Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
1.
J Neurosci ; 41(30): 6511-6525, 2021 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-34131030

RESUMO

Just as hippocampal lesions are principally responsible for "temporal lobe" amnesia, lesions affecting the anterior thalamic nuclei seem principally responsible for a similar loss of memory, "diencephalic" amnesia. Compared with the former, the causes of diencephalic amnesia have remained elusive. A potential clue comes from how the two sites are interconnected, as within the hippocampal formation, only the subiculum has direct, reciprocal connections with the anterior thalamic nuclei. We found that both permanent and reversible anterior thalamic nuclei lesions in male rats cause a cessation of subicular spatial signaling, reduce spatial memory performance to chance, but leave hippocampal CA1 place cells largely unaffected. We suggest that a core element of diencephalic amnesia stems from the information loss in hippocampal output regions following anterior thalamic pathology.SIGNIFICANCE STATEMENT At present, we know little about interactions between temporal lobe and diencephalic memory systems. Here, we focused on the subiculum, as the sole hippocampal formation region directly interconnected with the anterior thalamic nuclei. We combined reversible and permanent lesions of the anterior thalamic nuclei, electrophysiological recordings of the subiculum, and behavioral analyses. Our results were striking and clear: following permanent thalamic lesions, the diverse spatial signals normally found in the subiculum (including place cells, grid cells, and head-direction cells) all disappeared. Anterior thalamic lesions had no discernible impact on hippocampal CA1 place fields. Thus, spatial firing activity within the subiculum requires anterior thalamic function, as does successful spatial memory performance. Our findings provide a key missing part of the much bigger puzzle concerning why anterior thalamic damage is so catastrophic for spatial memory in rodents and episodic memory in humans.


Assuntos
Amnésia/fisiopatologia , Núcleos Anteriores do Tálamo/fisiologia , Hipocampo/fisiologia , Vias Neurais/fisiologia , Memória Espacial/fisiologia , Animais , Masculino , Ratos
2.
Saudi Pharm J ; 30(10): 1454-1463, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36387333

RESUMO

Objective: Resveratrol is a polyphenolic compound that possesses strong antioxidant and anti-inflammatory activities. This study evaluated the effects of resveratrol on oxidative stress, fibrosis and multiple genes regulation in the kidneys of high fat (HF) diet-fed rats. Methods: Wistar rats were fed with HF diet for eight weeks. These rats were also treated with resveratrol for eight weeks. Finally, kidney tissue samples were isolated from all sacrificed rats. The histological changes, creatinine and uric acid levels, oxidative stress parameters such as malondialdehyde (MDA), nitric oxide, and advanced oxidation protein product (AOPP) levels were analyzed. The antioxidant enzymes such as catalase, superoxide dismutase (SOD) activities and reduced glutathione (GSH) levels; gene expression of inflammatory and fibrosis-related genes namely, inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), transforming growth factor beta1 (TGF-ß1), and collagen-1 were assessed. Moreover, gene expression of oxidative stress-related genes such as nuclear factor erythroid 2-related factor 2 (Nrf-2), SOD, catalase, and glutathione reductase, were also assessed. Results: HF diet-fed rats showed increased creatinine and uric acid levels in plasma which were lowered by resveratrol treatment. The study findings also revealed that resveratrol counterbalanced the oxidative stress and prevented the expression of the inflammatory genes; restored the catalase and SOD activities followed by the up-regulation of antioxidant genes expression in the kidneys of HF diet-fed rats. HF diet caused the Nrf-2 down-regulation followed by the decreased expression of HO-1 and HO-2 genes, which was restored by resveratrol treatment. Moreover, the histological assessment showed lipotoxicity and increased fibrosis in the kidneys of HF diet-fed rats. Resveratrol prevented the kidney fibrosis probably by limiting oxidative stress, inflammation, and down-regulating TGF-ß1 mediated signaling pathway. Conclusion: In conclusion, resveratrol treatment showed beneficial effects in preventing oxidative stress and fibrosis in the kidneys of HF diet-fed rats probably by modulating the gene expression of oxidative stress and inflammation related factors and enzymes.

3.
Nat Chem Biol ; 13(8): 895-901, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28604695

RESUMO

The genomes of filamentous fungi contain up to 90 biosynthetic gene clusters (BGCs) encoding diverse secondary metabolites-an enormous reservoir of untapped chemical potential. However, the recalcitrant genetics, cryptic expression, and unculturability of these fungi prevent scientists from systematically exploiting these gene clusters and harvesting their products. As heterologous expression of fungal BGCs is largely limited to the expression of single or partial clusters, we established a scalable process for the expression of large numbers of full-length gene clusters, called FAC-MS. Using fungal artificial chromosomes (FACs) and metabolomic scoring (MS), we screened 56 secondary metabolite BGCs from diverse fungal species for expression in Aspergillus nidulans. We discovered 15 new metabolites and assigned them with confidence to their BGCs. Using the FAC-MS platform, we extensively characterized a new macrolactone, valactamide A, and its hybrid nonribosomal peptide synthetase-polyketide synthase (NRPS-PKS). The ability to regularize access to fungal secondary metabolites at an unprecedented scale stands to revitalize drug discovery platforms with renewable sources of natural products.


Assuntos
Aspergillus/genética , Aspergillus/metabolismo , Genes Fúngicos/genética , Família Multigênica , Metabolismo Secundário/genética , Sesterterpenos/análise , Benzodiazepinas/análise , Benzodiazepinas/metabolismo , Pirimidinonas/análise , Pirimidinonas/metabolismo , Sesterterpenos/metabolismo
4.
Foodborne Pathog Dis ; 16(10): 661-670, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31268372

RESUMO

Endophytic bacteria (EB) are a prospective source of natural and novel bioactive compounds with pharmaceutical relevance. In the present study, a total of 50 EB were isolated from the fruits and leaves of ginkgo tree (Ginkgo biloba L.), the only living species in the division Ginkgophyta and popularly known as a living fossil. All the isolated EB were screened for their antibacterial activity against five deleterious foodborne pathogenic bacteria namely Escherichia coli ATCC 43890, Salmonella Typhimurium ATCC 19586, Bacillus cereus ATCC 10876, Listeria monocytogenes ATCC19115, and Staphylococcus aureus ATCC 12600. Among the isolated EB, GbF-96, GbF-97, and GbF-98 exhibited antibacterial activity against all the pathogenic bacteria tested, with inhibition zone ranging from 33.47 to 9.55 mm. GbF-96, identified as Bacillus subtilis, exerted the highest antibacterial activity against all the tested bacteria. In contrast, the ethyl acetate extract of GbF-96 showed antibacterial activity against only B. cereus, E. coli, and Salmonella Typhimurium. Scanning electron microscopy results indicated cracked and irregular, swollen, shrunken, and lysed cell surfaces of the pathogenic bacteria treated with ethyl acetate extract of GbF-96 or B. subtilis, indicating that the metabolites of GbF-96 might penetrate the bacterial cell membranes and evoke pathways inducing cell lysis. Together, the data suggest that B. subtilis from G. biloba can be a potential candidate for controlling dreadful foodborne pathogenic bacteria, either by itself or by its metabolites.


Assuntos
Antibiose , Bacillus subtilis/fisiologia , Endófitos/isolamento & purificação , Ginkgo biloba/microbiologia , Bacillus cereus/crescimento & desenvolvimento , Bacillus subtilis/isolamento & purificação , Endófitos/fisiologia , Escherichia coli/crescimento & desenvolvimento , Microbiologia de Alimentos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Salmonella typhimurium/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento
5.
Biochemistry ; 57(23): 3237-3243, 2018 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-29533658

RESUMO

The benzodiazepine benzomalvin A/D is a fungally derived specialized metabolite and inhibitor of the substance P receptor NK1, biosynthesized by a three-gene nonribosomal peptide synthetase cluster. Here, we utilize fungal artificial chromosomes with metabolomic scoring (FAC-MS) to perform molecular genetic pathway dissection and targeted metabolomics analysis to assign the in vivo role of each domain in the benzomalvin biosynthetic pathway. The use of FAC-MS identified the terminal cyclizing condensation domain as BenY-CT and the internal C-domains as BenZ-C1 and BenZ-C2. Unexpectedly, we also uncovered evidence suggesting BenY-CT or a yet to be identified protein mediates benzodiazepine formation, representing the first reported benzodiazepine synthase enzymatic activity. This work informs understanding of what defines a fungal CT domain and shows how the FAC-MS platform can be used as a tool for in vivo analyses of specialized metabolite biosynthesis and for the discovery and dissection of new enzyme activities.


Assuntos
Aspergillus nidulans , Benzodiazepinas/metabolismo , Cromossomos Artificiais/genética , Cromossomos Fúngicos/genética , Proteínas Fúngicas , Peptídeo Sintases , Pirimidinonas/metabolismo , Aspergillus nidulans/enzimologia , Aspergillus nidulans/genética , Cromossomos Artificiais/metabolismo , Cromossomos Fúngicos/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Peptídeo Sintases/química , Peptídeo Sintases/genética , Peptídeo Sintases/metabolismo , Domínios Proteicos
6.
Eur J Neurosci ; 47(8): 1003-1012, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29512927

RESUMO

The stress response serves vital adaptive functions. However, acute stress episodes often negatively impact cognitive processing. Here, we aimed to elucidate whether stress detrimentally affects the head-direction cells of the postsubiculum, which may in turn impair downstream spatial information processing. We recorded neurons in the rats' postsubiculum during a pellet-chasing task during baseline non-stress conditions and after a 30-min acute photic stress exposure. Based on their baseline firing rate, we identified a subpopulation of head-direction cells that drastically decreased its firing rate as a response to stress while preserving their head directionality. The remaining population of head-direction cells as well as other neurons recorded in the postsubiculum were unaffected. The observed altered activity in the subpopulation might be the basis for spatial processing deficits observed following acute stress episodes.


Assuntos
Cabeça/fisiopatologia , Hipocampo/fisiologia , Orientação/fisiologia , Percepção Espacial/fisiologia , Estresse Psicológico/fisiopatologia , Animais , Masculino , Neurônios/fisiologia , Estimulação Luminosa , Ratos
7.
Adv Perit Dial ; 34(2018): 38-41, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30480535

RESUMO

Continuous ambulatory peritoneal dialysis (CAPD) is becoming increasingly known to the patients of Bangladesh, and patient numbers are increasing. Here, we report our experience and clinical outcomes in this field.Our analysis included all CAPD patients managed in a tertiary care hospital in Bangladesh between 2003 and 2015. All patients received a Tenckhoff double-cuff catheter by mini-laparotomy, and twin bags were used in most patients. In acute cases, regular exchanges were started manually with small-volume dwells the same or the next day.During the study period, 500 patients (mean age: 62 ± 18 years; 62% men; 86% percent with diabetes) were managed. Selection of CAPD was made by choice (47%) or for hemodynamic instability (32%), remote residence (17%), or poor vascular access (4%). Total duration of follow-up was 9364 patient-months (range: 1 - 78 months). The peritonitis rate was 1 episode in 30 patient-months. Fewer than 5% of patients required catheter removal. Similarly, the percentages of catheter tip migration and fluid leak were at the lower end. Patient survival was 68%, 48%, 38%, 22%, and 8% at 1, 2, 3, 5, and 7 years. Deaths were mostly attributable to vascular events.In a population with predominantly diabetic patients, CAPD was shown to be a viable mode of renal replacement therapy. The rates of peritonitis and catheter-related complications were low. Survival in the initial years can be considered acceptable.


Assuntos
Falência Renal Crônica , Diálise Peritoneal Ambulatorial Contínua , Diálise Peritoneal , Peritonite , Adulto , Idoso , Idoso de 80 Anos ou mais , Bangladesh , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias
8.
J Biosoc Sci ; 49(4): 498-508, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27866490

RESUMO

The aim of this study was to investigate the socioeconomic and demographic factors influencing the body mass index (BMI) of non-pregnant married Bangladeshi women of reproductive age. Secondary (Hierarchy) data from the 2011 Bangladesh Demographic and Health Survey, collected using two-stage stratified cluster sampling, were used. Two-level linear regression analysis was performed to remove the cluster effect of the variables. The mean BMI of married non-pregnant Bangladeshi women was 21.60±3.86 kg/m2, and the prevalence of underweight, overweight and obesity was 22.8%, 14.9% and 3.2%, respectively. After removing the cluster effect, age and age at first marriage were found to be positively (p<0.01) related with BMI. Number of children was negatively related with women's BMI. Lower BMI was especially found among women from rural areas and poor families, with an uneducated husband, with no television at home and who were currently breast-feeding. Age, total children ever born, age at first marriage, type of residence, education level, level of husband's education, wealth index, having a television at home and practising breast-feeding were found to be important predictors for the BMI of married Bangladeshi non-pregnant women of reproductive age. This information could be used to identify sections of the Bangladeshi population that require special attention, and to develop more effective strategies to resolve the problem of malnutrition.


Assuntos
Índice de Massa Corporal , Países em Desenvolvimento , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Cônjuges , Magreza/epidemiologia , Adolescente , Adulto , Bangladesh/epidemiologia , Criança , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Modelos Lineares , Pessoa de Meia-Idade , Fatores Socioeconômicos , Adulto Jovem
9.
Dev Dyn ; 244(3): 488-96, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25410786

RESUMO

BACKGROUND: The rodent salivary gland is not fully developed at birth and the cellular definitive differentiation takes place postnatally. However, little is known about its molecular mechanism. RESULTS: Here we provide the loss-of-function genetic evidence that Runx signaling affects postnatal development of the submandibular gland (SMG). Core binding factor ß (Cbfb) is a cotranscription factor which forms a heterodimer with Runx proteins. Cbfb was specifically expressed in the duct epithelium, specifically in the SMG. Epithelial Cbfb deficiency resulted in decrease in the size of the SMG and in the saliva secretion on postnatal day 35. The Cbfb mutant SMG specifically exhibited involution of the granular convoluted tubules (GCT), with a down-regulated expression of its marker genes, such as Klk1, Ngf, and Egf. The induction of GCT is under the control of androgens, and the Cbfb mutant SMG demonstrated down-regulated expression of Crisp3, an androgen-dependent transcript. Because the circulating testosterone or tissue dihydrotestosterone levels were not affected in the Cbfb mutants, it appears that Runx/Cbfb signaling regulate androgen receptor pathway, but does not affect the circulating testosterone levels or the enzymatic conversion to DHT. CONCLUSIONS: Runx signaling is important in the postnatal development of androgen-dependent GCT in the SMG.


Assuntos
Subunidades alfa de Fatores de Ligação ao Core/metabolismo , Subunidade beta de Fator de Ligação ao Core/metabolismo , Transdução de Sinais/fisiologia , Glândula Submandibular/embriologia , Animais , Subunidades alfa de Fatores de Ligação ao Core/genética , Subunidade beta de Fator de Ligação ao Core/genética , Fator de Crescimento Epidérmico/biossíntese , Fator de Crescimento Epidérmico/genética , Camundongos , Camundongos Transgênicos , Mutação , Fator de Crescimento Neural/biossíntese , Fator de Crescimento Neural/genética , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Proteínas e Peptídeos Salivares/biossíntese , Proteínas e Peptídeos Salivares/genética , Proteínas de Plasma Seminal/biossíntese , Proteínas de Plasma Seminal/genética , Glândula Submandibular/citologia
10.
Educ Health (Abingdon) ; 29(2): 124-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27549650

RESUMO

BACKGROUND: Political crisis and worsening security situation in Egypt in late 2013 resulted in Malaysian students who were pursuing their dental education in Egypt being recalled home to Malaysia. The Ministry of Higher Education in Malaysia took steps to integrate these students into public and private universities in Malaysia. METHODS: We used a questionnaire and informal interviews to learn from students returning from Egypt about their experiences transitioning from dental schools in Egypt to Malaysia. RESULTS: We discuss the challenges students faced with regards to credit transfer, pastoral care, the differences in the curriculum between the dental faculties of the two nations, and the financial implications of this disruption of their training. DISCUSSION: We live in a fragile world where similar political situations will surely arise again. The approaches used by the Malaysian government and the lessons learned from these students may help others. The perspectives of these students may help educators reintegrate expatriate students who are displaced by political instability back into the education system of their own countries.


Assuntos
Educação em Odontologia , Política , Faculdades de Odontologia/organização & administração , Estudantes de Odontologia/psicologia , Currículo/normas , Egito , Humanos , Malásia/etnologia , Faculdades de Odontologia/economia , Inquéritos e Questionários
11.
BMC Oral Health ; 16: 25, 2016 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-26920573

RESUMO

BACKGROUND: Virtual Reality Exposure Therapy (VRET) is found to be a promising and a viable alternative for in vivo exposure in the treatment of specific phobias. However, its usefulness for treating dental phobia is unexplored. The aims of the present study are to determine: (a) the efficacy of VRET versus informational pamphlet (IP) control group in terms of dental trait and state anxiety reductions at 1 week, 3 months and 6 months follow-up (b) the real-time physiological arousal [heart rate (HR)] of VRET group participants during and following therapy (c) the relation between subjective (presence) and objective (HR) measures during VRET. METHODS: This study is a single blind, randomized controlled trial with two parallel arms in which participants will be allocated to VRET or IP with a ratio of 1:1. Thirty participants (18-50 years) meeting the Phobia Checklist criteria of dental phobia will undergo block randomization with allocation concealment. The primary outcome measures include participants' dental trait anxiety (Modified Dental Anxiety Scale and Dental Fear Survey) and state anxiety (Visual Analogue Scale) measured at baseline (T0), at intervention (T1), 1-week (T2), 3 months (T3) and 6 months (T4) follow-up. A behavior test will be conducted before and after the intervention. The secondary outcome measures are real-time evaluation of HR and VR (Virtual Reality) experience (presence, realism, nausea) during and following the VRET intervention respectively. The data will be analyzed using intention-to-treat and per-protocol analysis. DISCUSSION: This study uses novel non-invasive VRET, which may provide a possible alternative treatment for dental anxiety and phobia. TRIAL REGISTRATION NUMBER: ISRCTN25824611 , Date of registration: 26 October 2015.


Assuntos
Ansiedade ao Tratamento Odontológico/terapia , Transtornos Fóbicos/terapia , Terapia de Exposição à Realidade Virtual , Humanos , Projetos de Pesquisa , Método Simples-Cego , Resultado do Tratamento
12.
Amino Acids ; 46(10): 2435-44, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25048030

RESUMO

Inhibitors of histone deacetylases (HDACs) are a promising class of anticancer agents that have an effect on gene regulation. The naturally occurring cyclic depsipeptide FK228 containing disulfide and Largazole possessing thioester functionalities act as pro-drugs and share the same HDAC inhibition mechanism in cell. Inspired from these facts, we have reported bicyclic tetrapeptide disulfide HDAC inhibitors resembling FK228 with potent activity and enhanced selectivity. In the present study, we report the design and synthesis of several mono and bicyclic tetrapeptide thioester HDAC inhibitors that share the inhibition mechanism similar to Largazole. Most of the compounds showed HDAC1 and HDAC4 inhibition and p21 promoting activity in nanomolar ranges. Among these the monocyclic peptides 1, 2 and bicyclic peptide, 4 are notable demanding more advanced research to be promising anticancer drug candidates.


Assuntos
Antineoplásicos/síntese química , Desenho de Fármacos , Inibidores de Histona Desacetilases/síntese química , Oligopeptídeos/síntese química , Peptídeos Cíclicos/síntese química , Pró-Fármacos/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular , Genes Reporter/efeitos dos fármacos , Células HEK293 , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/genética , Histona Desacetilase 1/metabolismo , Desacetilase 6 de Histona , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/química , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Camundongos , Vison , Estrutura Molecular , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Concentração Osmolar , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Regiões Promotoras Genéticas/efeitos dos fármacos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
13.
Bioorg Med Chem ; 22(15): 3862-70, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25022972

RESUMO

Several histone deacetylase (HDAC) inhibiting bicyclic tetrapeptides have been designed and synthesized through intramolecular ring-closing metathesis (RCM) reaction and peptide cyclization. We designed bicyclic tetrapeptides based on CHAP31, trapoxin B and HC-toxin I. The HDAC inhibitory and p21 promoter assay results showed that the aliphatic loop position as well as the hydrophobicity plays an important role toward the activity of the bicyclic tetrapeptide HDAC inhibitors.


Assuntos
Inibidores de Histona Desacetilases/química , Oligopeptídeos/química , Peptídeos Cíclicos/química , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/metabolismo , Histona Desacetilases/química , Histona Desacetilases/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Peptídeos e Proteínas de Sinalização Intercelular , Oligopeptídeos/síntese química , Peptídeos/química , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/metabolismo , Ligação Proteica
14.
Bioorg Med Chem ; 22(15): 3850-5, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24997578

RESUMO

The naturally occurring cyclic depsipeptide, FK228 inhibits histone deacetylase (HDAC) enzymes after reductive cleavage of intra-molecular disulfide bond. One of the sulfhydryl groups produced in the reduction interacts with zinc atom that involved in the catalytic mechanism of type 1 and 2 HDACs such as HDAC1, HDAC4, and HDAC6. In the present study, we describe the development of CHAP31, trapoxin B and HC-toxin based cyclic tetrapeptides with intra-molecular disulfide bond as HDAC inhibitors. The bicyclic tetrapeptides disulfide showed potent HDAC1 and HDAC4 inhibition and p21 promoting activity.

15.
Eur J Nutr ; 53(1): 233-42, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23575770

RESUMO

PURPOSE: Accumulating evidence suggests that inhibitors of aldose reductase (AR) may prevent hyperglycemia-induced long-term complications in diabetes mellitus. In the present study, we evaluated the AR inhibitory potential of ethanolic (EtOH) extracts from 22 seaweed species. METHODS: AR inhibitory activities of the selected seaweed species were evaluated using the rat lens aldose reductase (RLAR) inhibitory assay. RESULTS: All extracts exhibited RLAR inhibitory activity, which ranged from 5.87 to 92.71 % at a concentration of 50 µg/mL. Since Capsosiphon fulvescens exhibited significant inhibitory potential and is a frequently used foodstuff, it was selected for a detailed investigation using RLAR and advanced glycation end products (AGE) formation inhibitory assays. Among the different solvent-soluble fractions, the CH2Cl2, EtOAc, and n-BuOH fractions showed promising RLAR and AGE formation inhibitory activities. Considering the AR inhibitory potential, CH2Cl2 and EtOAc fractions were selected for chromatographic separation and yielded 11 compounds in which capsofulvesin A, capsofulvesin B, and chalinasterol showed potential RLAR inhibitory activity with the respective IC50 values of 52.53, 101.92, and 345.27 µM. Kinetic studies revealed that capsofulvesin A and chalinasterol exhibited mixed type inhibition, while capsofulvesin B exhibited noncompetitive inhibition. To our knowledge, this is the first report of AR inhibitory activity of the glycolipids capsofulvesin A and capsofulvesin B. CONCLUSIONS: Our results clearly indicate the potential RLAR and AGE formation inhibitory activities of C. fulvescens as well as its isolated constituents, which could be further explored to develop therapeutic modalities for the treatment of diabetes and related complications.


Assuntos
Aldeído Redutase/metabolismo , Clorófitas/química , Produtos Finais de Glicação Avançada/metabolismo , Cristalino/efeitos dos fármacos , Cristalino/enzimologia , Extratos Vegetais/farmacologia , Aldeído Redutase/antagonistas & inibidores , Animais , Diabetes Mellitus/prevenção & controle , Inibidores Enzimáticos/farmacologia , Produtos Finais de Glicação Avançada/antagonistas & inibidores , Ratos
16.
Bioorg Chem ; 57: 121-126, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25462987

RESUMO

Histone deacetylase (HDAC) inhibitors are a class of potential therapeutics for the treatment of cancer. Bicyclic tetrapeptides equipped with methoxymethyl ketone and boronic acid as zinc-binding group were designed and synthesized. The inhibitory activities of these compounds were evaluated against HDAC enzymes. The cell-free and cell-based assay data showed that both potency and selectivity changed with the change in zinc-binding group. Boronic acid-based compound showed poor activity whereas methoxymethyl ketone-based compound displayed impressive activity in both cell-free and cell-based conditions.


Assuntos
Ácidos Borônicos/química , Ácidos Borônicos/farmacologia , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Sítios de Ligação , Linhagem Celular , Histona Desacetilases/metabolismo , Humanos , Cetonas/metabolismo , Metilação , Zinco/metabolismo
17.
Biol Res ; 47: 51, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25299149

RESUMO

BACKGROUND: Tribolium castaneum (Herbst) is a harmful pest of stored grain and flour-based products in tropical and subtropical region. In the present study, rhizome of Drynaria quercifolia (J. Smith) was evaluated for pesticidal and pest repellency activities against T. castaneum, using surface film method and filter paper disc method, respectively. In addition, activity of the isolated compound 3,4-dihydroxybenzoic acid was evaluated against the pest. RESULTS: Chloroform soluble fraction of ethanol extract of rhizome of D. quercifolia showed significant pesticidal activity at doses 0.88 to 1.77 mg/cm(2) and significant pest repellency activity at doses 0.94 to 0.23 mg/cm(2). No pesticidal and pest repellency activity was found for petroleum ether, ethyl acetate and methanol soluble fractions of ethanol extract as well as for 3,4-dihydroxybenzoic acid. CONCLUSION: Considering our findings it can be concluded that chloroform soluble fraction of rhizome of D. quercifolia is useful in controlling T. castaneum of stored grain and flour-based products.


Assuntos
Hidroxibenzoatos/farmacologia , Repelentes de Insetos/farmacologia , Controle de Pragas/métodos , Praguicidas , Polypodiaceae/química , Rizoma/química , Tribolium/efeitos dos fármacos , Acetatos , Alcanos , Animais , Clorofórmio , Etanol , Hidroxibenzoatos/isolamento & purificação , Dose Letal Mediana , Metanol , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação
18.
Foods ; 13(9)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38731656

RESUMO

The traditional practice of harvesting and processing raw date palm sap is not only culturally significant but also provides an essential nutritional source in South Asia. However, the potential for bacterial or viral contamination from animals and environmental sources during its collection remains a serious and insufficiently studied risk. Implementing improved food safety measures and collection techniques could mitigate the risk of these infections. Additionally, the adoption of advanced food analytical methods offers the potential to identify pathogens and uncover the natural bacterial diversity of these products. The advancement of next-generation sequencing (NGS) technologies, particularly nanopore sequencing, offers a rapid and highly mobile solution. In this study, we employed nanopore sequencing for the bacterial metabarcoding of a set of raw date palm sap samples collected without protective coverage against animals in Bangladesh in 2021. We identified several bacterial species with importance in the natural fermentation of the product and demonstrated the feasibility of this NGS method in the surveillance of raw palm sap products. We revealed two fermentation directions dominated by either Leuconostoc species or Lactococcus species in these products at the first 6 h from harvest, along with opportunistic human pathogens in the background, represented with lower abundance. Plant pathogens, bacteria with the potential for opportunistic human infection and the sequences of the Exiguobacterium genus are also described, and their potential role is discussed. In this study, we demonstrate the potential of mobile laboratory solutions for food safety purposes in low-resource areas.

19.
Res Microbiol ; : 104229, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38992820

RESUMO

The global human population is growing and demand for food is increasing. Global agriculture faces numerous challenges, including excessive application of synthetic pesticides, emergence of herbicide-and pesticide-resistant pathogenic microbes, and more frequent natural disasters associated with global warming. Searches for valuable endophytes have increased, with the aim of making agriculture more sustainable and environmentally friendly. Endophytic microbes are known to have a variety of beneficial effects on plants. They can effectively transfer nutrients from the soil into plants, promote plant growth and development, increase disease resistance, increase stress tolerance, prevent herbivore feeding, reduce the virulence of pathogens, and inhibit the growth of rival plant species. Endophytic microbes can considerably minimize the need for agrochemicals, such as fertilizers, fungicides, bactericides, insecticides, and herbicides in the cultivation of crop plants. This review summarizes current knowledge on the roles of endophytes focusing on their mechanisms of disease control against phytopathogens through the secretion of antimicrobial substances and volatile organic compounds, and the induction of systemic resistance in plants. Additionally, the beneficial roles of these endophytes and their metabolites in the control of postharvest diseases in plants have been summarized.

20.
Heliyon ; 10(3): e25057, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38322874

RESUMO

The aim of this study was to evaluate the effect of l-carnitine (L-CAR) treatment on isoprenaline (ISO) administered kidney and heart impairment in male Long Evans rats. Four groups of rats were engaged in this study such as control, ISO, control + L-CAR, and ISO + L-CAR, where n = 6 in each group. The rats were also provided with chow food and water ad libitum. At the end of the study, all rats were sacrificed, and blood and tissue samples were collected for bio-chemical analysis. Oxidative stress parameters and antioxidant enzyme activities were determined in plasma and tissues. Antioxidant and inflammatory genes expression were analyzed in the kidney cortex, and histopathological studies of kidney tissues were performed. This study showed that creatinine and uric acid in plasma were significantly increased in ISO-administered rats. l-carnitine treatment lowered the uric acid and creatinine level. ISO-administered rats showed increased lipid peroxidation and declined levels of antioxidant enzymes activities in kidneys and heart. l-carnitine treatment restored antioxidant enzymes activities and protect against oxidative stress in kidney and heart. This effect is correlated with the restoration of Nrf-2-HO-1 genes expression followed by increased SOD and catalase genes expression in the kidney. l-carnitine treatment also prevented the TNF-α, IL-6, and NF-кB expression in kidneys of ISO administered rats. Histopathology staining showed that l-carnitine treatment prevented kidney damage and collagen deposition in ISO administered rats. The result of this study exhibited that l-carnitine treatment reduced oxidative stress and increased antioxidant enzyme activities by enhancing antioxidant genes expression in ISO administered rats.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa