Hierarchical Virtual Screening and Binding Free Energy Prediction of Potential Modulators of Aedes Aegypti Odorant-Binding Protein 1

The Aedes aegypti mosquito is the main hematophagous vector responsible for arbovirus transmission in Brazil. The disruption of A. aegypti hematophagy remains one of the most efficient and least toxic methods against these diseases and, therefore, efforts in the research of new chemical entities with repellent activity have advanced due to the elucidation of the functionality of the olfactory receptors and the behavior of mosquitoes. With the growing interest of the pharmaceutical and cosmetic industries in the development of chemical entities with repellent activity, computational studies (e.g., virtual screening and molecular modeling) are a way to prioritize potential modulators with stereoelectronic characteristics (e.g., pharmacophore models) and binding affinity to the AaegOBP1 binding site (e.g., molecular docking) at a lower computational cost. Thus, pharmacophore- and docking-based virtual screening was employed to prioritize compounds from Sigma-Aldrich (R) (n = 126,851) and biogenic databases (n = 8766). In addition, molecular dynamics (MD) was performed to prioritize the most potential potent compounds compared to DEET according to free binding energy calculations. Two compounds showed adequate stereoelectronic requirements (QFIT > 81.53), AaegOBP1 binding site score (Score > 42.0), volatility and non-toxic properties and better binding free energy value (Delta G < -24.13 kcal/mol) compared to DEET ((N,N-diethyl-meta-toluamide)) (Delta G = -24.13 kcal/mol)

In Silico Study to Identify New Antituberculosis Molecules from Natural Sources by Hierarchical Virtual Screening and Molecular Dynamics Simulations

The authors acknowledge the Graduate Program in Biotechnology/UEFS for academic support.Tuberculosis (TB) is an infection caused by Mycobacterium tuberculosis, responsible for 1.5 million documented deaths in 2016. The increase in reported cases of M. tuberculosis resistance to the main drugs show the need for the development of new and efficient drugs for better TB control. Based on these facts, this work aimed to use combined in silico techniques for the discovery of potential inhibitors to β-ketoacyl-ACP synthase (MtKasA). Initially compounds from natural sources present in the ZINC database were selected, then filters were sequentially applied by virtual screening, initially with pharmacophoric modeling, and later the selected compounds (based on QFIT scores) were submitted to the DOCK 6.5 program. After recategorization of the variables (QFIT score and GRID score), compounds ZINC35465970 and ZINC31170017 were selected. These compounds showed great hydrophobic contributions and for each established system 100 ns of molecular dynamics simulations were performed and the binding free energy was calculated. ZINC35465970 demonstrated a greater capacity for the KasA enzyme inhibition, with a ΔGbind = −30.90 kcal/mol and ZINC31170017 presented a ΔGbind = −27.49 kcal/mol. These data can be used in other studies that aim at the inhibition of the same biological targets through drugs with a dual action

Investigating of scopolamine-induced cognitive impairment in a complex cognitive test battery in rats

Tese de mestrado, Ciências Biofarmacêuticas, 2022, Universidade de Lisboa, Faculdade de Farmácia.A escopolamina, um composto anticolinérgico, é frequentemente aplicada como modelo farmacológico para debilitar funções cognitivas. É usado principalmente em dose única e em animais jovens. O objetivo deste estudo foi investigar os efeitos do tratamento crónico com escopolamina em várias funções cognitivas em ratos experientes. Também foi testado até que ponto o donepezil pode melhorar o deficite cognitivo. Ratos da espécie Long-Evans de 8,5 meses de idade foram treinados regularmente em paradigmas como 5CSRTT (medindo a atenção), MWM (aprendizado espacial), Pot jumping (aprendizado da função motora), discriminação em tela sensível ao toque de caixa (TS) (aprendizagem visual) e uma tarefa de cooperação (aprendizagem social). Após as medições iniciais, os ratos foram distribuídos aleatoriamente em três grupos de tratamento: solução salina, escopolamina (0,3 mg/kg) e escopolamina+donepezil (3 mg/kg). Os grupos de salina e escopolamina receberam tratamento via ip por 20 dias, o grupo escopolamina+donepezil foi injetado com escopolamina por 10 dias e então escopolamina e donepezil durante os 10 dias seguintes. A escopolamina prejudicou significativamente o desempenho em 5CSRTT, COOP e PJ: em 5CSRTT, os animais de controlo acertaram mais e produziram menos omissões do que os animais tratados. Os ratos tratados com escopolamina realizaram ensaios fracos em testes de cooperação, quando comparado com os de controlo. No entanto, o desempenho melhorou gradualmente durante o período de tratamento. Em PJ, o grupo de controlo pôde saltar distâncias significativamente maiores do que o grupo tratado com escopolamina, e a magnitude do efeito da escopolamina aumentou com tratamentos repetidos. A escopolamina exerceu um efeito fraco em TS e não mostrou efeitos significativos em MWM. Donepezil não melhorou o deficite de desempenho de aprendizagem em nenhum dos testes. Todos os grupos apresentaram desempenho semelhante aos níveis iniciais logo dois dias após a descontinuação dos tratamentos. Com base nos nossos resultados, o tratamento repetido com escopolamina não induziu mudanças duradouras no funcionamento das redes neurais cognitivas, portanto, provavelmente não será um modelo adequado para testar medicamentos de tratamento para demência especialmente em animais jovens.Scopolamine, an anticholinergic compound is frequently applied as a pharmacological model of cognitive impairment. It is mainly used in single dose and in naïve animals. The aim of this study was to investigate the effects of repeated scopolamine treatment on several cognitive functions in experienced rats. It was also assessed to what extent donepezil could improve the induced impairment. 8.5 months old Long-Evans rats had been trained regularly in 5-choice serial reaction time task (5CSRTT, measuring attention), Morris water maze (MWM, spatial learning), pot jumping test (PJ, motor learning), pairwise discrimination in touchscreen box (TS, visual learning) and a cooperation task (social learning). After baseline measurements rats were randomly assigned into three treatment groups: saline, scopolamine (0.3 mg/kg) and scopolamine+donepezil (3 mg/kg). Saline and scopolamine groups received ip. treatment for 20 days, the scopolamine+donepezil group was injected scopolamine for 10 days then scopolamine and donepezil during the following 10 days. Scopolamine significantly impaired performance in 5CSRTT, COOP and PJ: in 5CSRTT, control animals gave more correct answers and produced less omissions than treated animals. The scopolamine-treated rats yielded less successful trials in cooperation tests, than the control. However, these impairments gradually decreased during the treatment period. In PJ, the control group could jump significantly longer distances than the scopolamine-treated, and the magnitude of the scopolamine-effect increased by repeated treatments. Scopolamine exerted a weak effect in TS and did not show significant effects in MWM. Donepezil did not ameliorate the learning performance deficit in any of the tests. All groups showed similar performance to their baseline levels already two days after discontinuation of the treatments. Based on our results, repeated scopolamine treatment could not induce lasting changes in the functioning of cognitive neural networks. Therefore, it may not be an appropriate model for testing potential antidementia drugs, especially in young animals.Semmelweis University, Cognitive Translational Behavioral Pharmacology Group

Shrinking the Malaria Map: A Prospectus on Malaria Elimination

\ud Thirty-nine countries across the world are making progress toward malaria elimination. Some are committed to nationwide elimination, while others are pursuing spatially progressive elimination within their borders. Influential donor and multilateral organizations are supporting their goals of achieving malaria-free status. With elimination back on the global agenda, countries face a myriad of questions. Should they change their programs to eliminate rather than control malaria? What tools are available? What policies need to be put into place? How will they benefit from elimination? Unfortunately, answers to these questions, and resources for agencies and country program managers considering or pursuing elimination, are scarce. The 39 eliminating countries are all positioned along the endemic margins of the disease, yet they naturally experience a variety of country characteristics and epidemiologies that make their malaria situations different from one another. The Malaria Elimination Group (MEG) and this Prospectus recognize\ud that there is no single solution, strategy, or time line that will be appropriate for every country, and each is encouraged to initiate a comprehensive evaluation of its readiness and strategy for elimination. The Prospectus is designed to guide countries in conducting these assessments. The Prospectus provides detailed and informed discussion on the practical means of achieving and sustaining zero transmission. It is designed as a road map, providing direction and options from which to choose an appropriate path. As on all maps, the destination is clearly marked, but the possible routes to reach it are numerous. The Prospectus is divided into two sections: Section 1 Eliminating Malaria comprises four chapters covering the strategic components important to the periods before, during, and after an elimination program. Section 2 Tools for the Job, comprises six chapters that outline basic information about how interventions in an elimination program will be different from those in a control setting. Chapter 1, Making the Decision, evaluates the issues that a country should consider when deciding whether or not to eliminate malaria. The chapter begins with a discussion about the quantitative and qualitative benefits that a country could expect from eliminating malaria and then recommends a thorough feasibility assessment. The feasibility assessment is based on three major components: operational, technical, and financial feasibility. Cross-border and regional collaboration is a key subject in this chapter. Chapter 2, Getting to Zero, describes changes that programs must consider when moving from sustained control to an elimination goal. The key strategic issues that must be addressed are considered, including supply chains, surveillance systems, intersectoral collaboration, political will, and legislative framework. Cross-border collaboration is again a key component in Getting to Zero. Chapter 3, Holding the Line, provides recommendations on how to conduct an assessment of two key factors that will affect preventing the reemergence of malaria once transmission is interrupted: outbreak risk and importation risk. The chapter emphasizes the need for a strong surveillance system in order to prevent and, if necessary, respond to imported cases. Chapter 4, Financing Elimination, reviews the cost-effectiveness of elimination as compared with sustained control and then presents the costs of selected elimination programs as examples. It evaluates four innovative financing mechanisms that must support elimination, emphasizing the need for predictable and stable financing. Case studies from Swaziland and two provinces in China are provided. Chapter 5, Understanding Malaria, considers malaria from the point of view of elimination and provides a concise overview of the current burden of the disease, malaria transmission, and the available interventions that can be used in an elimination program. Chapter 6, Learning from History, extracts important lessons from the Global Malaria Eradication Program and analyzes some elimination efforts that were successful and some that were unsuccessful. The chapter also reviews how the malaria map has been shrinking since 1900. xiv A Prosp ectus on Mala ria Elimi natio n\ud Chapter 7, Measuring Malaria for Elimination, provides a precise language for discussing malaria and gives the elimination discussion a quantitative structure. The chapter also describes the role of epidemiological theory and mathematical modeling in defining and updating an elimination agenda for malaria. Chapter 8, Killing the Parasite, outlines the importance of case detection and management in an elimination setting. Options for diagnosis, the hidden challenge of Plasmodium vivax in an elimination setting, and the impact of immunity are all discussed. Chapter 9, Suppressing the Vector, explores vector control, a necessary element of any malaria program. It considers optimal methods available to interrupt transmission and discusses potential changes, such as insecticide resistance, that may affect elimination efforts. Chapter 10, Identifying the Gaps — What We Need to Know, reviews the gaps in our understanding of what is required for elimination. The chapter outlines a short-term research agenda with a focus on the operational needs that countries are facing today. The Prospectus reviews the operational, technical, and financial feasibility for those working on the front lines and considers whether, when, and how to eliminate malaria. A companion document, A Guide on Malaria Elimination for Policy Makers, is provided for those countries or agencies whose responsibility is primarily to make the policy decisions on whether to pursue or support a malaria elimination strategy. The Guide is available at www.malaria eliminationgroup.org

MRI Guided Analysis of Changes in Tumor Oxygenation in Response to Hypoxia Activated/Targeted Therapeutics

abstract: A tumor is a heterogeneous combination of proliferating tumor cells, infiltrating immune cells and stromal components along with a variety of associated host tissue cells, collectively termed the tumor microenvironment (TME). The constituents of the TME and their interaction with the host organ shape and define the properties of tumors and contribute towards the acquisition of hallmark traits such as hypoxia. Hypoxia imparts resistance to cancer from chemotherapy and radiotherapy due to the decreased production of reactive oxygen species and also promotes angiogenesis, malignant progression and metastasis. It also provides a powerful physiological stimulus that can be exploited as a tumor-specific condition, allowing for the rational design of anticancer hypoxia-activated pro-drugs (HAP). Accurate evaluation of tumor oxygenation in response to therapeutics interventions at various stages of growth should provide a better understanding of tumor response to therapy, potentially allowing therapy to be tailored to individual characteristics. The primary goal of this research was to investigate the utility of prospective identification of hypoxic tumors, by two different Magnetic Resonance Imaging (MRI) based oximetry approaches, in successful treatment with hypoxia activated therapy. In the present study, I report the utility of these two techniques 1) PISTOL (Proton Imaging of Siloxanes to map Tissue Oxygenation Levels) and 2) use of a hypoxia binding T1 contrast agent GdDO3NI in reporting the modulations of hypoxia pre and post hypoxia activated therapies in pre-clinical models of cancer. I have performed these studies in non-small cell lung cancer (NSCLC) and epidermoid carcinoma (NCI-H1975 and A431 cell lines, respectively) as well as in patient derived xenograft models of NSCLC. Both the oximetry techniques have the potential to differentiate between normoxic and hypoxic regions of the tumor and reveal both baseline heterogeneity and differential response to therapeutic intervention. The response of the tumor models to therapeutic interventions indicates that, in conjunction with pO2, other factors such as tumor perfusion (essential for delivering HAPs) and relative expression of nitroreductases (essential for activating HAPs) may play an important role. The long term goal of the proposed research is the clinical translation of both the MRI techniques and aiding the design and development of personalized therapy (e.g. patient stratification for novel hypoxia activated pro-drugs) particularly for cancer.Dissertation/ThesisDoctoral Dissertation Bioengineering 201

A Combined Therapeutic Regimen of Buspirone and Environmental Enrichment is more Efficacrious than Either Alone in Enhancing Spatial Learning in Brain-Injured Rats

Abstract Buspirone, a 5-HT1A receptor agonist, and environmental enrichment (EE) enhance cognition and reduce histopathology after traumatic brain injury (TBI) in adult rats, but have not been fully evaluated after pediatric TBI, which is the leading cause of death in children. Hence, the aims of this study were to assess the efficacy of buspirone alone (Experiment 1) and in combination with EE (Experiment 2) in TBI postnatal day-17 male rats. The hypothesis was that both therapies would confer cognitive and histological benefits when provided singly, but their combination would be more efficacious. Anesthetized rats received a cortical impact or sham injury and then were randomly assigned to receive intraperitoneal injections ofbuspirone (0.08 mg/kg, 0.1 mg/kg, and 0.3 mg/kg) or saline vehicle (1.0 mL/kg) 24 h after surgery and once daily for 16 days (Experiment 1). Spatial learning and memory were assessed using the Morris water maze (MWM) on post-operative days 11-16, and cortical lesion volume was quantified on day 17. Sham controls for each condition were significantly better than all TBI groups. In the TBI groups, buspirone (0.1 mg/kg) enhanced MWM performance versus vehicle and buspirone (0.08 mg/kg and 0.3 mg/kg) (p\u3c0.05) and reduced lesion volume relative to vehicle (p=0.038). In Experiment 2, buspirone (0.1 mg/kg) or vehicle was combined with EE after TBI, and the data were compared to the standard (STD)-housed groups from Experiment 1. EE lead to a significant enhancement of spatial learning and a reduction in lesion size versus STD. Moreover, the combined treatment group (buspirone+EE) performed markedly better than the buspirone+STD and vehicle+EE groups, which suggests an additive effect and supports the hypothesis. The data replicate previous studies assessing these therapies in adult rats. These novel findings may have important rehabilitation-relevant implications for clinical pediatric TBI