scholarly journals Modulation of metabolic activity of phagocytes by antihistamines

2011 ◽  
Vol 4 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Antonin Lojek ◽  
Milan Číž ◽  
Michaela Pekarová ◽  
Gabriela Ambrožová ◽  
Ondřej Vašíček ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Metabolic Activity ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Inhibitory Effect ◽  
Oxygen Species ◽  
Antioxidative Properties ◽  
Enhanced Chemiluminescence ◽  
Inos Protein Expression

Modulation of metabolic activity of phagocytes by antihistaminesThe purpose of the study was to investigate the effects of H1-antihistamines of the 1stgeneration (antazoline, bromadryl, brompheniramine, dithiaden, cyclizine, chlorcyclizine, chlorpheniramine, clemastine) and the 2ndgeneration (acrivastine, ketotifen, and loratadine) on the respiratory burst of phagocytes. Reactive oxygen species generation in neutrophils isolated from rat blood was measured using luminol-enhanced chemiluminescence. Changes in nitrite formation and iNOS protein expression by RAW 264.7 macrophages were analysed using Griess reaction and Western blotting. The antioxidative properties of drugs in cell-free systems were detected spectrophotometrically, luminometrically, fluorimetrically, and amperometrically. The majority of the H1-antihistamines tested (bromadryl, brompheniramine, chlorcyclizine, chlorpheniramine, clemastine, dithiaden, and ketotifen) exhibited a significant inhibitory effect on the chemiluminescence activity of phagocytes. H1-antihistamines did not show significant scavenging properties against superoxide anion and hydroxyl radical, thus this could not contribute to the inhibition of chemiluminescence. H1-antihistamines had a different ability to modulate nitric oxide production by LPS-stimulated macrophages. Bromadryl, clemastine, and dithiaden were the most effective since they inhibited iNOS expression, which was followed by a significant reduction in nitrite levels. H1-antihistamines had no scavenging activity against nitric oxide. It can be concluded that the effects observed in the H1-antihistamines tested are not mediated exclusively via H1-receptor pathway or by direct antioxidative properties. Based on our results, antihistamines not interfering with the microbicidal mechanisms of leukocytes (antazoline, acrivastine and cyclizine) could be used preferentially in infections. Other antihistamines should be used, under pathological conditions accompanied by the overproduction of reactive oxygen species.

Regulatory mechanisms of nitric oxide and reactive oxygen species generation and their role in plant immunity

Nitric Oxide ◽  
2011 ◽  
Vol 25 (2) ◽  
pp. 216-221 ◽  
Author(s):  
Hirofumi Yoshioka ◽  
Keisuke Mase ◽  
Miki Yoshioka ◽  
Michie Kobayashi ◽  
Shuta Asai
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Plant Immunity ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Regulatory Mechanisms ◽  
Oxygen Species

scholarly journals The H2S Donor GYY4137 Stimulates Reactive Oxygen Species Generation in BV2 Cells While Suppressing the Secretion of TNF and Nitric Oxide

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2966 ◽  
Author(s):  
Milica Lazarević ◽  
Emanuela Mazzon ◽  
Miljana Momčilović ◽  
Maria Basile ◽  
Giuseppe Colletti ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Microglial Cells ◽  
Oxygen Species ◽  
Bv2 Cells ◽  
The Central Nervous System

GYY4137 is a hydrogen sulfide (H2S) donor that has been shown to act in an anti-inflammatory manner in vitro and in vivo. Microglial cells are among the major players in immunoinflammatory, degenerative, and neoplastic disorders of the central nervous system, including multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, and glioblastoma multiforme. So far, the effects of GYY4137 on microglial cells have not been thoroughly investigated. In this study, BV2 microglial cells were stimulated with interferon-gamma and lipopolysaccharide and treated with GYY4137. The agent did not influence the viability of BV2 cells in concentrations up to 200 μM. It inhibited tumor necrosis factor but not interleukin-6 production. Expression of CD40 and CD86 were reduced under the influence of the donor. The phagocytic ability of BV2 cells and nitric oxide production were also affected by the agent. Surprisingly, GYY4137 upregulated generation of reactive oxygen species (ROS) by BV2 cells. The effect was mimicked by another H2S donor, Na2S, and it was not reproduced in macrophages. Our results demonstrate that GYY4137 downregulates inflammatory properties of BV2 cells but increases their ability to generate ROS. Further investigation of this unexpected phenomenon is warranted.

Mechanistic Study of Hemoglobin Induced Platelet Activation

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5262-5262
Author(s):  
Christine R. Carlisle ◽  
Mary Stahle ◽  
Ryan Vest ◽  
Roy Hantgan ◽  
Janet Lee ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Platelet Activation ◽  
Reactive Oxygen ◽  
Inhibitory Effect ◽  
Mechanistic Study ◽  
Blood Collection ◽  
Oxygen Species ◽  
Free Hemoglobin ◽  
No Donor

Abstract Abstract 5262 Nitric oxide (NO) has been previously shown to inhibit adenosine diphosphate (ADP)- and thrombin- mediated platelet activation. This inhibitory effect of NO is blocked by cell-free oxyhemoglobin (Villagra, Shiva et al. 2007). Cell-free hemoglobin (Hb) also appears to directly activate platelets even in the absence of ADP. However, the precise mechanisms for cell-free Hb-induced platelet activation have not been fully delineated. We hypothesized that oxyhemoglobin can promote platelet activation through one of three potential mechanisms: 1) direct apoprotein interaction with platelet receptors, 2) reactive oxygen species (ROS) production, and/or 3) scavenging of endogenous NO. Platelets were isolated from whole blood obtained from healthy volunteers (n=15) using sodium citrate blood collection tubes. Platelet activation was measured by examining immunofluorescent Pac-1 labeling by flow cytometry using activated glycoprotein IIb/IIIa as a measure of activation. In the presence of 10 uM concentration of NO donor mahmaNONOate, ADP-induced platelet activation was inhibited by 44%. Incubation of 100 uM cell-free oxyhemoglobin eliminated the inhibitory effect of NO. In addition, cell-free oxyhemoglobin (100 uM concentration) induced platelet activation by 17% above unstimulated controls even in the absence of ADP. Methemoglobin was used to test if direct Hb protein interaction with platelets was sufficient for platelet activation, independent of heme redox state. To produce methemoglobin, the ferrous iron in oxyhemoglobin was oxidized to its ferric form, thus methemoglobin is likely to preserve all direct protein interactions. However, unlike oxyhemoglobin, incubation of 100 uM methemoglobin did not induce platelet activation. Next, we tested whether reactive oxygen species production was responsible for hemoglobin-induced platelet activation. In the absence of hemoglobin, superoxide dismutase (SOD) (100 U/ml) and catalase (100 U/ml) reduced baseline platelet activation, verifying a ROS (Pignatelli, Pulcinelli et al. 1998). However, in the presence of oxyhemoglobin, SOD and catalase did not significantly abrogate the effect of Hb on platelet activation, suggesting that the ROS superoxide and hydrogen peroxide are not involved in hemoglobin-induced platelet activation. To determine if scavenging of endogenous NO was responsible for hemoglobin-induced platelet activation, platelets were incubated in the presence or absence of NO scavengers, carboxy-PTIO (5mM) and Fe-DTCS (3 mM), or nitric oxide synthase (NOS) inhibitor, LNMMA (100 uM). Results from these investigations suggest scavenging of endogenous NO was not responsible for hemoglobin-induced platelet activation. Overall our data suggest a complex mechanism for oxyhemoglobin-mediated platelet activation that is likely to involve more than a single contributing pathway. These data aid in elucidating the mechanism of platelet activation by cell-free hemoglobin and may provide novel insights to designing potential treatments to reduce the platelet activation underlying hypercoagulable states associated with a variety of pathological conditions including hemolytic anemias, stroke, and diabetes. This work was supported by NIH grants HL058091 and HL098032 Disclosures: Gladwin: Patents filed related to treating hemolysis.: Patents & Royalties. Kim-Shapiro:Patents filed related to treating hemolysis. Honororia from Sangart Inc.: Honoraria, Patents & Royalties.

scholarly journals MoS2-quantum dot triggered reactive oxygen species generation and depletion: responsible for enhanced chemiluminescence

2019 ◽  
Vol 10 (2) ◽  
pp. 497-500 ◽  
Author(s):  
Xiangnan Dou ◽  
Qiang Zhang ◽  
Syed Niaz Ali Shah ◽  
Mashooq Khan ◽  
Katsumi Uchiyama ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Quantum Dot ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Enhanced Chemiluminescence

Activated MoS2-QDs exhibit a promising capability for the generation of reactive oxygen species.

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