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1.
Bioorg Chem ; 144: 107152, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38290187

RESUMO

Alzheimer's disease (AD) is the most common form of dementia affecting specifically older population. AD is an irreversible neurodegenerative CNS disorder associated with complex pathophysiology. Presently, the USFDA has approved only four drugs viz. Donepezil, Rivastigmine, Memantine, and Galantamine for the treatment of AD. These drugs exhibit their neuroprotective effects either by inhibiting cholinesterase enzyme (ChE) or N-methyl-d-aspartate (NMDA) receptor. However, the conventional therapy "one target, one molecule" has failed to provide promising therapeutic effects due to the multifactorial nature of AD. This triggered the development of a novel strategy called Multi-Target Directed Ligand (MTDL) which involved designing one molecule that acts on multiple targets simultaneously. The present review discusses the detailed pathology involved in AD and the various MTDL design strategies bearing different heterocycles, in vitro and in vivo activities of the compounds, and their corresponding structure-activity relationships. This knowledge will allow us to identify and design more effective MTDLs for the treatment of AD.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Ligantes , Donepezila/uso terapêutico , Rivastigmina/uso terapêutico , Acetilcolinesterase
2.
J Invertebr Pathol ; 204: 108114, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636720

RESUMO

Agricultural Productivity and plant health are threatened by the root-knot nematode. The use of biocontrol agents reduces the need for chemical nematicides and improves the general health of agricultural ecosystems by offering a more environmentally friendly and sustainable method of managing nematode infestations. Plant-parasitic nematodes can be efficiently managed with the use of entomopathogenic nematodes (EPNs), which are widely used biocontrol agents. This study focused on the nematicidal activity of the secondary metabolites present in the bacteria Ochrobactrum sp. identified in the EPN, Heterorhabditisindica against Root-Knot Nematode (Meloidogyne incognita). Its effect on egg hatching and survival of juveniles of root- knot nematode (RKN) was examined. The ethyl acetate component of the cell-free culture (CFC) filtrate of the Ochrobactrum sp. bacteria was tested at four different concentrations (25 %, 50 %, 75 % and 100 %) along with broth and distilled water as control. The bioactive compounds of Ochrobactrum sp. bacteria showed the highest suppression of M. incognita egg hatching (100 %) and juvenile mortality (100 %) at 100 % concentration within 24 h of incubation. In this study, unique metabolite compounds were identified through the Gas Chromatography- Mass Spectrometry (GC-MS) analysis, which were found to have anti- nematicidal activity. In light of this, molecular docking studies were conducted to determine the impact of biomolecules from Ochrobactrum sp. using significant proteins of M. incognita, such as calreticulin, sterol carrier protein 2, flavin-containing monooxygenase, pectate lyase, candidate secreted effector, oesophageal gland cell secretory protein and venom allergen-like protein. The results also showed that the biomolecules from Ochrobactrum sp. had a significant inhibitory effect on the different protein targets of M. incognita. 3-Epimacronine and Heraclenin were found to inhibit most of the chosen target protein. Among the targets, the docking analysis revealed that Heraclenin exhibited the highest binding affinity of -8.6 Kcal/mol with the target flavin- containing monooxygenase. Further, the in vitro evaluation of 3- Epimacronine confirmed their nematicidal activity against M. incognita at different concentrations. In light of this, the present study has raised awareness of the unique biomolecules of the bacterial symbiont Ochrobactrum sp. isolated from H. indica that have nematicidal properties.


Assuntos
Simulação de Acoplamento Molecular , Ochrobactrum , Tylenchoidea , Animais , Ochrobactrum/metabolismo , Antinematódeos/farmacologia , Antinematódeos/metabolismo , Antinematódeos/química , Controle Biológico de Vetores
3.
Inj Prev ; 29(1): 29-34, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36096654

RESUMO

BACKGROUND: Serious car seat installation errors occur at high rates in infants and children. These errors significantly increase the risk of child injury in a motor vehicle crash, and few interventions have addressed the challenge longitudinally. METHODS: This was a pilot randomised controlled feasibility trial of virtual car seat safety checks for caregivers of newborns recruited from an urban newborn nursery. The control (enhanced usual care (EUC)) group received an in-person car seat check as a newborn and virtual check at 9 months. The intervention group received two additional virtual checks at 3 and 6 months. Installation and infant positioning errors were documented and corrected by a child passenger safety technician (CPST). We measured feasibility and acceptability by tracking caregiver and CPST challenges, and caregiver retention. Group differences were tested for statistical significance using χ2 or Fisher's exact test for categorical variables, and two sample t-tests for continuous variables. RESULTS: 33 caregivers were randomised to the EUC and 28 to the intervention group. Virtual checks were feasible, with variable participation levels at each quarter. Wi-Fi and app challenges noted in 30%. There was satisfaction with the virtual car seat checks. At baseline, car seat installation and infant positioning errors occurred at equal frequency, and at 9 months the intervention group had a significantly lower mean proportion than the EUC group in all categories of errors. In summary, virtual seat checks are feasible and the optimal timing of repeat checks requires additional study. A larger study is needed to further evaluate the effect of longitudinal virtual checks on errors.


Assuntos
Sistemas de Proteção para Crianças , Criança , Lactente , Recém-Nascido , Humanos , Estudos de Viabilidade , Acidentes de Trânsito/prevenção & controle
4.
Int J Mol Sci ; 24(18)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37762083

RESUMO

Mitochondria are involved in the regulation of cellular energy metabolism, calcium homeostasis, and apoptosis. For mitochondrial quality control, dynamic processes, such as mitochondrial fission and fusion, are necessary to maintain shape and function. Disturbances of mitochondrial dynamics lead to dysfunctional mitochondria, which contribute to the development and progression of numerous diseases, including Type 2 Diabetes (T2D). Compelling evidence has been put forward that mitochondrial dynamics play a significant role in the metabolism-secretion coupling of pancreatic ß cells. The disruption of mitochondrial dynamics is linked to defects in energy production and increased apoptosis, ultimately impairing insulin secretion and ß cell death. This review provides an overview of molecular mechanisms controlling mitochondrial dynamics, their dysfunction in pancreatic ß cells, and pharmaceutical agents targeting mitochondrial dynamic proteins, such as mitochondrial division inhibitor-1 (mdivi-1), dynasore, P110, and 15-oxospiramilactone (S3).


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Secreção de Insulina , Dinâmica Mitocondrial , Apoptose , Proteínas Mitocondriais
5.
BMC Pregnancy Childbirth ; 22(1): 571, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35850663

RESUMO

BACKGROUND: Perinatal depression (PD) affects 10-20% of childbearing women. Telehealth is increasingly utilized for mental health services to increase access to care and overcome COVID-19 pandemic barriers. Women's perspectives on telehealth services for PD is unknown, however. This study's primary objective was to obtain the perspectives of women who participated in an 8-week group videoconference intervention for PD symptoms, including how technology impacted their experience. METHODS: We utilized theoretical sampling and included perinatal women who had completed the 8-week mindfulness-based cognitive-behavioral intervention group. Semi-structured focus groups with four to six women were conducted on a videoconference platform. Primary analysis used grounded theory and a secondary analysis used qualitative description and was conducted by two coding teams. The teams collaborated on the final themes across the analyses. RESULTS: Three groups, with a total of 17 participants were conducted. Composition consisted of seven postpartum and ten pregnant women from the 47 total participants. Identified core themes regarding their experiences of the videoconference intervention were: positive experiences, negative experiences, suggestions and ideas, and screening and communication. CONCLUSION: This study provides growing evidence informed by perinatal women of positive experiences with engagement in a videoconference intervention for PD. Telehealth may be a reasonable and acceptable platform to increase access and retention for mental health services in childbearing women. Further, this pilot work showcases videoconferencing delivery for a wide range of effective and affordable mental health services in low-resource communities.


Assuntos
COVID-19 , Telemedicina , Depressão/terapia , Feminino , Humanos , Pandemias , Gravidez , Pesquisa Qualitativa , Tecnologia
6.
Int J Mol Sci ; 23(20)2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36293194

RESUMO

Mitochondrial dynamics and bioenergetics are central to glucose-stimulated insulin secretion by pancreatic beta cells. Previously, we demonstrated that a disturbance in glucose-invoked fission impairs insulin secretion by compromising glucose catabolism. Here, we investigated whether the overexpression of mitochondrial fission regulator Drp1 in MIN6 cells can improve or rescue insulin secretion. Although Drp1 overexpression slightly improves the triggering mechanism of insulin secretion of the Drp1-knockdown cells and has no adverse effects on mitochondrial metabolism in wildtype MIN6 cells, the constitutive presence of Drp1 unexpectedly impairs insulin content, which leads to a reduction in the absolute values of secreted insulin. Coherent with previous studies in Drp1-overexpressing muscle cells, we found that the upregulation of ER stress-related genes (BiP, Chop, and Hsp60) possibly impacts insulin production in MIN6 cells. Collectively, we confirm the important role of Drp1 for the energy-coupling of insulin secretion but unravel off-targets effects by Drp1 overexpression on insulin content that warrant caution when manipulating Drp1 in disease therapy.


Assuntos
Células Secretoras de Insulina , Insulina , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Dinâmica Mitocondrial/genética , Glucose/metabolismo , Insulina Regular Humana
7.
N Engl J Med ; 379(9): 823-833, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30157391

RESUMO

BACKGROUND: Approximately 5% of patients with drug-susceptible tuberculosis have a relapse after 6 months of first-line therapy, as do approximately 20% of patients after 4 months of short-course therapy. We postulated that by analyzing pretreatment isolates of Mycobacterium tuberculosis obtained from patients who subsequently had a relapse or were cured, we could determine any correlations between the minimum inhibitory concentration (MIC) of a drug below the standard resistance breakpoint and the relapse risk after treatment. METHODS: Using data from the Tuberculosis Trials Consortium Study 22 (development cohort), we assessed relapse and cure isolates to determine the MIC values of isoniazid and rifampin that were below the standard resistance breakpoint (0.1 µg per milliliter for isoniazid and 1.0 µg per milliliter for rifampin). We combined this analysis with clinical, radiologic, and laboratory data to generate predictive relapse models, which we validated by analyzing data from the DMID 01-009 study (validation cohort). RESULTS: In the development cohort, the mean (±SD) MIC of isoniazid below the breakpoint was 0.0334±0.0085 µg per milliliter in the relapse group and 0.0286±0.0092 µg per milliliter in the cure group, which represented a higher value in the relapse group by a factor of 1.17 (P=0.02). The corresponding MIC values of rifampin were 0.0695±0.0276 and 0.0453±0.0223 µg per milliliter, respectively, which represented a higher value in the relapse group by a factor of 1.53 (P<0.001). Higher MIC values remained associated with relapse in a multivariable analysis that included other significant between-group differences. In an analysis of receiver-operating-characteristic curves of relapse based on these MIC values, the area under the curve (AUC) was 0.779. In the development cohort, the AUC in a multivariable model that included MIC values was 0.875. In the validation cohort, the MIC values either alone or combined with other patient characteristics were also predictive of relapse, with AUC values of 0.964 and 0.929, respectively. The use of a model score for the MIC values of isoniazid and rifampin to achieve 75.0% sensitivity in cross-validation analysis predicted relapse with a specificity of 76.5% in the development cohort and a sensitivity of 70.0% and a specificity of 100% in the validation cohort. CONCLUSIONS: In pretreatment isolates of M. tuberculosis with decrements of MIC values of isoniazid or rifampin below standard resistance breakpoints, higher MIC values were associated with a greater risk of relapse than lower MIC values. (Funded by the National Institute of Allergy and Infectious Diseases.).


Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana , Isoniazida/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Rifampina/farmacologia , Tuberculose/tratamento farmacológico , Adulto , Antituberculosos/uso terapêutico , Área Sob a Curva , Feminino , Humanos , Isoniazida/uso terapêutico , Masculino , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/isolamento & purificação , Curva ROC , Recidiva , Rifampina/uso terapêutico , Falha de Tratamento , Tuberculose/microbiologia
8.
J Liposome Res ; 31(3): 217-229, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32648792

RESUMO

The anti-inflammatory property of ratite oils as well as its ability to act as a penetration enhancer makes it an ideal agent to be used in transdermal formulations. The present study aims to develop an effective transfersomal delivery of 4-hydroxytamoxifen (4-OHT), an anti-cancer drug, using ratite oil as a carrier agent for the treatment of breast cancer (BC). The 4-OHT transfersomes were prepared with and without ratite oils using soy phosphatidylcholine and three different edge activators (EAs) in five different molar ratios using the rotary evaporation-ultrasonication method. Optimal transfersome formulations were selected using physical-chemical characterization and ex vivo studies. Results from physical-chemical characterization of the developed formulations found sodium taurocholate to be the most suitable EA, which recorded highest entrapment efficiency of 95.1 ± 2.70% with 85:15, (w/w) and lowest vesicle size of 82.3 ± 0.02 nm with 75:25, (w/w) molar ratios. TEM and DSC studies showed that the vesicles were readily identified and present in a nearly perfect spherical shape. In addition, formulations with emu oil had better stability than formulations with ostrich oil. Physical stability studies at 4 °C showed that ratite oil transfersomes were stable up to 4 weeks, while transfersomes without ratite oils were stable for 8 weeks. Ex vivo permeability studies using porcine skin concluded that 4-OHT transfersomal formulations with (85:15, w/w) without emu oil have the potential to be used in transdermal delivery approach to enhance permeation of 4-OHT, which may be beneficial in the treatment of BC.


Assuntos
Portadores de Fármacos , Paleógnatas , Administração Cutânea , Animais , Sistemas de Liberação de Medicamentos , Lipossomos , Óleos , Tamoxifeno
9.
Int J Food Sci Nutr ; 72(4): 470-477, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33032478

RESUMO

Hypertension is defined as the persistence of elevated blood pressure in the circulation system. The renin-angiotensin-aldosterone system is a major modulator of blood pressure. Among the risk factors of cardiovascular disease, hypertension is the most preventable and treatable, with drugs such as ACE inhibitors. Many ACE inhibitors are known to have undesirable side effects and hence, natural alternatives are being sought. Dietary polyphenols, particularly ellagitannins, are derived from plant products and are known to exhibit a variety of bioactivities. Geraniin, an ellagitannin has been shown to have antihypertensive activity in animal experiments. It is speculated that the metabolites of geraniin are responsible for its ACE inhibitory activity. We have performed in vitro ACE inhibition and in silico studies with geraniin and its metabolites (ellagic acid, urolithins). Our studies confirm that ellagic acid exhibited similar inhibitory potential to ACE as the positive control captopril.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Carboxipeptidases/efeitos dos fármacos , Glucosídeos/metabolismo , Taninos Hidrolisáveis/metabolismo , Enzima de Conversão de Angiotensina 2 , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Simulação por Computador , Cumarínicos , Ácido Elágico/metabolismo , Ácido Elágico/farmacologia , Ácido Elágico/uso terapêutico , Humanos , Hipertensão/tratamento farmacológico , Simulação de Acoplamento Molecular , Peptidil Dipeptidase A/efeitos dos fármacos , Polifenóis/farmacologia , Coelhos
10.
J Nematol ; 532021.
Artigo em Inglês | MEDLINE | ID: mdl-34661117

RESUMO

Guava is an important edible and economic fruit crop distributed worldwide. It is widely infested with root knot nematode, Meloidogyne enterolobii which plays a vital role in causing economic losses. Several management strategies were performed to enhance the health status of guava and also to reduce root knot nematode infestation. Among the different aspects, application of plant growth regulators on guava plants under nursery conditions against root knot nematode, M. enterolobii was performed. The guava plants were treated with Salicylic acid (100 ppm), Jasmonic acid (100 ppm), and Indole 3-Butyric Acid (1000 ppm) alone and in combination of two and three. The result of this study revealed that IBA at 1,000 ppm alone (T3) and combined application of plant growth regulators viz., (T4) - Salicylic acid (100 ppm) + Jasmonic acid (100 ppm) + Indole 3-Butyric Acid (1,000 ppm) showed reduction in the nematode population and establishment of new roots (compensatory) and tertiary roots. The combined application of PGRs also increased the Plant height, root length, chlorophyll index, photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll fluorescence. The activity of various enzymes like total phenols, peroxidase, polyphenol oxidase, acid phosphatase, and phenylalanine ammonia lyase were influenced and developed resistance against root knot nematode, M. enterolobii. Under field conditions, application of Pochonia chlamydosporia and Purpureocilium lilacinum reduced the nematode infestation besides increasing the yield attributes of guava plants.

11.
Physiol Mol Biol Plants ; 26(7): 1477-1488, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32647462

RESUMO

Phytic acid is a ubiquitous compound that chelates the micronutrients in food and hinder their absorption. Hence, breeding for low phytate content for producing stable low phytic acid (lpa) hybrids is essential. Phytic acid content in maize grains has been found to vary across environments and its stable expression has yet to be explored. In a view of this, forty inbreds were screened with two checks viz., CO-6 and CO-H(M)-8 across three locations. Twenty morphological and three quality traits were observed to identify the stable lines for low phytic acid with higher free inorganic phosphorous and starch. Among all the lines, UMI-467, LPA-2-285, LPA-2-395 and UMI-447 recorded a stable performance in both AMMI and GGE biplot analysis for low phytic acid (2.52-3.32 mg/g). These lines also had a higher free inorganic phosphorous, ensuring its bioavailability (1.78-1.88 mg/g). There were perturbations in yield, starch and seed characteristics of the stable low phytic acid lines due to their lower phytic acid concentrations. This stated the role of phytic acid in plant physiology and established the constraints to be faced in breeding for low phytic acid in maize. Among the lpa lines, LPA-2-285 (57.83%) and UMI-447 (55.78%) had the highest average starch content. The lowest stable phytic acid content was observed in UMI-467 (2.52 mg/g) and this line had severe reductions in yield parameters. Considering the seed and yield characteristics, LPA-2-285, LPA-2-395 and UMI-447 performed better than UMI-467. Although these four stable lines were poor in their adaptability among all the genotypes, they could be utilised as promising stable donors to facilitate the development of stable lpa hybrids.

13.
Virol J ; 16(1): 26, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30813954

RESUMO

BACKGROUND: Dengue continues to be a major international public health concern. Despite that, there is no clinically approved antiviral for treatment of dengue virus (DENV) infections. In this study, geraniin extracted from the rind of Nephelium lappaceum was shown to inhibit the replication of DENV-2 in both in vitro and in vivo experiments. METHODS: The effect of geraniin on DENV-2 RNA synthesis in infected Vero cells was tested using quantitative RT-PCR. The in vivo efficacy of geraniin in inhibiting DENV-2 infection was then tested using BALB/c mice with geraniin administered at three different times. The differences in spleen to body weight ratio, DENV-2 RNA load and liver damage between the three treatment groups as compared to DENV-2 infected mice without geraniin administration were determined on day eight post-infection. RESULTS: Quantitative RT-PCR confirmed the decrease in viral RNA synthesis of infected Vero cells when treated with geraniin. Geraniin seemed to provide a protective effect on infected BALB/c mice liver when given at 24 h pre- and 24 h post-infection as liver damage was observed to be very mild even though a significant reduction of DENV-2 RNA load in serum was not observed in these two treatment groups. However, when administered at 72 h post-infection, severe liver damage in the form of necrosis and haemorrhage had prevailed despite a substantial reduction of DENV-2 RNA load in serum. CONCLUSIONS: Geraniin was found to be effective in reducing DENV-2 RNA load when administered at 72 h post-infection while earlier administration could prevent severe liver damage caused by DENV-2 infection. These results provide evidence that geraniin is a potential candidate for the development of anti-dengue drug.


Assuntos
Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Dengue/tratamento farmacológico , Glucosídeos/farmacologia , Taninos Hidrolisáveis/farmacologia , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular , Chlorocebus aethiops , Vírus da Dengue/fisiologia , Frutas/química , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase , RNA Viral/sangue , RNA Viral/genética , Sapindaceae/química , Células Vero , Carga Viral
14.
Pak J Pharm Sci ; 32(3): 1121-1128, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31278729

RESUMO

There has been a number of studies looking into an alternative mode of therapy for the treament of breast cancer via 4-hydroxytamoxifen (4-OHT) transdermal administration.This systematic review aims to compare the safety and efficacy of a transdermal 4-OHT local therapy and oral tamoxifen (oral-T) on the treatment of ductal carcinoma in situ breast cancer. Through a systematic search of health science databases, eligible trials were located and the end points assessed were Ki-67 labeling index, concentration of 4-OHT in breast adipose tissue (ng/g) and plasma (ng/ml). Revman 5.3 version was used to perfom the meta-analysis. Three trials were identified (n=103), while only two were included for meta analysis. The mean difference between the two studies included were 0.40 and -10.58. Overall the I2 value was 89.0%, (Tau2 =53.86) and the differences between the two trials were statistically significant p=0.002. The meta analysis of the randomized controlled trials showed that the use of local transdermal therapy of 4-OHT gel is more safer than oral-T. However, due to the limited number of studies, the potential use of 4-OHT topical transdermal therapy for the treatment of breast cancer could not be concluded for healthcare professionals.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Tamoxifeno/análogos & derivados , Tamoxifeno/administração & dosagem , Administração Cutânea , Administração Oral , Antineoplásicos/farmacocinética , Carcinoma Intraductal não Infiltrante/tratamento farmacológico , Feminino , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Tamoxifeno/farmacocinética , Tamoxifeno/farmacologia
15.
Virol J ; 14(1): 229, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29162124

RESUMO

BACKGROUND: The rapid rise and spread in dengue cases, together with the unavailability of safe vaccines and effective antiviral drugs, warrant the need to discover and develop novel anti-dengue treatments. In this study the antiviral activity of geraniin, extracted from the rind of Nephelium lappaceum, against dengue virus type-2 (DENV-2) was investigated. METHODS: Geraniin was prepared from Nephelium lappaceum rind by reverse phase C-18 column chromatography. Cytotoxicity of geraniin towards Vero cells was evaluated using MTT assay while IC50 value was determined by plaque reduction assay. The mode-of-action of geraniin was characterized using the virucidal, attachment, penetration and the time-of-addition assays'. Docking experiments with geraniin molecule and the DENV envelope (E) protein was also performed. Finally, recombinant E Domain III (rE-DIII) protein was produced to physiologically test the binding of geraniin to DENV-2 E-DIII protein, through ELISA competitive binding assay. RESULTS: Cytotoxicity assay confirmed that geraniin was not toxic to Vero cells, even at the highest concentration tested. The compound exhibited DENV-2 plaque formation inhibition, with an IC50 of 1.75 µM. We further revealed that geraniin reduced viral infectivity and inhibited DENV-2 from attaching to the cells but had little effect on its penetration. Geraniin was observed to be most effective when added at the early stage of DENV-2 infection. Docking experiments showed that geraniin binds to DENV E protein, specifically at the DIII region, while the ELISA competitive binding assay confirmed geraniin's interaction with rE-DIII with high affinity. CONCLUSIONS: Geraniin from the rind of Nephelium lappaceum has antiviral activity against DENV-2. It is postulated that the compound inhibits viral attachment by binding to the E-DIII protein and interferes with the initial cell-virus interaction. Our results demonstrate that geraniin has the potential to be developed into an effective antiviral treatment, particularly for early phase dengue viral infection.


Assuntos
Vírus da Dengue/fisiologia , Dengue/tratamento farmacológico , Glucosídeos/metabolismo , Glucosídeos/farmacologia , Taninos Hidrolisáveis/metabolismo , Taninos Hidrolisáveis/farmacologia , Proteínas do Envelope Viral/metabolismo , Ligação Viral/efeitos dos fármacos , Animais , Antivirais/metabolismo , Antivirais/farmacologia , Chlorocebus aethiops , Cromatografia de Fase Reversa , Dengue/virologia , Vírus da Dengue/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica/efeitos dos fármacos , Sapindaceae/química , Células Vero , Ensaio de Placa Viral , Replicação Viral/efeitos dos fármacos
16.
J Biol Chem ; 290(33): 20284-94, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26152724

RESUMO

In response to fasting or hyperglycemia, the pancreatic ß-cell alters its output of secreted insulin; however, the pathways governing this adaptive response are not entirely established. Although the precise role of microRNAs (miRNAs) is also unclear, a recurring theme emphasizes their function in cellular stress responses. We recently showed that miR-184, an abundant miRNA in the ß-cell, regulates compensatory proliferation and secretion during insulin resistance. Consistent with previous studies showing miR-184 suppresses insulin release, expression of this miRNA was increased in islets after fasting, demonstrating an active role in the ß-cell as glucose levels lower and the insulin demand ceases. Additionally, miR-184 was negatively regulated upon the administration of a sucrose-rich diet in Drosophila, demonstrating strong conservation of this pathway through evolution. Furthermore, miR-184 and its target Argonaute2 remained inversely correlated as concentrations of extracellular glucose increased, underlining a functional relationship between this miRNA and its targets. Lastly, restoration of Argonaute2 in the presence of miR-184 rescued suppression of miR-375-targeted genes, suggesting these genes act in a coordinated manner during changes in the metabolic context. Together, these results highlight the adaptive role of miR-184 according to glucose metabolism and suggest the regulatory role of this miRNA in energy homeostasis is highly conserved.


Assuntos
Glucose/metabolismo , Ilhotas Pancreáticas/fisiologia , MicroRNAs/fisiologia , Animais , Proteínas Argonautas/metabolismo , Linhagem Celular , Homeostase/fisiologia , Ilhotas Pancreáticas/metabolismo , Camundongos , MicroRNAs/genética , Mitocôndrias/metabolismo
17.
Reprod Biomed Online ; 32(6): 635-41, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27061682

RESUMO

Polycystic ovarian syndrome (PCOS) is associated with anovulatory infertility. Luteinizing hormone/chorionic gonadotrophin receptor (LHCGR), which is critical for ovulation, has been suggested to be expressed prematurely in the ovarian follicles of women with PCOS. This study aimed to analyse the expression and activity of LHCGR in ovarian granulosa cells from PCOS patients and the involvement of ARF6 small GTPase in LHCGR internalization. Granulosa cells (GC) isolated from follicular fluid collected during oocyte retrieval from normal women (n = 19) and women with PCOS (n = 17) were used to study differences in LHCGR protein expression and activity between normal and PCOS patients. LHCGR expression is up-regulated in GC from PCOS women. LHCGR in PCOS GC is functionally active, as shown by increased cAMP production upon human gonadotrophin (HCG)-stimulation. Moreover, ARF6 is highly expressed in GC from PCOS patients and HCG-stimulation increases the concentrations of active ARF6. The inhibition of ARF6 activation attenuates HCG-induced LHCGR internalization in both normal and PCOS GC, indicating that there are no alterations in LHCGR internalisation in GC from PCOS. In conclusion, the expression and activation of LHCGR and ARF6 are up-regulated in GC from PCOS women but the mechanism of agonist-induced LHCGR internalization is unaltered.


Assuntos
Fatores de Ribosilação do ADP/metabolismo , Células da Granulosa/citologia , Síndrome do Ovário Policístico/metabolismo , Receptores do LH/metabolismo , Fator 6 de Ribosilação do ADP , Gonadotropina Coriônica/metabolismo , AMP Cíclico/metabolismo , Feminino , Líquido Folicular/metabolismo , GTP Fosfo-Hidrolases/química , Humanos , Luteína/química , Hormônio Luteinizante/metabolismo , Folículo Ovariano/metabolismo , Ovário/metabolismo , Ovulação/metabolismo , Fatores de Tempo
18.
Am J Otolaryngol ; 37(4): 304-10, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27105977

RESUMO

PURPOSE: The goal of this study was to correlate volumetric image guided disease response to clinical outcomes in patients receiving chemoradiation therapy (CRT) for locally advanced head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: Thirty four patients completing definitive CRT for locally advanced HNSCC with megavoltage computed tomography (MVCT) guided tomotherapy IMRT were retrospectively reviewed for volumetric response. Grossly identifiable primary tumor (PT) and nodal disease (ND) response was evaluated by weekly MVCT regression. Percent end-of-treatment (EOT) residual volumes and regression rates were correlated with risk of local failure (LF), progression free survival (PFS), and overall survival (OS). RESULTS: A total of 7 LFs were identified in 6 patients at a median follow-up of 8months. The mean percent EOT residual volumes for PT and ND in patients with and without LF were 20% vs. 5% (p=0.005) and 47% vs. 6% (p=0.0001), respectively. The PT and ND volume regression rates for patients with and without LF were 12.7% per week vs. 15.9% per week (p=0.04) and 3.4% per week vs. 10.5% per week (p<0.001), respectively. Utilizing an EOT cut-off value of 25% residual volume, the relative risks of LF for PT and ND were 14.7 (p=0.03) and 25 (p=0.001), respectively. Patients found with PT and/or ND residual volumes <25% at EOT had longer 2year OS of 100% vs. 67% (p=0.0023) and PFS of 87% vs. 17% (p<0.001) compared with patients with residual volumes >/= 25% at EOT. CONCLUSION: Patients with locally advanced HNSCC who have significant MVCT volume reduction over the course of definitive CRT tend to have favorable clinical outcomes.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/terapia , Radioterapia Guiada por Imagem , Idoso , Carcinoma de Células Escamosas/mortalidade , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Taxa de Sobrevida , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Carga Tumoral
19.
Prostate ; 75(6): 616-27, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25560638

RESUMO

BACKGROUND: Tissue inhibitor of metalloproteinase-1 (TIMP-1) is a 28.5 kDa secreted glycoprotein that inhibits matrix metalloproteinase (MMP) activity. Our group has previously shown that elevated plasma TIMP-1 levels predict poor survival in metastatic castration-resistant prostate cancer (CRPC) patients; however, the underlying source and impact of elevated circulating TIMP-1 protein is unknown. METHODS: In this study, we used qRT-PCR, ELISA and immunohistochemistry to evaluate TIMP-1 expression in androgen-sensitive and resistant prostate cancer (PC) cell lines, tumor tissues and patient sera, and to correlate TIMP-1 levels to expression of chromogranin A (CGA), an established marker of neuroendocrine differentiation (NED). We also explored the relationship between TIMP-1 overexpression and induction of NED by overexpressing TIMP-1 in androgen-sensitive LNCaP cells, as well as by inducing NED of LNCaP cells with IL-6. RESULTS: Patients with CRPC have significantly higher serum TIMP-1 levels compared to patients with hormone-sensitive disease. Although circulating TIMP-1 levels were increased, peripheral blood cells were not the source of elevation. Instead, elevated TIMP-1 expression was associated with higher expression of CGA in both blood and metastatic tumor tissue. We further show that androgen receptor (AR) and PSA non-expressing prostate cancer cell lines known to display NED phenotypes such as PC-3, PC-3M, and DU145 cells, expressed high levels of TIMP-1, in contrast to AR (+) and PSA (+) adenocarcinoma cell lines such as LNCaP, VCaP, and LAPC-4, which had barely detectable levels of TIMP-1. In addition, ectopic overexpression of TIMP-1 in LNCaP cells did not induce NED. However, TIMP-1 mRNA expression was elevated >10-fold during IL-6-induced NED of LNCaP cells, suggesting that TIMP-1 overexpression accompanies, but is not the driving force for NED. Finally, we show that conditioned media from androgen-resistant PC-3, PC-3M, and DU145 cells induced TIMP-1 mRNA expression in primary prostate stromal fibroblasts in an ERK and NF-κB dependent manner. CONCLUSIONS: We provide in vitro and clinical evidence to support the association between NED and elevated circulating TIMP-1 expression in CRPC. Our observation supports further evaluation of TIMP-1 as a tissue and serum biomarker for NED in CRPC.


Assuntos
Células Neuroendócrinas/citologia , Neoplasias de Próstata Resistentes à Castração/patologia , Inibidor Tecidual de Metaloproteinase-1/sangue , Diferenciação Celular , Linhagem Celular Tumoral , Cromogranina A/sangue , Humanos , Interleucina-6/farmacologia , Masculino , Quinases de Proteína Quinase Ativadas por Mitógeno/fisiologia , NF-kappa B/fisiologia , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue
20.
Pharm Biol ; 53(12): 1719-26, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25853977

RESUMO

CONTEXT: Natural products play a vital role in the discovery of leads for novel pharmacologically active drugs. Geraniin (GE) was identified as the major compound in the rind of Nephelium lappaceum L. (Sapindaceae), while ellagic and gallic acids have been shown to be its main metabolites. GE and its metabolites possess a range of bioactive properties including being an anti-infective, anticarcinogenic, antihyperglycemic, and antihypertensive. OBJECTIVE: GE and its metabolites were investigated to establish its gastrointestinal absorption and physicochemical properties. MATERIALS AND METHODS: GE was purified from N. lappaceum rind extract using reverse-phase C18 column chromatography. Lipophilicity (log P) was determined using the 1-octanol/water shake-flask method. Equilibrium solubility of GE and its metabolites (20 mg) was determined in water and four biorelevant media: simulated gastric, simulated intestinal, fasted state-simulated intestinal, and fed state-simulated intestinal after 72 h. RESULTS AND DISCUSSION: The purification yield was 10.8%; where a 97-99% pure GE was obtained. Log P values for GE, ellagic, and gallic acids were established as -0.73 ± 0.17, 0.11 ± 0.06, and 0.71 ± 0.21, respectively, establishing them as polar compounds. All three compounds were found to exhibit poor solubility in gastric (0.61-8.10 mg/mL) but good solubility in intestinal fluids (3.59-14.32 mg/mL). CONCLUSION: The above results indicate that the compounds have limited gastrointestinal absorption due to its polarities. To consider these compounds as oral drug candidates, formulation strategies are being developed.


Assuntos
Glucosídeos/química , Taninos Hidrolisáveis/química , Hipoglicemiantes/química , Extratos Vegetais/química , Sapindaceae , Fenômenos Químicos , Cristalização , Glucosídeos/isolamento & purificação , Taninos Hidrolisáveis/isolamento & purificação , Hipoglicemiantes/isolamento & purificação , Extratos Vegetais/isolamento & purificação
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