scholarly journals Time-Dependent Effects of Anesthetic Isoflurane on Reactive Oxygen Species Levels in HEK-293 Cells

2014 ◽  
Vol 4 (2) ◽  
pp. 311-320 ◽  
Author(s):  
Yongxing Sun ◽  
Baiqi Cheng ◽  
Yuanlin Dong ◽  
Tianzuo Li ◽  
Zhongcong Xie ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Time Dependent ◽  
Oxygen Species ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells

scholarly journals Antioxidant, α-Glucosidases and α-Amylase Inhibitory Activities of Persicaria odorata

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Kanya Thongra-ar ◽  
Piyanuch Rojsanga ◽  
Savita Chewchinda ◽  
Supachoke Mangmool ◽  
Pongtip Sithisarn
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Enzymes ◽  
Reactive Oxygen ◽  
Total Flavonoid ◽  
Total Phenolic ◽  
Oxygen Species ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Ic50 Values

The objects of this study were to determine the effects to reactive oxygen species and antioxidant enzymes levels in HEK-293 cells and inhibition of α-glucosidases and α-amylase enzymes of extracts from Persicaria odorata or phak phaeo. The ethanol extracts from the leaves and the stems of phak phaeo were investigated for their 2,2-diphenyl-1-picryhydrazyl (DPPH) scavenging activities (IC50 were 7.74 ± 0.47 and 7.91 ± 0.43 µg/mL, respectively). Cellular antioxidant effects in human embryonic kidney-293 (HEK-293) cells with these extracts (0.1 mg/mL) also increased the mRNA expressions of manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx-1), catalase and glutathione reductase (GRe). The leaf extract showed the higher efficacies in the induction of the mRNA expressions of Mn-SOD, GPx-1 and GRe while the stem extract exhibited a stronger effect to the induction of catalase. Phak phaeo in vitro inhibitory effects to α-glucosidase enzyme (IC50 values of 9.82 ± 1.64 and 13.99 ± 1.45 µg/mL, respectively and also strong inhibition to α-amylase with IC50 values of 90.66 ± 8.75 and 19.96 ± 5.37 µg/mL, respectively). Lineweaver-Burk plot demonstrated that phak phaeo extracts inhibited α-glucosidase and α- amylase in non-competitive manners. Total phenolic and total flavonoid contents were determined by Folin-Ciocalteu and aluminium chloride methods (the leaf and stem extracts were 22.89 ± 9.16 and 22.27 ± 8.77 g gallic acid equivalent in 100 g extract (g% GAE) and 7.20 ± 3.61 and 4.06 ± 1.73 g quercetin equivalent in 100 g extract (g% QE), respectively). Keywords: Antioxidant enzymes, DPPH, HEK-293, MTT assay, Persicaria odorata, Reactive oxygen species, Total phenolic, Total flavonoid, α-glucosidases, α-amylase

scholarly journals Time-dependent degradation of carbon nanotubes correlates with decreased reactive oxygen species generation in macrophages

2019 ◽  
Vol Volume 14 ◽  
pp. 2797-2807 ◽  
Author(s):  
Mei Yang ◽  
Minfang Zhang ◽  
Hideaki Nakajima ◽  
Masako Yudasaka ◽  
Sumio Iijima ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Carbon Nanotubes ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Time Dependent ◽  
Oxygen Species

scholarly journals Time dependent activation of transcription factors in freshly isolated cardiomyocytes: Adrenaline and reactive oxygen species incubation

2007 ◽  
Vol 172 ◽  
pp. S5-S6
Author(s):  
Vera Marisa Costa ◽  
Felix Carvalho ◽  
Maria de Lourdes Bastos ◽  
Rui Carvalho ◽  
Márcia Carvalho ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factors ◽  
Reactive Oxygen ◽  
Time Dependent ◽  
Oxygen Species ◽  
Isolated Cardiomyocytes ◽  
Activation Of Transcription

scholarly journals Reactive Oxygen Species-Responsive Miktoarm Amphiphile for Triggered Intracellular Release of Anti-Cancer Therapeutics

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4418
Author(s):  
Hyun-Chul Kim ◽  
Eunjoo Kim ◽  
Se Guen Lee ◽  
Sung Jun Lee ◽  
Sang Won Jeong ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Cancer Therapeutics ◽  
In Vitro Cytotoxicity ◽  
Oxygen Species ◽  
Normal Cells ◽  
Research Attention ◽  
Hek 293 ◽  
Release Device

Reactive oxygen species (ROS)-responsive nanocarriers have received considerable research attention as putative cancer treatments because their tumor cell targets have high ROS levels. Here, we synthesized a miktoarm amphiphile of dithioketal-linked ditocopheryl polyethylene glycol (DTTP) by introducing ROS-cleavable thioketal groups as linkers between the hydrophilic and hydrophobic moieties. We used the product as a carrier for the controlled release of doxorubicin (DOX). DTTP has a critical micelle concentration (CMC) as low as 1.55 μg/mL (4.18 × 10−4 mM), encapsulation efficiency as high as 43.6 ± 0.23% and 14.6 nm particle size. The DTTP micelles were very responsive to ROS and released their DOX loads in a controlled manner. The tocopheryl derivates linked to DTTP generated ROS and added to the intracellular ROS in MCF-7 cancer cells but not in HEK-293 normal cells. In vitro cytotoxicity assays demonstrated that DOX-encapsulated DTTP micelles displayed strong antitumor activity but only slightly increased apoptosis in normal cells. This ROS-triggered, self-accelerating drug release device has high therapeutic efficacy and could be a practical new strategy for the clinical application of ROS-responsive drug delivery systems.

scholarly journals Selective Open-Channel Block of Shaker (Kv1) Potassium Channels by S-Nitrosodithiothreitol (Sndtt)

2001 ◽  
Vol 118 (1) ◽  
pp. 113-134 ◽  
Author(s):  
Mathew W. Brock ◽  
Chris Mathes ◽  
William F. Gilly
Keyword(s):  
Open Channel ◽  
Single Channel ◽  
Time Dependent ◽  
Channel Block ◽  
Giant Fiber ◽  
Open Channel Block ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Kv Channels ◽  
293 Cells

Large quaternary ammonium (QA) ions block voltage-gated K+ (Kv) channels by binding with a 1:1 stoichiometry in an aqueous cavity that is exposed to the cytoplasm only when channels are open. S-nitrosodithiothreitol (SNDTT; ONSCH2CH(OH)CH(OH)CH2SNO) produces qualitatively similar “open-channel block” in Kv channels despite a radically different structure. SNDTT is small, electrically neutral, and not very hydrophobic. In whole-cell voltage-clamped squid giant fiber lobe neurons, bath-applied SNDTT causes reversible time-dependent block of Kv channels, but not Na+ or Ca2+ channels. Inactivation-removed ShakerB (ShBΔ) Kv1 channels expressed in HEK 293 cells are similarly blocked and were used to study further the action of SNDTT. Dose–response data are consistent with a scheme in which two SNDTT molecules bind sequentially to a single channel, with binding of the first being sufficient to produce block. The dissociation constant for the binding of the second SNDTT molecule (Kd2 = 0.14 mM) is lower than that of the first molecule (Kd1 = 0.67 mM), indicating cooperativity. The half-blocking concentration (K1/2) is ∼0.2 mM. Steady-state block by this electrically neutral compound has a voltage dependence (about −0.3 e0) similar in magnitude but opposite in directionality to that reported for QA ions. Both nitrosyl groups on SNDTT (one on each sulfur atom) are required for block, but transfer of these reactive groups to channel cysteine residues is not involved. SNDTT undergoes a slow intramolecular reaction (τ ≈ 770 s) in which these NO groups are liberated, leading to spontaneous reversal of the SNDTT effect. Competition with internal tetraethylammonium indicates that bath-applied SNDTT crosses the cell membrane to act at an internal site, most likely within the channel cavity. Finally, SNDTT is remarkably selective for Kv1 channels. When individually expressed in HEK 293 cells, rat Kv1.1–1.6 display profound time-dependent block by SNDTT, an effect not seen for Kv2.1, 3.1b, or 4.2.

scholarly journals Phenolic Rich Fractions from Mycelium and Fruiting Body of Ganoderma lucidum Inhibit Bacterial Pathogens Mediated by Generation of Reactive Oxygen Species and Protein Leakage and Modulate Hypoxic Stress in HEK 293 Cell Line

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jigni Mishra ◽  
Anivesh Joshi ◽  
Rakhee Rajput ◽  
Kaushlesh Singh ◽  
Anju Bansal ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Fruiting Body ◽  
Ganoderma Lucidum ◽  
Chemical Constituents ◽  
Reactive Oxygen ◽  
Total Phenolic ◽  
Therapeutic Effects ◽  
Oxygen Species ◽  
Antioxidant Power ◽  
Hek 293

Ganoderma lucidum (G. lucidum) fungus (Family Ganodermataceae) is widely used as a traditional medicine in China, Japan, and many Asian countries on account of its numerous medicinal properties such as antioxidant, anticancer, antimicrobial, energy enhancing, and immunostimulatory. This broad spectrum of therapeutic effects exhibited by G. lucidum is ascribed to its abundance in several classes of chemical constituents, namely, carbohydrates, flavonoids, minerals, phenolics, proteins, and steroids which possess substantial bioactivities. The aim of the current study was to prepare phenolic rich fractions (PRFs) from aqueous extract of the Indian variety of G. lucidum mycelium and fruiting body. These fractions were assessed for their antioxidant capacity by TPC (total phenolic content), TFC (total flavonoid content), FRAP (ferric reducing antioxidant power), and ABTS [2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid] assays. Quantification of flavonoids and nucleobases present in the fractions was carried out by high-performance thin layer chromatography (HPTLC). The antibacterial activity of the fractions was evaluated against Escherichia coli, Salmonella typhi, and Staphylococcus aureus. The antibacterial mechanism of action of the PRFs was established to be generation of reactive oxygen species and leakage of proteins within bacterial cells. Additionally, the protective effect of the PRFs in counteracting hypoxia was observed in HEK 293 cell lines.

scholarly journals Reactive Oxygen Species Evoked by Potassium Deprivation and Staurosporine Inactivate Akt and Induce the Expression of TXNIP in Cerebellar Granule Neurons

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Marco Antonio Zaragoza-Campillo ◽  
Julio Morán
Keyword(s):  
Reactive Oxygen Species ◽  
Neuronal Apoptosis ◽  
Reactive Oxygen ◽  
Time Dependent ◽  
Akt Pathway ◽  
Cerebellar Granule Neurons ◽  
Dependent Manner ◽  
Granule Neurons ◽  
Oxygen Species ◽  
Cerebellar Granule

The reactive oxygen species (ROS) play a critical role in neuronal apoptosis; however, the mechanisms are not well understood. It has been shown that thioredoxin-interacting protein (TXNIP) overexpression renders cells more susceptible to oxidative stress and promotes apoptosis and that the activation of PI3K/Akt pathway leads to a downregulation of TXNIP. Here, we evaluated the role of ROS in the regulation of Akt activity and the subsequent regulation of the TXNIP expression in a model of apoptotic death of cerebellar granule neurons (CGN). We observed that two apoptotic conditions that generate ROS at short times led to an increase in the expression of TXNIP in a time-dependent manner; antioxidants significantly reduced this expression. Also,H2O2caused an increase in TXNIP expression. Moreover, apoptotic conditions induced inactivation of Akt in a time-dependent manner similar to TXNIP expression andH2O2treatment led to Akt inactivation. Besides, the pharmacological inhibition of Akt increases TXNIP expression and induces CGN cell death. Together, these results suggest that ROS promote neuronal apoptosis through the Akt-TXNIP signaling pathway, supporting the idea that the PI3K/Akt pathway regulates the TXNIP expression. This study highlights the potential importance of this mechanism in neuronal death.

scholarly journals Modeling the Kinetic Behavior of Reactive Oxygen Species with Cerium Dioxide Nanoparticles

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 447 ◽  
Author(s):  
Kenneth Reed ◽  
Nathan Bush ◽  
Zachary Burns ◽  
Gwendolyn Doherty ◽  
Thomas Foley ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Self Regulation ◽  
Reactive Oxygen ◽  
Molecular Structures ◽  
Time Dependent ◽  
Mathematical Treatment ◽  
Oxygen Species ◽  
Research Activity

The world of medicinal therapies has been historically, and remains to be, dominated by the use of elegant organic molecular structures. Now, a novel medical treatment is emerging based on CeO2 nano-crystals that are discrete clusters of a few hundred atoms. This development is generating a great deal of exciting and promising research activity, as evidenced by this Special Issue of Biomolecules. In this paper, we provide both a steady-state and time-dependent mathematical description of a sequence of reactions: superoxide generation, superoxide dismutase, and hydrogen peroxide catalase and ceria regeneration. This sequence describes the reactive oxygen species (ROS); superoxide, O2–, molecular oxygen, O2, hydroxide ion OH– and hydrogen peroxide, H2O2, interacting with the Ce3+, and Ce4+ surface cations of nanoparticle ceria, CeO2. Particular emphasis is placed on the predicted time-dependent role of the Ce3+/Ce4+ ratio within the crystal. The net reaction is succinctly described as: H2O2 + 2O2– + 2H+ → 2H2O + 2O2. The chemical equations and mathematical treatment appears to align well with several critical in vivo observations such as; direct and specific superoxide dismutase (SOD), ROS control, catalytic regeneration, ceria self-regulation and self-limiting behavior. However, in contrast to experimental observations, the model predicts that the 4+ ceric ion state is the key SOD agent. Future work is suggested based on these calculations.

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