RESUMO
The study aimed to evaluate the antithrombotic action of Acrocomia aculeata pulp oil (AAPO) in natura, in an in vitro experimental model. AAPO was obtained by solvent extraction, and its chemical characterization was performed by gas chromatography coupled to a mass spectrometer (GC-MS). In vitro toxicity was evaluated with the Trypan Blue exclusion test and in vivo by the Galleria mellonella model. ADP/epinephrine-induced platelet aggregation after treatment with AAPO (50, 100, 200, 400, and 800 µg/mL) was evaluated by turbidimetry, and coagulation was determined by prothrombin activity time (PT) and activated partial thromboplastin time (aPTT). Platelet activation was measured by expression of P-selectin on the platelet surface by flow cytometry and intraplatelet content of reactive oxygen species (ROS) by fluorimetry. The results showed that AAPO has as major components such as oleic acid, palmitic acid, lauric acid, caprylic acid, and squalene. AAPO showed no toxicity in vitro or in vivo. Platelet aggregation decreased against agonists using treatment with different concentrations of AAPO. Oil did not interfere in PT and aPTT. Moreover, it expressively decreased ROS-induced platelet activation and P-selectin expression. Therefore, AAPO showed antiplatelet action since it decreased platelet activation verified by the decrease in P-selectin expression as well as in ROS production.
Assuntos
Fibrinolíticos , Selectina-P , Óleos de Plantas , Agregação Plaquetária , Espécies Reativas de Oxigênio , Animais , Agregação Plaquetária/efeitos dos fármacos , Selectina-P/metabolismo , Humanos , Óleos de Plantas/farmacologia , Óleos de Plantas/química , Espécies Reativas de Oxigênio/metabolismo , Fibrinolíticos/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Coagulação Sanguínea/efeitos dos fármacos , Ativação Plaquetária/efeitos dos fármacosRESUMO
Platelets are the critical target for preventing and treating pathological thrombus formation. However, despite current antiplatelet therapy, cardiovascular mortality remains high, and cardiovascular events continue in prescribed patients. In this study, first results were obtained with ortho-carbonyl hydroquinones as antiplatelet agents; we found that linking triphenylphosphonium cation to a bicyclic ortho-carbonyl hydroquinone moiety by a short alkyl chain significantly improved their antiplatelet effect by affecting the mitochondrial functioning. The mechanism of action involves uncoupling OXPHOS, which leads to an increase in mitochondrial ROS production and a decrease in the mitochondrial membrane potential and OCR. This alteration disrupts the energy production by mitochondrial function necessary for the platelet activation process. These effects are responsive to the complete structure of the compounds and not to isolated parts of the compounds tested. The results obtained in this research can be used as the basis for developing new antiplatelet agents that target mitochondria.
Assuntos
Plaquetas , Hidroquinonas , Potencial da Membrana Mitocondrial , Compostos Organofosforados , Inibidores da Agregação Plaquetária , Humanos , Plaquetas/metabolismo , Plaquetas/efeitos dos fármacos , Hidroquinonas/farmacologia , Hidroquinonas/química , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Compostos Organofosforados/farmacologia , Compostos Organofosforados/química , Fosforilação Oxidativa/efeitos dos fármacos , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Inibidores da Agregação Plaquetária/química , Espécies Reativas de Oxigênio/metabolismoRESUMO
This study reports the synthesis of novel neolignans-celecoxib hybrids and the evaluation of their biological activity. Analogs8-13(L13-L18) exhibited anti-inflammatory activity, inhibited glycoprotein expression (P-selectin) related to platelet activation, and were considered non- ulcerogenic in the animal model, even with the administration of 10 times higher than the dose used in reference therapy. In silico drug-likeness showed that the analogs are compliant with Lipinski's rule of five. A molecular docking study showed that the hybrids8-13(L13-L18) fitted similarly with celecoxib in the COX-2 active site. According to this data, it is possible to infer that extra hydrophobic interactions and the hydrogen interactions with the triazole core may improve the selectivity towards the COX-2 active site. Furthermore, the molecular docking study with P-selectin showed the binding affinity of the analogs in the active site, performing important interactions with amino acid residues such as Tyr 48. Whereas the P-selectin is a promising target to the design of new anti-inflammatory drugs with antithrombotic properties, a distinct butterfly-like structure of 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids synthesized in this work may be a safer alternative to the traditional COX-2 inhibitors.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antiulcerosos/farmacologia , Edema/tratamento farmacológico , Peritonite/tratamento farmacológico , Inibidores da Agregação Plaquetária/farmacologia , Úlcera/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Antiulcerosos/síntese química , Antiulcerosos/química , Carragenina , Celecoxib/química , Celecoxib/farmacologia , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Lignanas/química , Lignanas/farmacologia , Masculino , Camundongos , Estrutura Molecular , Peritonite/induzido quimicamente , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/síntese química , Inibidores da Agregação Plaquetária/química , Ratos , Relação Estrutura-Atividade , Triazóis/química , Triazóis/farmacologia , Úlcera/induzido quimicamenteRESUMO
Cardiovascular disease is strongly influenced by platelet activation. Platelet activation and thrombus formation at atherosclerotic plaque rupture sites is a dynamic process regulated by different signaling networks. Therefore, there are now focused efforts to search for novel bioactive compounds which target receptors and pathways in the platelet activation process while preserving normal hemostatic function. The antiplatelet activity of numerous fruits and vegetables and their multiple mechanisms of action have recently been highlighted. In this review, we review the antiplatelet actions of bioactive compounds via key pathways (protein disulfide isomerase, mitogen-activated protein kinases, mitochondrial function, cyclic adenosine monophosphate, Akt, and shear stress-induced platelet aggregation) with no effects on bleeding time. Therefore, targeting these pathways might lead to the development of effective antiplatelet strategies that do not increase the risk of bleeding.
Assuntos
Plaquetas/metabolismo , Hemorragia/prevenção & controle , Compostos Fitoquímicos/uso terapêutico , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Trombose/tratamento farmacológico , Animais , Plaquetas/efeitos dos fármacos , Hemorragia/metabolismo , Hemostasia/efeitos dos fármacos , Humanos , Compostos Fitoquímicos/farmacologia , Placa Aterosclerótica/metabolismo , Inibidores da Agregação Plaquetária/farmacologia , Trombose/metabolismoRESUMO
Ideal wound dressings should be biocompatible, exhibit high antibacterial activity, and promote blood coagulation. To impart these imperative functions, carboxymethyl-kappa-carrageenan was incorporated into poly(vinyl alcohol) nanofibers (PVA-CMKC). The antibacterial activity of the nanofibers was evaluated. Adsorption of two important blood proteins, fibrinogen and albumin, was also assessed. The adhesion and activation of platelets, and the clotting of whole blood were evaluated to characterize the ability of the nanofibers to promote hemostasis. Adhesion and morphology of both Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using fluorescence microscopy and scanning electron microscopy. CMKC-containing nanofibers demonstrated significant increases in platelet adhesion and activation, percentage of coagulation in whole blood clotting test and fibrinogen adsorption, compared to PVA nanofibers, showing blood coagulation activity. Incorporating CMKC also reduces adhesion and viability of S. aureus and P. aeruginosa bacteria after 24 h of incubation. PVA-CMKC nanofibers show potential application as dressings for wound healing applications.
Assuntos
Antibacterianos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Carragenina/farmacologia , Nanofibras/química , Cicatrização/efeitos dos fármacos , Albuminas/metabolismo , Antibacterianos/química , Bandagens , Materiais Biocompatíveis/farmacologia , Carragenina/química , Fibrinogênio/metabolismo , Humanos , Microscopia Eletrônica de Varredura/métodos , Ativação Plaquetária/efeitos dos fármacos , Álcool de Polivinil/química , Álcool de Polivinil/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacosRESUMO
Gliflozins (canagliflozin, dapagliflozin and empagliflozin) are the newest anti-hyperglycemic class and have offered cardiovascular and renal benefits. Because platelets are involved in the atherothrombosis process, this study is aimed to evaluate the direct effect of gliflozins on platelet reactivity. Platelet-rich plasma (PRP) or washed platelets (WP) were obtained from healthy volunteers. Aggregation, flow cytometry for glycoprotein IIb/IIIa, cyclic nucleotides and intracellular calcium levels, Western blot, thromboxane B2 (TXB2) measurement and COX-1 activity were performed in the presence of gliflozins (1-30 µM) alone or in combination with sodium nitroprusside (SNP, 10 or 100 nM) + iloprost (ILO, 0.1 or 1 nM). SGLT2 protein is not expressed on human platelets. Gliflozins produced little inhibitory effect in agonists-induced aggregation and this effect was greatly potentiated by ~10-fold in the presence of SNP + ILO, accompanied by lower levels of TXB2 (58.1 ± 5.1%, 47.1 ± 7.2% and 43.4 ± 9.2% inhibition for canagliflozin, dapagliflozin and empagliflozin, respectively). The activity of COX-1 was not affected by gliflozins. Collagen increased Ca2+ levels and α(IIb)ß(3) activation, both of which were significantly reduced by gliflozins + SNP + ILO. The intracellular levels of cAMP and cGMP and the protein expression of p-VASPSer157 and p-VASPSer239 were not increased by gliflozins while the expression of the serine-threonine kinase, AktSer473 was markedly reduced. Our results showed that the antiplatelet activity of gliflozins were greatly enhanced by nitric oxide and prostacyclin, thus suggesting that the cardiovascular protection seen by this class of drugs could be in part due to platelet inhibition.
Assuntos
Epoprostenol/administração & dosagem , Óxido Nítrico/administração & dosagem , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Inibidores do Transportador 2 de Sódio-Glicose/administração & dosagem , Adulto , Células Cultivadas , Sinergismo Farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/fisiologia , Transportador 2 de Glucose-Sódio/metabolismo , Adulto JovemRESUMO
Platelet activation plays a key role in cardiovascular diseases. The generation of mitochondrial reactive oxygen species (ROS) has been described as a critical step required for platelet activation. For this reason, it is necessary to find new molecules with antiplatelet activity and identify their mechanisms of action. Mitoquinone (MitoQ) is a mitochondria-targeted antioxidant that reduces mitochondrial overproduction of ROS. In this work, the antiplatelet effect of MitoQ through platelet adhesion and spreading, secretion, and aggregation was evaluated. Thus MitoQ, in a non-toxic effect, decreased platelet adhesion and spreading on collagen surface, and expression of P-selectin and CD63, and inhibited platelet aggregation induced by collagen, convulxin, thrombin receptor activator peptide-6 (TRAP-6), and phorbol 12-myristate 13-acetate (PMA). As an antiplatelet mechanism, we showed that MitoQ produced mitochondrial depolarization and decreased ATP secretion. Additionally, in platelets stimulated with antimycin A and collagen MitoQ significantly decreased ROS production. Our findings showed, for the first time, an antiplatelet effect of MitoQ that is probably associated with its mitochondrial antioxidant effect.
Assuntos
Antioxidantes/farmacologia , Plaquetas/metabolismo , Compostos Organofosforados/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Ubiquinona/análogos & derivados , Trifosfato de Adenosina/metabolismo , Animais , Plaquetas/efeitos dos fármacos , Células Cultivadas , Colágeno/metabolismo , Humanos , Camundongos , Mitocôndrias/metabolismo , Oligopeptídeos/farmacologia , Selectina-P/metabolismo , Ésteres de Forbol/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Tetraspanina 30/metabolismo , Ubiquinona/farmacologiaRESUMO
INTRODUCTION: Ticagrelor is an antiplatelet agent approved for the treatment of patients with an acute coronary syndrome or a history of myocardial infarction. Considering the evidence demonstrating that ticagrelor-mediated inhibition of platelet activation and aggregation have beneficial effects in the treatment of thrombotic conditions, clinical studies have been conducted to evaluate the use of this drug for the treatment of sickle cell disease (SCD), demonstrating satisfactory tolerability and safety. AREAS COVERED: Clinical investigation has characterized the pharmacokinetic and pharmacodynamical profile, as well as the efficacy and safety of ticagrelor to prevent painful vaso-occlusive crisis (painful episodes and acute chest syndrome) in SCD patients. EXPERT OPINION: While phase 1 and 2 clinical trials demonstrated satisfactory tolerability and safety, the conclusion of phase 3 clinical trials is crucial to prove the efficacy of ticagrelor as a therapeutic option for the treatment of SCD. Thus, it is expected that ticagrelor, especially in combination with other drugs, will improve the clinical profile and quality of life of patients with SCD.
Assuntos
Anemia Falciforme/complicações , Inibidores da Agregação Plaquetária/uso terapêutico , Antagonistas do Receptor Purinérgico P2Y/uso terapêutico , Trombofilia/tratamento farmacológico , Trombofilia/etiologia , Ticagrelor/uso terapêutico , Anemia Falciforme/sangue , Coagulação Sanguínea/efeitos dos fármacos , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Monitoramento de Medicamentos , Humanos , Estrutura Molecular , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacologia , Antagonistas do Receptor Purinérgico P2Y/química , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Trombofilia/prevenção & controle , Ticagrelor/química , Ticagrelor/farmacocinética , Resultado do TratamentoRESUMO
G protein-coupled receptors are critical mediators of platelet activation whose signaling can be modulated by members of the regulator of G protein signaling (RGS) family. The 2 most abundant RGS proteins in human and mouse platelets are RGS10 and RGS18. While each has been studied individually, critical questions remain about the overall impact of this mode of regulation in platelets. Here, we report that mice missing both proteins show reduced platelet survival and a 40% decrease in platelet count that can be partially reversed with aspirin and a P2Y12 antagonist. Their platelets have increased basal (TREM)-like transcript-1 expression, a leftward shift in the dose/response for a thrombin receptor-activating peptide, an increased maximum response to adenosine 5'-diphosphate and TxA2, and a greatly exaggerated response to penetrating injuries in vivo. Neither of the individual knockouts displays this constellation of findings. RGS10-/- platelets have an enhanced response to agonists in vitro, but platelet count and survival are normal. RGS18-/- mice have a 15% reduction in platelet count that is not affected by antiplatelet agents, nearly normal responses to platelet agonists, and normal platelet survival. Megakaryocyte number and ploidy are normal in all 3 mouse lines, but platelet recovery from severe acute thrombocytopenia is slower in RGS18-/- and RGS10-/-18-/- mice. Collectively, these results show that RGS10 and RGS18 have complementary roles in platelets. Removing both at the same time discloses the extent to which this regulatory mechanism normally controls platelet reactivity in vivo, modulates the hemostatic response to injury, promotes platelet production, and prolongs platelet survival.
Assuntos
Plaquetas/metabolismo , Ativação Plaquetária/genética , Proteínas RGS/genética , Trombopoese/genética , Animais , Plaquetas/efeitos dos fármacos , Sobrevivência Celular/genética , Camundongos , Camundongos Knockout , Fosforilação , Fator de Ativação de Plaquetas/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Contagem de Plaquetas , Proteínas RGS/metabolismo , Trombopoese/efeitos dos fármacosRESUMO
OBJECTIVE: The objective of this study was to investigate the effects of low triiodothyronine syndrome (LT3S) on platelet function and clotting factors in patients with nephrotic syndrome(NS). METHODS: Patients with primary nephrotic syndrome were divided into two groups, normal thyroid function (group A) and LT3S (group B), based on whether they had LT3S or not. Healthy subjects were selected as the control group (group C). Blood coagulation function was detected in each group. The platelet activation function (CD62P, CD63) was determined by flow cytometry. The platelet aggregation rate was detected by an optical method using adenosine diphosphate and arachidonic acid as inducers. RESULTS: The proportion of primary nephrotic syndrome with LT3S was 23.2% (69/298). Compared with group C, group A had higher CD62P and PAgTADP, and group B had higher CD62P, CD63, PAgTAA, and PAgTADP; the difference was statistically significant (all P < 0.05). There was no significant difference in renal pathology between group A and group B (X2 = 4.957, P = 0.421). Compared with group A, the 24-hour urine protein, CD63, PAgTAA, and PAgTADP were higher in group B, and APTT and Alb were lower. The difference was statistically significant (P < 0.05). Logistic regression analysis showed that LT3S was associated with CD36 (OR: 3.516; 95% CI: 1.742~8.186; P = 0.004) and PAgTAA (OR: 0.442; 95% CI: 1.001~1.251; P = 0.037). CONCLUSION: NS patients are prone to LT3S. Patients with LT3S may have abnormal platelet activation and increase of platelet aggregation.