Classification (Agonist/Antagonist) and Regression "Structure-Activity" Models of Drug Interaction with 5-HT6

INTRODUCTION

One promising target for novel psychotropic drugs is the 5-HT6 receptor, GProtein- Coupled Receptor (GPCR) family, displaying seven transmembrane domains. There is considerable interest in how both 5-HT6 receptor agonist and antagonist compounds can have marked procognitive effects.

METHODS

An exact structure of the 5-HT6 receptor is not available, so application of powerful methods of (Q)SAR and molecular modelling, which play an essential role in modern drug design, are currently limited to structure-based homology models. The present study is devoted to a detailed QSAR analysis of 61 drugs (26 agonists and 35 antagonists) acting on the 5-HT6 receptor (rattus norvegicus and homo sapiens). Five classification methods were used: k-Nearest Neighbors (k-NN), Logistic Regression (LG), Linear Discriminant Analysis (LDA), Random Forest (RF), and Support Vector Machine (SVM). Multiple Regression Analysis (MRA) was involved also for regression analysis. Spectra of Inter Atomic Interactions (SIAI) were applied in the search for ligand centres interacting with the 5- HT6 receptor.

RESULTS & CONCLUSION

SAR and QSAR models based on the use of HYBOT, MOLTRA, VolSurf+, and SYBYL programs, and having cross-validated coefficients of determination of at least 0.80, show a predominant influence of H-bond acceptor ability and hydrophobicity on the type of ligand activity and degree of inhibition.

Cerebrospinal Fluid, Brain Electrolytes Balance, and the Unsuspected Intrinsic Property of Melanin to Dissociate the Water Molecule

BACKGROUND & OBJECTIVE

Regulation of composition, volume and turnover of fluids surrounding the brain and damp cells is vital. These fluids transport all substances required for cells and remove the unwanted materials. This regulation tends to act as barrier to prevent free exchange of materials between the brain and blood. There are specific mechanisms concerned with fluid secretion of the controlled composition of the brain, and others responsible for reabsorption eventually to blood and the extracellular fluid whatever their composition is. The current view assumes that choroidal plexuses secrete the major part of Cerebrospinal Fluid (CSF), while the Blood-Brain Barrier (BBB) has a much less contribution to fluid production, generating Interstitial Fluid (ISF) that drains to CSF. The skull is a rigid box; thereby the sum of volumes occupied by the parenchyma with its ISF, related connective tissue, the vasculature, the meninges and the CSF must be relatively constant according to the Monroe-Kellie dogma. This constitutes a formidable challenge that normal organisms surpass daily. The ISF and CSF provide water and solutes influx and efflux from cells to these targeted fluids in a quite precise way. Microvessels within the parenchyma are sufficiently close to every cell where diffusion areas for solutes are tiny. Despite this, CSF and ISF exhibit very similar compositions, but differ significantly from blood plasma. Many hydrophilic substances are effectively prevented from the entry into the brain via blood, while others like neurotransmitters are extremely hindered from getting out of the brain. Anatomical principle of the barrier and routes of fluid transfer cannot explain the extraordinary accuracy of fluids and substances needed to enter or leave the brain firmly. There is one aspect that has not been deeply analyzed, despite being prevalent in all the above processes, it is considered a part of the CSF and ISF dynamics. This aspect is the energy necessary to propel them properly in time, form, space, quantity and temporality.

CONCLUSION

The recent hypothesis based on glucose and ATP as sources of energy presents numerous contradictions and controversies. The discovery of the unsuspected intrinsic ability of melanin to dissociate and reform water molecules, similar to the role of chlorophyll in plants, was confirmed in the study of ISF and CSF biology.

Approaches of the Transcriptomic Analysis in Astrocytes: Potential Pharmacological Targets

Astrocytes are important glial cells involved in the ionic regulation of the extracellular fluid in the Central Nervous System (CNS), the formation of the blood brain barrier (BBB) and the support to neurons for the maintenance of the Krebs cycle intermediaries. Even though these cells are known to be important for the brain functioning, several of their functions and their development have not been fully elucidated. In this context, identifying the algorithms used for their analysis plays a pivotal role in the development of new strategies in the study of astrocytes. The main objective of this review is to summarize the techniques that have helped to obtain transcriptomic data in astrocytes and the new algorithms that were used to perform the analysis of experimental data, elucidating new studies in which these had been used. We also highlight the current transcriptomics approaches targeting astrocytes function as a possible target for pharmacological interventions.

Is VEGF a Key Target of Cotinine and Other Potential Therapies Against Alzheimer Disease?

BACKGROUND

The vascular endothelial growth factor (VEGF) is a neuroprotective cytokine that promotes neurogenesis and angiogenesis in the brain. In animal models, it has been shown that environmental enrichment and exercise, two non-pharmacological interventions that are beneficial decreasing the progression of Alzheimer disease (AD) and depressive-like behavior, enhance hippocampal VEGF expression and neurogenesis. Furthermore, the stimulation of VEGF expression promotes neurotransmission and synaptic plasticity processes such as neurogenesis. It is thought that these VEGF actions in the brain, may underly its beneficial therapeutic effects against psychiatric and other neurological conditions.

CONCLUSION

In this review, evidence linking VEGF deficit with the development of AD as well as the potential role of VEGF signaling as a therapeutic target for cotinine and other interventions in neurodegenerative conditions are discussed.

Nanotechnology for Alzheimer Disease

BACKGROUND

Alzheimer disease (AD) typically affects behavior, memory and thinking. The change in brain have been reported to begin approx. 10-20 years before the appearance of actual symptoms and diagnosis of AD. An early stage diagnosis and treatment of this lethal disease is the prime challenge, which is mainly halted by the lack of validated biomarkers.

METHOD

Recent nanotechnological advancements have the potential to offer large scale effective diagnostic and therapeutic options. Targeted drug (e.g. Rivastigmine) delivery with the help of nanoparticles (NPs) in the range of 1-100 nm diameters can effectively cross the blood brain barrier with minimized side effects. Moreover, biocompatible nanomaterials with increased magnetic and optical properties can act as excellent alternative agents for an early diagnosis. With the high volume of research coming in support of the effective usage of NP based drug delivery in critical environment of CNS, it is quite likely that this approach can end up providing remarkable breakthroughs in early stage diagnosis and therapy of AD.

CONCLUSION

In the current review, we have presented a comprehensive outlook on the current challenges in diagnosis and therapy of AD, with an emphasis on the effective options provided by biocompatible NPs as imaging contrast agents and drug carriers.

Sleep Disorders Associated With Alzheimer's Disease: A Perspective

Sleep disturbances, as well as sleep-wake rhythm disturbances, are typical symptoms of Alzheimer's disease (AD) that may precede the other clinical signs of this neurodegenerative disease. Here, we describe clinical features of sleep disorders in AD and the relation between sleep disorders and both cognitive impairment and poor prognosis of the disease. There are difficulties of the diagnosis of sleep disorders based on sleep questionnaires, polysomnography or actigraphy in the AD patients. Typical disturbances of the neurophysiological sleep architecture in the course of the AD include deep sleep and paradoxical sleep deprivation. Among sleep disorders occurring in patients with AD, the most frequent disorders are sleep breathing disorders and restless legs syndrome. Sleep disorders may influence circadian fluctuations of the concentrations of amyloid-β in the interstitial brain fluid and in the cerebrovascular fluid related to the glymphatic brain system and production of the amyloid-β. There is accumulating evidence suggesting that disordered sleep contributes to cognitive decline and the development of AD pathology. In this mini-review, we highlight and discuss the association between sleep disorders and AD.

The cytochrome P450 isoenzyme and some new opportunities for the prediction of negative drug interaction in vivo

Cytochrome (CYP) 450 isoenzymes are the basic enzymes involved in Phase I biotransformation. The most important role in biotransformation belongs to CYP3A4, CYP2D6, CYP2C9, CYP2C19 and CYP1A2. Inhibition and induction of CYP isoenzymes caused by drugs are important and clinically relevant pharmacokinetic mechanisms of drug interaction. Investigation of the activity of CYP isoenzymes by using phenotyping methods (such as the determination of the concentration of specific substrates and metabolites in biological fluids) during drug administration provides the prediction of negative side effects caused by drug interaction. In clinical practice, the process of phenotyping of CYP isoenzymes and some endogenous substrates in the ratio of cortisol to 6β-hydroxycortisol in urine for the evaluation of CYP3A4 activity has been deemed to be a quite promising, safe and minimally invasive method for patients nowadays.

Correction to: Cotinine: A Therapy for Memory Extinction in Post-traumatic Stress Disorder

The original version of this article unfortunately contained mistake in its Funding inforation. That is, the Grant Number has an error currently read as "This work was supported by the Fondo de Ciencia y Tecnología (FONDECYT) de Chile, Grant #1150149".

Cotinine: A Therapy for Memory Extinction in Post-traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a mental disorder that may develop after exposure to exceptionally threatening or unescapable horrifying events. Actual therapies fail to alleviate the emotional suffering and cognitive impairment associated with this disorder, mostly because they are ineffective in treating the failure to extinguish trauma memories in a great percentage of those affected. In this review, current behavioral, cellular, and molecular evidence supporting the use of cotinine for treating PTSD are reviewed. The role of the positive modulation by cotinine of the nicotinic acetylcholine receptors (nAChRs) and their downstream effectors, the protection of astroglia, and the inhibition of microglia in the PTSD brain are also discussed.

Diabetes Mellitus and Male Aging: Pharmacotherapeutics and Clinical Implications

Andropause or male menopause is defined as androgen decline and onset of hypogonadism in the aging male. Testosterone deficiency in adult male is associated with diabetes mellitus, coronary artery disease, and heart failure. Type 2 diabetic male patients aged above 30 years showed low testosterone levels which is common in diabetic men and had symptoms of hypogonadism. Male sexual dysfunction among diabetic patients can include disorders of libido, ejaculatory problems, and erectile dysfunctions are common among people with diabetes, particularly in older men who had diabetes for years. Older diabetics tend to have both impaired insulin release as well as insulin resistance. There is growing evidence indicating the pathophysiological connections among the mechanisms of oxidative damage by disruption of the oxidative balance, increased levels of enzymatic glycation products in testicular region and glucose transporters, obesity and proinflammatory cytokines in male infertile patients with diabetes. Epidemiological studies suggest that many clinical findings in diabetics are linked to low testosterone levels. This article reviews pathophysiological mechanisms, observational studies, and clinical implications of testosterone therapy in type 2 diabetes mellitus.

[On Choice of Profession of Pharmacist by Students of Moscow Universities]

The development of personality strongly depends on correspondence of chosen profession to capacities and interests of specialist, labor market demand and possibility of career making. The particular dynamics is observed in alteration of conception of professions and professional activities because information revolution resulted in shifting from mono-professionalism to mastering of several professions at once. The profession of pharmacist also passed through several alterations following development of pharmaceutical industry. The results of survey of opinions of students of pharmaceutical faculties concerning choice of profession of pharmacist demonstrate an actual situation at industry market and give an opportunity of forecasting its development in Moscow for nearest years.

Implication of Gastric Cancer Molecular Genetic Markers in Surgical Practice

INTRODUCTION

We have investigated aberrant methylation of genes CDH1, RASSF1A, MLH1, N33, DAPK, expression of genes hTERT, MMP7, MMP9, BIRC5 (survivin), PTGS2, and activity of telomerase of 106 gastric tumor samples obtained intra-operatively and 53 gastric tumor samples from the same group of patients obtained endoscopically before surgery. Biopsy specimens obtained from 50 patients with chronic calculous cholecystitis were used as a control group. Together with tissue samples obtained from different sites remote to tumors, a total of 727 samples have been studied. The selected parameters comprise a system of molecular markers that can be used in both diagnostics of gastric cancer and in dynamic monitoring of patients after surgery. Special attention was paid to the use of molecular markers for the diagnostics of malignant process in the material obtained endoscopically since the efficacy of morphological diagnostics in biopsies is compromised by intratumoral heterogeneity, which may prevent reliable identification of tumor cells in the sampling. Our data indicated that certain molecular genetic events provided more sensitive yet specific markers of the tumor.

CONCLUSION

We demonstrated that molecular profiles detected in preoperative biopsies were confirmed by the material obtained intra-operatively. The use of endoscopic material facilitates gastric tumors pre-operative diagnostics, improving early detection of gastric cancer and potential effective treatment strategies.

A Systematic In-silico Analysis of Helicobacter pylori Pathogenic Islands for Identification of Novel Drug Target Candidates

Background:

Helicobacter pylori is associated with inflammation of different areas, such as the duodenum and stomach, causing gastritis and gastric ulcers leading to lymphoma and cancer. Pathogenic islands are a type of clustered mobile elements ranging from 10-200 Kb contributing to the virulence of the respective pathogen coding for one or more virulence factors. Virulence factors are molecules expressed and secreted by pathogen and are responsible for causing disease in the host. Bacterial genes/virulence factors of the pathogenic islands represent a promising source for identifying novel drug targets.

Objective:

The study aimed at identifying novel drug targets from pathogenic islands in H. pylori.

Material & Methods:

The genome of 23 H. pylori strains were screened for pathogenic islands and bacterial genes/virulence factors to identify drug targets. Protein-protein interactions of drug targets were predicted for identifying interacting partners. Further, host-pathogen interactions of interacting partners were predicted to identify important molecules which are closely associated with gastric cancer.

Results:

Screening the genome of 23 H. pylori strains revealed 642 bacterial genes/virulence factors in 31 pathogenic islands. Further analysis identified 101 genes which were non-homologous to human and essential for the survival of the pathogen, among them 31 are potential drug targets. Protein-protein interactions for 31 drug targets predicted 609 interacting partners. Predicted interacting partners were further subjected to host-pathogen interactions leading to identification of important molecules like TNF receptor associated factor 6, (TRAF6) and MAPKKK7 which are closely associated with gastric cancer.

Conclusion:

These provocative studies enabled us to identify important molecules in H. pylori and their counter interacting molecules in the host leading to gastric cancer and also a pool of novel drug targets for therapeutic intervention of gastric cancer.

Synthesis of Saccharumoside-B analogue with potential of antiproliferative and pro-apoptotic activities

A new series of phenolic glycoside esters, saccharumoside-B and its analogs (9b-9n, 10) have been synthesized by the Koenigs-Knorr reaction. Antiproliferative activities of the compounds (9b-9n, 10) were evaluated on various cancer cell lines including, MCF-7 breast, HL-60 leukemia, MIA PaCa-2 pancreatic, DU145 prostate, HeLa cervical and CaCo-2 colon, as well as normal human MCF10A mammary epithelial and human peripheral blood mononuclear cells (PBMC) by MTT assay. Compounds (9b-9n, 10) exhibited considerable antiproliferative effects against cancer cells with IC₅₀ range of 4.43 ± 0.35 to 49.63 ± 3.59 µM, but they are less cytotoxic on normal cells (IC₅₀ > 100 µM). Among all the compounds, 9f showed substantial antiproliferative activity against MCF-7 and HL-60 cells with IC₅₀ of 6.13 ± 0.64 and 4.43 ± 0.35, respectively. Further mechanistic studies of 9f were carried out on MCF-7 and HL-60 cell lines. 9f caused arrest of cell cycle of MCF-7 and HL-60 cells at G0/G1 phase. Apoptotic population elevation, mitochondrial membrane potential loss, increase of cytosolic cytochrome c and Bax levels, decrease of Bcl-2 levels and enhanced caspases-9 and -3 activities were observed in 9f-treated MCF-7 and HL-60 cells. These results demonstrate anticancer and apoptosis-inducing potentials of 9f in MCF-7 and HL-60 cells via intrinsic pathway.

Insulin Resistance in Alzheimer Disease: p53 and MicroRNAs as Important Players

Glucose homeostasis is crucial for neuronal survival, synaptic plasticity, and is indispensable for learning and memory. Reduced sensitivity of cells to insulin and impaired insulin signaling in brain neurons participate in the pathogenesis of Alzheimer disease (AD). The tumor suppressor protein p53 coordinates with multiple cellular pathways in response to DNA damage and cellular stresses. However, prolonged stress conditions unveil deleterious effects of p53-evoked insulin resistance in neurons; enhancement of transcription of pro-oxidant factors, accumulation of toxic metabolites (e.g. ceramide and products of advanced glycation) and ROS-modified cellular components, together with the activation of proapoptotic genes, could finally induce a suicide death program of autophagy/apoptosis in neurons. Recent studies reveal the impact of p53 on expression and processing of several microRNAs (miRs) under DNA damage-inducing conditions. Additionally, the role of miRs in promotion of insulin resistance and type 2 diabetes mellitus has been well documented. Detailed recognition of the role of p53/miRs crosstalk in driving insulin resistance in AD brains could improve the disease diagnostics and aid future therapy.

Type 3 Diabetes Mellitus: A Novel Implication of Alzheimers Disease

The brain of patients with Alzheimer disease (AD) showed the evidence of reduced expression of insulin and neuronal insulin receptors, as compared with those of age-matched controls. This event gradually and certainly leads to a breakdown of the entire insulin-signaling pathway, which manifests insulin resistance. This in turn affects brain metabolism and cognitive functions, which are the bestdocumented abnormalities in AD. These observations led Dr. de la Monte and her colleagues to suggest that AD is actually a neuroendocrine disorder that resembles type 2 diabetes mellitus. The truth would be more complex with understanding the role of low-density lipoprotein receptor-related protein 1, Aβ derived diffusible ligands, and advanced glycation end products. However, now it known as "brain diabetes" and is called type 3 diabetes mellitus (T3DM). This review provides an overview of "brain diabetes" focusing on the reason why the phenomenon is called T3DM.

Gliomas: New Perspectives in Diagnosis, Treatment and Prognosis

Gliomas are central nervous system tumors originated from glial cells, whose incidence and mortality is expected to rise in coming years, especially in developing countries. Diagnosis and classification of gliomas have largely relied on tumor histopathologic features that provide limited information regarding response to therapy or prognosis. Current treatment of gliomas is surgery combined with chemotherapy and/or radiotherapy. However, many tumors show a high resistance to these interventions, and recurrences are frequent since conventional therapies do not take into account the unique molecular features of different subtypes of glioma. Molecular genetics provide new insights in classifying gliomas and predicting response to therapy that can range from conventional treatments to new revolutionary therapeutic approaches. This article offers a review of the intracellular signaling pathways involved in carcinogenesis of gliomas, as well as a description of new tools for their diagnosis, prognosis, and treatment with a target-oriented approach.

Blockade of Neuroglobin Reduces Protection of Conditioned Medium from Human Mesenchymal Stem Cells in Human Astrocyte Model (T98G) Under a Scratch Assay

Previous studies have indicated that paracrine factors (conditioned medium) increase wound closure and reduce reactive oxygen species in a traumatic brain injury in vitro model. Although the beneficial effects of conditioned medium from human adipose tissue-derived mesenchymal stem cells (hMSCA-CM) have been previously suggested for various neurological diseases, their actions on astrocytic cells are not well understood. In this study, we have explored the effect of hMSCA-CM on human astrocyte model (T98G cells) subjected to scratch assay. Our results indicated that hMSCA-CM improved cell viability, reduced nuclear fragmentation, attenuated the production of reactive oxygen species, and preserved mitochondrial membrane potential and ultrastructural parameters. In addition, hMSCA-CM upregulated neuroglobin in T98G cells and the genetic silencing of this protein prevented the protective action of hMSCA-CM on damaged cells, suggesting that neuroglobin is mediating, at least in part, the protective effect of hMSCA-CM. Overall, this evidence suggests that the use of hMSCA-CM is a promising therapeutic strategy for the protection of astrocytic cells in central nervous system (CNS) pathologies.

Biogenic synthesis of Zinc oxide nanostructures from Nigella sativa seed: Prospective role as food packaging material inhibiting broad-spectrum quorum sensing and biofilm

Bacterial spoilage of food products is regulated by density dependent communication system called quorum sensing (QS). QS control biofilm formation in numerous food pathogens and Biofilms formed on food surfaces act as carriers of bacterial contamination leading to spoilage of food and health hazards. Agents inhibiting or interfering with bacterial QS and biofilm are gaining importance as a novel class of next-generation food preservatives/packaging material. In the present study, Zinc nanostructures were synthesised using Nigella sativa seed extract (NS-ZnNPs). Synthesized nanostructures were characterized hexagonal wurtzite structure of size ~24 nm by UV-visible, XRD, FTIR and TEM. NS-ZnNPs demonstrated broad-spectrum QS inhibition in C. violaceum and P. aeruginosa biosensor strains. Synthesized nanostructures inhibited QS regulated functions of C. violaceum CVO26 (violacein) and elastase, protease, pyocyanin and alginate production in PAO1 significantly. NS-ZnNPs at sub-inhibitory concentrations inhibited the biofilm formation of four-food pathogens viz. C. violaceum 12472, PAO1, L. monocytogenes, E. coli. Moreover, NS-ZnNPs was found effective in inhibiting pre-formed mature biofilms of the four pathogens. Therefore, the broad-spectrum inhibition of QS and biofilm by biogenic Zinc oxide nanoparticles and it is envisaged that these nontoxic bioactive nanostructures can be used as food packaging material and/or as food preservative.