scholarly journals In vitro modulation of hippocampal pyramidal cell response by quinolones: effects of HA 966 and gamma-hydroxybutyric acid.

1996 ◽  
Vol 40 (11) ◽  
pp. 2573-2576 ◽  
Author(s):  
W Dimpfel ◽  
A Dalhoff ◽  
E von Keutz
Keyword(s):  
Nmda Receptor ◽  
Side Effects ◽  
Pyramidal Cell ◽  
Cell Activity ◽  
Population Spike ◽  
Dependent Manner ◽  
Glycine Site ◽  
Hydroxybutyric Acid ◽  
Concentration Dependent Manner

The influence of quinolones on electrically evoked pyramidal cell activity in the rat hippocampus in vitro was studied by using the slice technique. We hoped to learn more about the possible mechanisms for the development of side effects of different quinolones and to find a possible treatment. As reported earlier (W. Dimpfel, M. Spüler, A. Dalhoff, W. Hofmann, and G. Schlüter, Antimicrob. Agents Chemother. 35:1142-1146, 1991), the amplitude of the population spike increased in the presence of ciprofloxacin, lomefloxacin, or ofloxacin about twofold in comparison with reference values. This increase could be prevented in a concentration-dependent manner by the concomitant presence of 3-amino-1-hydroxy-2-pyrrolidone (HA 966), a compound acting at the so-called glycine site of the N-methyl-D-aspartate (NMDA) receptor, but not in the presence of aminophosphonovaleric acid (APV), which acts at a different recognition site of the NMDA receptor. Another tool, 6,7-dinitroquinoxaline-2,3-dione, an antagonist of the so-called AMPA receptor (named after the binding of L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid [AMPA] to this site), could not antagonize the effect induced by the quinolones. Activation of the glycine site of the NMDA receptor induced by the presence of D-serine in the superfusion medium also resulted in a concentration-dependent increase in the population spike amplitude. This response remained unchanged in the presence of ciprofloxacin, whereas lomefloxacin and ofloxacin led to further increases in the amplitude, especially in the presence of higher concentrations of D-serine. These results also point to an involvement of the glycine site of the central NMDA receptor in the development of side effects by different quinolones. A complete attenuation of the quinolone-induced effects was obtained in the presence of 2.5 microM gamma-hydroxybutyric acid (GHB), a physiological neuromodulator which is marketed in some countries of Europe as a sedative. It is therefore concluded that the excitatory adverse effects of quinolones might be treated by the administration of GHB.

scholarly journals Effect of Conantokin G on NMDA Receptor–Mediated Spontaneous EPSCs in Cultured Cortical Neurons

2006 ◽  
Vol 96 (3) ◽  
pp. 1084-1092 ◽  
Author(s):  
Anitha B. Alex ◽  
Anthony J. Baucum ◽  
Karen S. Wilcox
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Binding Site ◽  
Cortical Neurons ◽  
Dependent Manner ◽  
Patch Clamp Technique ◽  
Concentration Dependent Manner ◽  
Whole Cell ◽  
Cultured Cortical Neurons

Conantokin G (Con G), derived from the venom of Conus geographus, is the most characterized natural peptide antagonist targeted to N-methyl-d-aspartate (NMDA) receptors. Although Con G is known to bind to the glutamate binding site on the NR2 subunit of the receptor, it is unclear whether it can allosterically modulate the function of the receptor through the glycine binding site on the NR1 subunit. This study was designed to evaluate the action of Con G on NMDA receptor–mediated spontaneous excitatory postsynaptic currents (sEPSCs) and its modulation by glycine in cultured cortical neurons (13–19 days in vitro) using the whole cell patch-clamp technique. Con G inhibited NMDA receptor–mediated sEPSCs in a concentration-dependent manner. Also, the potency of Con G decreased as a function of time in culture. The inhibition of EPSCs observed after application of Con G in the presence of high (10 μM) and nominal (no added) concentrations of glycine was not different at 13 days in vitro (DIV). Furthermore, similar results were obtained with experiments on Con G–induced inhibition of NMDA-evoked whole cell currents. These results indicate that glycine concentrations do not have a direct effect on Con G–induced inhibition of NMDA currents. In addition, age dependency in the action of Con G on cortical neurons in vitro suggests that this model system would be useful in examining the effects of different agonists/antagonists on native synaptic NMDA receptors.

scholarly journals Inhibition of neural phospholipase D activity by aminoglycoside antibiotics

1991 ◽  
Vol 279 (1) ◽  
pp. 319-321 ◽  
Author(s):  
M Liscovitch ◽  
V Chalifa ◽  
M Danin ◽  
Y Eli
Keyword(s):  
Side Effects ◽  
Rat Brain ◽  
Phospholipase D ◽  
Aminoglycoside Antibiotics ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Brain Membranes ◽  
Rat Brain Membranes ◽  
Isolated Rat

The effects of aminoglycoside antibiotics on phospholipase D (PLD) activity were investigated in permeabilized NG108-15 cells and in isolated rat brain membranes. Neomycin inhibited guanosine 5′-[gamma-thio]triphosphate-stimulated PLD activity in digitonin-permeabilized NG108-15 cells in a concentration-dependent manner (50% inhibition at 100 microM). Neomycin similarly inhibited PLD activity present in rat brain membranes and assayed in vitro with [3H]phosphatidylcholine as substrate (50% inhibition at 65 microM). Other aminoglycosides tested (kanamycin, geneticin and streptomycin) were nearly equipotent inhibitors of rat brain PLD. These results indicate that aminoglycoside antibiotics inhibit phosphatidylcholine-PLD activity with comparable and sometimes greater potency than their well known inhibition of phosphoinositide-phospholipase C. The possibility that PLD inhibition could mediate some of the toxic side effects of aminoglycosides is suggested.

scholarly journals Discovery of Galangin as a Potential DPP-4 Inhibitor That Improves Insulin-Stimulated Skeletal Muscle Glucose Uptake: A Combinational Therapy for Diabetes

2019 ◽  
Vol 20 (5) ◽  
pp. 1228 ◽  
Author(s):  
Poonam Kalhotra ◽  
Veera Chittepu ◽  
Guillermo Osorio-Revilla ◽  
Tzayhri Gallardo-Velázquez
Keyword(s):  
Diabetes Mellitus ◽  
Skeletal Muscle ◽  
Side Effects ◽  
Therapeutic Drug ◽  
Diabetic Patients ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Glucose Levels ◽  
Muscle Health

Dipeptidyl peptidase-4 (DPP-4) is a well-known therapeutic drug target proven to reduce blood glucose levels in diabetes mellitus, and clinically, DPP-4 inhibitors are used in combination with other anti-diabetic agents. However, side effects and skeletal muscle health are not considered in the treatment for diabetic patients. Recently, natural compounds have been proven to inhibit DPP-4 with fewer side effects. In this work, initially, molecular docking simulations revealed that a natural compound, Galangin, possess a binding energy of −24 KJ/mol and interaction residues SER 630 and TYR 547, that are responsible for potent DPP-4 inhibition. In vitro studies showed that galangin not only inhibits DPP-4 in a concentration-dependent manner but also regulates glucose levels, enabling the proliferation of rat L6 skeletal muscle cells. The combination of galangin with insulin benefits regulation of glucose levels significantly in comparison to galangin alone (p < 0.05). These findings suggest the beneficial effect of the use of galangin, both alone or in combination with insulin, to reduce glucose levels and improve skeletal muscle health in diabetes mellitus.

scholarly journals Ethyl 2-Succinate-Anthraquinone Attenuates Inflammatory Response and Oxidative Stress via Regulating NLRP3 Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Burong Feng ◽  
Xiuye Zhao ◽  
Wei Zhao ◽  
Huiwei Jiang ◽  
Zijing Ren ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Cell Activity ◽  
The Body ◽  
Alveolar Wall ◽  
Dependent Manner ◽  
Sod Activity ◽  
Concentration Dependent Manner ◽  
Anti Inflammatory

Aloe-emodin widely possesses antibacterial, anti-inflammatory, antioxidant, antiviral, and anti-infectious properties. This study investigated the effect of ethyl 2-succinate-anthraquinone (Luhui derivative, LHD) on inflammation. In vitro, a THP-1 macrophage inflammation model, made by 100 ng/ml phorbol-12-myristate-13-acetate (PMA) and 1 μg/ml LPS for 24 h, was constructed. The LHD group (6.25 μmol/L, 12.5 μmol/L, 25 μmol/L, 50 μmol/L) had no effect on THP-1 cell activity, and the expression of IL-6 mRNA was down-regulated in a concentration-dependent manner, of which the 25 μmol/L group had the best inhibitory effect. The migration of THP-1 macrophages induced by LPS was decreased by the LHD. Moreover, the LHD suppressed ROS fluorescence expression by inhibiting MDA expression and increasing SOD activity. In vivo, we revealed that the LHD, in different doses (6.25 mg/kg, 12.5 mg/kg, 25 mg/kg, 50 mg/kg), has a protective effect on stress physiological responses by assessing the body temperature of mice. Interestingly, acute lung injury (e.g., the structure of the alveoli disappeared and capillaries in the alveolar wall were dilated and congested) and liver damage (e.g., hepatocyte swelling, neutrophil infiltration, and hepatocyte apoptosis) were obviously improved at the same condition. Furthermore, we initially confirmed that the LHD can down-regulate the expression of NLRP3, IL-1β, and caspase-1 proteins, thereby mediating the NLRP3 inflammasome signaling pathway to produce anti-inflammatory effects. In conclusion, our results indicate that the LHD exerts anti-inflammatory activity via regulating the NLRP3 signaling pathway, inhibition of oxidative stress, and THP-1 macrophage migration.

Chickpea (Cicer arietinum L.) Lectin Exhibit Inhibition of ACE-I, α-amylase and α-glucosidase Activity

2019 ◽  
Vol 26 (7) ◽  
pp. 494-501 ◽  
Author(s):  
Sameer Suresh Bhagyawant ◽  
Dakshita Tanaji Narvekar ◽  
Neha Gupta ◽  
Amita Bhadkaria ◽  
Ajay Kumar Gautam ◽  
...  
Keyword(s):  
Biological Effects ◽  
Exchange Chromatography ◽  
Health Concern ◽  
Carbohydrate Binding ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ic50 Values ◽  
Chickpea Lectin

Background: Diabetes and hypertension are the major health concern and alleged to be of epidemic proportions. This has made it a numero uno subject at various levels of investigation. Glucosidase inhibitor provides the reasonable option in treatment of Diabetes Mellitus (DM) as it specifically targets post prandial hyperglycemia. The Angiotensin Converting Enzyme (ACE) plays an important role in hypertension. Therefore, inhibition of ACE in treatment of elevated blood pressure attracts special interest of the scientific community. Chickpea is a food legume and seeds contain carbohydrate binding protein- a lectin. Some of the biological properties of this lectin hitherto been elucidated. Methods: Purified by ion exchange chromatography, chickpea lectin was tested for its in vitro antioxidant, ACE-I inhibitory and anti-diabetic characteristic. Results: Lectin shows a characteristic improvement over the synthetic drugs like acarbose (oral anti-diabetic drug) and captopril (standard antihypertensive drug) when, their IC50 values are compared. Lectin significantly inhibited α-glucosidase and α-amylase in a concentration dependent manner with IC50 values of 85.41 ± 1.21 ҝg/ml and 65.05 ± 1.2 µg/ml compared to acarbose having IC50 70.20 ± 0.47 value of µg/ml and 50.52 ± 1.01 µg/ml respectively. β-Carotene bleaching assay showed antioxidant activity of lectin (72.3%) to be as active as Butylated Hydroxylanisole (BHA). In addition, lectin demonstrated inhibition against ACE-I with IC50 value of 57.43 ± 1.20 µg/ml compared to captopril. Conclusion: Lectin demonstrated its antioxidant character, ACE-I inhibition and significantly inhibitory for α-glucosidase and α-amylase seems to qualify as an anti-hyperglycemic therapeutic molecule. The biological effects of chickpea lectin display potential for reducing the parameters of medically debilitating conditions. These characteristics however needs to be established under in vivo systems too viz. animals through to humans.

Improved Method for Obtaining of Arctigenin from Arctium Lappa L. and its Antiproliferative Effect on Human Hepatocarcinoma HepG2 Cells

2020 ◽  
Vol 16 (3) ◽  
pp. 358-362
Author(s):  
Renan S. Teixeira ◽  
Paulo H.D. Carvalho ◽  
Jair A.K. Aguiar ◽  
Valquíria P. Medeiros ◽  
Ademar A. Da Silva Filho ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Crude Extract ◽  
Hepg2 Cells ◽  
Liver Carcinoma ◽  
Adhesion Assay ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Arctium Lappa ◽  
Nih 3T3

Background: Arctigenin is a lignan found in Arctium lappa L. (Asteraceae) that displays anti-inflammatory activities. Previous studies showed that the crude extract of A. Lappa has antitumor activity in human liver carcinoma, lung and stomach cancer cells. The aim of this study was to obtain arctigenin from A. lappa L., as well as to evaluate its antiproliferative effects in cells of liver carcinoma (HepG2) and fibroblasts (NIH/3T3). Methods: Arctigenin was obtained from the hydrolysis of arctiin, which was isolated from the crude extract of A. lappa. The effects of arctigenin and arctiin on HepG2 cell viability and cell adhesion were analyzed by MTT method. Adhesion assay was also carried out to evaluate the antitumor activity. Results: Our results showed that the analytical process to obtain arctigenin was fast and easy. In vitro experiments showed that arctigenin (107-269 μM) decreased HepG2 cells viability and did not cause cytotoxicity on NIH/3T3 cells. Arctigenin (27-269 μM) demonstrated anti-adhesion in HepG2 cells in a concentration-dependent manner, when compared with control. Conclusion: These results suggest a promising pharmacological activity for arctigenin as an antiproliferative compound.

scholarly journals Human Neuronal Cell Lines as An In Vitro Toxicological Tool for the Evaluation of Novel Psychoactive Substances

2021 ◽  
Vol 22 (13) ◽  
pp. 6785
Author(s):  
Valeria Sogos ◽  
Paola Caria ◽  
Clara Porcedda ◽  
Rafaela Mostallino ◽  
Franca Piras ◽  
...  
Keyword(s):  
Cell Death ◽  
Neuronal Cell ◽  
In Vitro Study ◽  
Dependent Manner ◽  
Novel Psychoactive Substances ◽  
Psychoactive Substances ◽  
Concentration Dependent Manner ◽  
Mechanisms Of Toxicity ◽  
Neuronal Cell Lines

Novel psychoactive substances (NPS) are synthetic substances belonging to diverse groups, designed to mimic the effects of scheduled drugs, resulting in altered toxicity and potency. Up to now, information available on the pharmacology and toxicology of these new substances is very limited, posing a considerable challenge for prevention and treatment. The present in vitro study investigated the possible mechanisms of toxicity of two emerging NPS (i) 4′-methyl-alpha-pyrrolidinoexanophenone (3,4-MDPHP), a synthetic cathinone, and (ii) 2-chloro-4,5-methylenedioxymethamphetamine (2-Cl-4,5-MDMA), a phenethylamine. In addition, to apply our model to the class of synthetic opioids, we evaluated the toxicity of fentanyl, as a reference compound for this group of frequently abused substances. To this aim, the in vitro toxic effects of these three compounds were evaluated in dopaminergic-differentiated SH-SY5Y cells. Following 24 h of exposure, all compounds induced a loss of viability, and oxidative stress in a concentration-dependent manner. 2-Cl-4,5-MDMA activates apoptotic processes, while 3,4-MDPHP elicits cell death by necrosis. Fentanyl triggers cell death through both mechanisms. Increased expression levels of pro-apoptotic Bax and caspase 3 activity were observed following 2-Cl-4,5-MDMA and fentanyl, but not 3,4-MDPHP exposure, confirming the different modes of cell death.

scholarly journals The Modulation of PCSK9 and LDLR by Supercritical CO2 Extracts of Mentha longifolia and Isolated Piperitone Oxide, an In Vitro Study

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3886
Author(s):  
Stefania Sut ◽  
Irene Ferrarese ◽  
Maria Giovanna Lupo ◽  
Nicola De Zordi ◽  
Elisa Tripicchio ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Lines ◽  
Hepatoma Cell ◽  
Density Lipoprotein ◽  
In Vitro Study ◽  
Volatile Constituent ◽  
Dependent Manner ◽  
Human Hepatoma Cell ◽  
Concentration Dependent Manner

In the present study the ability of supercritical carbon dioxide (SCO2) extracts of M. longifolia L. leaves to modulate low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9) expression was evaluated in cultured human hepatoma cell lines Huh7 and HepG2. Two SCO2 extracts, one oil (ML-SCO2) and a semisolid (MW-SCO2), were subjected to detailed chemical characterization by mono- and bidimensional nuclear magnetic resonance (1D, 2D-NMR), gas chromatography coupled with mass spectrometry (GC-MS) and liquid chromatography coupled with mass spectrometry (LC-MS). Chemical analysis revealed significant amounts of fatty acids, phytosterols and terpenoids. ML-SCO2 was able to induce LDLR expression at a dose of 60 µg/mL in HuH7 and HepG2 cell lines. Furthermore, ML-SCO2 reduced PCSK9 secretion in a concentration-dependent manner in both cell lines. Piperitone oxide, the most abundant compound of the volatile constituent of ML-SCO2 (27% w/w), was isolated and tested for the same targets, showing a very effective reduction of PCSK9 expression. The overall results revealed the opportunity to obtain a new nutraceutical ingredient with a high amount of phytosterols and terpenoids using the SCO2 extraction of M. longifolia L., a very well-known botanical species used as food. Furthermore, for the first time we report the high activity of piperitone oxide in the reduction of PCSK9 expression.

184 Two types of anti-TIGIT antibodies with distinct binding epitope and functional activities

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A198-A198
Author(s):  
Tingting Zhong ◽  
Xinghua Pang ◽  
Zhaoliang Huang ◽  
Na Chen ◽  
Xiaoping Jin ◽  
...  
Keyword(s):  
T Cells ◽  
Mixed Culture ◽  
Cell Activity ◽  
Cross Reactivity ◽  
Binding Activity ◽  
Jurkat Cells ◽  
List Type ◽  
Dependent Manner ◽  
Vitro Assay

BackgroundTIGIT is an inhibitory receptor mainly expressed on natural killer (NK) cells, CD8+ T cells, CD4+ T cells and Treg cells. TIGIT competes with CD226 for binding with CD155. In cancers, CD155 has been reported to up-regulate on tumor cells, and TIGIT was found to increase on TILs.1 Activation of TIGIT/CD155 pathway would mediate immunosuppression in tumor; while blockade of TIGIT promotes anti-tumor immune response.MethodsAK126 and AK113 are two humanized anti-human TIGIT monoclonal antibodies developed by Akesobio. Binding activity of AK126 and AK113 to human TIGIT, and competitive binding activity with CD155 and CD112, were performed by using ELISA, Fortebio, and FACS assays. Cross-reactivity with cynomolgus monkey TIGIT and epitope binning were also tested by ELISA assay. In-vitro assay to investigate the activity to promote IL-2 secretion was performed in mixed-culture of Jurkat-TIGIT cells and THP-1 cells.ResultsAK126 and AK113 could specifically bind to human TIGIT with comparative affinity and effectively blocked the binding of human CD155 and CD112 to human TIGIT. X-ray crystal structure of TIGIT and PVR revealed the C’-C’’ loop and FG loop regions of TIGIT are the main PVR interaction regions.2 The only amino acid residue differences in these regions between human and monkey TIGIT are 70C and 73D. AK126 binds to both human and monkey TIGIT, AK113 binds only to monkey TIGIT. This suggests that these residues are required for AK113 binding to human TIGIT, but not required for AK126. Interestingly, results from cell-based assays indicated that AK126 and AK113 showed significantly different activity to induce IL-2 secretion in mixed-culture of Jurkat-TIGIT cells and THP-1 cells (figure 1A and B), in which AK126 had a comparable capacity of activity to 22G2, a leading TIGIT mAb developed by another company, to induce IL-2 secretion, while, AK113 showed a significantly higher capacity than 22G2 and AK126.Abstract 184 Figure 1Anti-TIGIT Antibodies Rescues IL-2 Production in Vitro T-Cell Activity Assay in a dose dependent manner. Jurkat-TIGIT cells (Jurkat cells engineered to over-express human TIGIT) were co-cultured with THP-1 cells, and stimulated with plate-bound anti-CD3 mAb in the presence of TIGIT ligand CD155 (A) or CD112 (B) with anti-TIGIT antibodies. After incubated for 48h at 37° C and 5.0% CO2, IL-2 levels were assessed in culture supernatants by ELISA. Data shown as mean with SEM for n = 2.ConclusionsWe discovered two distinct types of TIGIT antibodies with differences in both epitope binding and functional activity. The mechanism of action and clinical significance of these antibodies require further investigation.ReferencesSolomon BL, Garrido-Laguna I. TIGIT: a novel immunotherapy target moving from bench to bedside. Cancer Immunol Immunother 2018;67:1659–1667.Stengel KF, Harden-Bowles K, Yu X, et al. Structure of TIGIT immunoreceptor bound to poliovirus receptor reveals a cell-cell adhesion and signaling mechanism that requires cis-trans receptor clustering. Proc Natl Acad Sci USA 2012;109:5399–5404.

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