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1.
Nutrients ; 13(3)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803760

RESUMO

The role of docosahexaenoic acid (DHA) and arachidonic acid (AA) in neurogenesis and brain development throughout the life cycle is fundamental. DHA and AA are long-chain polyunsaturated fatty acids (LCPUFA) vital for many human physiological processes, such as signaling pathways, gene expression, structure and function of membranes, among others. DHA and AA are deposited into the lipids of cell membranes that form the gray matter representing approximately 25% of the total content of brain fatty acids. Both fatty acids have effects on neuronal growth and differentiation through the modulation of the physical properties of neuronal membranes, signal transduction associated with G proteins, and gene expression. DHA and AA have a relevant role in neuroprotection against neurodegenerative pathologies such as Alzheimer's disease and Parkinson's disease, which are associated with characteristic pathological expressions as mitochondrial dysfunction, neuroinflammation, and oxidative stress. The present review analyzes the neuroprotective role of DHA and AA in the extreme stages of life, emphasizing the importance of these LCPUFA during the first year of life and in the developing/prevention of neurodegenerative diseases associated with aging.


Assuntos
Ácido Araquidônico/farmacologia , Ácidos Docosa-Hexaenoicos/farmacologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Nutrientes/farmacologia , Envelhecimento/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Humanos , Doenças Neurodegenerativas/metabolismo , Neurogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
2.
Ecotoxicol Environ Saf ; 208: 111665, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396175

RESUMO

Microplastics are ubiquitous in aquatic ecosystems, but little information is currently available on the dangers and risks to living organisms. In order to assess the ecotoxicity of environmental microplastics (MPs), samples were collected from the beaches of two islands in the Guadeloupe archipelago, Petit-Bourg (PB) located on the main island of Guadeloupe and Marie-Galante (MG) on the second island of the archipelago. These samples have a similar polymer composition with mainly polyethylene (PE) and polypropylene (PP). However, these two samples are very dissimilar with regard to their contamination profile and their toxicity. MPs from MG contain more lead, cadmium and organochlorine compounds while those from PB have higher levels of copper, zinc and hydrocarbons. The leachates of these two samples of MPs induced sublethal effects on the growth of sea urchins and on the pulsation frequency of jellyfish ephyrae but not on the development of zebrafish embryos. The toxic effects are much more marked for samples from the PB site than those from the MG site. This work demonstrates that MPs can contain high levels of potentially bioavailable toxic substances that may represent a significant ecotoxicological risk, particularly for the early life stages of aquatic animals.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Ecossistema , Ecotoxicologia , Ilhas , Microplásticos/química , Cifozoários/efeitos dos fármacos , Cifozoários/crescimento & desenvolvimento , Ouriços-do-Mar/efeitos dos fármacos , Ouriços-do-Mar/crescimento & desenvolvimento , Poluentes Químicos da Água/química
3.
Nat Commun ; 12(1): 269, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431834

RESUMO

Chemical matter is needed to target the divergent biology associated with the different life cycle stages of Plasmodium. Here, we report the parallel de novo screening of the Medicines for Malaria Venture (MMV) Pandemic Response Box against Plasmodium asexual and liver stage parasites, stage IV/V gametocytes, gametes, oocysts and as endectocides. Unique chemotypes were identified with both multistage activity or stage-specific activity, including structurally diverse gametocyte-targeted compounds with potent transmission-blocking activity, such as the JmjC inhibitor ML324 and the antitubercular clinical candidate SQ109. Mechanistic investigations prove that ML324 prevents histone demethylation, resulting in aberrant gene expression and death in gametocytes. Moreover, the selection of parasites resistant to SQ109 implicates the druggable V-type H+-ATPase for the reduced sensitivity. Our data therefore provides an expansive dataset of compounds that could be redirected for antimalarial development and also point towards proteins that can be targeted in multiple parasite life cycle stages.


Assuntos
Antimaláricos/uso terapêutico , Descoberta de Drogas , Malária/tratamento farmacológico , Malária/transmissão , Pandemias , Aedes/parasitologia , Animais , Antimaláricos/química , Antimaláricos/farmacologia , Análise por Conglomerados , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Concentração Inibidora 50 , Estágios do Ciclo de Vida/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/parasitologia , Malária/epidemiologia , Masculino , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento
4.
Ecotoxicol Environ Saf ; 210: 111875, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33454577

RESUMO

Coccinella septempunctata (ladybird) is one of the foremost natural predators that feed on aphids. Thus, C. septempunctata serves as an effective biological control agent in integrated pest management (IPM) programs. To supplement the activity of biological control agents, IPM programs often incorporate chemical pesticides to bolster crop protection. To evaluate the effects of a potent insecticide, tolfenpyrad, on C. septempunctata, we tested the sublethal effects of tolfenpyrad on all developmental stages of the life cycle of C. septempunctata and its effects on the next generation. For sublethal testing of the parent generation, the LR50 of tolfenpyrad for C. septempunctata was determined to range from 1.04 to 8.43 g a.i. /hm2 within a set exposure period, while the hazard quotient (HQ) values were above our threshold value of 2 during the entire observation period. These data indicated a potential toxicity risk from tolfenpyrad exposure. The no observed effect application rates (NOERs) of tolfenpyrad on parents (F0) were determined for survival (0.485 g a.i. /hm2), developmental time of pupation (0.242 g a.i. /hm2), and fecundity (0.485 g a.i. /hm2). Application of sublethal doses to unexposed progeny (F1) of exposed parents, prolonged the L1 (1st instar of larvae) and L2 (2nd instar of larvae) stage, while the total longevity, intrinsic rate of increase (r), finite rate of increase (γ), net reproductive rate (R0), and mean generation time (T) were significantly reduced. These results demonstrated the negative influence of sublethal concentrations of tolfenpyrad on C. septempunctata and its persistent effects on subsequent generations.


Assuntos
Besouros/efeitos dos fármacos , Inseticidas/toxicidade , Pirazóis/toxicidade , Animais , Besouros/fisiologia , Feminino , Fertilidade/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/fisiologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Controle de Pragas , Reprodução/efeitos dos fármacos
5.
Biochim Biophys Acta Gen Subj ; 1865(3): 129813, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33321150

RESUMO

BACKGROUND: Malaria is a parasitic disease that compromises the human host. Currently, control of the Plasmodium falciparum burden is centered on artemisinin-based combination therapies. However, decreased sensitivity to artemisinin and derivatives has been reported, therefore it is important to identify new therapeutic strategies. METHOD: We used human erythrocytes infected with P. falciparum and experimental cerebral malaria (ECM) animal model to assess the potential antimalarial effect of eugenol, a component of clove bud essential oil. RESULTS: Plasmodium falciparum cultures treated with increasing concentrations of eugenol reduced parasitemia in a dose-dependent manner, with IC50 of 532.42 ± 29.55 µM. This effect seems to be irreversible and maintained even in the presence of high parasitemia. The prominent effect of eugenol was detected in the evolution from schizont to ring forms, inducing important morphological changes, indicating a disruption in the development of the erythrocytic cycle. Aberrant structural modification was observed by electron microscopy, showing the separation of the two nuclear membrane leaflets as well as other subcellular membranes, such as from the digestive vacuole. Importantly, in vivo studies using ECM revealed a reduction in blood parasitemia and cerebral edema when mice were treated for 6 consecutive days upon infection. CONCLUSIONS: These data suggest a potential effect of eugenol against Plasmodium sp. with an impact on cerebral malaria. GENERAL SIGNIFICANCE: Our results provide a rational basis for the use of eugenol in therapeutic strategies to the treatment of malaria.


Assuntos
Antimaláricos/farmacologia , Edema Encefálico/tratamento farmacológico , Eugenol/farmacologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Malária Cerebral/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/parasitologia , Edema Encefálico/parasitologia , Modelos Animais de Doenças , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Humanos , Concentração Inibidora 50 , Estágios do Ciclo de Vida/fisiologia , Malária Cerebral/parasitologia , Malária Falciparum/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Plasmodium berghei/efeitos dos fármacos , Plasmodium berghei/crescimento & desenvolvimento , Plasmodium berghei/parasitologia , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/patogenicidade
6.
PLoS One ; 15(9): e0238707, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925934

RESUMO

Clothianidin is a second-generation neonicotinoid insecticide, widely used against sap-sucking insect pest including melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae). This pest causes severe economic damage to Cucurbitaceae plants worldwide. In this study, we investigated clothianidin resistance development under continuous selection pressure. Moreover, the age-stage, two-sex life table approach was used to evaluate the impact of clothianidin resistance on the fitness of A. gossypii. A clothianidin resistant strain (CT-R) with a 23.17-fold resistance level was developed from a susceptible strain (CT-S) after continuous selection for 24 generations. Life table results showed a significant reduction in the relative fitness (0.847) of CT-R strain compared to the CT-S strain of A. gossypii. The developmental duration, oviposition days, total pre-oviposition period (TPOP), longevity, and fecundity of CT-R strain were found to be significantly lower when compared to CT-S strain. The demographic parameters, including the intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R0), and mean generation time (T) were also significantly decreased in CT-R strain compared to the CT-S strain. Both the reproductive and survival rates were affected by clothianidin resistance in CT-R strain compared with the CT-S strain of A. gossypii. Overall, our results demonstrate that in-depth knowledge about the trade-off at play between resistance degree and fitness cost might be useful to design resistance management strategies against A. gossypii.


Assuntos
Afídeos/genética , Cucurbitaceae/parasitologia , Aptidão Genética , Guanidinas/toxicidade , Resistência a Inseticidas/genética , Neonicotinoides/toxicidade , Tiazóis/toxicidade , Envelhecimento/fisiologia , Animais , Afídeos/efeitos dos fármacos , Afídeos/crescimento & desenvolvimento , Feminino , Fertilidade , Estágios do Ciclo de Vida/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Análise de Sobrevida
7.
Parasitol Res ; 119(10): 3503-3515, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32772176

RESUMO

Malaria, babesiosis, trypanosomosis, and leishmaniasis are some of the most life-threatening parasites, but the range of drugs to treat them is limited. An effective, safe, and low-cost drug with a large activity spectrum is urgently needed. For this purpose, an aryl amino alcohol derivative called Alsinol was resynthesized, screened in silico, and tested against Plasmodium, Babesia, Trypanosoma, and Leishmania. In silico Alsinol follows the Lipinski and Ghose rules. In vitro it had schizontocidal activity against Plasmodium falciparum and was able to inhibit gametocytogenesis; it was particularly active against late gametocytes. In malaria-infected mice, it showed a dose-dependent activity similar to chloroquine. It demonstrated a similar level of activity to reference compounds against Babesia divergens, and against promastigotes, and amastigotes stages of Leishmania in vitro. It inhibited the in vitro growth of two African animal strains of Trypanosoma but was ineffective in vivo in our experimental conditions. It showed moderate toxicity in J774A1 and Vero cell models. The study demonstrated that Alsinol has a large spectrum of activity and is potentially affordable to produce. Nevertheless, challenges remain in the process of scaling up synthesis, creating a suitable clinical formulation, and determining the safety margin in preclinical models.


Assuntos
Amino Álcoois/farmacologia , Antiprotozoários/farmacologia , Amino Álcoois/síntese química , Amino Álcoois/química , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Babesia/efeitos dos fármacos , Babesia/crescimento & desenvolvimento , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Modelos Animais de Doenças , Leishmania/efeitos dos fármacos , Leishmania/crescimento & desenvolvimento , Estágios do Ciclo de Vida/efeitos dos fármacos , Camundongos , Plasmodium/efeitos dos fármacos , Plasmodium/crescimento & desenvolvimento , Infecções por Protozoários/tratamento farmacológico , Infecções por Protozoários/parasitologia , Resultado do Tratamento , Trypanosoma/efeitos dos fármacos , Trypanosoma/crescimento & desenvolvimento , Células Vero
8.
Nat Commun ; 11(1): 4015, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782246

RESUMO

Intracellular pathogens mobilize host signaling pathways of their host cell to promote their own survival. Evidence is emerging that signal transduction elements are activated in a-nucleated erythrocytes in response to infection with malaria parasites, but the extent of this phenomenon remains unknown. Here, we fill this knowledge gap through a comprehensive and dynamic assessment of host erythrocyte signaling during infection with Plasmodium falciparum. We used arrays of 878 antibodies directed against human signaling proteins to interrogate the activation status of host erythrocyte phospho-signaling pathways at three blood stages of parasite asexual development. This analysis reveals a dynamic modulation of many host signalling proteins across parasite development. Here we focus on the hepatocyte growth factor receptor (c-MET) and the MAP kinase pathway component B-Raf, providing a proof of concept that human signaling kinases identified as activated by malaria infection represent attractive targets for antimalarial intervention.


Assuntos
Antimaláricos/farmacologia , Eritrócitos/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais , Eritrócitos/parasitologia , Interações Hospedeiro-Parasita , Humanos , Concentração Inibidora 50 , Estágios do Ciclo de Vida/efeitos dos fármacos , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Fosforilação/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/metabolismo , Plasmodium falciparum/fisiologia , Análise Serial de Proteínas , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-met/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
Mikrobiyol Bul ; 54(3): 479-489, 2020 Jul.
Artigo em Turco | MEDLINE | ID: mdl-32755522

RESUMO

This study was aimed to investigate the anti-leishmanial effects of bee products (honey and propolis) by using the causative agent of cutaneous leishmaniasis Leishmania tropica promastigotes, in in vitro culture. In vitro anti-leishmanial efficacy of honey (pine, flower and chestnut) and propolis used in the study were evaluated using the microdilution method. Honey, which is a bee product, was dissolved with RPMI medium containing fetal calf serum (FCS) and diluted in the same medium, and serial dilutions were prepared in concentrations between 62.5-1000 mg/ml. Propolis, on the other hand, was dissolved with ethyl alcohol and only 2.5 µl was used from all these concentrations since the alcohol content was more than 50% in these concentrations prepared and we thought that this rate would negatively effect the parasite development. Then, RPMI containing FCS was diluted in the medium and serial dilutions were prepared at concentrations between 50-800 µg/ml. To the dilutions prepared, the promastigot suspension was added so that their final concentrations in the wells were 1 x 106 promastigot/ml and then the medium was incubated for 24 and 48 hours in 26°C. After the incubation, promastigotes were determined microscopically for morphology, mobility and live parasite density, and cell viability was determined by MTS method and 50% inhibitor concentrations (IC50) were compared with control groups. Anti-leishmanial activity of propolis (50, 100, 200, 400 and 800 µg/ml) and honey (62.5, 125, 250, 500 and 1000 mg/ml) on promastigotes was evaluated in vitro. In microscopic examinations, pine honey showed anti-leishmanial activity starting from 62.5 mg/ml, flower honey 250 mg/ml, and chestnut honey 125 mg/ml, and pine honey was more effective on promastigotes (p< 0.05), and propolis was effective from 100 µg/ml concentration. It has been determined that very low concentrations of propolis caused changes in the morphological structure of the parasites and were more effective than the other bee products. The prevention of cell proliferation and decreasing of the IC50 values according with the time of pine honey (IC50= 109.28 mg/ml), flower honey (IC50= 248.07 mg/ml), chestnut honey (IC50= 147.65 mg/ml) and propolis (IC50= 82.98 µg/ml) applied on L.tropica promastigot cell culture was determined by MTS method. In this study, it was found that various concentrations of pine, flower, chestnut honey and propolis showed anti-leishmanial activity on L. tropica promastigotes. It has been observed that pine honey is more effective on promastigotes after 48 hours of incubation period, and propolis is more effective in both morphology and cell inhibition of the parasites even at very low concentrations. It is believed that these data can be used as an alternative treatment method against cutaneous leishmaniasis infections and further studies are required.


Assuntos
Mel , Leishmania tropica , Própole , Animais , Antiparasitários/farmacologia , Abelhas/química , Sobrevivência Celular/efeitos dos fármacos , Leishmania tropica/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Própole/farmacologia
10.
Ecotoxicol Environ Saf ; 205: 111176, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32846301

RESUMO

The effects of 17α-ethinylestradiol (EE2) on sex ratio, gonopodium morphology, and gonadal histology of C. decemmaculatus were assessed by a full-lifecycle exposure experiment. Newborn fish were waterborne exposed to 30, 100, and 300 ng EE2/L for 90 d, using 50 fish per treatment. Additionally, in December of 2016, a field survey was conducted on a C. decemmaculatus population inhabiting the Girado Creek downstream of the Chascomus city wastewater effluent discharge. After 90 d of exposure, EE2 was able to histologically skew the sex ratio toward females and inhibit the full gonopodium development since the lowest tested concentration (LOEC = 30 ng/L). At higher concentrations, EE2 was toxic, inducing mortality in a concentration-dependent fashion (90 d-LC50 = 109.9 ng/L) and altering the gonadal histoarchitecture, causing neither testes nor ovaries discernible histologically (LOEC = 100 ng/L). In addition, a novel response, perianal hyperpigmentation, was discovered been induced by the EE2 exposure in a concentration-dependent fashion (90 d-EC50 = 39.3 ng/L). A higher proportion of females and perianal hyperpigmentation were observed in wild fish collected from the Girado Creek. The major reached conclusions are: i) EE2 induce different effects on the sexual traits of C. decemmaculatus when exposed from early-life or adult stages. ii) The most sensitive effects observed in the laboratory occur in a creek receiving wastewater effluent. iii) The perianal hyperpigmentation comes-up as a promising biomarker of exposure to estrogenic compounds.


Assuntos
Ciprinodontiformes/crescimento & desenvolvimento , Disruptores Endócrinos/toxicidade , Etinilestradiol/toxicidade , Gônadas/efeitos dos fármacos , Hiperpigmentação/induzido quimicamente , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Feminino , Gônadas/crescimento & desenvolvimento , Gônadas/patologia , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Ovário/efeitos dos fármacos , Ovário/crescimento & desenvolvimento , Ovário/patologia , Fenótipo , Razão de Masculinidade , Testículo/efeitos dos fármacos , Testículo/crescimento & desenvolvimento , Testículo/patologia
11.
Cell Signal ; 74: 109721, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32711111

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a positive-sense, single-stranded RNA virus that causes the potentially lethal Covid-19 respiratory tract infection. It does so by binding to host cell angiotensin converting enzyme 2 (ACE2) receptors, leading to endocytosis with the receptor, and subsequently using the host cell's machinery to replicate copies of itself and invade new cells. The extent of the spread of infection in the body is dependent on the pattern of ACE2 expression and overreaction of the immune system. Additionally, by inducing an imbalance in the renin-angiotensin-aldosterone system (RAAS) and the loss of ACE2 would favour the progression of inflammatory and thrombotic processes in the lungs. No drug or vaccine has yet been approved to treat human coronaviruses. Hundreds of clinical trials on existing approved drugs from different classes acting on a multitude of targets in the virus life cycle are ongoing to examine potential effectiveness for the prevention and treatment of the infection. This review summarizes the SARS-CoV-2 virus life cycle in the host cell and provides a biological and pathological point of view for repurposed and experimental drugs for this novel coronavirus. The viral life cycle provides potential targets for drug therapy.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/metabolismo , Infecções por Coronavirus/tratamento farmacológico , Reposicionamento de Medicamentos/métodos , Estágios do Ciclo de Vida/efeitos dos fármacos , Terapia de Alvo Molecular/métodos , Pneumonia Viral/tratamento farmacológico , Betacoronavirus/química , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Humanos , Pandemias/prevenção & controle , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , Sistema Renina-Angiotensina/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinas Virais/imunologia , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
12.
Parasitol Res ; 119(8): 2703-2711, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32537718

RESUMO

It is known that the current treatment for toxoplasmosis causes side effects. Thus, it is essential to develop new therapies with reduced adverse effects while concurrently maintaining broad coverage and prophylactic therapy. Melatonin is a hormone that participates in the circadian cycle in vertebrates and has antioxidant, immunomodulatory, and antitumoral functions. In addition, it has been shown that melatonin can modulate immune responses and parasitic development during infection by Trypanosoma cruzi and Leishmania spp. Furthermore, studies indicate that melatonin increases the number of lymphocytes in rats infected by Toxoplasma gondii. However, there is no information on the possible effects of melatonin in T. gondii-infected host cells in vitro. This study analyzed the effects of melatonin treatment in the monkey kidney cell epithelial cell line, LLC-MK2, after infection with T. gondii. LLC-MK2 cells were infected and treated/not treated with melatonin, and the infection index was then quantified. Melatonin treatment did not alter host cell viability and was able to reduce parasite proliferation in LLC-MK2 cells at 24 and 48 h and at 6 days. Analysis by scanning electron microscopy confirmed reduction of parasite proliferation and alterations of tachyzoite shapes. Transmission electron microscopy images showed parasites with ruptured plasma membranes and cytoplasmic leakage. After treatment, parasites showed positive staining for apoptotic-like cell death. These results suggest that the use of melatonin as the lead compound for the synthesis of new compounds may constitute an alternative treatment for toxoplasmosis.


Assuntos
Coccidiostáticos/farmacologia , Melatonina/farmacologia , Toxoplasma/efeitos dos fármacos , Toxoplasma/crescimento & desenvolvimento , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Células Epiteliais/parasitologia , Haplorrinos , Estágios do Ciclo de Vida/efeitos dos fármacos
13.
J Med Chem ; 63(11): 6179-6202, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32390431

RESUMO

The global impact of malaria remains staggering despite extensive efforts to eradicate the disease. With increasing drug resistance and the absence of a clinically available vaccine, there is an urgent need for novel, affordable, and safe drugs for prevention and treatment of malaria. Previously, we described a novel antimalarial acridone chemotype that is potent against both blood-stage and liver-stage malaria parasites. Here, we describe an optimization process that has produced a second-generation acridone series with significant improvements in efficacy, metabolic stability, pharmacokinetics, and safety profiles. These findings highlight the therapeutic potential of dual-stage targeting acridones as novel drug candidates for further preclinical development.


Assuntos
Acridonas/química , Antimaláricos/química , Acridonas/farmacocinética , Acridonas/farmacologia , Acridonas/uso terapêutico , Administração Oral , Animais , Antimaláricos/farmacocinética , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Meia-Vida , Células Hep G2 , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Malária/tratamento farmacológico , Malária/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/isolamento & purificação , Relação Estrutura-Atividade
14.
J Med Chem ; 63(11): 5734-5751, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32392053

RESUMO

Leishmania (L.) infantum causes visceral, cutaneous, and mucosal leishmaniasis in humans and canine leishmaniasis in dogs. Herein, we describe that O-alkyl hydroxamate derivatives displayed potent and selective in vitro activity against the amastigote stage of L. infantum while no activity was observed against promastigotes. Compound 5 showed potent in vivo activity against L. infantum. Moreover, the combination of compound 5 supported on gold nanoparticles and meglumine antimoniate was also effective in vivo and improved the activity of these compounds compared to that of the individual treatment. Docking studies showed that compound 5 did not reach highly conserved pocket C and established interactions with the semiconserved residues V44, A45, R242, and E243 in pocket A of LiSIR2rp1. The surface space determined by these four amino acids is not conserved in human sirtuins. Compound 5 represents a new class of selective ligands with antileishmanial activity.


Assuntos
Antiprotozoários/farmacologia , Ácidos Hidroxâmicos/química , Leishmania infantum/efeitos dos fármacos , Animais , Antiprotozoários/química , Sítios de Ligação , Feminino , Ouro/química , Histona Desacetilase 1/química , Histona Desacetilase 1/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Leishmania infantum/crescimento & desenvolvimento , Estágios do Ciclo de Vida/efeitos dos fármacos , Antimoniato de Meglumina/farmacologia , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Baço/parasitologia
15.
Lancet Infect Dis ; 20(8): 964-975, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32275867

RESUMO

BACKGROUND: (+)-SJ000557733 (SJ733) is a novel, orally bioavailable inhibitor of Plasmodium falciparum ATP4. In this first-in-human and induced blood-stage malaria phase 1a/b trial, we investigated the safety, tolerability, pharmacokinetics, and antimalarial activity of SJ733 in humans. METHODS: The phase 1a was a single-centre, dose-escalation, first-in-human study of SJ733 allowing modifications to dose increments and dose-cohort size on the basis of safety and pharmacokinetic results. The phase 1a took place at St Jude Children's Research Hospital and at the University of Tennessee Clinical Research Center (Memphis, TN, USA). Enrolment in more than one non-consecutive dose cohort was allowed with at least 14 days required between doses. Participants were fasted in seven dose cohorts and fed in one 600 mg dose cohort. Single ascending doses of SJ733 (75, 150, 300, 600, 900, or 1200 mg) were administered to participants, who were followed up for 14 days after SJ733 dosing. Phase 1a primary endpoints were safety, tolerability, and pharmacokinetics of SJ733, and identification of an SJ733 dose to test in the induced blood-stage malaria model. The phase 1b was a single-centre, open-label, volunteer infection study using the induced blood-stage malaria model in which fasted participants were intravenously infected with blood-stage P falciparum and subsequently treated with a single dose of SJ733. Phase 1b took place at Q-Pharm (Herston, QLD, Australia) and was initiated only after phase 1a showed that exposure exceeding the threshold minimum exposure could be safely achieved in humans. Participants were inoculated on day 0 with P falciparum-infected human erythrocytes (around 2800 parasites in the 150 mg dose cohort and around 2300 parasites in the 600 mg dose cohort), and parasitaemia was monitored before malaria inoculation, after inoculation, immediately before SJ733 dosing, and then post-dose. Participants were treated with SJ733 within 24 h of reaching 5000 parasites per mL or at a clinical score higher than 6. Phase 1b primary endpoints were calculation of a parasite reduction ratio (PRR48) and parasite clearance half-life, and safety and tolerability of SJ733 (incidence, severity, and drug-relatedness of adverse events). In both phases of the trial, SJ733 hydrochloride salt was formulated as a powder blend in capsules containing 75 mg or 300 mg for oral administration. Healthy men and women (of non-childbearing potential) aged 18-55 years were eligible for both studies. Both studies are registered with ClinicalTrials.gov (NCT02661373 for the phase 1a and NCT02867059 for the phase 1b). FINDINGS: In the phase 1a, 23 healthy participants were enrolled and received one to three non-consecutive doses of SJ733 between March 14 and Dec 7, 2016. SJ733 was safe and well tolerated at all doses and in fasted and fed conditions. 119 adverse events were recorded: 54 (45%) were unrelated, 63 (53%) unlikely to be related, and two (2%) possibly related to SJ733. In the phase 1b, 17 malaria-naive, healthy participants were enrolled. Seven participants in the 150 mg dose cohort were inoculated and dosed with SJ733. Eight participants in the 600 mg dose cohort were inoculated, but two participants could not be dosed with SJ733. Two additional participants were subsequently inoculated and dosed with SJ733. SJ733 exposure increased proportional to the dose through to the 600 mg dose, then was saturable at higher doses. Fasted participants receiving 600 mg exceeded the target area under the concentration curve extrapolated to infinity (AUC0-∞) of 13 000 µg × h/L (median AUC0-∞ 24 283 [IQR 16 135-31 311] µg × h/L, median terminal half-life 17·4 h [IQR 16·1-24·0], and median timepoint at which peak plasma concentration is reached 1·0 h [0·6-1·3]), and this dose was tested in the phase 1b. All 15 participants dosed with SJ733 had at least one adverse event. Of the 172 adverse events recorded, 128 (74%) were mild. The only adverse event attributed to SJ733 was mild bilateral foot paraesthesia that lasted 3·75 h and resolved spontaneously. The most common adverse events were related to malaria. Based on parasite clearance half-life, the derived log10PRR48 and corresponding parasite clearance half-lives were 2·2 (95% CI 2·0-2·5) and 6·47 h (95% CI 5·88-7·18) for 150 mg, and 4·1 (3·7-4·4) and 3·56 h (3·29-3·88) for 600 mg. INTERPRETATION: The favourable pharmacokinetic, tolerability, and safety profile of SJ733, and rapid antiparasitic effect support its development as a fast-acting component of combination antimalarial therapy. FUNDING: Global Health Innovative Technology Fund, Medicines for Malaria Venture, and the American Lebanese Syrian Associated Charities.


Assuntos
Antimaláricos/uso terapêutico , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Isoquinolinas/uso terapêutico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Inibidores da Bomba de Prótons/uso terapêutico , Adulto , Antimaláricos/administração & dosagem , Antimaláricos/efeitos adversos , Antimaláricos/farmacocinética , Estudos de Casos e Controles , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Feminino , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Compostos Heterocíclicos de 4 ou mais Anéis/efeitos adversos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacocinética , Humanos , Isoquinolinas/administração & dosagem , Isoquinolinas/efeitos adversos , Isoquinolinas/farmacocinética , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/metabolismo , Inibidores da Bomba de Prótons/administração & dosagem , Inibidores da Bomba de Prótons/efeitos adversos , Inibidores da Bomba de Prótons/farmacocinética , Resultado do Tratamento , Adulto Jovem
16.
Parasit Vectors ; 13(1): 99, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32113471

RESUMO

BACKGROUND: Ancylostomatids ('hookworms') are among the most important zoonotic nematode parasites infecting dogs worldwide. Ancylostoma caninum and Uncinaria stenocephala are two of the most common hookworm species that infect dogs. Both immature and adult stages of hookworms are voracious blood feeders and can cause death in young dogs before infection can be detected by routine fecal examination. Hence, treatment of both immature and adult stages of hookworms will decrease the risk of important clinical disease in the dog as well as the environmental contamination caused by egg-laying adults, which should reduce the risk of infection for both dogs and humans. The studies presented here were conducted to evaluate the efficacy of a novel, oral chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™), against induced larval (L4), immature adult (L5) and adult A. caninum, and adult U. stenocephala infections in dogs. METHODS: Eight negative-controlled, masked, randomized laboratory studies were conducted. Two separate studies were conducted against each of the target parasites and stages. Sixteen or 18 purpose bred dogs, 8 or 9 in each of the two treatment groups, were included in each study. Dogs experimentally infected with the target parasite were dosed once on Day 0 with either placebo tablets or Simparica Trio™ tablets to provide minimum dosages of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5.0 mg/kg pyrantel (as pamoate salt). Timing of dosing relative to parasite inoculation allowed for efficacy to be evaluated primarily against the target parasite stage. Worm counts were conducted 7 or 8 days after treatments during necropsy. Efficacy was based on the number of worms recovered at necropsy compared to placebo control. RESULTS: Based on geometric mean worm counts, efficacy of Simparica Trio™ was ≥ 98.4% against L4 larval stage of A. caninum, ≥ 99.8% against immature adult (L5) A. caninum, and 100% against adult A. caninum and adult U. stenocephala. CONCLUSIONS: These studies confirm the efficacy of a single oral dose of a novel, chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against L4 larval and immature adult (L5) A. caninum, and adult A. caninum and U. stenocephala infections in dogs.


Assuntos
Antinematódeos/administração & dosagem , Doenças do Cão/tratamento farmacológico , Infecções por Uncinaria/veterinária , Administração Oral , Ancylostomatoidea/crescimento & desenvolvimento , Animais , Azetidinas/administração & dosagem , Doenças do Cão/parasitologia , Cães , Combinação de Medicamentos , Infecções por Uncinaria/tratamento farmacológico , Infecções por Uncinaria/parasitologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Macrolídeos/administração & dosagem , Carga Parasitária , Pirantel/administração & dosagem , Compostos de Espiro/administração & dosagem , Comprimidos , Resultado do Tratamento
17.
Parasitol Res ; 119(5): 1653-1661, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32219548

RESUMO

Ethanamizuril (EZL) is a novel triazine compound with excellent anticoccidial activity. We carried out a preliminary investigation of the effects of EZL on the different life cycle stages of Eimeria tenella. EZL mainly acted on the schizogony stage, with peak activity during the second-generation merozoite stage. We also studied the possible target of EZL by identifying the majorly differentially expressed gene affected by EZL in second-generation merozoites using real-time polymerase chain reaction, and screening for surface antigen proteins (SAGs). The relative expression levels of SAGs were compared by Western blot analysis showing that expression levels of surface antigen family member (SAGfm) and SAG19 were significantly downregulated by EZL. Immunofluorescence analysis indicated that SAGfm and SAG19 were localized on the surface of second-generation merozoites. In addition, fluorescence signals were significantly stronger in second-generation merozoites of infected non-medicated control (INC) group compared with that of the EZL group. Therefore, it was speculated that SAGs might be a potential target of EZL action. The inhibitory effects of anticoccidial drugs on SAG levels in coccidia thus warrant further research.


Assuntos
Coccidiose/tratamento farmacológico , Eimeria tenella/efeitos dos fármacos , Doenças das Aves Domésticas/prevenção & controle , Triazinas/farmacologia , Animais , Antígenos de Superfície/metabolismo , Western Blotting , Galinhas/parasitologia , Coccidiose/parasitologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Merozoítos/efeitos dos fármacos , Proteínas de Protozoários/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real
18.
Parasit Vectors ; 13(1): 65, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32051008

RESUMO

BACKGROUND: In three randomized, controlled laboratory efficacy studies, the efficacy in the prevention of patent infections of a topical combination of imidacloprid 10%/moxidectin 1% (Advocate® spot-on formulation for cats, Bayer Animal Health GmbH) against larval stages and immature adults of Aelurostrongylus abstrusus, as well as the treatment efficacy of a single or three monthly treatments against adult A. abstrusus, were evaluated. METHODS: Cats were experimentally inoculated with 300-800 third-stage larvae (L3). Each group comprised 8 animals and the treatment dose was 10 mg/kg bodyweight (bw) imidacloprid and 1 mg/kg bw moxidectin in each study. Prevention of the establishment of patent infections was evaluated by two treatments at a monthly interval at three different time points before and after challenge infection. Curative efficacy was tested by one or three treatments after the onset of patency. Worm counts at necropsy were used for efficacy calculations. RESULTS: In Study 1, the control group had a geometric mean (GM) of 28.8 adult nematodes and the single treatment group had a GM of 3.4 (efficacy 88.3%). In Study 2, the control group had a GM of 14.3, the prevention group had a GM of 0 (efficacy 100%), while the treatment group had a GM of 0.1 (efficacy 99.4%). In Study 3, the GM worm burden in the control group was 32.6 compared to 0 in all three prevention groups (efficacy 100% for all of those groups). CONCLUSIONS: The monthly administration of Advocate® reliably eliminated early larval stages and thereby prevented lung damage from and patent infections with A. abstrusus in cats. Regarding treatment, a single application of Advocate® reduced the worm burden, but it did not sufficiently clear the infection. In contrast, three monthly treatments were safe and highly efficacious against A. abstrusus.


Assuntos
Doenças do Gato/tratamento farmacológico , Doenças do Gato/prevenção & controle , Macrolídeos/administração & dosagem , Metastrongyloidea/efeitos dos fármacos , Neonicotinoides/administração & dosagem , Nitrocompostos/administração & dosagem , Infecções por Strongylida/veterinária , Administração Tópica , Animais , Doenças do Gato/parasitologia , Gatos , Esquema de Medicação , Composição de Medicamentos , Feminino , Larva/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/parasitologia , Masculino , Infecções por Strongylida/tratamento farmacológico , Infecções por Strongylida/prevenção & controle , Resultado do Tratamento
19.
PLoS Negl Trop Dis ; 14(1): e0007481, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31961864

RESUMO

BACKGROUND: Crystal violet (CV) was used for several years in blood banks to eliminate the parasite Trypanosoma cruzi in endemic areas in order to prevent transfusion-transmitted Chagas disease. One mechanism of action described for CV involves inhibition of proline uptake. In T. cruzi, proline is essential for host cell infection and intracellular differentiation among other processes, and can be obtained through the proline permease TcAAAP069. METHODOLOGY/PRINCIPAL FINDINGS: CV inhibited proline transporter TcAAAP069 and parasites overexpressing this permease were 47-fold more sensitive to this compound than control parasites. Using CV as reference molecule, loratadine, cyproheptadine, olanzapine and clofazimine were identified as structurally related compounds to CV (structural analogues) by in silico drug repurposing through a similarity-based virtual screening protocol. All these already-approved drugs for clinical use inhibited TcAAAP069 activity with different efficacies and also presented trypanocidal action in epimastigotes, trypomastigotes and amastigotes of the Y, CL Brener and Dm28c T. cruzi strains. Finally, a synergistic effect between benznidazole and the CV chemical analogues was evidenced by combination and dose-reduction indexes values in epimastigotes and trypomastigotes of the Y strain. CONCLUSIONS/SIGNIFICANCE: Loratadine, cyproheptadine and clofazimine inhibit TcAAAP069 proline transporter and also present trypanocidal effect against all T. cruzi life stages in strains from three different DTUs. These CV structural analogues could be a starting point to design therapeutic alternatives to treat Chagas disease by finding new indications for old drugs. This approach, called drug repurposing is a recommended strategy by the World Health Organization to treat neglected diseases, like Chagas disease, and combination therapy may improve the possibility of success of repositioned drugs.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros/antagonistas & inibidores , Violeta Genciana/química , Violeta Genciana/farmacologia , Proteínas de Protozoários/antagonistas & inibidores , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Doença de Chagas/parasitologia , Clofazimina/farmacologia , Simulação por Computador , Reposicionamento de Medicamentos , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Loratadina/farmacologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Tripanossomicidas/química , Trypanosoma cruzi/genética , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/metabolismo
20.
Chem Biodivers ; 17(2): e1900597, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31804031

RESUMO

A series of bis-naphthoquinone derivatives prepared by condensation of aryl aldehydes with lawsone were tested for antiparasitic activities against Toxoplasma gondii and Trypanosoma brucei parasites. Monofluorophenyl derivative 1a, 3,4-difluorophenyl analog 1c and furyl compound 1l exhibited significant activity against T. gondii cells and appear to be new promising drug candidates against this parasite. The 3,4,5-trifluorophenyl derivative 1g and the isovanillyl derivative 1j displayed selective activity against Leishmania major amastigotes.


Assuntos
Antiparasitários/química , Naftoquinonas/química , Antiparasitários/síntese química , Antiparasitários/farmacologia , Humanos , Leishmania major/efeitos dos fármacos , Leishmania major/crescimento & desenvolvimento , Estágios do Ciclo de Vida/efeitos dos fármacos , Naftoquinonas/síntese química , Naftoquinonas/farmacologia , Relação Estrutura-Atividade , Toxoplasma/efeitos dos fármacos , Trypanosoma brucei brucei/efeitos dos fármacos
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