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

Base de dados
Intervalo de ano de publicação
BMC Plant Biol ; 21(1): 404, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488625


BACKGROUND: Brassica carinata (A) Braun has recently gained increased attention across the world as a sustainable biofuel crop. B. carinata is grown as a summer crop in many regions where high temperature is a significant stress during the growing season. However, little research has been conducted to understand the mechanisms through which this crop responds to high temperatures. Understanding traits that improve the high-temperature adaption of this crop is essential for developing heat-tolerant varieties. This study investigated lipid remodeling in B. carinata in response to high-temperature stress. A commercial cultivar, Avanza 641, was grown under sunlit-controlled environmental conditions in Soil-Plant-Atmosphere-Research (SPAR) chambers under optimal temperature (OT; 23/15°C) conditions. At eight days after sowing, plants were exposed to one of the three temperature treatments [OT, high-temperature treatment-1 (HT-1; 33/25°C), and high-temperature treatment-2 (HT-2; 38/30°C)]. The temperature treatment period lasted until the final harvest at 84 days after sowing. Leaf samples were collected at 74 days after sowing to profile lipids using electrospray-ionization triple quadrupole mass spectrometry. RESULTS: Temperature treatment significantly affected the growth and development of Avanza 641. Both high-temperature treatments caused alterations in the leaf lipidome. The alterations were primarily manifested in terms of decreases in unsaturation levels of membrane lipids, which was a cumulative effect of lipid remodeling. The decline in unsaturation index was driven by (a) decreases in lipids that contain the highly unsaturated linolenic (18:3) acid and (b) increases in lipids containing less unsaturated fatty acids such as oleic (18:1) and linoleic (18:2) acids and/or saturated fatty acids such as palmitic (16:0) acid. A third mechanism that likely contributed to lowering unsaturation levels, particularly for chloroplast membrane lipids, is a shift toward lipids made by the eukaryotic pathway and the channeling of eukaryotic pathway-derived glycerolipids that are composed of less unsaturated fatty acids into chloroplasts. CONCLUSIONS: The lipid alterations appear to be acclimation mechanisms to maintain optimal membrane fluidity under high-temperature conditions. The lipid-related mechanisms contributing to heat stress response as identified in this study could be utilized to develop biomarkers for heat tolerance and ultimately heat-tolerant varieties.

Brassica/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Folhas de Planta/metabolismo , Estresse Fisiológico , Temperatura Alta
Front Mol Neurosci ; 13: 592126, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33281551


Cell adhesion molecules (CAMs) mediate interactions of neurons with the extracellular environment by forming adhesive bonds with CAMs on adjacent membranes or via binding to proteins of the extracellular matrix. Binding of CAMs to their extracellular ligands results in the activation of intracellular signaling cascades, leading to changes in neuronal structure and the molecular composition and function of neuronal contacts. Ultimately, many of these changes depend on the synthesis of new proteins. In this review, we summarize the evidence showing that CAMs regulate protein synthesis by modulating the activity of transcription factors, gene expression, protein translation, and the structure and distribution of organelles involved in protein synthesis and transport.

J Tradit Complement Med ; 10(6): 599-604, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33134137


Background and aim: Andrographis paniculata (Kalmegh), a valuable ancient medicinal herb is used in the treatment of several diseases in most Asian countries including India. Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial infections in human. We have investigated the antimicrobial susceptibility and the presence of AmpC gene in K. pneumoniae strain isolated from the sputum of the patient. Experimental procedure: Antibiotic susceptibility test and phenotypic detection of AmpC/ESBL beta-lactamase were performed by combined disc diffusion test. The CEA of A. paniculata was analyzed for its antibacterial potential against susceptible and resistant strains of K. pneumoniae through the broth microdilution method. Molecular detection of AmpC gene was carried by polymerase chain reaction (PCR). Results: Antibiotic susceptibility test displayed that the clinical isolate of K. pneumoniae were resistant towards cephalosporins, quinolone and monobactam but susceptible to carbapenems. Combined disk diffusion demonstrated AmpC+ve/ESBL-ve beta-lactamase. 250 µg/ml of CEA extract confirmed the inhibition of bacterial growth and biofilm formation compared to the antibiotic. CEA treated K. pneumoniae displayed a reduction of AmpC by polymerase chain reaction. Conclusion: The present study illustrates that CEA extract of A. paniculata demonstrated potentiality to control K. pneumoniae growth and biofilm formation. CEA was able to suppress the expression of gene encoding AmpC. This study proves to be an economical approach to control the growth of K. pneumoniae which causes serious infections.

BMC Complement Altern Med ; 18(1): 244, 2018 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-30176904


BACKGROUND: A. paniculata is widely known for its medicinal values and is traditionally used to treat a wide range of diseases such as cancer, diabetes, skin infections, influenza, diarrhoea, etc. The phytochemical constituents of this plant possess unique and interesting biological activities. The main focus of this study was to evaluate the antibacterial property of crude ethyl acetate (CEA) extract of A. paniculata against E. coli clinical isolates along with molecular docking of 10 different bioactive components from this plant with CTX-M-15. METHODS: CEA extract was subjected to phytochemical and FTIR analysis. The E. coli isolates were tested for antibiotic susceptibility through disk-diffusion method to observe their resistance pattern towards different antibiotics. Antibacterial activity and biofilm assay were performed through broth microdilution using a 96-well microplate. CEA extract was further utilized to observe its effect on the expression of a gene encoding CTX-M-15. Finally, in-silico studies were performed where 10 different bioactive compounds from A. paniculata were molecularly docked with CTX-M-15. RESULTS: Phytochemical and FTIR analysis detected the presence of various secondary metabolites and functional groups in CEA extract respectively. Molecular docking provided the number of residues and bond lengths together with a positive docking score. Antibiotic susceptibility showed the multi-drug resistance of all the clinical strains of E. coli. The antibacterial and antibiofilm efficiency of CEA extract (25, 50 and 100 µg/ml) was tested and 100 µg/ml of the extract was more effective in all the strains of E. coli. All 3 ESBL producing strains of E. coli were subjected to gene expression analysis through PCR. Strains treated with 100 µg/ml of the extract showed a downregulation of the gene encoding CTX-M-15 compared to untreated controls. CONCLUSIONS: The utilization of CEA extract of A. paniculata proved an economical way of controlling the growth and biofilm formation of ESBL strains of E. coli. CEA extract was also able to downregulate the expression of a gene encoding CTX-M-15. Molecular docking of 10 different bioactive compounds from A. paniculata with CTX-M-15 provided the residues and bond lengths with a positive docking score.

Andrographis/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Extratos Vegetais/farmacologia , Acetatos , Antibacterianos/química , Antibacterianos/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Escherichia coli/enzimologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Resistência beta-Lactâmica , beta-Lactamases/química , beta-Lactamases/metabolismo
Biochem Biophys Res Commun ; 493(1): 731-736, 2017 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-28865961


High-fat diet (HFD)-induced obesity is a risk factor for cognitive impairment in Alzheimer's disease (AD). It has been reported that two typical neuropathological markers of AD, ß-amyloid (Aß) peptide and hyperphosphorylated protein tau can cause neuronal apoptosis via oxidative stress, which ultimately leads to cognitive dysfunction. In this study, we tried to explore the molecular pathway underlying memory impairment in young AD transgenic mice model in response to HFD. We maintained non-transgenic control mice (non-Tg) and triple transgenic AD (3xTg-AD) mice aged 8 weeks on either normal diet (ND) containing 10% fat or HFD (60% fat) for 16 weeks. Cognitive functions were evaluated by Morris water maze and Y-maze tests. Behavioral tests showed a significant memory impairment in 3xTg-AD mice fed with HFD. HFD did not alter the levels of Aß and phospho-tau protein in the cortical region regardless of groups. However, 3xTg-AD mice fed with HFD exhibited increased neuronal oxidative stress and apoptosis as assessed by augmentation of lipid peroxidation, activation of caspase-3 and elevated ratio of Bax/Bcl-2. Furthermore, HFD markedly reduced the activation of redox-sensitive transcription factor NF-E2-related factor 2 (Nrf2) by suppressing its up-stream regulatory protein kinase B/Akt as well as down-stream targets such as heme oxygenase-1 and manganese superoxide dismutase in these mice. Our findings suggest that HFD may accelerate cognitive impairment by enhancing oxidative stress and aggravating neuronal apoptosis via inactivation of Nrf2 signaling pathway.

Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Encéfalo/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Cognição , Dieta Hiperlipídica/efeitos adversos , Proteínas tau/metabolismo , Doença de Alzheimer/complicações , Animais , Transtornos Cognitivos/etiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fatores Sexuais
Front Plant Sci ; 7: 571, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27200044


Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, abscisic acid (ABA) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression.