Effect of Aloe-emodin on Aβ42 Aggregation and Cytotoxicity in Presence of Al3+ / 中国实验方剂学杂志

ObjectiveTo study the inhibitory effect of aloe-emodin （AE） on aluminum ion （Al3+）-induced β-amyloid protein 42 （Aβ42） aggregation and its depolymerization on formed Aβ42-Al3+ aggregates in vitro， and to investigate the effect of AE on the cytotoxicity of Aβ42 aggregation in the presence of Al3+. MethodThe Aβ42 group， Aβ42+Al3+ group， Aβ42+AE group， Aβ42+Al3++AE group and the depolymerization test group were set up in the experiment. The aggregation fibrosis process， aggregation morphology， aggregation size and cytotoxicity of Aβ42 in each group were detected by thioflavin T （ThT） fluorescence assay， transmission electron microscopy （TEM）， dynamic light scattering （DLS） experiment and thiazolyl blue （MTT） cytotoxicity assay. ResultCompared with the Aβ42 group， Al3+ could promote Aβ42 aggregation， increase the fluorescence intensity of ThT by 124.48%， induce the aggregation of Aβ42 to form fiber bundles with larger particle size， and significantly reduce the cell viability of human neuroblastoma SH-SY5Y cells （P<0.01）， thus reducing the cell survival rate to 51.05%. AE not only inhibited Aβ42 aggregation， but also inhibited Al3+-induced Aβ42 aggregation in a concentration-dependent manner. Compared with the Aβ42+Al3+ group， high concentration of AE could reduce the ThT fluorescence intensity to 41.66%， and change the polypeptide aggregation pathway to form amorphous aggregates with small particle size. Besides， it significantly inhibited the cytotoxicity of Aβ42 induced by Al3+ （P<0.01）， and restored the cell survival rate to 84.87%. Further depolymerization was conducted， AE could depolymerize Aβ42-Al3+ aggregates to make the formed aggregates disappear and form some small-particle short fibers and amorphous structure aggregates with low toxicity. ConclusionAE can inhibit Aβ42 aggregation and cytotoxicity in the presence of Al3+， depolymerize the formed Aβ42-Al3+ aggregates and alleviate the cytotoxicity， thus laying the foundation for exploring the mechanism of AE in the treatment of Alzheimer's disease.

Effect of Aloe-emodin on Aβ42 Aggregation and Cytotoxicity in Presence of Al3+ / 中国实验方剂学杂志

ObjectiveTo study the inhibitory effect of aloe-emodin （AE） on aluminum ion （Al3+）-induced β-amyloid protein 42 （Aβ42） aggregation and its depolymerization on formed Aβ42-Al3+ aggregates in vitro， and to investigate the effect of AE on the cytotoxicity of Aβ42 aggregation in the presence of Al3+. MethodThe Aβ42 group， Aβ42+Al3+ group， Aβ42+AE group， Aβ42+Al3++AE group and the depolymerization test group were set up in the experiment. The aggregation fibrosis process， aggregation morphology， aggregation size and cytotoxicity of Aβ42 in each group were detected by thioflavin T （ThT） fluorescence assay， transmission electron microscopy （TEM）， dynamic light scattering （DLS） experiment and thiazolyl blue （MTT） cytotoxicity assay. ResultCompared with the Aβ42 group， Al3+ could promote Aβ42 aggregation， increase the fluorescence intensity of ThT by 124.48%， induce the aggregation of Aβ42 to form fiber bundles with larger particle size， and significantly reduce the cell viability of human neuroblastoma SH-SY5Y cells （P<0.01）， thus reducing the cell survival rate to 51.05%. AE not only inhibited Aβ42 aggregation， but also inhibited Al3+-induced Aβ42 aggregation in a concentration-dependent manner. Compared with the Aβ42+Al3+ group， high concentration of AE could reduce the ThT fluorescence intensity to 41.66%， and change the polypeptide aggregation pathway to form amorphous aggregates with small particle size. Besides， it significantly inhibited the cytotoxicity of Aβ42 induced by Al3+ （P<0.01）， and restored the cell survival rate to 84.87%. Further depolymerization was conducted， AE could depolymerize Aβ42-Al3+ aggregates to make the formed aggregates disappear and form some small-particle short fibers and amorphous structure aggregates with low toxicity. ConclusionAE can inhibit Aβ42 aggregation and cytotoxicity in the presence of Al3+， depolymerize the formed Aβ42-Al3+ aggregates and alleviate the cytotoxicity， thus laying the foundation for exploring the mechanism of AE in the treatment of Alzheimer's disease.

Enhancement of Solubility And Dissolution Profile of Clopidogrel By Various Solid Dispersion Formulations

The present research is aimed at enhancing solubility and drug dissolution of clopidogrel (CPG) used as oral antiplatelet agent by employing solid dispersion (SD) technique. Total 40 SDs formulated with drug: polymers (pluronic F127, poloxamer 407, labrafil PG, PEG 6000, gelucire 50/13), in varying ratios (1:0.5, 1:1, 1:2, 1:3, 1:4) of which CPG1 to CPG20 and CPG21 to CPG40 prepared by adopting solvent evaporation method fusion (melt) method respectively. The formulation CPG40 containing pluronic F127 as polymer showed highest solubility of 6.57±0.04 mg/ml) that is 45 folds than pure drug. Similar results reflected in the dissolution studies where CPG40 containing CPG: pluronic F127 in 1:4 ratio showed maximum % drug content, % practical yield and drug dissolution of 99.14% in 60 minutes when compared with other formulations and pure drug (32.76%) obtained by fusion melt method. From FTIR studies the optimized formulation CPG40 showed the compatibility between drug and polymers. XRD and SEM studies showed CPG40 exists in amorphous form that fetched in better drug release from the SD formulation in comparison to pure drug.

Deciphering the platelet function test inacute coronary syndrome patients subjected to anti-platelet therapy / 中华检验医学杂志

Anti-platelet therapy plays a key role in acute coronary syndrome ( ACS ) treatments.Platelet function tests could monitor the effect of anti-platelet drugs′, however, it is still under debate that whether platelet function monitoring could be used to adjust antiplatelet therapy.Additionally, there are a number of platelet function assays, and each of them has specifically advantages and disadvantages.This article reviewed evidence-based information, guidelines, consensus and clinical experience about platelet function monitoring in ACS patients, which was intend to help laboratory technicians and clinicians understanding the value of platelet function tests in monitoring anti-platelet therapy.

Formulation Development and Evaluation of Ticagrelor Tablet for Regulatory Market.

The aim of the study was to develop a formulation of Ticagrelor 90 mg tablets that is equivalent to the reference product using similar excipients to match the in-vitro dissolution profile. A compressed coated tablet was formulated consisting of Ticagrelor and excipients conforming to the USP/BP monograph and below maximum amount allowed per unit dose. The physical characteristics of powder blends were evaluated for bulk density, tapped density, compressibility index, hausner ratio, angle of repose and moisture content. The compressed core and coated tablets were evaluated for thickness, hardness, weight variation, friability, disintegration, dissolution, drug content and stability. The powder blends for all formulations showed satisfactory bulk density, tapped density, compressibility index, hausner ratio, angle of repose and moisture content. All the core and coated tablets showed acceptable pharmaco-technical properties in terms of thickness, hardness, weight variation, friability, disintegration. Dissolution performances were varied depending on the composition of matrix tablet. Finally a formulation batch B05 consisting of Ticagrelor (34.61%), mannitol (61.15%), sodium starch glycolate (2.69%), hypromellose (HPMC-2910, 5cps) (0.77%), purified talc (0.38%), magnesium stearate (0.38%) and opadry grey (21k57558) (2%) showed maximum similarity with the reference product. Using this formulation a pharmaceutical will be able to met regulatory compliance.

A Clinical Analysis in Risk Factors of Chronic Subdural Hematoma: Focusing on the Age / 대한신경손상학회지

OBJECTIVE: The current understanding reveals that chronic subdural hematoma (CSDH) is mostly the results of direct or indirect head trauma. Other factors such as alcoholism, medication (such as anticoagulants or antiplatelet agents), liver cirrhosis, chronic renal failure and hematologic disease are also well known as causes of CSDH. Of them, the authors attempted to identify the risk factors of CSDH by focusing on the age with a view point of recent increase in the elderly population. METHODS: We retrospectively reviewed 216 consecutive CSDH patients who underwent surgery at our institute between 2002 and 2011. We classified them into two groups according to the patients' age (Group A: or =65 years old). Various factors were investigated for risk factor of CSDH, such as head trauma, chronic alcoholism, epilepsy, previous shunt surgery, underlying disease having bleeding tendency or medication affecting blood coagulation. And these factors were compared between the two groups for statistical significance. RESULTS: Among the 216 patients, group A included 81 patients (37.5%), group B included 135 patients (62.5%). The medication of group B had significantly more proportion than group A, comparing to the result that group B had relatively less proportion of head trauma and alcoholism (p<0.05). And medication was more associated with non-traumatic CSDH, especially in group B. CONCLUSION: As previously reported, head trauma or alcoholism are also most important causes as a risk factor of CSDH of all ages in our study. But medication is more closely related to the incidence of CSDH in group A, than group B.

Clonagem, expressão e caracterização de um inibidor de agregação plaquetária proveniente dos complexos salivares de sanguessugas Haementeria depressa / Cloning, expression and characterization of a platelet aggregation inhibitor from Haementeria depressa leech salivary complexes

Animais hematófagos possuem em sua saliva substâncias que permitem a fluidez do sangue, para o sucesso de sua alimentação. Com isso, têm sido descritos diversos componentes com atividades nos diferentes processos hemostáticos (coagulação, fibrinólise e agregação plaquetária). O complexo salivar da sanguessuga Haementeria depressa vem sendo estudado através de bioquímica clássica e análises transcriptômica e proteômica deste tecido determinaram o perfil dos transcritos e das proteínas produzidas. Dentre os transcritos mais abundantes foram encontrados três clones (H06A09, H06A02 e L02F02) que apresentaram 45%, 87% e 94% de similaridade ao LAPP, um inibidor de agregação plaquetária da sanguessuga Haementeria officinallis, a produção destes componentes pelo tecido foi confirmada pela análise proteômica. O LAPP é um inibidor que age pela via do colágeno e possui cerca de 14 kDa e pI de 4,0 e inibe a ligação da plaqueta ao colágeno tanto pelo epítopo do FvW quanto pelo domínio a2b1. Assim, o objetivo do presente trabalho foi clonar, expressar e caracterizar a proteína recombinante ativa, a partir do clone H06A09 para estudos de atividade desta molécula. Para obter a proteína recombinante de interesse inicialmente a clonagem do transcrito foi realizada com sucesso em vetor pAE, porém, a expressão em sistema procarioto apresentou alguns obstáculos já que a molécula não tinha atividade. Uma nova estratégia foi proposta, sendo realizada clonagem em vetor pPIC9K e expressão em sistema eucariótico (leveduras Pichia pastoris - GS115). Desta forma, o presente trabalho caracteriza o primeiro inibidor recombinante de agregação plaquetária pela via do colágeno proveniente de sanguessugas Haementeria depressa, e comprova que apesar de apresentar 45% de similaridade estrutural ao LAPP é um inibidor com características funcionais diferentes, e com grande potencial a ser estudado.

Hematophagous animals have in their saliva substances that maintain the blood fluidity to the success of their feeding. Therefore, components have been described by their activities in the hemostatic processes (coagulation, fibrinolysis and platelet aggregation).The salivary complex of Haementaria depressa leech has been studied by classical biochemical and transcriptomic and proteomic analysis of this tissue determined the profile of transcripts and proteins produced by it. Among the most abundant transcripts were found three clones (H06A09, H06A02 e L02F02) that showed 45%, 87% e 94% of similarity to LAPP, an inhibitor of platelet aggregation from Haementeria officinallis, the components production was confirmed by proteomic analysis. LAPP is a inhibitor that acts by collagen pathway and has around 14 kDa and pI of 4.0, and inhibits the binding of platelet to collagen by both the epitope domain of vWF as the a2b1. Thereby, the aim of this study was to clone, express and characterize the active recombinant protein from the clone H06A09 for studies of activity of this molecule. To obtain the recombinant protein initially cloning of transcript was successfully performed in pAE vector, however, the protein expressed in prokaryotic system presented some obstacles not presenting activity. A new strategy was proposed, being held in pPIC9K vector and expression in eukaryotic system - yeast Pichia pastoris (GS115). Thus, this study characterized the first recombinant inhibitor of platelet aggregation through collagen pathway from Haementeria depressa leeches, and proves that despite having 45% structural similarity to the LAPP is an inhibitor with different functional characteristics, and great potential to be studied.

A Case of Delayed Onset Tirofiban Induced Thrombocytopenia in a Chronic Renal Failure Patient

Compared with heparin induced thrombocytopenia (HIT), glycoprotein (GP) IIb/IIIa inhibitor induced thrombocytopenia is characterized by a rapid and profound fall in the platelet count. In severe cases, the platelet count decreases below 20,000/mm3 within the initial 24 hours after exposure to the drugs. It is often associated with severe bleeding complications. Tirofiban is one of the GP IIb/IIIa inhibitors. A case of severe thrombocytopenia in a 60-year-old man, with chronic renal failure (CRF) and acute myocardial infarction (AMI), was recently experienced. Tirofiban was administered to treat the AMI without ST segment elevation. The platelet count fell to 1,000/mm3 with hemoptysis and petechiae 80 hours after the initiation of tirofiban infusion. In this case, the clinical course was similar to that of the typical GP IIb/IIIa inhibitors induced thrombocytopenia, with the exception that its onset time was unusually delayed. The platelet count was normalized in 9 days after cessation of tirofiban infusion. Thus, this unusual case is reported as delayed onset tirofiban induced thrombocytopenia in a CRF patient.

Purification of a small peptide to inhibit platelet aggregation from Agkistrodon acutus venom / 中国药理学通报

Aim To purify a small platide inhibiting platelet aggregation from Agkistrodon Acutus snake venom,and to identify its physical and chemical properties and its effects on the platelet aggregation stimulated by ADP, collagen, and thrombin. Methods Extract snake venom through Superdex 75 gel filtration, ultrafiltration and DEAE-Sepharose CL-6B ionexchange. The purified product was identified by HPLC C_ 18 . The molecular weight was determined by SDS-polyacrylamid gel electrphoresis. Platelet aggragation was measured by nephelometry. Results The molecular weight of the peptide was 7 862 u and its purified from Agkistrodon Acutus snake venom is oelectric point was pH 4.29. This peptide dose-dependently inhibited the platelet aggregation induced by ADP,collagen,and thrombin. Conclusion The method has been proved to be successful for the purification of low molecular weight peptide fraction that inhibits platelet aggregation.