving a non-TDF regimen, 78 a non-boosted TDF scheme and 50 were receiving TDF + boosted PI. We observed a statistically significant decrease in eGFR during treatment in all groups (non TDF p = 0.03, 95%CI [0.23-3.86], non-boosted TDF p < 0.01, 95%CI [3.36-7.44], TDF + PI p = 0.01, 95%CI [1.09-7.53]). The decrease was more pronounced in those receiving unboosted TDF (- 5.40 ml/min/1.73m2), but differences in eGFR decrease between the three groups were small and not statistically different (p = 0.06). eGFR decrease was greater in patients treated for 24 weeks (p = 0.009) and in cirrhotic patients (p = 0.036). At the end of follow up a recovery of eGFR was observed in all groups. CONCLUSION: We observed a significant decrease in eGFR during treatment in all study groups, that was small and reversible after SOF/LDV discontinuation. TDF was not associated with an increase in renal toxicity.info:eu-repo/semantics/publishedVersio

Drug screening using shape-based virtual screening and in vitro experimental models of cutaneous Leishmaniasis

Cutaneous leishmaniasis (CL) is one of the most disregarded tropical neglected disease with the occurrence of self-limiting ulcers and triggering mucosal damage and stigmatizing scars, leading to huge public health problems and social negative impacts. Pentavalent antimonials are the first-line drug for CL treatment for over 70 years and present several drawbacks in terms of safety and efficacy. Thus, there is an urgent need to search for non-invasive, non-toxic and potent drug candidates for CL. In this sense, we have implemented a shape-based virtual screening approach and identified a set of 32 hit compounds. In vitro phenotypic screenings were conducted using these hit compounds to check their potential leishmanicidal effect towards Leishmania amazonensis (L. amazonensis). Two (Cp1 and Cp2) out of the 32 compounds revealed promising antiparasitic activities, exhibiting considerable potency against intracellular amastigotes present in peritoneal macrophages (IC₅₀ values of 9.35 and 7.25 μm, respectively). Also, a sterile cidality profile was reached at 20 μm after 48 h of incubation, besides a reasonable selectivity (≈8), quite similarly to pentamidine, a diamidine still in use clinically for leishmaniasis. Cp1 with an oxazolo[4,5-b]pyridine scaffold and Cp2 with benzimidazole scaffold could be developed by lead optimization studies to enhance their leishmanicidal potency

Saccharomyces cerevisiae as a toxicological model to study synthetic cannabinoids and its pyrolysis products

Poster presented at the 7th European Academy of Forensic Science Conference. Prague, 6-11 September 2015"Synthetic cannabinoids are among the major psychoactive drugs widespread as safe and legal alternatives to cannabis. They are commercially available as herbal incense products intended for smoke. This has led most of developed countries to concentrate efforts in order to ban the so called “legal highs”. Despite of their increasing use, there is still a lack of information on both synthetic and natural ingredients, pharmacokinetic properties and toxic effects. In fact some of the substances seem to have stronger toxicological effects when compared to their legal counterpart. Toxicological assays are paramount to know how harmful these new substances are, helping increase public awareness since several hospitalization cases have been reported due to consumption. To tackle the new challenges posed by novel drugs worldwide, we developed an approach using Saccharomyces cerevisiae as a model to investigate the toxicity of pyrolysis products of synthetic cannabinoids. S. cerevisiae.

Phosphorus supply for the establishment of palisade grass and forage peanut grown in association.

Fósforo (P) é um nutriente-chave para o estabelecimento de consórcio de gramíneas e leguminosas forrageiras. O objetivo deste trabalho foi determinar a necessidade de P para o estabelecimento de capim-braquiarão e amendoim forrageiro cultivados em associação sob condições controladas. Um experimento de vasos foi conduzido em casa de vegetação usando o delineamento em blocos completos ao acaso com oito tratamentos e quatro repetições. Os tratamentos foram as seguintes doses de P: 0 mg dm-3 (controle), 80 mg dm-3, 160 mg dm-3, 240 mg dm-3, 320 mg dm-3, 400 mg dm-3 e 560 mg dm-3 [fonte: Ca(H2PO4)2.H2O]. Capim-braquiarão (Urochloa brizantha 'Marandu') e amendoim forrageiro (Arachis pintoi 'BRS Mandobi') foram cultivados por 24 dias depois do corte de uniformização e então cortados a 10 cm de altura para determinação da matéria seca do topo da planta. O suprimento adequado de P para o crescimento do topo da planta diferiu entre as espécies. Capim-braquiarão necessitou de 80 mg dm-3 de P, ao passo que 160 mg dm-3 de P foram exigidos pelo amendoim forrageiro. O amendoim forrageiro necessitou de mais P do que o capim-braquiarão para o estabelecimento de ambas as espécies cultivadas em associação sob condições controladas

VIABILIDADE DA UTILIZAÇÃO DO BIOGÁS COMO FONTE ALTERNATIVA DE ENERGIA

O presente trabalho consiste numa revisão da literatura acerca da produção de biogás, residual ou em processo controlado, para a produção de energia elétrica. O estudo constitui-se de uma Pesquisa Aplicada, visto que “objetiva gerar conhecimentos para aplicação prática e dirigidos à solução de problemas específicos”. Do ponto de vista da forma de abordagem do problema é uma pesquisa qualitativa. Os resultados obtidos apontam que existe viabilidade técnica e econômica para o emprego de pequenas estações de geração de energia elétrica a partir do biogás. Entretanto, as restrições de produção e espaço físico para grandes empreendimentos é um impeditivo para o aumento substancial de escala desse tipo de empreendimento

Assessment of direct radiological risk and indirect associated toxic risks originated by Coal-Fired Power Plants

Over the past few decades there has been some discussion concerning the increase of the natural background radiation originated by coal-fired power plants, due to the uranium and thorium content present in combustion ashes. The radioactive decay products of uranium and thorium, such as radium, radon, polonium, bismuth and lead, are also released in addition to a significant amount of 40K. Since the measurement of radioactive elements released by the gaseous emissions of coal power plants is not compulsory, there is a gap of information concerning this situation. Consequently, the prediction of dispersion and mobility of these elements in the environment, after their release, is based on limited data and the radiological impact from the exposure to these radioactive elements is unknown. This paper describes the methodology that is being developed to assess the radiological impact due to the raise in the natural background radiation level originated by the release and dispersion of the emitted radionuclides. The current investigation is part of a research project that is undergoing in the vicinity of Sines coal-fired power plant (south of Portugal) until 2013. Data from preliminary stages are already available and possible of interpretation

Radiation dose rates and exposure associated to Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) at locations of a Portuguese coal-fired power plant

Coal contains trace quantities of natural radionuclides such as Th-232, U-235, U-238, as well as their radioactive decay products and 40K. These radionuclides can be released as fly ash in atmospheric emissions from coal-fired power plants, dispersed into the environment and deposited on the surrounding top soils. Therefore, the natural radiation background level is enhanced and consequently increase the total dose for the nearby population. A radiation monitoring programme was used to assess the external dose contribution to the natural radiation background, potentially resulting from the dispersion of coal ash in past atmospheric emissions. Radiation measurements were carried out by gamma spectrometry in the vicinity of a Portuguese coal-fired power plant. The radiation monitoring was achieved both on and off site, being the boundary delimited by a 20 km circle centered in the stacks of the coal plant. The measured radionuclides concentrations for the uranium and thorium series ranged from 7.7 to 41.3 Bq/kg for Ra-226 and from 4.7 to 71.6 Bq/kg for Th-232, while K-40 concentrations ranged from 62.3 to 795.1 Bq/kg. The highest values were registered near the power plant and at distances between 6 and 20 km from the stacks, mainly in the prevailing wind direction. The absorbed dose rates were calculated for each sampling location: 13.97-84.00 ηGy/h, while measurements from previous studies carried out in 1993 registered values in the range of 16.6-77.6 ηGy/h. The highest values were registered at locations in the prevailing wind direction (NW-SE). This study has been primarily done to assess the radiation dose rates and exposure to the nearby population in the surroundings of a coal-fired power plant. The results suggest an enhancement or at least an influence in the background radiation due to the coal plant past activities

Novel amidines and analogues as promising agents against intracellular parasites: a systematic review

Parasitic protozoa comprise diverse aetiological agents responsible for important diseases in humans and animals including sleeping sickness, Chagas disease, leishmaniasis, malaria, toxoplasmosis and others. They are major causes of mortality and morbidity in tropical and subtropical countries, and are also responsible for important economic losses. However, up to now, for most of these parasitic diseases, effective vaccines are lacking and the approved chemotherapeutic compounds present high toxicity, increasing resistance, limited efficacy and require long periods of treatment. Many of these parasitic illnesses predominantly affect low-income populations of developing countries for which new pharmaceutical alternatives are urgently needed. Thus, very low research funding is available. Amidine-containing compounds such as pentamidine are DNA minor groove binders with a broad spectrum of activities against human and veterinary pathogens. Due to their promising microbicidal activity but their rather poor bioavailability and high toxicity, many analogues and derivatives, including pro-drugs, have been synthesized and screened in vitro and in vivo in order to improve their selectivity and pharmacological properties. This review summarizes the knowledge on amidines and analogues with respect to their synthesis, pharmacological profile, mechanistic and biological effects upon a range of intracellular protozoan parasites. The bulk of these data may contribute to the future design and structure optimization of new aromatic dicationic compounds as novel antiparasitic drug candidate

BAY 41-2272, a soluble guanylate cyclase agonist, activates human mononuclear phagocytes

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOPhagocyte function is critical for host defense against infections. Defects in phagocytic function lead to several primary immunodeficiencies characterized by early onset of recurrent and severe infections. In this work, we further investigated the effects of BAY 41-2272, a soluble guanylate cyclase (sGC) agonist, on the activation of human peripheral blood monocytes (PBM) and THP-1 cells. EXPERIMENTAL APPROACH THP-1 cells and PBM viability was evaluated by methylthiazoletetrazolium assay; reactive oxygen species production by lucigenin chemiluminescence; gene and protein expression of NAPDH oxidase components by qRT-PCR and Western blot analysis, respectively; phagocytosis and microbicidal activity by co-incubation, respectively, with zymosan and Escherichia coli; and cytokine release by elisa. KEY RESULTS BAY 41-2272, compared with the untreated group, increased spreading of monocytes by at least 35%, superoxide production by at least 50%, and gp91PHOX and p67PHOX gene expression 20 to 40 times, in both PBM and THP-1 cells. BAY 41-2272 also augmented phagocytosis of zymosan particles threefold compared with control, doubled microbicidal activity against E. coli and enhanced the release of TNF-a and IL-12p70 by both PBM and THP-1 cells. Finally, by inhibiting sGC with ODQ, we showed that BAY 41-2272-induced superoxide production and phagocytosis is not dependent exclusively on sGC activation. CONCLUSIONS AND IMPLICATIONS In addition to its ability to induce vasorelaxation and its potential application for therapy of vascular diseases, BAY 41-2272 was shown to activate human mononuclear phagocytes. Hence, it is a novel pro-inflammatory drug that may be useful for controlling infections in the immunocompromised host166516171630FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO06/51004-2; 06/52483-1470978/2008-