Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 14(1): 6368, 2024 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-38493219

RESUMO

Water is a scarce, strategic resource and the most important input for economic development, especially in agricultural countries such as Brazil. Cocoa production is directly related to water availability, and, as climate changes, selecting drought-tolerant genotypes is vital to keep cacao crops sustainable. Here, we evaluated cacao genotypes under irrigated and water-stressed conditions and selected drought-tolerant ones based on nutritional and physiological traits. Thirty-nine genotypes were monitored for three years for agronomic traits and higher fruit yield. After this evaluation, the 18 most promising genotypes were evaluated in a randomized block design, under a 2 (with and without irrigation)  ×  18 (genotypes) factorial arrangement, with three replicates and five plants per plot. We evaluated seven physiological and 11 nutritional traits, selecting genotypes based on the Genotype-by-Trait Biplot approach. Significant effects (p < 0.05) were observed for the nutritional traits N, P, Mg, S, Zn, Cu, Mn and for the physiological traits CO2 assimilation rate (A), stomatal conductance (gs), transpiration (E), intercellular and atmospheric CO2 concentrations (Ci/Ca), intrinsic water use efficiency (A/gs), instantaneous water use efficiency (A/E), and instantaneous carboxylation efficiency (A/Ci), as determined by analysis of variance. The genotype  ×  irrigation treatment interaction was significant (p < 0.05) for the traits A, gs, and E. Genotypes CP 41, CP 43, and CCN 51 exhibited superior performance for both nutritional and physiological traits (A, gs, and E). In the irrigated environment, CP 41 showed superiority in traits such as P, A/E, A/gs, Mn, S, and Zn. Conversely, under non-irrigated conditions, CP 43 exhibited better performance in nutritional properties, specifically Mn, Mg, and Zn. Notably, in both irrigated and non-irrigated environments, CCN 51 excelled in key physiological traits, including A/Ci, A/E, and A/gs. This robust performance across diverse conditions suggests that these three genotypes possess physiological mechanisms to endure water-stressed conditions. Our research can generate valuable insights into these genotypes informing suitable choices for cocoa cultivation, especially in the context of global climate change.


Assuntos
Cacau , Cacau/genética , Dióxido de Carbono , Fenótipo , Genótipo , Água/fisiologia , Desidratação
2.
Theor Appl Genet ; 137(4): 80, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472532

RESUMO

KEY MESSAGE: We propose an "enviromics" prediction model for recommending cultivars based on thematic maps aimed at decision-makers. Parsimonious methods that capture genotype-by-environment interaction (GEI) in multi-environment trials (MET) are important in breeding programs. Understanding the causes and factors of GEI allows the utilization of genotype adaptations in the target population of environments through environmental features and factor-analytic (FA) models. Here, we present a novel predictive breeding approach called GIS-FA, which integrates geographic information systems (GIS) techniques, FA models, partial least squares (PLS) regression, and enviromics to predict phenotypic performance in untested environments. The GIS-FA approach enables: (i) the prediction of the phenotypic performance of tested genotypes in untested environments, (ii) the selection of the best-ranking genotypes based on their overall performance and stability using the FA selection tools, and (iii) the creation of thematic maps showing overall or pairwise performance and stability for decision-making. We exemplify the usage of the GIS-FA approach using two datasets of rice [Oryza sativa (L.)] and soybean [Glycine max (L.) Merr.] in MET spread over tropical areas. In summary, our novel predictive method allows the identification of new breeding scenarios by pinpointing groups of environments where genotypes demonstrate superior predicted performance. It also facilitates and optimizes cultivar recommendations by utilizing thematic maps.


Assuntos
Interação Gene-Ambiente , Oryza , Meio Ambiente , Sistemas de Informação Geográfica , Modelos Genéticos , Melhoramento Vegetal , Genótipo , Oryza/genética
3.
Front Behav Neurosci ; 16: 919831, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35874651

RESUMO

Altered fear learning is a strong behavioral component of anxiety disorders such as post-traumatic stress disorder (PTSD). Recent efforts have attempted to combine exposure therapies with drugs that target fear memory retrieval and memory reconsolidation, in order to improve treatment efficacy. The noradrenergic (NA) signaling system is of particular interest, due to its role in regulating the stress response and its involvement in fear and learning processes. Importantly, propranolol (P), a non-selective ß-adrenergic antagonist, has shown the potential in decreasing exaggerated fear in both humans and animal models. In a previous study, we utilized an activity-dependent tagging murine model to determine the neural mechanisms by which propranolol attenuates learned fear. We found that propranolol acutely decreased memory trace reactivation specifically in the dorsal dentate gyrus (dDG), but not in CA3 or CA1. Here, we extended our previous study by investigating whether propranolol additionally altered activity in the hilus, a polymorphic layer that consists of neurons, mossy cells, and GABAergic interneurons. We found that propranolol acutely reduced overall hilar activity in both the dorsal and ventral hilus. Moreover, we report that propranolol significantly altered the activity of parvalbumin (PV)+ cells in the ventral (vDG), but not dorsal DG (dDG). Together, these results suggest that a ß-adrenergic blockade may affect the activity of excitatory and inhibitory cell types in the hilar layer of the DG, and that these alterations may contribute to manipulating fear memory traces.

4.
Parasitol Int ; 73: 101966, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31362122

RESUMO

The identification of new therapeutics to treat leishmaniasis is desirable, since available drugs are toxic and present high cost and/or poor availability. Therefore, the discovery of safer, more effective and selective pharmaceutical options is of utmost importance. Efforts towards the development of new candidates based on molecule analogs with known biological functions have been an interesting and cost-effective strategy. In this context, quinoline derivatives have proven to be effective biological activities against distinct diseases. In the present study, a new chloroquinoline derivate, AM1009, was in vitro tested against two Leishmania species that cause leishmaniasis. The present study analyzed the necessary inhibitory concentration to preclude 50% of the Leishmania promastigotes and axenic amastigotes (EC50 value), as well as the inhibitory concentrations to preclude 50% of the murine macrophages and human red blood cells (CC50 and RBC50 values, respectively). In addition, the treatment of infected macrophages and the inhibition of infection using pre-treated parasites were also investigated, as was the mechanism of action of the molecule in L. amazonensis. To investigate the in vivo therapeutic effect, BALB/c mice were infected with L. amazonensis and later treated with AM1009. Parasitological and immunological parameters were also evaluated. Clioquinol, a known antileishmanial quinoline derivate, and amphotericin B (AmpB), were used as molecule and drug controls, respectively. Results in both in vitro and in vivo experiments showed a better and more selective action of AM1009 to kill the in vitro parasites, as well as in treating infected mice, when compared to results obtained using clioquinol or AmpB. AM1009-treated animals presented significantly lower average lesion diameter and parasite burden in the infected tissue and organs evaluated in this study, as well as a more polarized antileishmanial Th1 immune response and low renal and hepatic toxicity. This result suggests that AM1009 should be considered a possible therapeutic target to be evaluated in future studies for treatment against leishmaniasis.


Assuntos
Antiprotozoários/farmacologia , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Quinolinas/farmacologia , Animais , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Especificidade da Espécie
5.
Exp Parasitol ; 199: 30-37, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30817917

RESUMO

The treatment against leishmaniasis presents problems, since the currently used drugs are toxic and/or have high costs. In addition, parasite resistance has increased. As a consequence, in this study, a chloroquinolin derivative, namely 7-chloro-N,N-dimethylquinolin-4-amine or GF1059, was in vitro and in vivo tested against Leishmania parasites. Experiments were performed to evaluate in vitro antileishmanial activity and cytotoxicity, as well as the treatment of infected macrophages and the inhibition of infection using pre-treated parasites. This study also investigated the GF1059 mechanism of action in L. amazonensis. Results showed that the compound was highly effective against L. infantum and L. amazonensis, presenting a selectivity index of 154.6 and 86.4, respectively, against promastigotes and of 137.6 and 74.3, respectively, against amastigotes. GF1059 was also effective in the treatment of infected macrophages and inhibited the infection of these cells when parasites were pre-incubated with it. The molecule also induced changes in the parasites' mitochondrial membrane potential and cell integrity, and caused an increase in the reactive oxygen species production in L. amazonensis. Experiments performed in BALB/c mice, which had been previously infected with L. amazonensis promastigotes, and thus treated with GF1059, showed that these animals presented significant reductions in the parasite load when the infected tissue, spleen, liver, and draining lymph node were evaluated. GF1059-treated mice presented both lower parasitism and low levels of enzymatic markers, as compared to those receiving amphotericin B, which was used as control. In conclusion, data suggested that GF1059 can be considered a possible therapeutic target to be tested against leishmaniasis.


Assuntos
Antiprotozoários/farmacologia , Cloroquinolinóis/farmacologia , Leishmania infantum/efeitos dos fármacos , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/parasitologia , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Anfotericina B/toxicidade , Animais , Antiprotozoários/uso terapêutico , Antiprotozoários/toxicidade , Cloroquinolinóis/uso terapêutico , Cloroquinolinóis/toxicidade , Modelos Animais de Doenças , Eritrócitos/efeitos dos fármacos , Feminino , Concentração Inibidora 50 , Leishmania infantum/crescimento & desenvolvimento , Leishmania mexicana/crescimento & desenvolvimento , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Visceral/tratamento farmacológico , Fígado/parasitologia , Linfonodos/parasitologia , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Espécies Reativas de Oxigênio/metabolismo , Baço/parasitologia
6.
Acta Trop ; 191: 29-37, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30586571

RESUMO

New therapeutics against leishmaniasis are desirable, since the current drugs applied against this disease complex presents problems, such as the toxicity, high cost and/or parasite resistance. In the present study, a new fluoroquinoline derivate, namely 7-chloro-N-(4-fluorophenethyl)quinolin-4-amine or GF1061, was evaluated regarding to its in vitro antileishmanial action against Leishmania infantum and L. amazonensis species, as well as by its toxicity in mammalian cells and efficacy in the treatment of infected macrophages. The mechanism of action of this molecule in L. amazonensis and the therapeutic efficacy in infected BALB/c mice were also evaluated. Results showed that GF1061 was effective against both parasite species, showing selectivity index (SI) of 38.7 and 42.7 against L. infantum and L. amazonensis promastigotes, respectively, and of 45.0 and 48.9 against the amastigotes, respectively. Amphotericin B (AmpB), used as control, showed SI values of 6.6 and 8.8 against L. infantum and L. amazonensis promastigotes, respectively, and of 2.2 and 2.7 against the amastigotes, respectively. The molecule was effective in treat infected macrophages, as well as it induced alterations in the mitochondrial membrane potential, increase in the reactive oxygen species production, and in the cell integrity of the parasites. Regarding to the in vivo experiments, BALB/c mice (n = 8 per group) were subcutaneously infected with 106L. amazonensis stationary promastigotes and, 60 days post-infection, they received saline or were treated during 10 days, once a day, with AmpB (1 mg/kg body weight) or GF1061 (5 mg/kg body weight). One day after the treatment, the infected tissue, spleen, liver, and draining lymph node (dLN) of the animals were collected, and the parasite load was evaluated. GF1061-treated mice, as compared to the saline and AmpB groups, showed significant reductions in the parasitism in the infected tissue (66% and 62%, respectively), liver (69% and 44%, respectively), spleen (71% and 38%, respectively), and dLN (72% and 48%, respectively). In conclusion, results suggested that GF1061 may be considered as a possible therapeutic target to be evaluated against leishmaniasis in other mammalian hosts.


Assuntos
Anfotericina B/farmacologia , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Fluoroquinolonas/uso terapêutico , Leishmania infantum/efeitos dos fármacos , Leishmania mexicana/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Animais , Leishmaniose/parasitologia , Fígado/parasitologia , Macrófagos/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Carga Parasitária , Espécies Reativas de Oxigênio , Baço/parasitologia
7.
Eur J Med Chem ; 73: 295-309, 2014 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-24469080

RESUMO

Twenty-seven 7-chloroquinolinotriazole derivatives with different substituents in the triazole moiety were synthesized via copper-catalyzed cycloaddition (CuAAC) click chemistry between 4-azido-7-chloroquinoline and several alkynes. All the synthetic compounds were evaluated for their in vitro activity against Plasmodium falciparum (W2) and cytotoxicity to Hep G2A16 cells. All the products disclosed low cytotoxicity (CC50 > 100 µM) and five of them have shown moderate antimalarial activity (IC50 from 9.6 to 40.9 µM). As chloroquine analogs it was expected that these compounds might inhibit the heme polymerization and SAR studies were performed aiming to explain their antimalarial profile. New structural variations can be designed on the basis of the results obtained.


Assuntos
Alcinos/química , Antimaláricos/síntese química , Azidas/química , Triazóis/síntese química , Antimaláricos/química , Antimaláricos/farmacologia , Antimaláricos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Química Click , Reação de Cicloadição , Resistência a Medicamentos , Células Hep G2 , Humanos , Estrutura Molecular , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Relação Estrutura-Atividade , Triazóis/química , Triazóis/farmacologia , Triazóis/toxicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...