scholarly journals Apocynin: Molecular Aptitudes

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
J. Stefanska ◽  
R. Pawliczak

Apocynin is a naturally occurring methoxy-substituted catechol, experimentally used as an inhibitor of NADPH-oxidase. It can decrease the production of superoxide (O2−) from activated neutrophils and macrophages while the ability of phagocytosis remains unaffected. The anti-inflammatory activity of apocynin has been demonstrated in a variety of cell and animal models of inflammation. Apocynin, after metabolic conversion, inhibits the assembly of NADPH-oxidase that is responsible for reactive oxygen species (ROS) production. It is, therefore, extensively used to reveal the role of this enzyme in cell and experimental models. Although some of the ROS serve as signaling molecules in the cells, excessive production is damaging and has been implicated to play an important role in the progression of many disease processes. This is why in many studies apocynin presents a promising potential treatment for some disorders; however, its utility with inflammatory diseases remains to be determined. Since its mode of action is not well defined, we tried to get a more precise insight into the mechanisms by which apocynin exerts its activity. Considering the anti-inflammatory activities of apocynin, we may conclude that this compound definitely deserves further study.

Author(s):  
Halina Leung ◽  
Jose Perdomo ◽  
Zohra Ahmadi ◽  
Feng Yan ◽  
Steven E. McKenzie ◽  
...  

Heparin-induced thrombocytopenia (HIT) is associated with severe and potentially lethal thrombotic complications. NETosis was recently shown to be an important driver of thrombosis in HIT. We investigated the role of reactive oxygen species (ROS) and NADPH oxidase 2 (NOX2) and their contributions to thrombus development in HIT. We showed that neutrophil activation by HIT immune complexes induced ROS-dependent NETosis. Analysis of thrombi formed in a microfluidics system showed ROS production in both platelets and neutrophils, and abundant NETs and ROS distributed throughout the clot. Neutrophil-targeted ROS inhibition was sufficient to block HIT-induced NETosis and thrombosis using human blood. Inhibition of NOX2 with diphenyleneiodonium chloride or GSK2795039 abrogated HIT-induced thrombi in vivo using FcγRIIa+/hPF4+ transgenic mice. Thrombocytopenia in mice remained unaffected by ROS inhibition. Increased ROS production in activated neutrophils were also confirmed using fresh blood from patients with active HIT. Our findings show that ROS and NOX2 play a crucial role in NETosis and thrombosis in HIT. This enhances our understanding of the processes driving thrombosis in HIT and identifies NOX2 as a potential new therapeutic target for antithrombotic treatment for HIT.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Mauricio Olguín-Albuerne ◽  
Guadalupe Domínguez ◽  
Julio Morán

Cell death implies morphological changes that may contribute to the progression of this process. In astrocytes, the mechanisms involving the cytoskeletal changes during cell death are not well explored. Although NADPH oxidase (NOX) has been described as being a critical factor in the production of ROS, not much information is available about the participation of NOX-derived ROS in the cell death of astrocytes and their role in the alterations of the cytoskeleton during the death of astrocytes. In this study, we have evaluated the participation of ROS in the death of cultured cerebellar astrocytes using staurosporine (St) as death inductor. We found that astrocytes express NOX1, NOX2, and NOX4. Also, St induced an early ROS production and NOX activation that participate in the death of astrocytes. These findings suggest that ROS produced by St is generated through NOX1 and NOX4. Finally, we showed that the reorganization of tubulin and actin induced by St is ROS independent and that St did not change the level of expression of these cytoskeletal proteins. We conclude that ROS produced by a NOX is required for cell death in astrocytes, but not for the morphological alterations induced by St.


2021 ◽  
Vol 14 (7) ◽  
pp. 692
Author(s):  
Ryldene Marques Duarte da Cruz ◽  
Francisco Jaime Bezerra Mendonça-Junior ◽  
Natália Barbosa de Mélo ◽  
Luciana Scotti ◽  
Rodrigo Santos Aquino de Araújo ◽  
...  

Rheumatoid arthritis, arthrosis and gout, among other chronic inflammatory diseases are public health problems and represent major therapeutic challenges. Non-steroidal anti-inflammatory drugs (NSAIDs) are the most prescribed clinical treatments, despite their severe side effects and their exclusive action in improving symptoms, without effectively promoting the cure. However, recent advances in the fields of pharmacology, medicinal chemistry, and chemoinformatics have provided valuable information and opportunities for development of new anti-inflammatory drug candidates. For drug design and discovery, thiophene derivatives are privileged structures. Thiophene-based compounds, like the commercial drugs Tinoridine and Tiaprofenic acid, are known for their anti-inflammatory properties. The present review provides an update on the role of thiophene-based derivatives in inflammation. Studies on mechanisms of action, interactions with receptors (especially against cyclooxygenase (COX) and lipoxygenase (LOX)), and structure-activity relationships are also presented and discussed. The results demonstrate the importance of thiophene-based compounds as privileged structures for the design and discovery of novel anti-inflammatory agents. The studies reveal important structural characteristics. The presence of carboxylic acids, esters, amines, and amides, as well as methyl and methoxy groups, has been frequently described, and highlights the importance of these groups for anti-inflammatory activity and biological target recognition, especially for inhibition of COX and LOX enzymes.


2021 ◽  
Vol 22 (5) ◽  
pp. 2633
Author(s):  
Giuseppina Adiletta ◽  
Marisa Di Matteo ◽  
Milena Petriccione

Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years.


2021 ◽  
Vol 28 ◽  
Author(s):  
Josiane Viana Cruz ◽  
Joaquín María Campos Rosa ◽  
Njogu Mark Kimani ◽  
Silvana Giuliatti ◽  
Cleydson Breno Rodrigues dos Santos

: This article presents a simplified view of celecoxib as a potential inhibitor in the treatment of inflammatory diseases. The enzyme cyclooxygenase (COX) has, predominantly, two isoforms called cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). The former plays a constitutive role that is related to homeostatic effects in renal and platelets, while the latter is mainly responsible for induction of inflammatory effects. Since COX-2 plays an important role in the pathogenesis of inflammatory diseases, it has been signaled as a target for the planning of anti-inflammatory intermediates. Many inhibitors developed and planned for COX-2 inhibition have presented side effects to humans, mainly in the gastrointestinal and/or cardiovascular tract. Therefore, it is necessary to design new potential COX-2 inhibitors, which are relatively safe and without side effects. To this end, of the generation of non-steroidal anti-inflammatory drugs from “coxibs”, celecoxib is the only potent selective COX-2 inhibitor that is still commercially available. Thus, the compound celecoxib became a commercial prototype inhibitor for the development of anti-inflammatory agents for COX-2 enzyme. In this review, we provide highlights where such inhibition should provide a structural basis for the design of promising new non-steroidal anti-inflammatory drugs (NSAIDs) which act as COX-2 inhibitors with lesser side effects on the human body.


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 688-688
Author(s):  
Toshihiro Ichiki ◽  
Kotaro Takeda ◽  
Akira Takeshita

58 Recent studies suggest a crucial role of reactive oxygen species (ROS) for the signaling of Angiotensin II (Ang II) through type 1 Ang II receptor (AT1-R). However, the role of ROS in the regulation of AT1-R expression has not been explored. In this study, we examined the effect of an antioxidant on the homologous downregulation of AT1-R by Ang II. Ang II (10 -6 mol/L) decreased AT1-R mRNA with a peak suppression at 6 hours of stimulation in rat aortic vascular smooth muscle cells (VSMC). Ang II dose-dependently (10 -8 -10 -6 ) suppressed AT1-R mRNA at 6 hours of stimulation. Preincubation of VSMC with N-acetylcysteine (NAC), a potent antioxidant, almost completely inhibited the Ang II-induced downregulation of AT1-R mRNA. The effect of NAC was due to stabilization of the AT1-R mRNA that was destabilized by Ang II. Ang II did not affect the promoter activity of AT1-R gene. Diphenylene iodonium (DPI), an inhibitor of NADH/NADPH oxidase failed to inhibit the Ang II-induced AT1-R mRNA downregulation. The Ang II-induced AT1-R mRNA downregulation was also blocked by PD98059, an extracellular signal-regulated protein kinase (ERK) kinase inhibitor. Ang II-induced ERK activation was inhibited by NAC as well as PD98059 whereas DPI did not inhibit it. To confirm the role of ROS in the regulation of AT1-R mRNA expression, VSMC were stimulated with H 2 O 2 . H 2 O 2 suppressed the AT1-R mRNA expression and activated ERK. These results suggest that production of ROS and activation of ERK are critical for downregulation of AT1-R mRNA. The differential effect of NAC and DPI on the downregulation of AT1-R mRNA may suggest the presence of other sources than NADH/NADPH oxidase pathway for ROS in Ang II signaling. Generation of ROS through stimulation of AT1-R not only mediates signaling of Ang II but may play a crucial role in the adaptation process of AT1-R to the sustained stimulation of Ang II.


2018 ◽  
Vol 132 (17) ◽  
pp. 1889-1899 ◽  
Author(s):  
Dragana Dragoljevic ◽  
Marit Westerterp ◽  
Camilla Bertuzzo Veiga ◽  
Prabhakara Nagareddy ◽  
Andrew J. Murphy

Cardiovascular (CV) diseases (CVD) are primarily caused by atherosclerotic vascular disease. Atherogenesis is mainly driven by recruitment of leucocytes to the arterial wall, where macrophages contribute to both lipid retention as well as the inflammatory milieu within the vessel wall. Consequently, diseases which present with an enhanced abundance of circulating leucocytes, particularly monocytes, have also been documented to accelerate CVD. A host of metabolic and inflammatory diseases, such as obesity, diabetes, hypercholesteraemia, and rheumatoid arthritis (RA), have been shown to alter myelopoiesis to exacerbate atherosclerosis. Genetic evidence has emerged in humans with the discovery of clonal haematopoiesis of indeterminate potential (CHIP), resulting in a disordered haematopoietic system linked to accelerated atherogenesis. CHIP, caused by somatic mutations in haematopoietic stem and progenitor cells (HSPCs), consequently provide a proliferative advantage over native HSPCs and, in the case of Tet2 loss of function mutation, gives rise to inflammatory plaque macrophages (i.e. enhanced interleukin (IL)-1β production). Together with the recent findings of the CANTOS (Canakinumab Anti-inflammatory Thrombosis Outcomes Study) trial that revealed blocking IL-1β using Canakinumab reduced CV events, these studies collectively have highlighted a pivotal role of IL-1β signalling in a population of people with atherosclerotic CVD. This review will explore how haematopoiesis is altered by risk-factors and inflammatory disorders that promote CVD. Further, we will discuss some of the recent genetic evidence of disordered haematopoiesis in relation to CVD though the association with CHIP and suggest that future studies should explore what initiates HSPC mutations, as well as how current anti-inflammatory agents affect CHIP-driven atherosclerosis.


2003 ◽  
Vol 89 (05) ◽  
pp. 926-935 ◽  
Author(s):  
Utta Berchner-Pfannschmidt ◽  
Christoph Wotzlaw ◽  
Robbert Cool ◽  
Joachim Fandrey ◽  
Helmut Acker ◽  
...  

SummaryThe hypoxia-inducible transcription factor HIF-1 mediates upregulation of plasminogen activator inhibitor-1 (PAI-1) expression under hypoxia. Reactive oxygen species (ROS) have also been implicated in PAI-1 gene expression. However, the role of ROS in HIF-1-mediated regulation of PAI-1 is not clear. We therefore investigated the role of the GTPase Rac1 which modulates ROS production in the pathway leading to HIF-1 and PAI-1 induction.Overexpression of constitutively activated (RacG12V) or dominant-negative (RacT17N) Rac1 increased or decreased, respectively, ROS production. In RacG12V-expressing cells, PAI-1 mRNA levels as well as HIF-1α nuclear presence were reduced under normoxia and hypoxia whereas expression of RacT17N resulted in opposite effects. Treatment with the antioxidant pyrrolidinedithiocarbamate or coexpression of the redox factor-1 restored HIF-1 and PAI-1 promoter activity in RacG12V-cells. In contrast, NFκB activation was enhanced in RacG12V-cells, but abolished by RacT17N. Thus, these findings suggest a mechanism explaining modified fibrinolysis and tissue remodeling in an oxidized environment.


2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Sunil Joshi ◽  
Ammon B. Peck ◽  
Saeed R. Khan

A major role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes is to catalyze the production of superoxides and other reactive oxygen species (ROS). These ROS, in turn, play a key role as messengers in cell signal transduction and cell cycling, but when they are produced in excess they can lead to oxidative stress (OS). Oxidative stress in the kidneys is now considered a major cause of renal injury and inflammation, giving rise to a variety of pathological disorders. In this review, we discuss the putative role of oxalate in producing oxidative stress via the production of reactive oxygen species by isoforms of NADPH oxidases expressed in different cellular locations of the kidneys. Most renal cells produce ROS, and recent data indicate a direct correlation between upregulated gene expressions of NADPH oxidase, ROS, and inflammation. Renal tissue expression of multiple NADPH oxidase isoforms most likely will impact the future use of different antioxidants and NADPH oxidase inhibitors to minimize OS and renal tissue injury in hyperoxaluria-induced kidney stone disease.


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