scholarly journals Superoxide dismutase, catalase and scavengers of hydroxyl radical protect against the toxic action of alloxan on pancreatic islet cells in vitro

1979 ◽  
Vol 182 (1) ◽  
pp. 17-25 ◽  
Author(s):  
K Grankvist ◽  
S Marklund ◽  
J Sehlin ◽  
I B Täljedal
Keyword(s):  
Superoxide Dismutase ◽  
Singlet Oxygen ◽  
Trypan Blue ◽  
Islet Cells ◽  
Direct Reaction ◽  
Oxygen Scavenger ◽  
Isolated Pancreatic Islets ◽  
Cytotoxicity Assays ◽  
Redox Cycles

Experiments with isolated pancreatic islets or dispersed islet cells from non-inbred ob/ob mice were performed to test the hypothesis that free radicals, notably OH., mediate the diabetogenic toxicity of alloxan. Accumulation of 86Rb+ by whole islets and exclusion of Trypan Blue by dispersed cells were used as previously validated criteria of islet-cell viability. Alloxan alone drastically inhibited the Rb+ accumulation and significantly decreased the frequency of cells excluding Trypan Blue. Enzymic scavengers of O2.- and H2O2 or non-enzymic scavengers of OH. or singlet oxygen were added to the incubation medium and tested for their ability to protect against these effects of alloxan. Superoxide dismutase, catalase, dimethyl sulphoxide, benzoate, and mannitol counteracted the effects of alloxan in both cytotoxicity assays. Significant protection of the Rb+-accumulating capacity was also afforded by butanol, caffeine, theophylline, NADH, NADPH and, to a small extent, NAD+. Urea has a poor affinity for OH. and did not protect against alloxan. No effect was obtained with the singlet-oxygen scavenger, histidine. Except for the protection by NADH and NADPH, which may be due to a direct reaction with alloxan in the medium, the results strongly support the hypothesis. beta-Cells may be particularly vulnerable to alloxan because their metabolic specialization facilitates reduction of the drug and perhaps of other substrates for O2.–yielding redox cycles.

scholarly journals Alloxan cytotoxicity in vitro. Microscope photometric analyses of Trypan Blue uptake by pancreatic islet cells in suspension

1977 ◽  
Vol 162 (1) ◽  
pp. 19-24 ◽  
Author(s):  
K Grankvist ◽  
Å Lernmark ◽  
I B Täljedal
Keyword(s):  
Pancreatic Islets ◽  
Beta Cells ◽  
Trypan Blue ◽  
Islet Cell ◽  
Visual Inspection ◽  
Islet Cells ◽  
Pancreatic Islet Cells ◽  
Cell Nuclei ◽  
20 Nm

Suspensions of islet cells were prepared by shaking pancreatic islets from non-inbred ob/ob mice in a Ca2+-free buffer. The cells were incubated with or without 20 mM-alloxan, and subsequently with Trypan Blue. The uptake of Trypan Blue by cell nuclei was analysed by microscope photometry and by counting the frequency of cells appearing stained on visual inspection. Cells classified as stained or unstained by inspection showed no overlap in nuclear absorbance. Suspensions not exposed to alloxan contained 70-80% of unstained cells. Alloxan markedly decreased the frequency of unstained cells, an effect counteracted by 5 or 20 mM-D-glucose. The spectrum of Trypan Blue in islet-cell nuclei was red-shifted by about 20 nm. A similar red-shift was observed on adding the dye to solutions of albumin or histones, but not on mixing the dye with DNA. Binding to basic proteins may explain the concentrative uptake of Trypan Blue in dead cells and contribute to the oncogenic transformation of phagocytotically active cells. Beta-Cells in vitro are killed by alloxan and hence represent a valid model for studying the diabetogenic action of the drug.

scholarly journals CuZn-superoxide dismutase, Mn-superoxide dismutase, catalase and glutathione peroxidase in pancreatic islets and other tissues in the mouse

1981 ◽  
Vol 199 (2) ◽  
pp. 393-398 ◽  
Author(s):  
K Grankvist ◽  
S L Marklund ◽  
I B Täljedal
Keyword(s):  
Superoxide Dismutase ◽  
Glutathione Peroxidase ◽  
Pancreatic Islets ◽  
Islet Cells ◽  
Blood Contamination ◽  
Tissue Samples ◽  
Mouse Islets ◽  
Cuzn Superoxide Dismutase ◽  
Endogenous Enzymes

Exogenous superoxide dismutase, catalase and scavengers of the hydroxyl radical protect pancreatic-islet cells against the toxic actions of alloxan in vitro [Grankvist et al. (1979) Biochem. J. 182, 17--25]. To test whether the extraordinary sensitivity of islet cells to alloxan is due to a deficiency of endogenous enzymes protecting against oxygen-reduction products, we assayed CuZn-superoxide dismutase, Mn-superoxide dismutase, catalase and glutathione peroxidase in mouse islets and other tissues. To correct for any blood contamination, haemoglobin was also measured in the tissue samples. Pancreatic islets were found to belong to tissues with relatively little activity of the protective enzymes. However, the deviation from other tissues in this respect is probably not large enough to explain the especially great susceptibility of islet cells to alloxan.

Superoxide, Xanthine Oxidase and Platelet Reactions: Further Studies on Mechanisms by which Oxidants Influence Platelets

1981 ◽  
Vol 45 (03) ◽  
pp. 290-293 ◽  
Author(s):  
Peter H Levine ◽  
Danielle G Sladdin ◽  
Norman I Krinsky
Keyword(s):  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Xanthine Oxidase ◽  
Direct Effect ◽  
Platelet Function ◽  
Experimental Conditions ◽  
Release Reaction

SummaryIn the course of studying the effects on platelets of the oxidant species superoxide (O- 2), Of was generated by the interaction of xanthine oxidase plus xanthine. Surprisingly, gel-filtered platelets, when exposed to xanthine oxidase in the absence of xanthine substrate, were found to generate superoxide (O- 2), as determined by the reduction of added cytochrome c and by the inhibition of this reduction in the presence of superoxide dismutase.In addition to generating Of, the xanthine oxidase-treated platelets display both aggregation and evidence of the release reaction. This xanthine oxidase induced aggreagtion is not inhibited by the addition of either superoxide dismutase or cytochrome c, suggesting that it is due to either a further metabolite of O- 2, or that O- 2 itself exerts no important direct effect on platelet function under these experimental conditions. The ability of Of to modulate platelet reactions in vivo or in vitro remains in doubt, and xanthine oxidase is an unsuitable source of O- 2 in platelet studies because of its own effects on platelets.

Efficient gene transfer to dispersed human pancreatic islet cells in vitro using adenovirus-polylysine/DNA complexes or polycationic liposomes

Diabetes ◽  
1996 ◽  
Vol 45 (9) ◽  
pp. 1197-1203 ◽  
Author(s):  
J. Saldeen ◽  
D. T. Curiel ◽  
D. L. Eizirik ◽  
A. Andersson ◽  
E. Strandell ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Pancreatic Islet ◽  
Islet Cells ◽  
Pancreatic Islet Cells ◽  
Dna Complexes ◽  
Human Pancreatic Islet ◽  
Efficient Gene

Synthesis and Biological Evaluations of Organoruthenium Scaffolds: A Comprehensive Update

2018 ◽  
Vol 15 (2) ◽  
pp. 179-207
Author(s):  
Ashaparna Mondal ◽  
Priyankar Paira
Keyword(s):  
Singlet Oxygen ◽  
Anticancer Agents ◽  
Ruthenium Complexes ◽  
Chemotherapeutic Agents ◽  
Quantum Yields ◽  
Ros Generation ◽  
Standard Drug ◽  
Cellular Environment ◽  
Theranostic Agents

Background: Currently ruthenium complexes are immerging as effective anticancer agents due to their less toxicity, better antiproliferative and antimetastatic activity, better stability in cellular environment and most importantly variable oxidation and co-ordination states of ruthenium allows binding this molecule with a variety of ligands. So in past few years researchers have shifted their interest towards organoruthenium complexes having good fluorescent profile that may be applicable for cancer theranostics. Nowadays, photodynamic therapy has become more acceptable because of its easy and effective approach towards killing cancer cells. Objective: Objective of this review article is to shed light on synthesis, characterization, stability and fluorescence studies of various ruthenium [Ru(II) and Ru(III)] complexes and different bioactivity studies conducted with the synthesized compounds to test their candidacy as potent chemotherapeutic agents. Methods: Various heterocyclic ligands containing N,O and S as heteroatom mainly were prepared and subjected to complexation with ruthenium-p-cymene moiety. In most cases [Ru(η6-p-cymene)(µ-Cl)Cl]2 was used as ruthenium precursor and the reactions were conducted in various alcohol medium such as methanol, ethanol or propanol. The synthesized complexes were characterized by 1H NMR and 13C NMR spectroscopy, GC-MS, ESI-MS, elemental analysis and single crystal X-ray crystallography methods. Fluorescence study and stability study were conducted accordingly using water, PBS buffer or DMSO. Stable compounds were considered for cell viability studies. To study the efficacy of the compounds in ROS generation as photosensitizers, in few cases, singlet oxygen quantum yields in presence of light were calculated. Suitable compounds were selected for in vitro & in vivo antiproliferative, anti-invasive activity studies. Result: Many newly synthesized compounds were found to have less IC50 compared to a standard drug cysplatin. Those compounds were also stable preferably in physiological conditions. Good fluorescence profile and ROS generation ability were observed for few compounds. Conclusion: Numerous ruthenium complexes were developed which can be used as cancer theranostic agents. Few molecules were synthesized as photosensitizers which were supposed to generate reactive singlet oxygen species in targeted cellular environment in presence of a particular type of light and thereby ceasing cancer cell growth.

Synthesis and antioxidant activity of new selenium-containing quinolines

2020 ◽  
Vol 16 ◽  
Author(s):  
Benedetta Bocchini ◽  
Bruna Goldani ◽  
Fernanda S.S. Sousa ◽  
Paloma T. Birmann ◽  
Cesar A. Brüning ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Superoxide Dismutase ◽  
Radical Scavenging ◽  
Building Blocks ◽  
Antioxidant Potential ◽  
In Vitro Assays ◽  
Pharmacological Activities ◽  
Antioxidant Power ◽  
Antioxidant Agents

Background: Quinoline derivatives have been attracted much attention in drug discovery and synthetic derivatives of these scaffolds present a range of pharmacological activities. Therefore, organoselenium compounds are valuable scaffolds in organic synthesis because their pharmacological activities and their use as versatile building blocks for regio-, chemio-and stereoselective reactions. Thus, the synthesis of selenium-containing quinolines has great significance, and their applicability range from simple antioxidant agents, to selective DNA-binding and photocleaving agents. Objective: In the present study we describe the synthesis and antioxidant activity in vitro of new 7-chloroN(arylselanyl)quinolin-4-amines 5 by the reaction of 4,7-dichloroquinoline 4 with (arylselanyl)-amines 3. Methods: For the synthesis of 7-chloro-N(arylselanyl)quinolin-4-amines 5, we performed the reaction of (arylselanyl)- amines 3 with 4,7-dichloroquinoline 4 in the presence of Et3N at 120 °C in a sealed tube. The antioxidant activities of the compounds 5 were evaluated by the following in vitro assays: 2,2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric ion reducing antioxidant power (FRAP), nitric oxide (NO) scavenging and superoxide dismutase-like activity (SOD-Like). Results: 7-Chloro-N(arylselanyl)quinolin-4-amines 5a-d has been synthesized in yields ranging from 68% to 82% by the reaction of 4,7-dichloroquinoline 4 with arylselanyl-amines 3a-d using Et3N as base, at 120 °C, in a sealed tube for 24 hours and tolerates different substituents, such as -OMe and -Cl, in the arylselanyl moiety. The obtained compounds 5a-d presented significant results with respect to the antioxidant potential, which had effect in the tests of inhibition of radical’s DPPH, ABTS+ and NO, as well as in the test that evaluates the capacity (FRAP) and in the superoxide dismutase-like activity assay (SOD-Like). It is worth mentioning that 7-chloro-N(arylselanyl)quinolin-4-amine 5b presented excellent results, demonstrating a better antioxidant capacity when compared to the others. Conclusion: According to the obtained results 7-chloro-N(arylselanyl)quinolin-4-amines 5 were synthesized in good yields by the reaction of 4,7-dichloroquinoline with arylselanyl-amines and tolerates different substituents in the arylselanyl moiety. The tested compounds presented significant antioxidant potential in the tests of inhibition of DPPH, ABTS+ and NO radicals, as well as in the FRAP and superoxide dismutase-like activity assays (SOD-Like).

scholarly journals A hydrogel platform for in vitro three dimensional assembly of human stem cell-derived islet cells and endothelial cells

2019 ◽  
Vol 97 ◽  
pp. 272-280 ◽  
Author(s):  
Punn Augsornworawat ◽  
Leonardo Velazco-Cruz ◽  
Jiwon Song ◽  
Jeffrey R. Millman
Keyword(s):  
Endothelial Cells ◽  
Stem Cell ◽  
Islet Cells ◽  
Three Dimensional ◽  
Human Stem Cell

10-gingerol induces oxidative stress through HTR1A in cumulus cells: in-vitro and in-silico studies

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kiptiyah Kiptiyah ◽  
Widodo Widodo ◽  
Gatot Ciptadi ◽  
Aulanni’am Aulanni’Am ◽  
Mohammad A. Widodo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Culture ◽  
Superoxide Dismutase ◽  
In Silico ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Sod Activity ◽  
In Silico Studies ◽  
Incubation Periods

AbstractBackgroundWe investigated whether 10-gingerol is able to induce oxidative stress in cumulus cells.MethodsFor the in-vitro research, we used a cumulus cell culture in M199, containing 10-gingerol in various concentrations (0, 12, 16, and 20 µM), and detected oxidative stress through superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations, with incubation periods of 24, 48, 72, and 96 h. The obtained results were confirmed by in-silico studies.ResultsThe in-vitro data revealed that SOD activity and MDA concentration increased with increasing incubation periods: SOD activity at 0 µM (1.39 ± 0.24i), 12 µM (16.42 ± 0.35ab), 16 µM (17.28 ± 0.55ab), 20 µM (17.81 ± 0.12a), with a contribution of 71.1%. MDA concentration at 0 µM (17.82 ± 1.39 l), 12 µM (72.99 ± 0.31c), 16 µM (79.77 ± 4.19b), 20 µM (85.07 ± 2.57a), with a contribution of 73.1%. Based on this, the in-silico data uncovered that 10˗gingerol induces oxidative stress in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.Conclusions10-gingerol induces oxidative stress in cumulus cells through enhancing SOD activity and MDA concentration by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.

scholarly journals Functionalization of Photosensitized Silica Nanoparticles for Advanced Photodynamic Therapy of Cancer

2021 ◽  
Vol 22 (12) ◽  
pp. 6618
Author(s):  
Ruth Prieto-Montero ◽  
Alejandro Prieto-Castañeda ◽  
Alberto Katsumiti ◽  
Miren P. Cajaraville ◽  
Antonia R. Agarrabeitia ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Absorption Capacity ◽  
Oxygen Production ◽  
Photodynamic Therapy Of Cancer ◽  
Custom Made ◽  
Fluorescence Efficiency ◽  
Covalently Linked

BODIPY dyes have recently attracted attention as potential photosensitizers. In this work, commercial and novel photosensitizers (PSs) based on BODIPY chromophores (haloBODIPYs and orthogonal dimers strategically designed with intense bands in the blue, green or red region of the visible spectra and high singlet oxygen production) were covalently linked to mesoporous silica nanoparticles (MSNs) further functionalized with PEG and folic acid (FA). MSNs approximately 50 nm in size with different functional groups were synthesized to allow multiple alternatives of PS-PEG-FA decoration of their external surface. Different combinations varying the type of PS (commercial Rose Bengal, Thionine and Chlorine e6 or custom-made BODIPY-based), the linkage design, and the length of PEG are detailed. All the nanosystems were physicochemically characterized (morphology, diameter, size distribution and PS loaded amount) and photophysically studied (absorption capacity, fluorescence efficiency, and singlet oxygen production) in suspension. For the most promising PS-PEG-FA silica nanoplatforms, the biocompatibility in dark conditions and the phototoxicity under suitable irradiation wavelengths (blue, green, or red) at regulated light doses (10–15 J/cm2) were compared with PSs free in solution in HeLa cells in vitro.

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