scholarly journals On the Inhibitability of Natural Products Isolated from Tetradium ruticarpum towards Tyrosine Phosphatase 1B (PTP1B) and α-Glucosidase (3W37): An In Vitro and In Silico Study

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3691
Author(s):  
Dao-Cuong To ◽  
Thanh Q. Bui ◽  
Nguyen Thi Ai Nhung ◽  
Quoc-Toan Tran ◽  
Thi-Thuy Do ◽  
...  
Keyword(s):  
Amino Acids ◽  
Natural Products ◽  
Density Functional ◽  
Tyrosine Phosphatase ◽  
Docking Simulation ◽  
In Vitro Study ◽  
Ic50 Values ◽  
Inhibitory Agents ◽  
The Stability

Folk experiences suggest natural products in Tetradium ruticarpum can be effective inhibitors towards diabetes-related enzymes. The compounds were experimentally isolated, structurally elucidated, and tested in vitro for their inhibition effects on tyrosine phosphatase 1B (PTP1B) and α-glucosidase (3W37). Density functional theory and molecular docking techniques were utilized as computational methods to predict the stability of the ligands and simulate interaction between the studied inhibitory agents and the targeted proteins. Structural elucidation identifies two natural products: 2-heptyl-1-methylquinolin-4-one (1) and 3-[4-(4-methylhydroxy-2-butenyloxy)-phenyl]-2-propenol (2). In vitro study shows that the compounds (1 and 2) possess high potentiality for the inhibition of PTP1B (IC50 values of 24.3 ± 0.8, and 47.7 ± 1.1 μM) and α-glucosidase (IC50 values of 92.1 ± 0.8, and 167.4 ± 0.4 μM). DS values and the number of interactions obtained from docking simulation highly correlate with the experimental results yielded. Furthermore, in-depth analyses of the structure–activity relationship suggest significant contributions of amino acids Arg254 and Arg676 to the conformational distortion of PTP1B and 3W37 structures overall, thus leading to the deterioration of their enzymatic activity observed in assay-based experiments. This study encourages further investigations either to develop appropriate alternatives for diabetes treatment or to verify the role of amino acids Arg254 and Arg676.

Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

Adverse Effects of Natural Products: A Brief Pre-Systematic Review

2020 ◽  
Vol 01 ◽  
Author(s):  
Carla Pires ◽  
Ana Fernandes
Keyword(s):  
Systematic Review ◽  
Adverse Event ◽  
Natural Products ◽  
Adverse Events ◽  
In Vitro Study ◽  
Google Scholar ◽  
Inclusion Criteria ◽  
Exclusion Criteria ◽  
Meta Analyses

Background: Natural products are commonly used for treating health problems. These products may be associated with adverse events, which are defined as "noxious and unintended response to a medicinal product" by the European Medicine Agency. Objectives: To identify studies describing at least one adverse event (or with potential to promote an adverse event) related to the use of natural products, as well as to describe the involved product(s) and adverse event(s). Methods: A pre-systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Keywords: "natural product(s)" and ["adverse drug reaction(s)" or "adverse effect(s)"]. Screened databases: PubMed, SciELO, DOAJ and Google Scholar. Inclusion criteria: papers describing at least one adverse event associated with the use of natural products and published between 2017 and 2019. Exclusion criteria: Repeated studies, reviews and papers written in other languages than English, Portuguese, French or Spanish. Results: 104 studies were identified (20 PubMed; 0 SciELO; 2 DOAJ; 82 Google Scholar), but only 10 were selected (4 PubMed and 6 Google Scholar): 1 in-vitro study; 2 non-clinical studies, 1 study reporting in-vitro and clinical data and 5 studies were cases reports. Globally, 997 reports of adverse drug reactions with natural products were identified, mainly non-severe cases. Conclusion: Since a limited number of studies was found, we conclude that adverse events due to natural products may be underreported, or natural products may have a good safety profile. This review contributes for assuring the safety of natural products consumers, by evaluating the knowledge/information on the potential adverse events and interactions of these products.

scholarly journals Biological and Computational Studies for Dual Cholinesterases Inhibitory Effect of Zerumbone

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1215 ◽  
Author(s):  
Jayeong Hwang ◽  
Kumju Youn ◽  
Yeongseon Ji ◽  
Seonah Lee ◽  
Gyutae Lim ◽  
...  
Keyword(s):  
Docking Simulation ◽  
Inhibitory Effect ◽  
Potential Effect ◽  
Van Der Waals Interactions ◽  
Inhibitory Effects ◽  
Computational Docking ◽  
In Silico Docking ◽  
Ic50 Values ◽  
Physiological Benefits

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) mediate the degradation of acetylcholine (ACh), a primary neurotransmitter in the brain. Cholinergic deficiency occurs during the progression of Alzheimer’s disease (AD), resulting in widespread cognitive dysfunction and decline. We evaluated the potential effect of a natural cholinesterase inhibitor, zerumbone, using in vitro target enzyme assays, as well as in silico docking and ADMET (absorption, distribution, metabolism, excretion, and toxicity) simulation. Zerumbone showed a predominant cholinesterase inhibitory property with IC50 values of 2.74 ± 0.48 µM and 4.12 ± 0.42 µM for AChE and BChE, respectively; however, the modes of inhibition were different. Computational docking simulation indicated that Van der Waals interactions between zerumbone and both the cholinesterases were the main forces responsible for its inhibitory effects. Furthermore, zerumbone showed the best physicochemical properties for both bioavailability and blood–brain barrier (BBB) permeability. Together, in the present study, zerumbone was clearly identified as a unique dual AChE and BChE inhibitor with high permeability across the BBB, suggesting a strong potential for its physiological benefits and/or pharmacological efficacy in the prevention of AD.

scholarly journals Design, Synthesis, and Biological Evaluation of Pyridineamide Derivatives Containing a 1,2,3-Triazole Fragment as Type II c-Met Inhibitors

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 10 ◽  
Author(s):  
Hehua Xiong ◽  
Jianxin Cheng ◽  
Jianqing Zhang ◽  
Qian Zhang ◽  
Zhen Xiao ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Lines ◽  
Inhibitory Activity ◽  
Docking Simulation ◽  
Binding Mode ◽  
Biological Evaluation ◽  
Design Synthesis ◽  
Ic50 Values ◽  
Mcf 7

A series of 4-(pyridin-4-yloxy)benzamide derivatives containing a 1,2,3-triazole fragment were designed, synthesized, and their inhibitory activity against A549, HeLa, and MCF-7 cancer cell lines was evaluated. Most compounds exhibited moderate to potent antitumor activity against the three cell lines. Among them, the promising compound B26 showed stronger inhibitory activity than Golvatinib, with IC50 values of 3.22, 4.33, and 5.82 μM against A549, HeLa, and MCF-7 cell lines, respectively. The structure–activity relationships (SARs) demonstrated that the modification of the terminal benzene ring with a single electron-withdrawing substituent (fluorine atom) and the introduction of a pyridine amide chain with a strong hydrophilic group (morpholine) to the hinge region greatly improved the antitumor activity. Meanwhile, the optimal compound B26 showed potent biological activity in some pharmacological experiments in vitro, such as cell morphology study, dose-dependent test, kinase activity assay, and cell cycle experiment. Finally, the molecular docking simulation was performed to further explore the binding mode of compound B26 with c-Met.

scholarly journals PTP1B Modulates the Association of β-Catenin with N-cadherin through Binding to an Adjacent and Partially Overlapping Target Site

2002 ◽  
Vol 277 (51) ◽  
pp. 49989-49997 ◽  
Author(s):  
Gang Xu ◽  
Carlos Arregui ◽  
Jack Lilien ◽  
Janne Balsamo
Keyword(s):  
Amino Acids ◽  
Cell Surface ◽  
Tyrosine Phosphatase ◽  
Target Site ◽  
Target Domain ◽  
Chick Retina ◽  
Cell Permeable Peptide ◽  
A Cell ◽  
Relationship Of

The nonreceptor tyrosine phosphatase PTP1B associates with the cytoplasmic domain of N-cadherin and may regulate cadherin function through dephosphorylation of β-catenin. We have now identified the domain on N-cadherin to which PTP1B binds and characterized the effect of perturbing this domain on cadherin function. Deletion constructs lacking amino acids 872–891 fail to bind PTP1B. This domain partially overlaps with the β-catenin binding domain. To further define the relationship of these two sites, we used peptides to competein vitrobinding. A peptide representing the most NH2-terminal 8 amino acids of the PTP1B binding site, the region of overlap with the β-catenin target, effectively competes for binding of β-catenin but is much less effective in competing PTP1B, whereas two peptides representing the remaining 12 amino acids have no effect on β-catenin binding but effectively compete for PTP1B binding. Introduction into embryonic chick retina cells of a cell-permeable peptide mimicking the 8 most COOH-terminal amino acids in the PTP1B target domain, the region most distant from the β-catenin target site, prevents binding of PTP1B, increases the pool of free, tyrosine-phosphorylated β-catenin, and results in loss of N-cadherin function. N-cadherin lacking this same region of the PTP1B target site does not associate with PTP1B or β-catenin and is not efficiently expressed at the cell surface of transfected L cells. Thus, interaction of PTP1B with N-cadherin is essential for its association with β-catenin, stable expression at the cell surface, and consequently, cadherin function.

In Vitro Study of the Effect of Osmotic Solutes on the Interactions between Cells from the Peritoneum and Peritoneal Cavity

1994 ◽  
Vol 14 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Andrzej Breborowicz ◽  
Elias Balaskas ◽  
George D. Oreopoulos ◽  
Leo Martis ◽  
Kenneth Serkes ◽  
...  
Keyword(s):  
Amino Acids ◽  
Growth Factors ◽  
Conditioned Medium ◽  
In Vitro Study ◽  
Mesothelial Cells ◽  
Peritoneal Mesothelial Cells ◽  
Inhibition Of Growth ◽  
Peritoneal Leukocytes ◽  
Osmotic Solutes

Objective To study how the presence of osmotic solutes in medium affects growth of the peritoneal mesothelial cells and fibroblasts and how osmotic solutes influence the production of factors regulating growth of these cells. Design The proliferation of mesothelial cells and fibroblasts was evaluated by measuring the incorporation of 3H-thymidine into the cells. Cells were exposed to osmotic solutes; the concentration of the latter in the medium was continuously lowered over the time of the experiment to simulate changes of their concentration in the dialysate. The synthesis of factors influencing the proliferation of the mesothelial cells or fibroblasts, by mesothelial cells or fibroblasts themselves, or by peritoneal leukocytes, was tested by the characteristics of the “conditioned” medium. The conditioned medium was produced by exposing standard medium to mesothelial or fibroblasts monolayer or to peritoneal leukocytes over 24 hours; following filtration it was applied to growing test cells for the study of growth factors. Results The effect of osmotic solutes on the growth of mesothelial cells is less inhibitory when their concentration is gradually lowered over the time of the study, compared to previous findings with a constant concentration. Peritoneal leukocytes produce growth factors for mesothelial cells and fibroblasts. Glucose and amino acids inhibit production of peritonealleukocyte-derived growth factors for mesothelial cells, while glycerol increases synthesis of such growth factors for fibroblasts. Mesothelial cells produce factors stimulating the proliferation of mesothelial cells and fibroblasts. In the presence of glycerol or amino acids synthesis of mesothelium derived growth factors for fibroblasts is augmented. Finally, fibroblasts produce factors that inhibit the proliferation of the mesothelial cells, and this effect is potentiated in the presence of amino acids. Conclusions Cytotoxicity of the osmotic solutes measured by the inhibition of growth of the mesothelial cells or their increased damage is significantly reduced during in vitro kinetic study when the concentration of these solutes is gradually lowered. Presence of osmotic solutes in the medium affects synthesis of growth factors derived from mesothelium, fibroblasts, or peritoneal leukocytes, which affect the proliferation of mesothelial cells or fibroblasts.

scholarly journals Anti-Inflammatory and Antibacterial Activity Constituents from the Stem of Cinnamomum validinerve

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3382 ◽  
Author(s):  
Chi-Lung Yang ◽  
Ho-Cheng Wu ◽  
Tsong-Long Hwang ◽  
Chu-Hung Lin ◽  
Yin-Hua Cheng ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Immune Cell ◽  
Intraperitoneal Administration ◽  
In Vitro Study ◽  
Human Neutrophils ◽  
Infection Model ◽  
Ic50 Values ◽  
Anti Inflammatory

One new dibenzocycloheptene, validinol (1), and one butanolide firstly isolated from the natural source, validinolide (2), together with 17 known compounds were isolated from the stem of Cinnamomum validinerve. Among the isolates, lincomolide A (3), secosubamolide (7), and cinnamtannin B1 (19) exhibited potent inhibition on both superoxide anion generation (IC50 values of 2.98 ± 0.3 µM, 4.37 ± 0.38 µM, and 2.20 ± 0.3 µM, respectively) and elastase release (IC50 values of 3.96 ± 0.31 µM, 3.04 ± 0.23 µM, and 4.64 ± 0.71 µM, respectively) by human neutrophils. In addition, isophilippinolide A (6), secosubamolide (7), and cinnamtannin B1 (19) showed bacteriostatic effects against Propionibacterium acnes in in vitro study, with minimal inhibitory concentration (MIC) values at 16 μg/mL, 16 μg/mL, and 500 μg/mL, respectively. Further investigations using the in vivo ear P. acnes infection model showed that the intraperitoneal administration of the major component cinnamtannin B1 (19) reduced immune cell infiltration and pro-inflammatory cytokines TNF-α and IL-6 at the infection sites. The results demonstrated the potential of cinnamtannin B1 (19) for acne therapy. In summary, these results demonstrated the anti-inflammatory potentials of Formosan C. validinerve during bacterial infections.

scholarly journals In-silico Molecular Docking and ADME/Pharmacokinetic Prediction Studies of Some Novel Carboxamide Derivatives as Anti-tubercular Agents

2020 ◽  
Vol 3 (4) ◽  
pp. 989-1000
Author(s):  
Mustapha Abdullahi ◽  
Shola Elijah Adeniji
Keyword(s):  
Molecular Docking ◽  
Binding Affinity ◽  
In Silico ◽  
Density Functional ◽  
Docking Simulation ◽  
Basis Set ◽  
Hybrid Functional ◽  
Standard Drug

AbstractMolecular docking simulation of thirty-five (35) molecules of N-(2-phenoxy)ethyl imidazo[1,2-a]pyridine-3-carboxamide (IPA) with Mycobacterium tuberculosis target (DNA gyrase) was carried out so as to evaluate their theoretical binding affinities. The chemical structure of the molecules was accurately drawn using ChemDraw Ultra software, then optimized at density functional theory (DFT) using Becke’s three-parameter Lee–Yang–Parr hybrid functional (B3LYP/6-311**) basis set in a vacuum of Spartan 14 software. Subsequently, the docking operation was carried out using PyRx virtual screening software. Molecule 35 (M35) with the highest binding affinity of − 7.2 kcal/mol was selected as the lead molecule for structural modification which led to the development of four (4) newly hypothetical molecules D1, D2, D3 and D4. In addition, the D4 molecule with the highest binding affinity value of − 9.4 kcal/mol formed more H-bond interactions signifying better orientation of the ligand in the binding site compared to M35 and isoniazid standard drug. In-silico ADME and drug-likeness prediction of the molecules showed good pharmacokinetic properties having high gastrointestinal absorption, orally bioavailable, and less toxic. The outcome of the present research strengthens the relevance of these compounds as promising lead candidates for the treatment of multidrug-resistant tuberculosis which could help the medicinal chemists and pharmaceutical professionals in further designing and synthesis of more potent drug candidates. Moreover, the research also encouraged the in vivo and in vitro evaluation study for the proposed designed compounds to validate the computational findings.

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