In silico modeling of the specific inhibitory potential of thiophene-2,3-dihydro-1,5-benzothiazepine against BChE in the formation of β-amyloid plaques associated with Alzheimer's disease

<p>Abstract</p> <p>Background</p> <p>Alzheimer's disease, known to be associated with the gradual loss of memory, is characterized by low concentration of acetylcholine in the hippocampus and cortex part of the brain. Inhibition of acetylcholinesterase has successfully been used as a drug target to treat Alzheimer's disease but drug resistance shown by butyrylcholinesterase remains a matter of concern in treating Alzheimer's disease. Apart from the many other reasons for Alzheimer's disease, its association with the genesis of fibrils by β-amyloid plaques is closely related to the increased activity of butyrylcholinesterase. Although few data are available on the inhibition of butyrylcholinesterase, studies have shown that that butyrylcholinesterase is a genetically validated drug target and its selective inhibition reduces the formation of β-amyloid plaques.</p> <p>Rationale</p> <p>We previously reported the inhibition of cholinesterases by 2,3-dihydro-1, 5-benzothiazepines, and considered this class of compounds as promising inhibitors for the cure of Alzheimer's disease. One compound from the same series, when substituted with a hydroxy group at C-3 in ring A and 2-thienyl moiety as ring B, showed greater activity against butyrylcholinesterase than to acetylcholinesterase. To provide insight into the binding mode of this compound (Compound A), molecular docking in combination with molecular dynamics simulation of 5000 ps in an explicit solvent system was carried out for both cholinesterases.</p> <p>Conclusion</p> <p>Molecular docking studies revealed that the potential of Compound A to inhibit cholinesterases was attributable to the cumulative effects of strong hydrogen bonds, cationic-π, π-π interactions and hydrophobic interactions. A comparison of the docking results of Compound A against both cholinesterases showed that amino acid residues in different sub-sites were engaged to stabilize the docked complex. The relatively high affinity of Compound A for butyrylcholinesterase was due to the additional hydrophobic interaction between the 2-thiophene moiety of Compound A and Ile69. The involvement of one catalytic triad residue (His438) of butyrylcholinesterase with the 3'-hydroxy group on ring A increases the selectivity of Compound A. C-C bond rotation around ring A also stabilizes and enhances the interaction of Compound A with butyrylcholinesterase. Furthermore, the classical network of hydrogen bonding interactions as formed by the catalytic triad of butyrylcholinesterase is disturbed by Compound A. This study may open a new avenue for structure-based drug design for Alzheimer's disease by considering the 3D-pharmacophoric features of the complex responsible for discriminating these two closely-related cholinesterases.</p

Molecular Docking and Quantitative Structure Activity Relationship (QSAR) Studies of Some Newly Synthesized Poly (Azomethine) Esters

Molecular docking procedure is well known for the investigation of small molecules; however, for macromolecules, it has attained limited success so far. Thus, in an attempt, a series of poly (azomethine) esters was synthesized in a laboratory, and their model oligomer units were studied by computer-aided computational MOE software package to investigate, specifically, binding modes that could influence their anticancer activities. Poly (azomethine) ester (PAME) was prepared by solution phase polycondensation of a preformed Schiff base (SB) 4-((4-(4-(4-hydroxybenzylideneamino)phenoxy)phenylimino)methyl) phenol with terephthaloyl chloride (TC). Terpolymers (PAMEF, PAMEB, PAMESi, PAMEPr, and PAMEH) were synthesized by the incorporation of various moieties along with TC and SB in the main chain. Structural elucidation was carried out by spectroscopic studies and elemental analysis. Docking procedure, adopted to investigate anticancer activity, showed that material was docked in the same pocket of active site as by anticancer protein complex (PDB code: 1T69). Molecular docking along with the quantitative structure activity relationship (QSAR) investigations showed groove binding as a preferred mode between the material and double-stranded DNA (PDB ID-1BNA). Binding strength indicated worthy correlation with various physicochemical parameters of the material like hydrophobic surface area (Vsurf), EHOMO, ELUMO, log P, and molar refractivity (MR). Calculated values for the formation constant (Kf) showed good binding strength for polymer-DNA complex. Consequently, the synthesized material is expected to exhibit anticancer activities and could be studied further as anticancer drugs

Electrochemical behavior of 1-ferrocenyl-3-phenyl-2-propen-1-one on glassy carbon electrode and evaluation of its interaction parameters with DNA

The electrochemical behavior of 1-ferrocenyl-3-phenyl-2-propen-1-one (ferrocenylone) and its interaction with DNA was studied by a glassy carbon electrode using cyclic voltammetry (CV) technique. The results from CV were supported by UV-Visible spectroscopy performed under the similar conditions. The positive peak potential shift in CV and the bathochromic shift in the UV-Vis absorption spectra suggested an intercalative mode of binding. The binding constant (K = 1.39 &plusmn; 0.02 × 10(4) mol-1 L) and the binding site size (0.53 bp) were obtained from voltammetric data which leads to a standard Gibbs free energy change (&#916;Gº= -RT lnK) of -23.64 kJ mol-1 and hence indicated the spontaneity of the binding interaction. The values of binding constants obtained from UV-Vis absorption and CV measurements, 1.26 &plusmn; 0.01 × 10(4) and 1.39 &plusmn; 0.02 × 10(4) mol-1 L respectively, were in close agreement

Transplantation in low resource countries

Thalassemia major (TM) is the most common deadly genetic disorder, a major cause of chronic non-infectious morbidity and financial burden in many low and middle-income regions. In these settings few children reach adulthood because proper long-term supportive care is seldom available. Bone marrow transplantation (BMT) is the only available curative modality and it can be very successful and cost-effective for young children with low-risk features and a compatible related donor. However, in countries where TM is most prevalent, there is a dire shortage of BMT centers. The Cure2Children Foundation has supported a feasibility study evaluating safety, efficacy and costs of developing a new BMT center in an underserved lower-middle-income country with relatively untrained professionals within a structured collaboration and knowledge-transfer program. A total of 24 consecutive patients who underwent BMT in Pakistan between September 2008 and August 2010 are included in this prospective analysis, 17 from an established bone marrow transplant center, the National Institute for Blood Diseases in Karachi, Pakistan and the initial 7 BMTs from a start up unit in a government civil hospital, the Pakistan Institute of Medical Sciences Children&rsquo;s Hospital in Islamabad. Patients were matched for age, nutritional status, growth, disease, disease status and post-BMT follow-up time. All patients had a matched-related sibling donor, were younger than 10 years of age at the time of transplantation, received the same conditioning regimen. All needy families could rely on a support program throughout the 8-month post-transplant period. The Cure2Children Foundation provided professional and financial support as well as a structured web-based data management and cooperation platform. At a median follow up of 19.6 months (range 8.7 to 31.5) actuarial thalassemia-free survival is 85.6% and 85.7% and overall survival 94.1% and 85.7% in the established and start-up center respectively with no statistically significant differences. Other outcome indices like infectious complications, engraftment parameters, transplant-related complications, and post-BMT performance scores also did not differ. The median cost of matched-related transplants in the start-up center, including pre-BMT evaluation, was 11,513 USD (range 7,518 to 21,176). Within structured cooperation strategies bone marrow transplantation for thalassemia major can be performed safely, effectively, and affordably even in start-up centers in lower-middleincome countries, like Pakistan, were most thalassemia patients live. This observation may have important implications to increase access to cure for thalassemia worldwide.&nbsp;重型地中海贫血（TM）是最常见的也是最致命的基因错乱，在许多中低收入地区，基因错乱是造成非传染性慢性疾病和经济负担的重大原因。 在这种情况下，许多儿童因接受不到长期支持治疗而活不到成年。 骨髓移植（BMT）是目前唯一能治愈该疾病的方法。若病患儿童有低风险的特点并且具有匹配的捐献物， BMT 将是治疗幼童成功且低成本的疗法。 然而，在重型地中海贫血多发国家，严重缺乏骨髓移植中心。 第二治愈儿童基金会与来自结构化合作和知识转换计划的未受训专业人员共同资助了一个可行性研究，评估在服务不到位的中低收入国家发展一个BMT中心的安全性、疗效和成本。 本预期分析收录了2008年9月到2010年10月间先后在巴基斯坦接受BMT的24名病人。其中，17名病人在成立的骨髓移植中心位于巴基斯坦卡拉奇市国家血液病研究所,完成手术；最先的7名在市立政府医院位于巴基斯坦医学研究院伊斯兰堡儿童医院,完成手术。 分析中，对比了病人的年龄、营养状态、发育、疾病、疾病状态和MBT后的随访时间。 所有病人都有一名相匹配的同胞捐献者。移植手术时，他们的年龄都在10岁以下，并都接受了相同的预处理方案。 所有困难家庭在骨髓移植手术后的8个月期间都可以得到资助计划的帮助。 第二治愈儿童基金会提供了专业上和经济上的支持以及结构化网络数据管理和合作平台。 在进行平均19.6个月的随访中（(8.7月-31.5月），在已成立的和新运作的卫生中心，地中海贫血症救活率保险估计为85.6% 和85.7%，总生存率为94.1%和85.7%。在统计上无明显区别。 其他结果指标，如传染性并发症、植入参数、移植相关并发症和BMT后表现分数等，都没有区别。 新运作卫生中心匹配相关移植手术的平均成本为11,513 USD （7,518至 21,176），包括BMT前评估费。 在结构化合作策略下，重型地中海贫血（TM）患者骨髓移植手术可以在诸如巴基斯坦等中低收入国家的新运作卫生中心进行，安全、有效，而且价格合理。通过这种手术，大多数病人都可以存活下来。 该观察对提高全球地中海贫血患者接受治疗具有重要意义。</p

Ticagrelor in patients with diabetes and stable coronary artery disease with a history of previous percutaneous coronary intervention (THEMIS-PCI) : a phase 3, placebo-controlled, randomised trial

Background: Patients with stable coronary artery disease and diabetes with previous percutaneous coronary intervention (PCI), particularly those with previous stenting, are at high risk of ischaemic events. These patients are generally treated with aspirin. In this trial, we aimed to investigate if these patients would benefit from treatment with aspirin plus ticagrelor. Methods: The Effect of Ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS) was a phase 3 randomised, double-blinded, placebo-controlled trial, done in 1315 sites in 42 countries. Patients were eligible if 50 years or older, with type 2 diabetes, receiving anti-hyperglycaemic drugs for at least 6 months, with stable coronary artery disease, and one of three other mutually non-exclusive criteria: a history of previous PCI or of coronary artery bypass grafting, or documentation of angiographic stenosis of 50% or more in at least one coronary artery. Eligible patients were randomly assigned (1:1) to either ticagrelor or placebo, by use of an interactive voice-response or web-response system. The THEMIS-PCI trial comprised a prespecified subgroup of patients with previous PCI. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, or stroke (measured in the intention-to-treat population). Findings: Between Feb 17, 2014, and May 24, 2016, 11 154 patients (58% of the overall THEMIS trial) with a history of previous PCI were enrolled in the THEMIS-PCI trial. Median follow-up was 3·3 years (IQR 2·8–3·8). In the previous PCI group, fewer patients receiving ticagrelor had a primary efficacy outcome event than in the placebo group (404 [7·3%] of 5558 vs 480 [8·6%] of 5596; HR 0·85 [95% CI 0·74–0·97], p=0·013). The same effect was not observed in patients without PCI (p=0·76, p interaction=0·16). The proportion of patients with cardiovascular death was similar in both treatment groups (174 [3·1%] with ticagrelor vs 183 (3·3%) with placebo; HR 0·96 [95% CI 0·78–1·18], p=0·68), as well as all-cause death (282 [5·1%] vs 323 [5·8%]; 0·88 [0·75–1·03], p=0·11). TIMI major bleeding occurred in 111 (2·0%) of 5536 patients receiving ticagrelor and 62 (1·1%) of 5564 patients receiving placebo (HR 2·03 [95% CI 1·48–2·76], p<0·0001), and fatal bleeding in 6 (0·1%) of 5536 patients with ticagrelor and 6 (0·1%) of 5564 with placebo (1·13 [0·36–3·50], p=0·83). Intracranial haemorrhage occurred in 33 (0·6%) and 31 (0·6%) patients (1·21 [0·74–1·97], p=0·45). Ticagrelor improved net clinical benefit: 519/5558 (9·3%) versus 617/5596 (11·0%), HR=0·85, 95% CI 0·75–0·95, p=0·005, in contrast to patients without PCI where it did not, p interaction=0·012. Benefit was present irrespective of time from most recent PCI. Interpretation: In patients with diabetes, stable coronary artery disease, and previous PCI, ticagrelor added to aspirin reduced cardiovascular death, myocardial infarction, and stroke, although with increased major bleeding. In that large, easily identified population, ticagrelor provided a favourable net clinical benefit (more than in patients without history of PCI). This effect shows that long-term therapy with ticagrelor in addition to aspirin should be considered in patients with diabetes and a history of PCI who have tolerated antiplatelet therapy, have high ischaemic risk, and low bleeding risk