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- Volume 17, Issue 5, 2020
Current Drug Discovery Technologies - Volume 17, Issue 5, 2020
Volume 17, Issue 5, 2020
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Drug Stereochemistry: A Prodigy For Pharmacology and Drug Development
Authors: Karan Gandhi, Umang Shah and Sandip PatelStereochemistry has evinced the importance of many chiral drugs with respect to drug designing and development. A literature review was conducted for several chiral drugs involving pharmacokinetic and pharmacodynamic parameters of their enantiomers along with their uses in certain diseased conditions. This article mainly includes the pharmacological profile review of some chiral drugs and the aspects due to which the single enantiomer is of importance as compared to the racemic mixture of the drug. This was achieved by moderating the side effects or toxic effects; or by the potentiated activity of the single enantiomer. Resolution deals with the separation of racemic compounds which shows up the credibility to obtain the desired enantiomeric properties. As isomers vary in their pharmacokinetic and pharmacodynamic profiles, chiral drugs have showcased considerable importance in the drug development process. Both the enantiomers have a different pharmacological profile in the treatment of a disease, which differentiates them from drug racemates.
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Biological Significance of Imidazole-based Analogues in New Drug Development
Authors: Pratiksha N. Chopra and Jagdish K. SahuIn the field of heterocyclic medicinal chemistry, especially five-membered ring structures containing a nitrogen atom, imidazole core is an imperative aromatic heterocycle which is usually present in naturally occurring products and synthetic bioactive molecules. The occurrence of imidazole moiety in therapeutic compounds may be beneficial in terms of improving water-soluble properties due to its two nitrogen atoms which leads to the creation of hydrogen bonds. The imidazole nucleus has also been recognized as an important isostere of triazole, pyrazole, thiazole, tetrazole, oxazole, amide etc. for the purpose of designing and development of various biologically active molecules. Moreover, imidazole core as an attractive binding site could interact with diverse cations and anions as well as biomolecules through different reactions in the human biological system thus displaying extensive biological activities. This effort thoroughly provides a wide-ranging assessment in current drug discovery and developments of imidazolebased analogues in the entire series of synthetic medicinal chemistry as antibacterial and antifungal, anticancer, anti-tubercular, analgesic and anti-inflammatory, anti-neuropathic, antihypertensive, anti-allergic, anti-parasitic, antiviral, antidepressant, anti-obesity and so on, altogether with their prospective approaches in diagnostic and pathological field. It is expected that the present review will be supportive on behalf of new opinions in the search for rational strategies of more efficacious and less toxic medicinal agents and drugs containing imidazole core.
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Targeting Small Molecule Tyrosine Kinases by Polyphenols: New Move Towards Anti-tumor Drug Discovery
Authors: Nikhil S. Sakle, Shweta A. More, Sachin A. Dhawale and Santosh N. MokaleBackground: Cancer is a complex disease involving genetic and epigenetic alteration that allows cells to escape normal homeostasis. Kinases play a crucial role in signaling pathways that regulate cell functions. Deregulation of kinases leads to a variety of pathological changes, activating cancer cell proliferation and metastases. The molecular mechanism of cancer is complex and the dysregulation of tyrosine kinases like Anaplastic Lymphoma Kinase (ALK), Bcr-Abl (Fusion gene found in patient with Chronic Myelogenous Leukemia (CML), JAK (Janus Activated Kinase), Src Family Kinases (SFKs), ALK (Anaplastic lymphoma Kinase), c-MET (Mesenchymal- Epithelial Transition), EGFR (Epidermal Growth Factor receptor), PDGFR (Platelet-Derived Growth Factor Receptor), RET (Rearranged during Transfection) and VEGFR (Vascular Endothelial Growth Factor Receptor) plays major role in the process of carcinogenesis. Recently, kinase inhibitors have overcome many problems of traditional cancer chemotherapy as they effectively separate out normal, non-cancer cells as well as rapidly multiplying cancer cells. Methods: Electronic databases were searched to explore the small molecule tyrosine kinases by polyphenols with the help of docking study (Glide-7.6 program interfaced with Maestro-v11.3 of Schrödinger 2017) to show the binding energies of polyphenols inhibitor with different tyrosine kinases in order to differentiate between the targets Results: From the literature survey, it was observed that the number of polyphenols derived from natural sources alters the expression and signaling cascade of tyrosine kinase in various tumor models. Therefore, the development of polyphenols as a tyrosine kinase inhibitor against targeted proteins is regarded as an upcoming trend for chemoprevention. Conclusion: In this review, we have discussed the role of polyphenols as chemoreceptive which will help in future for the development and discovery of novel semisynthetic anticancer agents coupled with polyphenols.
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Statins as the Controlling Agents for Non-Hodgkin's Lymphomas via Increasing the Casein Kinase 2 Interacting Protein-1: A Hypothesis
Authors: Kimia Kazemi, Negin Mozafari, Hajar Ashrafi, Pedram Rafiei and Amir AzadiBackground: Non-Hodgkin's lymphomas (NHL), derived from B- or T-cell, consist of a heterogeneous group of malignant lymphoproliferative disorders. Knockdown of Casein kinase 2 interacting protein-1 (CKIP-1) in NHL promoted cell proliferation and inhibited apoptosis via enhancing phosphorylated Protein Kinase B (PKB or AKT) expression. Statins are the class of drugs that inhibit the ratelimiting step of the mevalonate pathway, which is essential for the biosynthesis of various compounds, including cholesterol. Also, statins have anticancer properties being mediated by different mechanisms. Methods: A search on databases like Scopus and PubMed with keywords such as statin and non- Hodgkin's lymphomas was performed and Kyoto Encyclopedia of Genes and Genomes (KEGG) website was used to evaluate and reconfirm the involved cellular signaling pathway. Results: CKIP-1 is involved in the regulation of cell proliferation and apoptosis while plays an important role in many cancers. We can hypothesize that statins may increase the expression levels of CKIP-1 which could contribute to the reductions in phospho-AKT level. Hence, they may ameliorate the NHL patients via suppressing AKT phosphorylation and increasing CKIP- expression. Conclusion: Present review confirms the positive effect of statins on NHL by increasing CKIP-1 and reducing cell proliferation, subsequently.
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Virtual Structural Similarity Elucidates Bioactivity of Fenchone: A Phytochemical Enriched in Fennel Essential Oil
Authors: Sukhchain Singh, Pawan Gupta and Jeena GuptaBackground: Fenchone is a natural monoterpene abundantly present in fennel essential oil. It is known for its wound healing properties but its other biological activities are less explored. Methods: We used an in silico structural similarity searching approache to identify various biological activities of fenchone. The identified biological activities of fenchone (purchased from Sigma Aldrich) were validated by conducting DPPH free radical scavenging assay, MTT assay, well diffusion assay for antimicrobial activity and enzymatic assays to analyze the activity of different antioxidant enzymes. Results: Camphor was found to possess maximum structural similarity with fenchone (similarityindex 100). Molecular docking demonstrated that the binding modes of fenchone were also similar to camphor against protein Cytochrome CYP101D1 (PDB ID: 4C9K). Fenchone also demonstrated to possess an antioxidant activity (IC50: 3.32±0.008mM), an antimicrobial activity (MIC: 0.49mM) and a very strong antifungal activity. Fenchone protects yeast cells from H2O2 induced cytotoxicity and is cytotoxic to cancerous Hela cells (IC50: 12.63±0.12 μM). Fenchone treatment also showed the reduced activity of antioxidant enzymes i.e glutathione-S-transferase, catalase and lipid peroxidase. Conclusion: To the best of our knowledge, this is the first report that used structural similarity searching to explore the biological activities of fenchone.
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Design, Synthesis and Anticancer Activity of Site Specific Short Chain Cationic Peptide
Authors: Ravi D. Sharma, Jainendra Jain and Ratan L. KhosaBackground: In spite of current progress in treatment methods, cancer is a major source of morbidity and death rate all over the world. Traditional chemotherapeutic agents aim to divide cancerous cells, are often associated with deleterious side effects to healthy cells and tissues. Host defense peptides Cecropin A and B obtained from insects are capable to lyses various types of human cancer cells at peptide concentrations which are not fatal to normal eukaryotic cells. Methods: In the present work we have designed short chain α-helical linear and cyclic peptide from cecropin A having same cationic charge, hydrophobicity and helicity. Synthesis of designed novel short chain linear (10) and cyclic compound (12) was accomplished by using solution phase method. All the coupling reactions were carried out by using dicyclohexylcarbodiimide (DCC) as the coupling reagent at room temperature in the presence of N-methylmorpholine (NMM) as the base. The Structure of newly synthesized peptidse were elucidated by 1H-NMR, 13C-NMR, FT-IR, FABMS and elemental analysis data.Cytotoxicity of synthesized compound was tested against Dalton’s Lymphoma Ascites (DLA), Ehrlich’s Ascites Carcinoma (EAC) and MCF-7 cell lines by using MTT assay and 5-FU as reference compound. Result: From biological assessment,it was found that short chain cyclicpeptide12 showed high level of cytotoxic activity against DLA and EAC cell lines. Conclusion: By utilizing a structure-based rational approach to anticancer peptide design from cecropin A, we were able to develop short chain linear and cyclic peptides having same charge, hydrophobicity and with improved activity. Systematically removing amino acids, we were able to retaining peptide charge and hydrophobicity/hydrophilicity in linear and cyclic peptide which results to optimize the anticancer activity against DLA and EAC cell lines.
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Exploring the Potential of Capsaicin Against Cancer Metastasis Based on TGF-β Signaling Modulation Through Module-based Network Pharmacology Approach
Background: Capsaicin is an active alkaloid /principal component of red pepper responsible for the pungency of chili pepper. Capsaicin by changing the intracellular redox homeostasis regulate a variety of signaling pathways ultimately producing a divergent cellular outcome. Several reports showed the potential of capsaicin against cancer metastasis, however unexplored molecular mechanism is still an active part of the research. Several growth factors have a critical role during cancer metastasis among them TGF- β signaling play a vital role. Methods: The present study aimed at analyzing capsaicin modulation of TGF-β signaling using network pharmacology approach. The chemical and protein interaction data of capsaicin was curated and abstracted using STITCH4.0, PubChem and ChEMBL database. Further, the compiled data set was subjected to the pathway and functional enrichment analysis using Protein Analysis THrough Evolutionary Relationship (PANTHER) and, Database for Annotation, Visualization, and Integrated Discovery (DAVID) database. Meanwhile, the pattern of amino acid composition across the capsaicin targets was analyzed using the EMBOSS Pepstat tool. Capsaicin targets involved in TGF- β were identified and their Protein-Protein Interaction (PPI) network constructed using STRING v10 and Cytoscape (v 3.2.1). From the above-constructed network, the clusters were mined using the MCODE clustering algorithm and finally binding affinity of capsaicin with its targets involved in TGF-β signaling pathway was analyzed using Autodock Vina. Results: The analysis explored capsaicin targets and, their associated functional and pathway annotations. Besides, the analysis also provides a detailed distinct pattern of amino acid composition across the capsaicin targets. The capsaicin targets described as MAPK14, JUN, SMAD3, MAPK3, MAPK1 and MYC involved in TGF-β signaling pathway through pathway enrichment analysis. The binding mode analysis of capsaicin with its targets has shown high affinity with MAPK3, MAPK1, JUN and MYC. Conclusion: The study explores the potential of capsaicin as a potent modulator of TGF-β signaling pathway during cancer metastasis and proposes new methodology and mechanism of action of capsaicin against TGF-β signaling pathway.
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Photochemical /Photocytotoxicity Studies of New Tetrapyrrolic Structures as Potential Candidates for Cancer Theranostics
Background: Detailed photochemical and photocytotoxicity studies of two new porphyrins: 5,10,15,20-meso-tetrakis-(4-acetoxy-3-methoxyphenyl) porphyrin (P2.1) and 5-(4-hydroxy-3- methoxyphenyl)-10,15,20-tris-(4-acetoxy-3-methoxyphenyl)porphyrin (P2.2) are reported, as potential candidates for theranostics. For powdered samples of P2.1 and P2.2 adsorbed onto a powdered biocompatible substrate, polyethylene glycol (PEG), a concentration study was performed, correlating the fluorescence emission intensity with sample absorption to determine the useful concentration range for photodynamic therapy of cancer (PDT) in which aggregation does not occur. Cytotoxicity studies were performed in dark and illuminated conditions. Methods: The laser induced luminescence set-up is home-made, a N2 laser is used as the excitation source and a time gated charged-coupled device (ICCD) as the detector. Fluorescence lifetime determinations were made using pulsed light sources from the excitation LEDs and measures of the fluorescence intensities at different time delays after the excitation pulse. The singlet oxygen formation quantum yields φΔ measurements were obtained by comparing the total area of the emission spectra for the reference compound and also for the samples under study in the same solvent and with the same optical density at the excitation wavelength (405 nm). An integrating sphere for relative and absolute measurements was used in this work as an alternative methodology to obtain the values for the fluorescence emission quantum yields (φF) of the adsorbed porphyrin under study. The cytotoxicity evaluation was made in the dark and under irradiation, using four different human tumor cell lines and one non-tumor primary cell culture. Results: In order to establish the useful range of concentrations of the sensitizer for PDT, and due to the use of powdered samples, a special methodology was needed: the variations of the fluorescence lifetimes and fluorescence quantum yields were evaluated as a function of the concentration of the dye, measured by (1-R)*fdye. Both φF and ΤF are constant in the range from 0.002 to about 0.050 μmol g-1, and only after that a concentration quenching effect becomes visible, decreasing both φF and ΤF. This methodology is based in the correlations established between the Remission Function values and φF and ΤF obtained for increasing values of the sensitizer concentrations. Conclusions: The study of the aggregation effects of P2.1 and P2.2 porphyrins into a PEG matrix allowed us to determine the usable concentration range for photodynamic therapy use, where the aggregation of porphyrins decreases, therefore reducing the PDT action. The use of an integrating sphere for relative and absolute measurements of fluorescence quantum yields and also the lifetime studies as a function of the dye loading confirms the useful range for the use of P2.1 and P2.2 in PEG as powdered samples. The determination of the GI50, the porphyrin concentration which inhibits 50% of the cell growth, evidences that P2.2, the A3B porphyrin overtakes P2.1 (the A4 porphyrin) in terms of PDT efficiency and both porphyrins are much better PDT agents than the unsubstituted porphyrin, TPP. These data clearly show that porphyrins P2.2 and P2.1 exhibit an excellent behaviour in terms of its photocytotoxicity. These results encourage us to pursuit in the study of this family of porphyrins in which a balance of hydrophobic versus hydrophilic substituents in the phenyl group was achieved.
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Interaction with Modified Cyclodextrin as a Way to Increase the Antimalarial Activity of Primaquine
Background: Malaria is still a dangerous disease that impacts specifically Africa, Asia, and Latin America. The development of therapies to overcome the parasite infection is an important challenge nowadays. The medicine primaquine (PQ) is used in the treatment, although several side effects and low oral bioavailability are reported. Objective: This work focused on the preparation and characterization of a complex between PQ and 2- hydroxypropyl-β-cyclodextrin (HPCD), besides performing release tests of this formulation. Methods: PQ:HPCD complexes were prepared at 1:1 and 1:2 molar ratios, by the lyophilization method. The association between PQ and HPCD was tested using UV-vis, infrared (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy and NMR techniques (chemical shift, Job Plot, DOSY, and ROESY). Tests were also conducted to evaluate drug release before and after complexation with HPCD. Results: Results showed that there was a weak interaction of PQ with HPCD, forming non-inclusion complexes. These results were supported by FTIR results and spatial correlations between hydrogens from PQ with the external HPCD hydrogens. A 1:2 PQ:HPCD preferred molar ratio was determined by DSC and Job Plot experiments and the time to release 96% of the drug was 21.2 h slower after complexation. Conclusion: Conclusion indicate that PQ interacts poorly with HPCD, probably due to its hydrophilic character, as well as to its interaction with the external rim of HPCD. Our results demonstrate that there was a significant improvement in the release time after the complexation process, which could lead to an increase in the activity of the drug.
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Kaempferol as a Potential PAK4 Inhibitor in Triple Negative Breast Cancer: Extra Precision Glide Docking and Free Energy Calculation
Authors: Michael A. Arowosegbe, Oluwamuyiwa T. Amusan, Segun A. Adeola, Oluwatosin B. Adu, Israel A. Akinola, Bimpe F. Ogungbe, Olaposi I. Omotuyi, Gbemisola M. Saibu, Adewale J. Ogunleye, Ramon I. Kanmodi, Nekabari E. Lugbe, Oluwafemi J. Ogunmola, Damilola C. Ajayi, Sedoten O. Ogun, Faith O. Oyende, Ahmed O. Bello, Peter G. Ishola and Patrick E. ObasiekeBackground: P-21 activating kinase 4 (PAK4) is implicated in poor prognosis of many human tumors, particularly in Triple Negative Breast Cancer (TNBC) progression. Studies have revealed the crucial role of PAK4 in cell proliferation, anchorage-independent growth and cell migration among other hallmarks of cancer. Thus, PAK4 is an attractive target for anti-TNBC drug design and development. In our research, we used in silico methods to investigate the inhibitory potentials of kaempferol against PAK4 as compared with co-crystallized 4T6 and a standard PAK4 inhibitor-KPT-9274. The ligands were docked into the ATP-binding site of the target enzyme and post-docking validations were calculated. Results: In the molecular docking results, kaempferol had higher affinity than the standard KPT-9274. However, the SP and XP docking scores for the co-crystallized 4T6 were the highest. The analyses of the docking showed a favorable interaction between kaempferol and the catalytic-important aminoacyl residues, especially GLU396, LEU398 and ASP458 in the ATP-binding site of PAK4 when compared with what was obtained in the 4T6-PAK4 complex. Molecular mechanics based MM-GBSA was used to validate docking results. The free energy calculations revealed that kaempferol may have a favorable biological activity. Furthermore, the druggability of each ligand was assessed using the QikProp module and the SwissADME online tool. Kaempferol possessed a propitious drug-like property when compared to the standard ligands. Conclusions: We, therefore, put forward a logical argument that kaempferol can be further evaluated as a potential PAK4 inhibitor in TNBC.
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The Effect of Viola Odorata L. Oil for Fever in Children: A Randomized Triple-blinded Placebo-controlled Clinical Trial
Introduction: Finding non-systemic antipyretic option in cancer patients who simultaneously receive several other drugs seems be logical. This study was designed to evaluate complementary therapy with Viola odorata L. oil for fever control in febrile neutropenic children. Methods and Materials: In a randomized placebo controlled clinical trial, 41 febrile children were divided into two groups. Children in the active drug group received viola oil (20 drops) to be rubbed on the peripheral margin of the patient umbilicus. Primary outcome measure of the study was the mean axillary temperature in the 30, 60, and 240 minutes after the intervention. Results: The mean temperature reduced significantly in the viola group after 30 minutes of administration (p =0.005), while there was no significant change in the placebo group (p =1.00). The number of patients who received paracetamol as the rescue treatment was significantly lower in the viola group than that in the placebo group (5 vs. 17, p =0.001). Conclusion: The results of our study showed the safety and efficacy of complementary therapy with Viola odorata L. oil for fever control in febrile neutropenic children during hospital course.
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The Oral Administration Effect of Drug Mannuronic Acid (M2000) on Gene Expression of Matrix and Tissue Inhibitor of Metalloproteinases in Rheumatoid Arthritis Patients
Authors: Nada A.G. Gaafar, Mona Aslani, Zahra Aghazadeh, Alireza Razavi and Abbas MirshafieyBackground: Rheumatoid Arthritis (RA) is a complex disease involving an unknown number of genes, and affecting a large number of organs, tissues, and sites across the body. It is affecting approximately 1% of the population worldwide. The safety and therapeutic efficacy of β-D-mannuronic acid (M2000) as a novel NSAID with immunosuppressive property has been demonstrated under in vitro, in vivo examinations and clinical trials phase 1/11 in Ankylosing Spondylitis (AS) patients in addition to phase I/11 and 111 in Rheumatoid Arthritis (RA) patients. Objective: In this study, our goal is to evaluate the therapeutic efficacy of oral administration of M2000 on gene expression of the matrix metalloproteinase (MMP2, MMP9) and tissue inhibitor of metalloproteinase (TIMP1, TIMP2) as inflammatory molecules in the progression of rheumatoid arthritis. Methods: The study has included 15 RA patients who had an insufficient response to the conventional drug. Therefore, mannuronic acid was used as an additive to the conventional regime. The research was a single-blinded study. The dose of M2000 was 500mg orally twice per day for 12 weeks. There were 15 healthy participants considered as control. Blood samples have been collected from both groups once from the healthy control and twice from RA patients before and after treatment with M2000. The Peripheral Blood Mononuclear Cells (PBMCs) were isolated for assessment of the gene expression level of MMP2, MMP9, TIMP1, and TIMP2 using the real-time PCR method. Results: The gene expression level of MMP2 and MMP9 reported a significant reduction in RA patients after treatment with M2000 compared to before treatment. On the other hand, the gene expression level of TIMP2 demonstrated a significant increase in RA patients after treatment with mannuronic acid compared to before treatment, but there was no significant difference between the group of RA patients before treatment and the control group. Vice versa to other molecules, there was no significant difference in the level of TIMP1 in compression with RA patients before and after treatment. Conclusion: our findings proved that the β-D-mannuronic acid) as a novel NSAID with immunosuppressive property has a significant effect on the gene expression level of MMP2, MMP9 and TIMP2 molecules in RA patients.
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The Parsnip (Pastinaca sativa L), A Proposed Remedy as to a Fertile Agent in the Viewpoint of Iranian Traditional Medicine
Authors: Fatemeh Hakimi, Mojgan Tansaz and Roshanak MokaberinejadBackground and Objective: Infertility is a major problem in medical sciences. Despite recent advances in diagnosing and treatment of infertility, it is still one of the most important medical problems. The aim of this study is to review the role of the parsnip (Pastinaca sativa L), a proposed remedy as to a fertile agent in the viewpoint of Iranian traditional medicine (ITM) and review the evidence in the conventional medicine. Methods: In this literature research, we investigated some important Persian medical and pharmaceutical manuscripts in ITM. The search was conducted with the keyword of the fertile agent, and the parsnip was one of the choices mentioned as a fertile agent which is also available. In order assess the current findings, a search was done in the PubMed and Google Scholar databases. Results: In ITM, the parsnip is recognized as a stomach astringent, liver and uterine tonic and Stimulates ovulation. It is named as semen or sexual desire increaser and fertile agent. In the viewpoint of ITM, attention to the health of main or vital members of the body (including the heart, brain, and liver) in addition to the health of the urogenital system, may have led to the treatment of infertility. Conclusion: In some studies, the effects of the parsnip on spermatogenesis, number, and sperm motility are investigated but no studies have been done on women's infertility. This review shows that the parsnip can be as a fertile agent in female infertility. So, further clinical research is recommended.
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Large-scale High-throughput Screening Revealed 5'-(carbonylamino)-2,3'- bithiophene-4'-carboxylate as Novel Template for Antibacterial Agents
Authors: Yan A. Ivanenkov, Renat S. Yamidanov, Ilya A. Osterman, Petr V. Sergiev, Vladimir A. Aladinskiy, Anastasia V. Aladinskaya, Victor A. Terentiev, Mark S. Veselov, Andrey A. Ayginin, Dmitry A. Skvortsov, Katerina S. Komarova, Bogdan A. Zagribelnyy, Alexey Kh. Baimiev, Kseniya Yu. Shvetc, Andrey Kh. Baimiev, Alina A. Sofronova, Alexey E. Machulkin, Rostislav A. Petrov, Liana F. Zainullina, Marina A. Maximova, Zulfiya R. Zileeva, Yulia V. Vakhitova, Dmitry S. Bezrukov, Maria M. Puchinina and Olga A. DontsovaBackground: The key issue in the development of novel antimicrobials is a rapid expansion of new bacterial strains resistant to current antibiotics. Indeed, World Health Organization has reported that bacteria commonly causing infections in hospitals and in the community, e.g. E. Coli, K. pneumoniae and S. aureus, have high resistance vs the last generations of cephalosporins, carbapenems and fluoroquinolones. During the past decades, only few successful efforts to develop and launch new antibacterial medications have been performed. This study aims to identify new class of antibacterial agents using novel high-throughput screening technique. Methods: We have designed library containing 125K compounds not similar in structure (Tanimoto coeff.< 0.7) to that published previously as antibiotics. The HTS platform based on double reporter system pDualrep2 was used to distinguish between molecules able to block translational machinery or induce SOS-response in a model E. coli system. MICs for most active chemicals in LB and M9 medium were determined using broth microdilution assay. Results: In an attempt to discover novel classes of antibacterials, we performed HTS of a large-scale small molecule library using our unique screening platform. This approach permitted us to quickly and robustly evaluate a lot of compounds as well as to determine the mechanism of action in the case of compounds being either translational machinery inhibitors or DNA-damaging agents/replication blockers. HTS has resulted in several new structural classes of molecules exhibiting an attractive antibacterial activity. Herein, we report as promising antibacterials. Two most active compounds from this series showed MIC value of 1.2 (5) and 1.8 μg/mL (6) and good selectivity index. Compound 6 caused RFP induction and low SOS response. In vitro luciferase assay has revealed that it is able to slightly inhibit protein biosynthesis. Compound 5 was tested on several archival strains and exhibited slight activity against gram-negative bacteria and outstanding activity against S. aureus. The key structural requirements for antibacterial potency were also explored. We found, that the unsubstituted carboxylic group is crucial for antibacterial activity as well as the presence of bulky hydrophobic substituents at phenyl fragment. Conclusion: The obtained results provide a solid background for further characterization of the 5'- (carbonylamino)-2,3'-bithiophene-4'-carboxylate derivatives discussed herein as new class of antibacterials and their optimization campaign.
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In Silico Screening Reveals Histone Deacetylase 7 and ERK1/2 as Potential Targets for Artemisinin Dimer and Artemisinin Dimer Hemisuccinate
Authors: Ahmed A. Ishola and Kayode E. AdewoleBackground: Recent studies have observed overexpression of histone deacetylase 7 (HDAC7) and overactivity of extracellular signal-regulated kinases 1/2 (ERK1/2) in many tumors; therefore, pharmacological interventions to inhibit overexpression of HDAC7 and overactivity of ERK1/2 in cancerous cells holds great promise in cancer treatment. The promising anticancer properties of artemisinin and artemisinin-derivatives (ARTs) have been validated by various experimental reports, including advanced pre-clinical trials. Objective: Our aim in this in silico study is to identify additional inhibitors of HDAC7, ERK1 and ERK2 as potential anticancer drug agents and provide insight into the molecular level of interactions of such ligands relative to known standards. Methods: To achieve this aim, the binding affinities of ulixertinib (the standard ERK inhibitor), apicidin (the standard HDAC7 inhibitor) as well as 49 ARTs for HDAC7, ERK1 and ERK2 were evaluated using AutodockVina. The molecular binding interactions of compounds with remarkable binding affinity for all the 3 target proteins, relative to their respective standards, were viewed with Discovery Studio Visualizer, BIOVIA, 2016. Results: Out of the 49 ARTs, our study identified 2 compounds, artemisinin dimer and artemisinin dimer hemisuccinate, as having higher binding affinities for all the target proteins compared to their respective standard inhibitors. Conclusion: These findings suggest that artemisinin dimer and artemisinin dimer hemisuccinate could be promising anticancer drug agents, with better therapeutic efficacy than ulixertinib and apicidin for the treatment of cancer via inhibition of HDAC7, ERK1 and ERK2.
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Zebra Fish in Toxicology Research: Streptavidin Conjugated Peroxidase Assay in the Development Phase of Zebrafish Embryos to Study Liver Toxicities
Authors: Asis Bala, Chaitali Mondal and Pallab KantiHaldarBackground: Zebrafish have similar hepatic anatomy and cellular architecture just like mammals. Therefore, a number of investigators are using zebrafish to study liver pathologies. However, the evaluation model specific to liver toxicities in zebra fish was not clearly stated earlier. Aims and Objectives: The present study was designed to develop a model of embryonic liver toxicity using dexamethasone (DEXA, 0-20 μM) as a standard hepatotoxic agent. Methods: such toxicities are easily measured by streptavidin-conjugated peroxidase assay after 48- hour post-fertilization (hpf) of DEXA treatment. Results: In addition to morphological toxicities at different hpf, DEXA showed significant (*p< 0.05 &**p<0.01) reduction of peroxidase-chromogenic dye reaction in the assay as compared to DEXA untreated embryos at 10 & 20 μM concentration that concluded the hepatocellular toxicity of dexamethasone. Conclusion: Hopefully, the developed model for hepatotoxicity evaluation will be a promising model for the evaluation of new drugs or chemicals as an easy vertebrate model before the commencement of another animal model.
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A Definitive Pharmacophore Modelling Study on CDK2 ATP Pocket Binders: Tracing the Path of New Virtual High-Throughput Screenings
Authors: Marco Tutone, Giulia Culletta, Luca Livecchi and Anna M. AlmericoCyclin Dependent Kinases-2 (CDK2) are members of serine/threonine protein kinases family. They play an important role in the regulation events of the eukaryotic cell division cycle, especially during the G1 to S phase transition. Experimental evidence indicate that excessive expression of CDK2s should cause abnormal cell cycle regulation. Therefore, since a long time, CDK2s have been considered potential therapeutic targets for cancer therapy. In this work, onehundred and forty-nine complexes of inhibitors bound in the CDK2-ATP pocket were submitted to short MD simulations (10ns) and free energy calculation. Comparison with experimental data (Ki, Kd and pIC50) revealed that short simulations are exhaustive to examine the crucial ligand-protein interactions within the complexes. Information collected on MD simulations of protein-ligand complexes has been used to perform a molecular modelling approach that incorporates flexibility into structure-based pharmacophore modelling (Common Hits Approach, CHA). The high number of pharmacophore models resulting from the MD simulation was thus reduced to a few representative groups of pharmacophore models. The performance of the models has been assessed by using the ROC curves analysis. This definitive set of validated pharmacophore models could be used to screen in-house and/or commercial datasets for detection of new CDK-2 inhibitors. We provide the models to all the researchers involved in this field.
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Volumes & issues
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Volume 22 (2025)
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Volume 21 (2024)
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Volume 20 (2023)
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Volume 19 (2022)
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Volume 18 (2021)
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Volume 17 (2020)
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Volume 16 (2019)
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Volume 15 (2018)
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Volume 14 (2017)
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Volume 13 (2016)
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Volume 12 (2015)
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Volume 11 (2014)
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Volume 10 (2013)
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Volume 9 (2012)
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Volume 8 (2011)
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Volume 7 (2010)
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Volume 6 (2009)
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Volume 5 (2008)
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Volume 4 (2007)
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Volume 3 (2006)
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Volume 2 (2005)
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Volume 1 (2004)