scholarly journals PTP1B INHIBITORS FROM ISODON TERNIFOLIUS COLLECTED IN VIETNAM

2020 ◽  
Vol 58 (5) ◽  
pp. 533
Author(s):  
Nguyen Phi-Hung
Keyword(s):  
Enzyme Activity ◽  
Inhibitory Activity ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Chemical Structures ◽  
Whole Plant ◽  
Ic50 Values ◽  
Ptp1b Inhibitors ◽  
First Time

From the whole plant of Isodon ternifolius collected in Vietnam, four triterpens including ursaldehyde (1), ursolic acid (2), b-sitosterol (3) and b-sitosteryl ferulate (4) were purified. Their chemical structures were determined by interpretation of NMR and MS data and comparison with the literatures. Compounds 1-4 were evaluated for their inhibitory activity against PTP1B enzyme activity using in vitro assay. Compounds 1 and 2 displayed potential activities with IC50 values of 16.92 ± 0.12 and 3.42 ± 0.45 μM, respectively. This is the first time that compounds 1 and 4 have been isolated from the Isodon genus and I. ternifolius has been evaluated for the PTP1B inhibitory activity.

scholarly journals Mammalian Arginase Inhibitory Activity of Methanolic Extracts and Isolated Compounds from Cyperus Species

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1694
Author(s):  
Kamel Arraki ◽  
Perle Totoson ◽  
Alain Decendit ◽  
Andy Zedet ◽  
Justine Maroilley ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Methanolic Extract ◽  
Significant Inhibition ◽  
Isolation And Identification ◽  
Vasorelaxant Effect ◽  
Methanolic Extracts ◽  
Phytochemical Investigation ◽  
Ic50 Values ◽  
First Time

Polyphenolic enriched extracts from two species of Cyperus, Cyperus glomeratus and Cyperus thunbergii, possess mammalian arginase inhibitory capacities, with the percentage inhibition ranging from 80% to 95% at 100 µg/mL and 40% to 64% at 10 µg/mL. Phytochemical investigation of these species led to the isolation and identification of two new natural stilbene oligomers named thunbergin A-B (1–2), together with three other stilbenes, trans-resveratrol (3), trans-scirpusin A (4), trans-cyperusphenol A (6), and two flavonoids, aureusidin (5) and luteolin (7), which were isolated for the first time from C.thunbergii and C. glomeratus. Structures were established on the basis of the spectroscopic data from MS and NMR experiments. The arginase inhibitory activity of compounds 1–7 was evaluated through an in vitro arginase inhibitory assay using purified liver bovine arginase. As a result, five compounds (1, 4–7) showed significant inhibition of arginase, with IC50 values between 17.6 and 60.6 µM, in the range of those of the natural arginase inhibitor piceatannol (12.6 µM). In addition, methanolic extract from Cyperus thunbergii exhibited an endothelium and NO-dependent vasorelaxant effect on thoracic aortic rings from rats and improved endothelial dysfunction in an adjuvant-induced arthritis rat model.

scholarly journals A fast, miniaturised in-vitro assay developed for quantification of lipase enzyme activity

2019 ◽  
Vol 34 (1) ◽  
pp. 1474-1480 ◽  
Author(s):  
Ariane Menden ◽  
Davane Hall ◽  
Daniel Paris ◽  
Venkatarian Mathura ◽  
Fiona Crawford ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Lipase Enzyme

Assessment of Inhibition of Bovine Hepatic Cytochrome P450 by 43 Commercial Bovine Medicines Using a Combination of In Vitro Assays and Pharmacokinetic Data from the Literature

2020 ◽  
Vol 13 (2) ◽  
pp. 123-131
Author(s):  
Steven X. Hu ◽  
Chase A. Mazur ◽  
Kenneth L. Feenstra
Keyword(s):  
Liver Microsomes ◽  
In Vitro Assay ◽  
In Vitro Assays ◽  
Pharmacokinetic Studies ◽  
Pharmacokinetic Data ◽  
Vitro Assay ◽  
Administration Routes ◽  
Ic50 Values

Background: There has been a lack of information about the inhibition of bovine medicines on bovine hepatic CYP450 at their commercial doses and dosing routes. Objective: The aim of this work was to assess the inhibition of 43 bovine medicines on bovine hepatic CYP450 using a combination of in vitro assay and Cmax values from pharmacokinetic studies with their commercial doses and dosing routes in the literature. Methods: Those drugs were first evaluated through a single point inhibitory assay at 3 μM in bovine liver microsomes for six specific CYP450 metabolisms, phenacetin o-deethylation, coumarin 7- hydroxylation, tolbutamide 4-hydroxylation, bufuralol 1-hydroxylation, chlorzoxazone 6-hydroxylation and midazolam 1’-hydroxylation. When the inhibition was greater than 20% in the assay, IC50 values were then determined. The potential in vivo bovine hepatic CYP450 inhibition by those drugs was assessed using a combination of the IC50 values and in vivo Cmax values from pharmacokinetic studies at their commercial doses and administration routes in the literature. Results: Fifteen bovine medicines or metabolites showed in vitro inhibition on one or more bovine hepatic CYP450 metabolisms with different IC50 values. Desfuroylceftiour (active metabolite of ceftiofur), nitroxinil and flunixin have the potential to inhibit one of the bovine hepatic CYP450 isoforms in vivo at their commercial doses and administration routes. The rest of the bovine medicines had low risks of in vivo bovine hepatic CYP450 inhibition. Conclusion: This combination of in vitro assay and in vivo Cmax data provides a good approach to assess the inhibition of bovine medicines on bovine hepatic CYP450.

scholarly journals The refolding activity of the yeast heat shock proteins Ssa1 and Ssa2 defines their role in protein translocation.

1996 ◽  
Vol 135 (5) ◽  
pp. 1229-1237 ◽  
Author(s):  
G L Bush ◽  
D I Meyer
Keyword(s):  
Protein Translocation ◽  
In Vitro Assay ◽  
Secretory Proteins ◽  
Vitro Assay ◽  
Chaperone Function ◽  
Cotranslational Folding ◽  
Yeast Lysate ◽  
Shock Proteins ◽  
First Time

Ssa1/2p, members of one of the yeast cytosolic hsp70 subfamilies, have been implicated in the translocation of secretory proteins into the lumen of the ER. The involvement of these hsp70s in translocation was tested directly by examining the effect of immunodepleting Ssa1/2p from yeast cytosol and subsequently testing the cytosol for its ability to support co- and post-translational translocation of prepro-alpha-factor. Depletion of Ssa1/2p had no effect on the efficiency of translocation in this in vitro assay. The system was used to examine the effect of the absence of Ssa1/2p on two other putative hsp70 functions: cotranslational folding of nascent luciferase and refolding of denatured luciferase. Depletion of Ssa1/2p had no effect on the ability of the yeast lysate to synthesize enzymatically active luciferase, but had a dramatic effect on the ability of the lysate to refold chemically denatured luciferase. These results demonstrate, for the first time, the refolding activity of Ssa1/2p in the context of the yeast cytosol, and define refolding activity as a chaperone function specific to Ssa1/2p, aprt from other cytosolic hsp70s. They also suggest that Ssa1/2p do not play a significant role in chaperoning the folding of nascent polypeptides. The implications of these findings for Ssa1/2p activity on their proposed role in the process of translocation are discussed.

Phenylalanine ammonia-lyase, flavanone 3β-hydroxylase and flavonol synthase enzyme activity by a new in vitro assay method in berry fruits

2014 ◽  
Vol 153 ◽  
pp. 130-133 ◽  
Author(s):  
Gema Flores ◽  
Fernando De la Peña Moreno ◽  
Gracia Patricia Blanch ◽  
Maria Luisa Ruiz del Castillo
Keyword(s):  
Enzyme Activity ◽  
Phenylalanine Ammonia Lyase ◽  
In Vitro Assay ◽  
Assay Method ◽  
Vitro Assay ◽  
Flavonol Synthase ◽  
Berry Fruits

scholarly journals Araliachinoside A: A New Triterpene Glycoside From Aralia chinensis Leaves

2020 ◽  
Vol 15 (9) ◽  
pp. 1934578X2095275
Author(s):  
Pham Hai Yen ◽  
Nguyen Thi Cuc ◽  
Phan Thi Thanh Huong ◽  
Nguyen Xuan Nhiem ◽  
Nguyen Thi Hoai ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Inhibitory Concentration ◽  
In Vitro Assay ◽  
Ionization Mass ◽  
Vitro Assay ◽  
Chemical Structures ◽  
Hepg2 Cell Lines

From the leaves of Aralia chinensis, 3 oleanane-type triterpene glycosides have been isolated, including 1 new glycoside, 3β,23 -dihydroxyolean-12-ene-28-oic acid 3 -O-β-d-glucopyranosyl-(1→3)- α-l-arabinopyranosyl-(1→3)-β-d-glucuronopyranoside 28 -O-β-d-glucopyranosyl ester (named as araliachinoside A, 1), and 2 known ones, 3β,23 -dihydroxyolean-12-ene-28-oic acid 3 -O-α-l-arabinopyranosyl-(1→3)- β-d-glucuronopyranoside 28 -O-β-d-glucopyronosyl ester (2) and 3β-hydroxyolean-12-ene-28-oic acid 3 -O-β-d-glucurono pyranoside 28 -O-β-d-glucopyronosyl ester (3). Their chemical structures were elucidated by using a combination of high-resolution electrospray ionization-mass spectrometry, 1-dimensional and 2-dimensional nuclear magnetic resonance spectral data, and by comparison with previous literature. Compounds 1-3 displayed cytotoxic activity toward KB and HepG2 cell lines with half-maximal inhibitory concentration values ranging from 8.1 ± 0.1 to 15.7 ± 0.3 µM in in vitro assay.

scholarly journals In vitro antioxidant potency of some smaller chain glycopeptides with the prediction of IC50 values

2016 ◽  
Vol 4 (2) ◽  
pp. 127
Author(s):  
Kandasamy Nagarajan ◽  
Parul Grover ◽  
Roma Ghai ◽  
Ayushi Teharia ◽  
Sanjeev Chauhan ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
In Vitro Assay ◽  
Scavenging Activity ◽  
Vitro Assay ◽  
Standard Drug ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Antioxidant Potency

Hydrogen peroxide, 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) and Phosphomolybdenum in-vitro assay was employed to determine the antioxidant potency of glycopeptides RN Mannose, RK starch, RNRN Mannose and RHRCR Starch using ascorbic acid as the standard drug. The percentage scavenging activity of the glycopeptides were determined at different concentrations and the IC50 value of the test compounds were subsequently compared with that of ascorbic acid. RN Mannose was found to be most potent antioxidant compound. Also, Swiss dock study was performed with three glycopeptides, viz., RHRCR Mannose, RN Mannose and RNRN Mannose.Among these, RHRCR Mannose was found to have the best affinity for the receptor with stearic energy -0.2306kcal/mol.

Investigations on the effects of hyperbaric oxygen on enzyme activity

1969 ◽  
Vol 47 (4) ◽  
pp. 400-402 ◽  
Author(s):  
Nicole Bégin-Heick ◽  
P. Hochstein ◽  
Gale B. Hill
Keyword(s):  
Enzyme Activity ◽  
Hyperbaric Oxygen ◽  
Enzyme Activities ◽  
Liver Tissue ◽  
In Vitro Assay ◽  
Vitro Assay

The ability of hyperbaric oxygen to produce lasting effects on enzyme activities was investigated. Mice were subjected to hyperbaric oxygen until they suffered sustained convulsions. The enzyme activities were then determined in brain and liver tissue. The results presented indicate that under these conditions of in vivo exposure and in vitro assay, hyperbaric oxygen does not affect permanently the activities of the enzymes which were examined.

scholarly journals Sesquiterpenes from Myrrh and Their ICAM-1 Inhibitory Activity In Vitro

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 42
Author(s):  
Katrin Kuck ◽  
Guido Jürgenliemk ◽  
Bartosz Lipowicz ◽  
Jörg Heilmann
Keyword(s):  
Ethanolic Extract ◽  
2D Nmr ◽  
Preparative Hplc ◽  
Reference Compound ◽  
2D Nmr Spectroscopy ◽  
Vitro Assay ◽  
Chemical Structures ◽  
Inflammatory Processes ◽  
First Time

By using various chromatographic steps (silica flash, CPC, preparative HPLC), 16 sesquiterpenes could be isolated from an ethanolic extract of myrrh resin. Their chemical structures were elucidated by 1D and 2D NMR spectroscopy and HRESIMS. Among them, six previously unknown compounds (1–6) and another four metabolites previously not described for the genus Commiphora (7, 10, 12, 13) could be identified. Sesquiterpenes 1 and 2 are novel 9,10-seco-eudesmanes and exhibited an unprecedented sesquiterpene carbon skeleton, which is described here for the first time. New compound 3 is an 9,10 seco-guaian and the only peroxide isolated from myrrh so far. Compounds 1, 2, 4, 7–9, 11, 13–16 were tested in an ICAM-1 in vitro assay. Compound 7, as well as the reference compound furanoeudesma-1,3-diene, acted as moderate inhibitors of this adhesion molecule ICAM-1 (IC50: 44.8 and 46.3 μM, respectively). These results give new hints on the activity of sesquiterpenes with regard to ICAM-1 inhibition and possible modes of action of myrrh in anti-inflammatory processes.

α-Glucosidase Inhibitory Activity of the Extracts and Major Phytochemical Components of Smilax glabra Roxb

2020 ◽  
Vol 10 (1) ◽  
pp. 26-32
Author(s):  
Phuong T.M. Nguyen ◽  
Quang V. Ngo ◽  
Minh T.H. Nguyen ◽  
Alan T. Maccarone ◽  
Stephen G. Pyne
Keyword(s):  
Inhibitory Activity ◽  
In Vitro Cytotoxicity ◽  
Antidiabetic Activity ◽  
Ca 125 ◽  
Chemical Structures ◽  
Glucosidase Inhibitors ◽  
Ic50 Values ◽  
Inhibitory Activities ◽  
Phytochemical Components

Background: A therapeutic approach to treat diabetes is to decrease postprandial hyperglycemia. α-Glucosidase inhibitors from plant sources offer an attractive strategy for the control of hyperglycemia. Smilax glabra Roxb is a medicinal plant found in Asia, including Vietnam, which is used in the treatment of chronic diseases. However, the antidiabetic activity and the identification of α-glucosidase inhibitors from this plant have not been intensively investigated. This research was carried out to determine the α-glucosidase inhibitory activity of the extracts and that of the major phytochemical components of Smilax glabra Roxb. This could lead to further studies on the role of these compounds in hyperglycemia control, as well as identify their potential future applications. Methods: Column chromatography combined with crystallization procedures were used to isolate active fractions and two major compounds. The chemical structures of these compounds were determined by analysis of their NMR spectroscopic data, as well as MS data and comparisons made with the literature data. The α-glucosidase inhibitory activity was determined spectrophotometrically using p-nitrophenyl α-D-glucopyranoside as a substrate. The in vitro cytotoxicity of the isolated compounds and fractions was determined using the MTT assay. Results: The two major compounds, astilbin and 5-O-caffeoylshikimic acid together with two very active fractions, F7 and F8, were isolated from the rhizome. The two major compounds had α- glucosidase inhibitory activities with IC50 values of ca. 125 µg/mL and 38 µg/mL, respectively which are about 4 and 13 folds higher activity than the reference compound acarbose (IC50 of ca. 525 µg/mL). Fractions F7 and F8 showed very promising inhibitory activities towards α-glucosidase with IC50 values of 5.5 and 5.8 µg/mL, respectively. Cytotoxicity data on mouse fibroblast NIH3T3 cells indicated that the active compounds and fractions were not toxic at concentrations that are greater than their respective IC50 values. The α-glucosidase inhibitory activity of 5-Ocaffeoylshikimic acid and that of the two active fractions are reported here for the first time. Conclusion: The two major isolated compounds and fractions, F7 and F8, significantly contribute to the α-glucosidase inhibitory activity of S. glabra Roxb extract. Further work is needed to clarify their modes of action and potential application.

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