scholarly journals Synthesis and In Vitro Screening of Novel Heterocyclic β-d-Gluco- and β-d-Galactoconjugates as Butyrylcholinesterase Inhibitors

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2833
Author(s):  
Krešimir Baumann ◽  
Lorena Kordić ◽  
Marko Močibob ◽  
Goran Šinko ◽  
Srđanka Tomić
Keyword(s):  
Active Site ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
In Vitro Screening ◽  
Sugar Moiety ◽  
Brain Barrier Permeability ◽  
The Central Nervous System ◽  
Key Residues ◽  
Micromolar Range

The development of selective butyrylcholinesterase (BChE) inhibitors may improve the treatment of Alzheimer’s disease by increasing lower synaptic levels of the neurotransmitter acetylcholine, which is hydrolysed by acetylcholinesterase, as well as by overexpressed BChE. An increase in the synaptic levels of acetylcholine leads to normal cholinergic neurotransmission and improved cognitive functions. A series of 14 novel heterocyclic β-d-gluco- and β-d-galactoconjugates were designed and screened for inhibitory activity against BChE. In the kinetic studies, 4 out of 14 compounds showed an inhibitory effect towards BChE, with benzimidazolium and 1-benzylbenzimidazolium substituted β-d-gluco- and β-d-galacto-derivatives in a 10–50 micromolar range. The analysis performed by molecular modelling indicated key residues of the BChE active site, which contributed to a higher affinity toward the selected compounds. Sugar moiety in the inhibitor should enable better blood–brain barrier permeability, and thus increase bioavailability in the central nervous system of these compounds.

scholarly journals Phytochemical Constituents and In Vitro Anti-Diabetic Properties of Ziziphus jujubа (Rhamnaceae) Fruits

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Stoilova I ◽  
Trifonova D. ◽  
Marchev A. ◽  
Stanchev V. ◽  
Angelova G. ◽  
...  
Keyword(s):  
Phenolic Acids ◽  
Ethanol Extract ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
Total Phenolic ◽  
Fruit Extract ◽  
Quercetin Glycosides ◽  
Dried Extract ◽  
High Inhibition

In the current study the phytochemical profile of 70% ethanol extract of Ziziphus jujubа (Rhamnaceae), cultivated in Bulgaria has been investigated. The fruit extract contained numerous phytochemicals, such as triterpenes, phenolic acids and flavonoids. Five triterpenes, 11 phenolic acids and 5 flavonoids have been identified. The fruit extract had a total phenolic content of 21.62 ± 0.0265 mg/g and total flavonoid content 1.34 ± 0.017 mg/g dried extract. Among the triterpenes with the highest concentration was the betulinic acid 20943.17±527.06 µg/g dried extract, rosmarinic acid (1174.26±29.55 µg/g) among the phenolic acids, followed by myricetin (214.61±5.40 µg/g) as a representative of flavonoids and rutin 3 046.89±76.68 among the quercetin glycosides. The inhibitory effect of Z. jujubа fruit extract has been investigated on the key enzymes linked to diabetes – α-glucosidase and α-amylase. In order to evaluate the type of inhibition a Lineweaver-Burk plot was produced. The results obtained from the enzyme kinetic studies exhibited a mixed noncompetitive-uncompetitive type of inhibition on α-glucosidase and mixed competitive-non-competitive type of inhibition on α-amylase. Besides that the obtained results proved high inhibition of α-glucosidase (79.46% at 1.33 mg.ml-1 extract) and moderate inhibition of α-amylase (39.10% at 0.666 mg.ml-1 extract concentration). These results suggest the possible use of fruits of Z. jujubа in the management of diabetes mellitus.

scholarly journals Calcium ions and glycogen act synergistically as inhibitors of hepatic glycogen-synthase phosphatase

1985 ◽  
Vol 232 (3) ◽  
pp. 697-704 ◽  
Author(s):  
L Mvumbi ◽  
M Bollen ◽  
W Stalmans
Keyword(s):  
Proteinase Inhibitors ◽  
Glycogen Synthase ◽  
Liver Extract ◽  
Inhibitory Effect ◽  
Hepatic Glycogen ◽  
Calmodulin Antagonists ◽  
Maximal Inhibition ◽  
Fed State ◽  
Micromolar Range

We investigated the inhibitory effect of Ca2+ in the micromolar range on the activation of glycogen synthase in crude gel-filtered liver extracts [van de Werve (1981) Biochem. Biophys. Res. Commun. 102, 1323-1329]. The magnitude of the inhibition was highly dependent on the glycogen concentration in the final liver extract. Ca2+ inhibited the activation of purified hepatic synthase b by the G-component of synthase phosphatase, as present in the isolated glycogen-protein complex. The cytosolic S-component was not inhibited. Maximal inhibition of the crude G-component occurred at 0.3 microM-Ca2+. The inhibition was not influenced by the addition of either calmodulin or calmodulin antagonists, or by various proteinase inhibitors. The use of purified G-component revealed that the inhibition by 0.3 microM-Ca2+ increased from 45% to 85% when the concentration of glycogen was raised from 1.5 to 20 mg/ml. Muscle glycogen synthase, extensively phosphorylated in vitro, was also used as substrate for purified G-component. Activation and dephosphorylation were similarly inhibited by 0.3 microM-Ca2+, but the magnitude of the inhibition was much greater with the hepatic substrate. No effect of 0.3 microM-Ca2+ was found on the activity of phosphorylase phosphatase in various liver preparations. We conclude that the inhibition of synthase activation by Ca2+ is one of the mechanisms by which cyclic AMP-independent glycogenolytic hormones promote the inactivation of glycogen synthase in the liver, especially in the fed state.

scholarly journals Crystal Structure of Poliovirus 3CD Protein: Virally Encoded Protease and Precursor to the RNA-Dependent RNA Polymerase

2007 ◽  
Vol 81 (7) ◽  
pp. 3583-3596 ◽  
Author(s):  
Laura L. Marcotte ◽  
Amanda B. Wass ◽  
David W. Gohara ◽  
Harsh B. Pathak ◽  
Jamie J. Arnold ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Viral Replication ◽  
Active Site ◽  
Polymerase Activity ◽  
Rna Dependent Rna Polymerase ◽  
Multifunctional Protein ◽  
Biologically Relevant ◽  
N Terminus ◽  
Key Residues

ABSTRACT Poliovirus 3CD is a multifunctional protein that serves as a precursor to the protease 3Cpro and the viral polymerase 3Dpol and also plays a role in the control of viral replication. Although 3CD is a fully functional protease, it lacks polymerase activity. We have solved the crystal structures of 3CD at a 3.4-Å resolution and the G64S fidelity mutant of 3Dpol at a 3.0-Å resolution. In the 3CD structure, the 3C and 3D domains are joined by a poorly ordered polypeptide linker, possibly to facilitate its cleavage, in an arrangement that precludes intramolecular proteolysis. The polymerase active site is intact in both the 3CD and the 3Dpol G64S structures, despite the disruption of a network proposed to position key residues in the active site. Therefore, changes in molecular flexibility may be responsible for the differences in fidelity and polymerase activities. Extensive packing contacts between symmetry-related 3CD molecules and the approach of the 3C domain's N terminus to the VPg binding site suggest how 3Dpol makes biologically relevant interactions with the 3C, 3CD, and 3BCD proteins that control the uridylylation of VPg during the initiation of viral replication. Indeed, mutations designed to disrupt these interfaces have pronounced effects on the uridylylation reaction in vitro.

Bombesin inhibits thyrotrophin secretion in rats

1985 ◽  
Vol 108 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Terunori Mitsuma ◽  
Tsuyoshi Nogimori ◽  
Masahiro Chaya
Keyword(s):  
Thyroid Hormone ◽  
Plasma Concentrations ◽  
Treated Group ◽  
Inhibitory Effect ◽  
Thyrotrophin Releasing Hormone ◽  
Tsh Secretion ◽  
The Central Nervous System ◽  
Thyroid Hormone Levels ◽  
Tsh Levels

Abstract. The effects of peripheral administration of bombesin on thyrotrophin-releasing hormone (TRH) and thvrotrophin (TSH) secretion in rats were studied. Bombesin (200 μg/kg) was injected iv, and the rats were serially decapitated. TRH, TSH and thyroid hormone were measured by radioimmunoassay. The hypothalamic immunoreactive TRH (ir-TRH) content increased significantly after bombesin injection, whereas plasma concentrations tended to decrease, but not significantly. Plasma TSH levels decreased significantly in a dose-related manner with a nadir at 40 min after the injection. Plasma thyroid hormone levels did not change significantly. Plasma ir-TRH and TSH responses to cold were inhibited by bombesin, but the plasma TSH response to TRH was not affected. In the pimozide- or para-chlorophenylalanine pre-treated group, the inhibitory effect of bombesin on TSH levels was prevented, but not in the l-Dopa- or 5-hydroxytryptophan pre-treated group. These drugs alone had no effect on plasma TSH levels in terms of the dose used. The inactivation of TRH immunoreactivity in plasma or hypothalamus in vitro after bombesin injection did not differ from that of the controls. These findings suggest that bombesin acts on the hypothalamus to inhibit TRH release, and that its effects are at least partially modified by amines of the central nervous system.

scholarly journals Design and synthesis of novel pyrazole-benzofuran hybrids: in vitro α-glucosidase inhibitory activity, kinetic and molecular modeling study

2021 ◽  
Author(s):  
Fateme Azimi ◽  
Homa Azizian ◽  
Mohammad Najafi ◽  
Ghadamali khodarahmi ◽  
Motahareh hassanzadeh ◽  
...  
Keyword(s):  
Active Site ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Back Side ◽  
Binding Interaction ◽  
Dynamic Simulations ◽  
Standard Drug ◽  
Design And Synthesis ◽  
Derivatives Of

Abstract In this work, new derivatives of biphenyl pyrazole-benzofuran hybrids designed, synthesized and evaluated in vitro through enzymatic assay for inhibitory effect against α-glucosidase activity. Newly identified inhibitors were found to be four to eighteen folds more active with IC50 values in the range of 40.6 ± 0.2–164.3 ± 1.8 µM, as compared to the standard drug acarbose (IC50 = 750.0 ± 10.0 µM). Limited Structure-activity relationship was established. A kinetic binding study indicated that most active compound 8e acted as the competitive inhibitors of α-glucosidase with Ki = 38 µM. Molecular docking has also been performed to find the interaction modes responsible for the desired inhibitory activity. As expected, all pharmacophoric features used in the design of the hybrid, are involved in the interaction with the active site of the enzyme. In addition, molecular dynamic simulations showed compound 8e oriented vertically into the active site from mouth to the bottom and stabilized the enzyme domains by interacting with the interface of domain A and domain B and the back side of the active site while acarbose formed non-binding interaction with the residue belong to the domain A of the enzyme.

scholarly journals Differential MMP-14 Targeting by Lumican-Derived Peptides Unraveled by In Silico Approach

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4930
Author(s):  
Jonathan Dauvé ◽  
Nicolas Belloy ◽  
Romain Rivet ◽  
Nicolas Etique ◽  
Pierre Nizet ◽  
...  
Keyword(s):  
Amino Acids ◽  
In Silico ◽  
Primary Melanoma ◽  
Direct Interaction ◽  
Inhibitory Effect ◽  
Melanoma Tumor ◽  
And Migration ◽  
Key Residues

Lumican, a small leucine-rich proteoglycan (SLRP) of the extracellular matrix (ECM), displays anti-tumor properties through its direct interaction with MMP-14. Lumican-derived peptides, such as lumcorin (17 amino acids) or L9M (10 amino acids), are able to inhibit the proteolytic activity of MMP-14 and melanoma progression. This work aimed to visualize the interactions of lumican-derived peptides and MMP-14. Molecular modeling was used to characterize the interactions between lumican-derived peptides, such as lumcorin, L9M, and cyclic L9M (L9Mc, 12 amino acids), and MMP-14. The interaction of L9Mc with MMP-14 was preferential with the MT-Loop domain while lumcorin interacted more with the catalytic site. Key residues in the MMP-14 amino acid sequence were highlighted for the interaction between the inhibitory SLRP-derived peptides and MMP-14. In order to validate the in silico data, MMP-14 activity and migration assays were performed using murine B16F1 and human HT-144 melanoma cells. In contrast to the HT-144 melanoma cell line, L9Mc significantly inhibited the migration of B16F1 cells and the activity of MMP-14 but with less efficacy than lumican and lumcorin. L9Mc significantly inhibited the proliferation of B16F1 but not of HT-144 cells in vitro and primary melanoma tumor growth in vivo. Thus, the site of interaction between the domains of MMP-14 and lumcorin or L9Mc were different, which might explain the differences in the inhibitory effect of MMP-14 activity. Altogether, the biological assays validated the prediction of the in silico study. Possible and feasible improvements include molecular dynamics results.

scholarly journals Effect of Lipopolysaccharide and TNFα on Neuronal Ascorbic Acid Uptake

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Veedamali S. Subramanian ◽  
Trevor Teafatiller ◽  
Anshu Agrawal ◽  
Masashi Kitazawa ◽  
Jonathan S. Marchant
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Inhibitory Effect ◽  
Acid Uptake ◽  
Mrna Levels ◽  
The Central Nervous System ◽  
Factor Α ◽  
And Function

Vitamin C (ascorbic acid: AA) uptake in neurons occurs via the sodium-dependent vitamin C transporter-2 (SVCT2), which is highly expressed in the central nervous system (CNS). During chronic neuroinflammation or infection, CNS levels of lipopolysaccharide (LPS) and LPS-induced tumor necrosis factor-α (TNFα) are increased. Elevated levels of LPS and TNFα have been associated with neurodegenerative diseases together with reduced levels of AA. However, little is known about the impacts of LPS and TNFα on neuronal AA uptake. The objective of this study was to examine the effect of LPS and TNFα on SVCT2 expression and function using in vitro and in vivo approaches. Treatment of SH-SY5Y cells with either LPS or TNFα inhibited AA uptake. This reduced uptake was associated with a significant decrease in SVCT2 protein and mRNA levels. In vivo exposure to LPS or TNFα also decreased SVCT2 protein and mRNA levels in mouse brains. Both LPS and TNFα decreased SLC23A2 promoter activity. Further, the inhibitory effect of LPS on a minimal SLC23A2 promoter was attenuated when either the binding site for the transcription factor Sp1 was mutated or cells were treated with the NF-κB inhibitor, celastrol. We conclude that inflammatory signals suppress AA uptake by impairing SLC23A2 transcription through opposing regulation of Sp1 and NF-κB factors.

scholarly journals In silico study on anti-Chikungunya virus activity of hesperetin

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2602 ◽  
Author(s):  
Adrian Oo ◽  
Pouya Hassandarvish ◽  
Sek Peng Chin ◽  
Vannajan Sanghiran Lee ◽  
Sazaly Abu Bakar ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Chikungunya Virus ◽  
Md Simulations ◽  
Inhibitory Effect ◽  
Structural Proteins ◽  
In Vitro Screening ◽  
Intracellular Replication ◽  
Lipinski’S Rule ◽  
Lipinski’S Rule Of Five

BackgroundThe re-emerging,Aedes spp.transmitted Chikungunya virus (CHIKV) has recently caused large outbreaks in a wide geographical distribution of the world including countries in Europe and America. Though fatalities associated with this self-remitting disease were rarely reported, quality of patients’ lives have been severely diminished by polyarthralgia recurrence. Neither effective antiviral treatment nor vaccines are available for CHIKV. Our previous in vitro screening showed that hesperetin, a bioflavonoid exhibits inhibitory effect on the virus intracellular replication. Here, we present a study using the computational approach to identify possible target proteins for future mechanistic studies of hesperetin.Methods3D structures of CHIKV nsP2 (3TRK) and nsP3 (3GPG) were retrieved from Protein Data Bank (PDB), whereas nsP1, nsP4 and cellular factor SPK2 were modeled using Iterative Threading Assembly Refinement (I-TASSER) server based on respective amino acids sequence. We performed molecular docking on hesperetin against all four CHIKV non-structural proteins and SPK2. Proteins preparation and subsequent molecular docking were performed using Discovery Studio 2.5 and AutoDock Vina 1.5.6. The Lipinski’s values of the ligand were computed and compared with the available data from PubChem. Two non-structural proteins with crystal structures 3GPG and 3TRK in complexed with hesperetin, demonstrated favorable free energy of binding from the docking study, were further explored using molecular dynamics (MD) simulations.ResultsWe observed that hesperetin interacts with different types of proteins involving hydrogen bonds, pi-pi effects, pi-cation bonding and pi-sigma interactions with varying binding energies. Among all five tested proteins, our compound has the highest binding affinity with 3GPG at −8.5 kcal/mol. The ligand used in this study also matches the Lipinski’s rule of five in addition to exhibiting closely similar properties with that of in PubChem. The docking simulation was performed to obtain a first guess of the binding structure of hesperetin complex and subsequently analysed by MD simulations to assess the reliability of the docking results. Root mean square deviation (RMSD) of the simulated systems from MD simulations indicated that the hesperetin complex remains stable within the simulation timescale.DiscussionThe ligand’s tendencies of binding to the important proteins for CHIKV replication were consistent with our previous in vitro screening which showed its efficacy in blocking the virus intracellular replication. NsP3 serves as the highest potential target protein for the compound’s inhibitory effect, while it is interesting to highlight the possibility of interrupting CHIKV replication via interaction with host cellular factor. By complying the Lipinski’s rule of five, hesperetin exhibits drug-like properties which projects its potential as a therapeutic option for CHIKV infection.

scholarly journals PHYTOCHEMICAL SCREENING AND IN VITRO ANTIOXIDANT AND ANTI-DIABETIC POTENTIALS OF PERSEA AMERICANA MILL. (LAURACEAE) FRUIT EXTRACT

2018 ◽  
Author(s):  
Mahadeva Rao US
Keyword(s):  
Therapeutic Potential ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
Persea Americana ◽  
Phytochemical Screening ◽  
Fruit Extract ◽  
Avocado Fruit ◽  
Percentage Yield ◽  
Hydrolyzing Enzymes

Diabetes mellitus (DM) is a metabolic disorder characterized by insulin resistance and pancreatic β-cell dysfunction and the management of blood glucose level is an important strategy in the control of the disease and complications associated with it. Therefore, components that cause uptake of glucose from the bloodstream and inhibitors of carbohydrate hydrolyzing enzymes can be useful in treatment of DM and medicinal plants are often used to achieve this aim. Avocado fruit is rich in phytochemicals necessary for treatment of DM. The purpose of this study was to investigate the inhibitory effect of Persea americana fruit extracts on α-amylase and α-glucosidase enzymes. The percentage yield, phytochemical screening (both qualitative and quantitative), in vitro antioxidant and anti-diabeticassays, and kinetic studies were performed with different solvent extracts of Avocado fruit pulp. Results: Avocado hadgreat and promising potential as pharmaceutical agent, particularly to be developed as anti-diabetic through the inhibition of α-glucosidase and α- amylase enzymes.  In vitro studies of the antioxidant activity of the fruit extract gaveanevidence and strong biochemical rationale of their therapeutic potential. The fruit extract of P. americana may play an important role in the development of nutraceuticals and also in the management of oxidative stress induced DM.

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