RESUMO
Indigenous clients in need of residential care for substance use disorders (SUD) often present with the diagnosis of substance use disorder (SUD) combined with intergenerational trauma (IGT) or both. SUD is exceedingly prevalent amongst Indigenous peoples due to the health impacts of colonisation, residential school trauma, and IGT on this population's health. We evaluated the effectiveness of a Two-Eyed Seeing approach in a four-week harm reduction residential treatment programme for clients with a history of SUD and IGT. This treatment approach blended Indigenous Healing practices with Seeking Safety based on Dr. Teresa Marsh's research work known as Indigenous Healing and Seeking Safety (IHSS). The data presented in this study was drawn from a larger trial. This qualitative study was undertaken in collaboration with the Benbowopka Treatment Centre in Blind River, Northern Ontario, Canada. Patient characteristic data were collected from records for 157 patients who had enrolled in the study from April 2018 to February 2020. Data was collected from the Client Quality Assurance Survey tool. We used the qualitative thematic analysis method to analyse participants' descriptive feedback about the study. Four themes were identified: (1) Motivation to attend treatment; (2) Understanding Benbowopka's treatment programme and needs to be met; (3) Satisfaction with all interventions; and (4) Moving forward. We utilised a conceptualised descriptive framework for the four core themes depicted in the medicine wheel. This qualitative study affirmed that cultural elements and the SS Western model were highly valued by all participants. The impact of the harm reduction approach, coupled with traditional healing methods, further enhanced the outcome. This study was registered with clinicaltrials.gov (identifier number NCT0464574).
Assuntos
Tratamento Domiciliar , Transtornos Relacionados ao Uso de Substâncias , Humanos , Povos Indígenas , Ontário , Instituições Acadêmicas , Transtornos Relacionados ao Uso de Substâncias/terapiaRESUMO
The development of vaccines for the treatment of COVID-19 is paving the way for new hope. Despite this, the risk of the virus mutating into a vaccine-resistant variant still persists. As a result, the demand of efficacious drugs to treat COVID-19 is still pertinent. To this end, scientists continue to identify and repurpose marketed drugs for this new disease. Many of these drugs are currently undergoing clinical trials and, so far, only one has been officially approved by FDA. Drug repurposing is a much faster route to the clinic than standard drug development of novel molecules, nevertheless in a pandemic this process is still not fast enough to halt the spread of the virus. Artificial intelligence has already played a large part in hastening the drug discovery process, not only by facilitating the selection of potential drug candidates but also in monitoring the pandemic and enabling faster diagnosis of patients. In this chapter, we focus on the impact and challenges that artificial intelligence has demonstrated thus far with respect to drug repurposing of therapeutics for the treatment of COVID-19.
Assuntos
Antivirais/uso terapêutico , Inteligência Artificial , Tratamento Farmacológico da COVID-19 , Descoberta de Drogas , Reposicionamento de Medicamentos , SARS-CoV-2/efeitos dos fármacos , Animais , Antivirais/efeitos adversos , COVID-19/diagnóstico , COVID-19/virologia , Interações Hospedeiro-Patógeno , Humanos , Aprendizado de Máquina , Estrutura Molecular , SARS-CoV-2/patogenicidade , Relação Estrutura-AtividadeRESUMO
Latest research shows that SERPINE1 overexpression has an important role in Coronavirus 2019 (COVID-19)-associated coagulopathy leading to acute respiratory distress syndrome (ARDS). However, ways to target this protein remain elusive. In this forum, we discuss recent evidence linking SERPINE1 with COVID-19-related ARDS and summarize the available data on inhibitors of this target.
Assuntos
COVID-19 , Síndrome do Desconforto Respiratório , Ativação do Complemento , Humanos , SARS-CoV-2RESUMO
Naturally occurring point mutations in apolipoprotein A-I (apoA-I), the major protein component of high-density lipoprotein (HDL), may affect plasma HDL-cholesterol levels and cardiovascular risk. Here, we evaluated the effect of human apoA-I mutations L144R (associated with low HDL-cholesterol), L178P (associated with low HDL-cholesterol and increased cardiovascular risk) and A164S (associated with increased cardiovascular risk and mortality without low HDL-cholesterol) on the structural integrity and functions of lipid-free and lipoprotein-associated apoA-I in an effort to explain the phenotypes of subjects carrying these mutations. All three mutants, in lipid-free form, presented structural and thermodynamic aberrations, with apoA-I[L178P] presenting the greatest thermodynamic destabilization. Additionally, apoA-I[L178P] displayed reduced ABCA1-mediated cholesterol efflux capacity. When in reconstituted HDL (rHDL), apoA-I[L144R] and apoA-I[L178P] were more thermodynamically destabilized compared to wild-type apoA-I, both displayed reduced SR-BI-mediated cholesterol efflux capacity and apoA-I[L144R] showed severe LCAT activation defect. ApoA-I[A164S] was thermodynamically unaffected when in rHDL, but exhibited a series of functional defects. Specifically, it had reduced ABCG1-mediated cholesterol and 7-ketocholesterol efflux capacity, failed to reduce ROS formation in endothelial cells and had reduced capacity to induce endothelial cell migration. Mechanistically, the latter was due to decreased capacity of rHDL-apoA-I[A164S] to activate Akt kinase possibly by interacting with endothelial LOX-1 receptor. The impaired capacity of rHDL-apoA-I[A164S] to preserve endothelial function may be related to the increased cardiovascular risk for this mutation. Overall, our structure-function analysis of L144R, A164S and L178P apoA-I mutants provides insights on how HDL-cholesterol levels and/or atheroprotective properties of apoA-I/HDL are impaired in carriers of these mutations.
Assuntos
Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Apolipoproteína A-I/genética , Doenças Cardiovasculares/genética , HDL-Colesterol/genética , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Apolipoproteína A-I/metabolismo , Apolipoproteína A-I/ultraestrutura , Doenças Cardiovasculares/patologia , Movimento Celular/genética , HDL-Colesterol/metabolismo , HDL-Colesterol/ultraestrutura , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Fatores de Risco de Doenças Cardíacas , Humanos , Cetocolesteróis/genética , Cetocolesteróis/metabolismo , Lipoproteínas HDL/genética , Lipoproteínas HDL/metabolismo , Lipoproteínas HDL/ultraestrutura , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas Mutantes/ultraestrutura , Mutação/genética , Receptores Depuradores Classe E/genética , Receptores Depuradores Classe E/metabolismo , Relação Estrutura-Atividade , TermodinâmicaRESUMO
Serine protease inhibitors (serpins) are a large family of proteins that regulate and control crucial physiological processes, such as inflammation, coagulation, thrombosis and thrombolysis, and immune responses. The extraordinary impact that these proteins have on numerous crucial pathways makes them an attractive target for drug discovery. In this review, we discuss recent advances in research on small-molecule modulators of serpins, examine their mode of action, analyse the structural data from crystallised protein-ligand complexes, and highlight the potential obstacles and possible therapeutic perspectives. The application of in silico methods for rational drug discovery is also summarised. In addition, we stress the need for continued research in this field.
Assuntos
Descoberta de Drogas , Inibidores de Serina Proteinase/farmacologia , Serpinas/efeitos dos fármacos , Simulação por Computador , Cristalização , Humanos , Ligantes , Serpinas/metabolismoRESUMO
Renin-angiotensin aldosterone system inhibitors are for a long time extensively used for the treatment of cardiovascular and renal diseases. AT1 receptor blockers (ARBs or sartans) act as antihypertensive drugs by blocking the octapeptide hormone Angiotensin II to stimulate AT1 receptors. The antihypertensive drug candesartan (CAN) is the active metabolite of candesartan cilexetil (Atacand, CC). Complexes of candesartan and candesartan cilexetil with 2-hydroxylpropyl-ß-cyclodextrin (2-HP-ß-CD) were characterized using high-resolution electrospray ionization mass spectrometry and solid state 13C cross-polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) spectroscopy. The 13C CP/MAS results showed broad peaks especially in the aromatic region, thus confirming the strong interactions between cyclodextrin and drugs. This experimental evidence was in accordance with molecular dynamics simulations and quantum mechanical calculations. The synthesized and characterized complexes were evaluated biologically in vitro. It was shown that as a result of CAN's complexation, CAN exerts higher antagonistic activity than CC. Therefore, a formulation of CC with 2-HP-ß-CD is not indicated, while the formulation with CAN is promising and needs further investigation. This intriguing result is justified by the binding free energy calculations, which predicted efficient CC binding to 2-HP-ß-CD, and thus, the molecule's availability for release and action on the target is diminished. In contrast, CAN binding was not favored, and this may allow easy release for the drug to exert its bioactivity.
Assuntos
2-Hidroxipropil-beta-Ciclodextrina/química , Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Benzimidazóis/química , Compostos de Bifenilo/química , Composição de Medicamentos/métodos , Pró-Fármacos/química , Tetrazóis/química , Proteínas Adaptadoras de Transdução de Sinal/química , Benzimidazóis/síntese química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Células HEK293 , Humanos , Ligação de Hidrogênio , Conformação Molecular , Simulação de Dinâmica Molecular , Sistema Renina-Angiotensina , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização por Electrospray , Tetrazóis/síntese químicaRESUMO
Despite the anticancer potential of natural products (NPs), their limited bioavailability necessitates laborious derivatization or covalent conjugation to delivery vehicles. To unleash their potential, we developed a nanohybrid delivery platform with a noncovalently tunable surface. Initially, the active compound was encapsulated in a macrocycle, p-sulfonatocalix[4]arene, enabling a 62â¯000-fold aqueous solubility amplification as also a 2.9-fold enhancement in its cytotoxicity with respect to the parent compound in SW-620 colon cancer cells. A pH stimuli responsive behavior was recorded for this formulate, where a programmable release of quercetin from the macrocycle was monitored in an acidic environment. Then, a nanoparticle gold core was decorated with calixarene hosts to accommodate noncovalently NPs. The loaded nanocarrier with the NP quercetin dramatically enhanced the cytotoxicity (>50-fold) of the parent NP in colon cancer and altered its cell membrane transport mode. In vivo experiments in a mouse 4T1 tumor model showed a reduction of tumor volume in mice treated with quercetin-loaded nanoparticles without apparent toxic effects. Further analysis of the tumor-derived RNA highlighted that treatment with quercetin-loaded nanoparticles altered the expression of 27 genes related to apoptosis.
RESUMO
This chapter includes information about the structure in equilibrium of the bioactive molecule hIAPP22-29 (NFGAILSS). The experimental structure was derived using X-ray and its 2D NOESY NMR experiments in d 6-DMSO and d-HFIP solvents. This molecule contains eight of the ten amino acids of the 20-29 region of the human islet amyloid polypeptide (hIAPP) often referred as the "amyloidogenic core." Amyloid deposits are well-known to cause as many as 20 pathological neurodegenerative disorders such as Alzheimer, Parkinson, Huntington, and Creutzfeldt-Jakob. The experimental structure was relaxed using molecular dynamics (MD) in simulation boxes consisting in DMSO and HFIP; the latter not provided by the applied software. The calculations were performed in GPUs and supercomputers, and some basic scripting is described for reference. The simulations confirmed the inter- and intramolecular forces that led to an "amyloidogenic core" observed from NOE experiments. The results showed that in DMSO and HFIP environment, Phe is not in spatial proximity with Leu or Ile, and this is consistent with an amyloidogenic core. However, in an amphipathic environment such as the model lipid bilayers, this communication is possible and may influence peptide amyloidogenic properties. The knowledge gained through this study may contribute to the rational drug design of novel peptides or organic molecules acting by modifying preventing amyloidogenic properties of the hIAPP peptide.
Assuntos
Dimetil Sulfóxido/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Espectroscopia de Ressonância Magnética/métodos , Simulação de Dinâmica Molecular , Fragmentos de Peptídeos/química , Humanos , Estrutura Secundária de ProteínaRESUMO
Cardiovascular diseases (CVDs) are becoming major contributors to the burden of disease due to genetic and environmental factors. Despite current standard oral care, cardiovascular risk remains relatively high. A triple antiplatelet therapy with a cyclooxygenase-1 (COX-1) inhibitor, a P2Y12 receptor antagonist, and a protease-activated receptor-1 (PAR-1) antagonist has been established in the secondary prevention of atherothrombosis in patients with acute myocardial infraction and in those with peripheral artery disease. However, due to the combinatorial use of three different drugs, patients receiving this triple therapy are exposed to enhanced risk of bleeding. Conforming to polypharmacology principles, the discovery of a single compound that can simultaneously block the three platelet activation pathways (PAR-1, P2Y12, and COX-1) is of importance. Natural products have served as an inexhaustible source of bioactive compounds presenting a diverse pharmaceutical profile, including anti-inflammatory, antioxidant, anticancer, and antithrombotic activity. Indeed, principal component analysis indicated that natural products have the potential to inhibit the three aforementioned pathways, though existed reports refer to single inhibition mechanism on specific receptor(s) implicated in platelet activation. We thus set out to explore possibilities that take advantage of this potential of natural products and shape the basis to produce novel compounds that could simultaneously target PAR-1, P2Y12, and COX-1 platelet activation pathways. Polyunsaturated fatty acids (PUFAs) have multiple effects leading to improvements in blood pressure and cardiac function and arterial compliance. A promising approach to achieve the desirable goal is the bioconjugation of natural products with PUFAs. Herein, we describe the principles that should be followed to develop molecular hybrids bearing triple antiplatelet activity profile.
Assuntos
Plaquetas , Ciclo-Oxigenase 1 , Inibidores de Ciclo-Oxigenase , Ácidos Graxos Insaturados , Plasma/química , Inibidores da Agregação Plaquetária , Receptor PAR-1/antagonistas & inibidores , Receptores Purinérgicos P2Y12 , Plaquetas/química , Plaquetas/metabolismo , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacocinética , Inibidores de Ciclo-Oxigenase/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Estabilidade de Medicamentos , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/farmacocinética , Ácidos Graxos Insaturados/farmacologia , Humanos , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacocinética , Inibidores da Agregação Plaquetária/farmacologia , Antagonistas do Receptor Purinérgico P2Y/química , Antagonistas do Receptor Purinérgico P2Y/farmacocinética , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Receptor PAR-1/metabolismoRESUMO
For many years structural studies of the angiotensin II type 1 receptor (AT1R) solely relied on mutagenesis experiments combined with homology modeling. The recent publication of the co-crystallized structures of AT1R with the antagonists ZD7155 and olmesartan allows comparative studies. In this chapter the binding modes of olmesartan in the crystal structures and the homology models are compared utilizing mutagenesis data. The obtained results suggest that both homology and crystal structures should be used for future rational drug design. Of paramount importance are these co-crystallized structures or homology models to be simulated in a lipid bilayer environment that mimics the biological.
Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Imidazóis/química , Simulação de Dinâmica Molecular , Naftiridinas/química , Receptor Tipo 1 de Angiotensina/química , Homologia Estrutural de Proteína , Tetrazóis/química , Cristalografia por Raios X , Humanos , Mutagênese , Receptor Tipo 1 de Angiotensina/genéticaRESUMO
Anti-apoptotic proteins, like the Bcl-2 family proteins, present an important therapeutic cancer drug target. Their activity is orchestrated through neutralization upon interaction of pro-apoptotic protein counterparts that leads to immortality of cancer cells. Therefore, generating compounds targeting these proteins is of immense therapeutic importance. Herein, Induced Fit Docking (IFD) and Molecular Dynamics (MD) simulations were performed to rationally design quercetin analogues that bind in the BH3 site of the Bcl-xL protein. IFD calculations determined their binding cavity while Molecular Mechanics Poisson Boltzmann Surface Area (MM-PBSA) and Molecular Mechanics Generalised Born Surface Area (MM-GBSA) calculations provided an insight into the binding enthalpies of the analogues. The quercetin analogues were synthesized and their binding to Bcl-xL was verified with fluorescence spectroscopy. The binding affinity and the thermodynamic parameters between Bcl-xL and quercetin-glutamic acid were estimated through Isothermal Titration Calorimetry. 2D 1H-15N HSQC NMR chemical shift perturbation mapping was used to chart the binding site of the quercetin analogues in the Bcl-xL that overlapped with the predicted poses generated by both IFD and MD calculations. Furthermore, evaluation of the four conjugates against the prostate DU-145 and PC-3 cancer cell lines, revealed quercetin-glutamic acid and quercetin-alanine as the most potent conjugates bearing the higher cytostatic activity. This pinpoints that the chemical space of natural products can be tailored to exploit new hits for difficult tractable targets such as protein-protein interactions.
Assuntos
Aminoácidos/farmacologia , Antineoplásicos/farmacologia , Citostáticos/farmacologia , Desenho de Fármacos , Quercetina/farmacologia , Proteína bcl-X/antagonistas & inibidores , Aminoácidos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Citostáticos/síntese química , Citostáticos/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Quercetina/química , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
BACKGROUND: The current standard-of-care antiplatelet therapy in cardiovascular disease patients is consisted of cyclooxygenase-1 (COX-1) inhibitor aspirin, along with a platelet receptor P2Y12 antagonist. Recently, the triple antiplatelet therapy with aspirin, a P2Y12 receptor antagonist and a protease activated receptor-1 (PAR-1) antagonist, has been suggested for the secondary prevention of atherothrombotic events, however presented an increased risk of bleeding. Therefore, the quest for novel antiplatelet agents simultaneously targeting the three pathways with improved efficacy/safety profile is of immense importance. Flavonoids as pre-validated ligands for numerous targets could serve as scaffolds targeting the three platelet activation pathways. METHODS: Computational methods, Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS) plasma stability and in vitro platelet aggregation experiments were used to establish the antiplatelet activity of the flavonoid naringenin and its conjugates. RESULTS: In silico studies indicated that naringenin could bear a potent triple antiplatelet activity by inhibiting different platelet aggregation mechanisms. However, we found that in human platelets naringenin has diminished activity. We rationally designed and synthesized different naringenin conjugates aiming to amplify the antiplatelet activity of the parent compound. UHPLC-MS/MS revealed a slow degradation rate for a docosahexaenoic acid (DHA) - naringenin conjugate in human plasma. The antiplatelet profile of the new analogues was evaluated against in vitro platelet aggregation induced by several platelet agonists. CONCLUSIONS: The DHA - naringenin hybrid presented triple antiplatelet activity simultaneously targeting PAR-1, P2Y12 and COX-1 platelet activation pathways. GENERAL SIGNIFICANCE: Natural products could offer a rich source for novel bioactives as a powerful alternative to the current combinatorial use of three different antiplatelet drugs.
Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Ciclo-Oxigenase 1/metabolismo , Flavanonas/administração & dosagem , Inibidores da Agregação Plaquetária/administração & dosagem , Receptor PAR-1/metabolismo , Receptores Purinérgicos P2Y12/metabolismo , Aspirina/uso terapêutico , Doenças Cardiovasculares/sangue , Simulação por Computador , Ciclo-Oxigenase 1/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/química , Flavanonas/síntese química , Flavonoides/administração & dosagem , Flavonoides/síntese química , Hemorragia/sangue , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Humanos , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/síntese química , Receptor PAR-1/antagonistas & inibidores , Receptores Purinérgicos P2Y12/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Padrão de Cuidado , Espectrometria de Massas em TandemRESUMO
An open and a closed conformation of a surface loop in PhaZ7 extracellular poly(3-hydroxybutyrate) depolymerase were identified in two high-resolution crystal structures of a PhaZ7 Y105E mutant. Molecular dynamics (MD) simulations revealed high root mean square fluctuations (RMSF) of the 281-295 loop, in particular at residue Asp289 (RMSF 7.62 Å). Covalent docking between a 3-hydroxybutyric acid trimer and the catalytic residue Ser136 showed that the binding energy of the substrate is significantly more favorable in the open loop conformation compared to that in the closed loop conformation. MD simulations with the substrate covalently bound depicted 1 Å RMSF higher values for the residues 281-295 in comparison to the apo (substrate-free) form. In addition, the presence of the substrate in the active site enhanced the ability of the loop to adopt a closed form. Taken together, the analysis suggests that the flexible loop 281-295 of PhaZ7 depolymerase can act as a lid domain to control substrate access to the active site of the enzyme. Proteins 2017; 85:1351-1361. © 2017 Wiley Periodicals, Inc.
Assuntos
Proteínas de Bactérias/química , Burkholderiaceae/química , Hidrolases de Éster Carboxílico/química , Hidroxibutiratos/química , Simulação de Dinâmica Molecular , Poliésteres/química , Motivos de Aminoácidos , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Burkholderiaceae/enzimologia , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Expressão Gênica , Hidroxibutiratos/metabolismo , Cinética , Simulação de Acoplamento Molecular , Mutação , Poliésteres/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , TermodinâmicaRESUMO
The interactions of irbesartan (IRB) and irbesartan-2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) complex with dipalmitoyl phosphatidylcholine (DPPC) bilayers have been explored utilizing an array of biophysical techniques ranging from differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), ESI mass spectrometry (ESI-MS) and solid state nuclear magnetic resonance (ssNMR). Molecular dynamics (MD) calculations have been also conducted to complement the experimental results. Irbesartan was found to be embedded in the lipid membrane core and to affect the phase transition properties of the DPPC bilayers. SAXS studies revealed that irbesartan alone does not display perfect solvation since some coexisting irbesartan crystallites are present. In its complexed form IRB gets fully solvated in the membranes showing that encapsulation of IRB in HP-ß-CD may have beneficial effects in the ADME properties of this drug. MD experiments revealed the topological and orientational integration of irbesartan into the phospholipid bilayer being placed at about 1nm from the membrane centre.
Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Anti-Hipertensivos/química , Compostos de Bifenilo/química , Bicamadas Lipídicas/química , Lipossomos/química , Tetrazóis/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Composição de Medicamentos , Liofilização , Irbesartana , Cinética , Simulação de Dinâmica Molecular , Transição de Fase , TermodinâmicaAssuntos
Encefalomielite Autoimune Experimental/imunologia , Conformação Molecular , Glicoproteína Mielina-Oligodendrócito/química , Animais , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/terapia , Epitopos/química , Epitopos/imunologia , Camundongos , Simulação de Dinâmica Molecular , Glicoproteína Mielina-Oligodendrócito/genética , Glicoproteína Mielina-Oligodendrócito/imunologia , Glicoproteína Mielina-Oligodendrócito/metabolismo , Ressonância Magnética Nuclear Biomolecular , Oligodendroglia/imunologia , Oligodendroglia/patologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , RatosRESUMO
Natural products have served as a rich source for drug discovery and development. In the last decade their fruitful integration in the drug discovery pipeline declined due to their reduced bioavailability, mainly attributed to their poor aqueous solubility. We synthesized a quercetin (QUE)-(2-hydroxypropyl)-ß-cyclodextrin (HP-ß-CD) complex that enabled amplification of its solubility and in the same time retained its bioactivity in T24 human bladder cancer cell line. The stability of the complex and the molecular basis of the interactions developed in this host-guest complex were assayed by incorporating an array of analytical techniques and Molecular Dynamics (MD) experiments. 2D DOSY NMR experiment revealed that the diffusion coefficient of free HP-ß-CD was 3.55×10(-10)m(2)s(-1) while that of QUE-HP-ß-CD inclusion complex 3.09×10(-10)m(2)s(-1), indicating the formation of a complex. Solid and liquid high resolution NMR spectroscopy data showed that the most pronounced differences in chemical shifts at carbons and protons correspondingly during complexation occur in the aromatic ring Α (bearing the two phenolic hydroxyl groups meta to each other). The chemical shift differences in the aromatic ring Β (bearing the two phenolic hydroxyl groups ortho to each other) were less pronounced. The MD results confirmed the experimental data.
Assuntos
Quercetina/química , Quercetina/metabolismo , beta-Ciclodextrinas/química , beta-Ciclodextrinas/metabolismo , 2-Hidroxipropil-beta-Ciclodextrina , Linhagem Celular Tumoral , Combinação de Medicamentos , Humanos , Espectroscopia de Ressonância Magnética/métodos , Modelos MolecularesRESUMO
A thorough evaluation of the antiplatelet activity profile of hexane olive leaf extract in human platelets indicated a potent activity accomplished through a two axis inhibition of platelet activation triggered both by ADP and thrombin. To delineate the extract components responsible for this dual activity, an NMR based method was established to determine and quantify the triterpenoid content leading to the characterization of uvaol, erythrodiol, and oleanolic acid. The antiplatelet profile of the total extract and of the 3 determined triterpenoids was evaluated against in vitro platelet aggregation induced by several platelet agonists as also on PAC-1 binding and P-selectin membrane expression both in healthy volunteers and in platelets from patients with an acute coronary syndrome receiving dual antiplatelet therapy with aspirin and ticagrelor. The extract was identified to inhibit ADP-induced platelet activation due to its erythrodiol content and TRAP-induced platelet activation due to the activity of uvaol and oleanolic acid.
Assuntos
Olea/química , Extratos Vegetais/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Fosfatase 2 de Especificidade Dupla/metabolismo , Humanos , Selectina-P/metabolismo , Extratos Vegetais/química , Folhas de Planta/química , Inibidores da Agregação Plaquetária/químicaRESUMO
MOTIVATION: Transient S-sulfenylation of cysteine thiols mediated by reactive oxygen species plays a critical role in pathology, physiology and cell signaling. Therefore, discovery of new S-sulfenylated sites in proteins is of great importance towards understanding how protein function is regulated upon redox conditions. RESULTS: We developed PRESS (PRotEin S-Sulfenylation) web server, a server which can effectively predict the cysteine thiols of a protein that could undergo S-sulfenylation under redox conditions. We envisage that this server will boost and facilitate the discovery of new and currently unknown functions of proteins triggered upon redox conditions, signal regulation and transduction, thus uncovering the role of S-sulfenylation in human health and disease. AVAILABILITY AND IMPLEMENTATION: The PRESS web server is freely available at http://press-sulfenylation.cse.uoi.gr/ CONTACTS: agtzakos@gmail.com or gtzortzi@cs.uoi.gr SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Assuntos
Proteínas , Simulação por Computador , Cisteína , Humanos , Oxirredução , Processamento de Proteína Pós-Traducional , Análise de Sequência de Proteína/métodos , Compostos de Sulfidrila , Ácidos de Enxofre/metabolismoRESUMO
The angiotensin II type 1 receptor (AT1R) has been recently crystallized. A new era has emerged for the structure-based rational drug design and the synthesis of novel AT1R antagonists. In this critical review, the X-ray crystallographic data of commercially available AT1R antagonists in free form are analyzed and compared with the conformational analysis results obtained using a combination of NMR spectroscopy and Molecular Modeling. The same AT1R antagonists are docked and compared in terms of their interactions in their binding site using homology models and the crystallized AT1R receptor. Various aspects derived from these comparisons regarding rational drug design are outlined.
Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Descoberta de Drogas/métodos , Receptor Tipo 1 de Angiotensina/metabolismo , Animais , Cristalografia por Raios X/métodos , Humanos , Ligantes , Espectroscopia de Ressonância Magnética/métodos , Simulação de Acoplamento Molecular , Receptor Tipo 1 de Angiotensina/químicaRESUMO
INTRODUCTION: New drug formulations against hypertension have a vital role in the quality of human life, as this risk factor for cardiovascular disease can be life threatening. A modern life style characterized by less exercise, smoking, drinking and poor diet has increased the risk of developing hypertension, the so-called silent killer, in civilized communities and thus an urgent defense is needed against this enemy. AREAS COVERED: In this review, the authors provide extensive information on pharmaceutical formulations containing anti-hypertensive drugs, as well as on general and specific patents. Thus, readers can understand the advances and new trends in the field. EXPERT OPINION: A considerable effort has been made to provide new and improved formulations, comprising anti-hypertensive drugs with new excipients, appropriate particle size, containing alkaline salts or included in cyclodextrins in an attempt to avoid known existing problems. New types of formulations are expected to emerge in the near future that will allow for more effective and spatiotemporally controlled drug delivery, which will be better tolerated by the patients and will provide better pharmaceutical treatment. Such an example is the new cocktail formulations that contain more than one active component, act synergistically and therefore have optimized pharmacological benefits. Formulations using multitarget antihypertensive drugs are also expected to be commercially available in the near future.