scholarly journals In Vitro Electrochemical Detection of Hydrogen Peroxide in Activated Macrophages via a Platinum Microelectrode Array

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5607
Author(s):  
Victor M. Carriere ◽  
Jolin P. Rodrigues ◽  
Chao Tan ◽  
Prabhu Arumugam ◽  
Scott Poh

Oxidative stress, an excess of endogenous or exogenous reactive oxygen species (ROS) in the human body, is closely aligned with inflammatory responses. ROS such as hydrogen peroxide (H2O2), superoxide, and radical hydroxyl ions serve essential functions in fighting infection; however, chronic elevation of these species irreversibly damages cellular components. Given the central role of inflammation in a variety of diseases, including Alzheimer’s disease and rheumatoid arthritis, a low-cost, extracellular, non-invasive assay of H2O2 measurement is needed. This work reports the use of a platinum microelectrode array (Pt MEA)-based ceramic probe to detect time- and concentration-dependent variations in H2O2 production by activated RAW 264.7 macrophages. First, these cells were activated by lipopolysaccharide (LPS) to induce oxidative stress. Chronoamperometry was then employed to detect the quantity of H2O2 released by cells at various time intervals up to 48 h. The most stimulatory concentration of LPS was identified. Further experiments assessed the anti-inflammatory effect of dexamethasone (Dex), a commonly prescribed steroid medication. As expected, the probe detected significantly increased H2O2 production by LPS-doped macrophages, subsequently diminishing the pro-inflammatory effect in LPS-doped cells treated with Dex. These results strongly support the use of this probe as a non-invasive, robust, point-of-care test of inflammation, with a high potential for multiplexing in further studies.

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 379
Author(s):  
Sandra Cordeiro ◽  
Beatriz Silva ◽  
Ana Margarida Martins ◽  
Helena Margarida Ribeiro ◽  
Lídia Gonçalves ◽  
...  

There are several approaches to treat ocular diseases, which can be invasive or non-invasive. Within the non-invasive, new pharmaceutical strategies based on nanotechnology and mucoadhesive polymers are emerging methodologies, which aim to reach an efficient treatment of eye diseases. The aim of this work was the development of novel chitosan/hyaluronic acid nanoparticle systems with mucoadhesive properties, intended to encapsulate antioxidant molecules (e.g., crocin) aiming to reduce eye oxidative stress and, consequently, ocular disease. An ultraviolet (UV) absorber molecule, actinoquinol, was also added to the nanoparticles, to further decrease oxidative stress. The developed nanoparticles were characterized and the results showed a mean particle size lower than 400 nm, polydispersity index of 0.220 ± 0.034, positive zeta potential, and high yield. The nanoparticles were also characterized in terms of pH, osmolality, and viscosity. Mucoadhesion studies involving the determination of zeta potential, viscosity, and tackiness, showed a strong interaction between the nanoparticles and mucin. In vitro release studies using synthetic membranes in Franz diffusion cells were conducted to unravel the drug release kinetic profile. Ex vitro studies using pig eye scleras in Franz diffusion cells were performed to evaluate the permeation of the nanoparticles. Furthermore, in vitro assays using the ARPE-19 (adult retinal pigment epithelium) cell line showed that the nanoparticles can efficiently decrease oxidative stress and showed low cytotoxicity. Thus, the developed chitosan/hyaluronic acid nanoparticles are a promising system for the delivery of antioxidants to the eye, by increasing their residence time and controlling their delivery.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lingyu Yang ◽  
Dehai Xian ◽  
Xia Xiong ◽  
Rui Lai ◽  
Jing Song ◽  
...  

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerousin vitroandin vivostudies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.


2020 ◽  
Vol 175 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Nivedita Banerjee ◽  
Hui Wang ◽  
Gangduo Wang ◽  
M Firoze Khan

Abstract Trichloroethene (trichloroethylene, TCE) and one of its reactive metabolites dichloroacetyl chloride (DCAC) are associated with the induction of autoimmunity in MRL+/+ mice. Although oxidative stress plays a major role in TCE-/DCAC-mediated autoimmunity, the underlying molecular mechanisms still need to be delineated. Nuclear factor (erythroid-derived 2)-like2 (Nrf2) is an oxidative stress-responsive transcription factor that binds to antioxidant responsive element (ARE) and provides protection by regulating cytoprotective and antioxidant gene expression. However, the potential of Nrf2 in the regulation of TCE-/DCAC-mediated autoimmunity is not known. This study thus focused on establishing the role of Nrf2 and consequent inflammatory responses in TCE-/DCAC-mediated autoimmunity. To achieve this, we pretreated Kupffer cells (KCs) or T cells with/without tert-butylhydroquinone (tBHQ) followed by treatment with DCAC. In both KCs and T cells, DCAC treatment significantly downregulated Nrf2 and HO-1 expression along with induction of Keap-1 and caspase-3, NF-κB (p65), TNF-α, and iNOS, whereas pretreatment of these cells with tBHQ attenuated these responses. The in vitro findings were further verified in vivo by treating female MRL+/+ mice with TCE along with/without sulforaphane. TCE exposure in mice also led to reduction in Nrf2 and HO-1 but increased phospho-NF-κB (p-p65) and iNOS along with increased anti-dsDNA antibodies. Interestingly, sulforaphane treatment led to amelioration of TCE-mediated effects, resulting in Nrf2 activation and reduction in inflammatory and autoimmune responses. Our results show that TCE/DCAC mediates an impairment in Nrf2 regulation. Attenuation of TCE-mediated autoimmunity via activation of Nrf2 supports that antioxidants sulforaphane/tBHQ could be potential therapeutic agents for autoimmune diseases.


2020 ◽  
Author(s):  
Ramona Meanti ◽  
Laura Rizzi ◽  
Elena Bresciani ◽  
Laura Molteni ◽  
Vittorio Locatelli ◽  
...  

AbstractHexarelin, a synthetic hexapeptide, protects cardiac and skeletal muscles by inhibiting apoptosis, both in vitro and in vivo. Moreover, evidence suggests that hexarelin could have important neuroprotective bioactivity.Oxidative stress and the generation of free radicals has been implicated in the etiologies of several neurodegenerative diseases, including amyotrophic lateral sclerosis, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease and multiple sclerosis. In addition to direct oxidative stress, exogenous hydrogen peroxide (H2O2) can penetrate biological membranes and enhance the formation of other reactive oxygen species.The aim of this study was to examine the inhibitory influence of hexarelin on H2O2-induced apoptosis in Neuro-2A cells, a mouse neuroblastoma cell line. Our results indicate that H2O2 reduced the viability of Neuro-2A cells in a dose-related fashion. Furthermore, H2O2 induced significant changes in the morphology of Neuro-2A cells, reflected in the formation of apoptotic cell bodies, and an increase of nitric oxide (NO) production. Hexarelin effectively antagonized H2O2 oxidative damage to Neuro-2A cells as indicated by improved cell viability, normal morphology and reduced nitrite (NO2−) release. Hexarelin treatment of Neuro-2A cells also reduced mRNA levels of caspases−3 and −7 and those of the pro-apoptotic molecule Bax; by contrast, hexarelin treatment increased anti-apoptotic Bcl-2 mRNA levels. Hexarelin also reduced MAPKs phosphorylation induced by H2O2 and concurrently increased p-Akt protein expression.In conclusion, our results identify several neuroprotective and anti-apoptotic effects of hexarelin. These properties suggest that further investigation of hexarelin as a neuroprotective agent in an investigational and therapeutic context are merited.


2022 ◽  
Vol 23 (2) ◽  
pp. 774
Author(s):  
Yoon Mee Yang ◽  
Ye Eun Cho ◽  
Seonghwan Hwang

Alcoholic liver disease (ALD) is characterized by the injury, inflammation, and scarring in the liver owing to excessive alcohol consumption. Currently, ALD is a leading cause for liver transplantation. Therefore, extensive studies (in vitro, in experimental ALD models and in humans) are needed to elucidate pathological features and pathogenic mechanisms underlying ALD. Notably, oxidative changes in the liver have been recognized as a signature trait of ALD. Progression of ALD is linked to the generation of highly reactive free radicals by reactions involving ethanol and its metabolites. Furthermore, hepatic oxidative stress promotes tissue injury and, in turn, stimulates inflammatory responses in the liver, forming a pathological loop that promotes the progression of ALD. Accordingly, accumulating further knowledge on the relationship between oxidative stress and inflammation may help establish a viable therapeutic approach for treating ALD.


Author(s):  
Olga Verle ◽  
Oleg Ostrovskiy ◽  
Valerian Verovskiy ◽  
Galina Dudchenko

In the framework of the study, the degree of defragmentation of DNA by the DNA-comet method is evaluated when exposed to the cell culture of hydrogen peroxide (H2O2), and an in vitro model is developed to evaluate the antioxidant activity of new pharmacological agents. The results of working with cell lines show that the percentage of damage to the genetic material of cells of intact samples does not greatly vary from the method of removing the cellular monolayer from the culture plastic. Concerning the effect of H2O2 as an inducer of oxidative stress on DNA cell damage, the optimal level of DNA defragmentation has been modeled for subsequent studies of the protective action of antioxidants.


2021 ◽  
Author(s):  
Zongxiu Nie ◽  
Yuze Li ◽  
Lixia Jiang ◽  
Zhenpeng Wang ◽  
Xiaohua Cao ◽  
...  

Abstract The diagnosis of bladder cancer (BC) is currently based on cystoscopy, which is invasive and expensive. Here, we described a non-invasive, low-cost BC diagnosis method based on a desorption, separation, and ionization mass spectrometry platform (DSI-MS) that adopts N, N- Dimethylethylenediamine (DMED) as a differential labeling reagent. The DSI-MS platform avoids the interferences from intra- and/or inter-samples, while the DMED increases detection sensitivity and distinguishes carboxyl, aldehyde, and ketone groups from untreated samples. Carbonyl metabolic fingerprints of urine from 28 BC patients and 38 controls were portrayed and significant differences of some potential biomarkers were observed. The mechanisms of the changes have been discussed. Logistic regression (LR) was applied to discriminate BC from controls and an accuracy of 87% was achieved. We believe this patient-friendly method provides a hopeful approach for BC rapid point-of-care diagnostic.


Author(s):  
Annayara C. F. Fernandes ◽  
Jeane B. Melo ◽  
Vanize M. Genova ◽  
Ádina L. Santana ◽  
Gabriela Macedo

Background: Glycation is a chemical reaction that synthesize advanced glycation endproducts (AGEs). The AGEs irreversibly damage macromolecules present in tissues and organs, leading to the impairment of biological functions. For instance, the accumulation of AGEs induces oxidative stress and consequently inflammatory responses in human body, leading to the on set/worsening of diseases, including obesity, asthma, cognitive impairment, and cancer. There is a current demand on natural and low-cost sources of antiglycant agents. As a result, food phytochemicals presented promising results to inhibit glycation and consequently, the formation of AGEs. Objective: Here, we describe the mechanism of glycation on the worsening of diseases, the methods os detection, and the current findings on the use of phytochemicals (phenolic compounds, phytosterols, carotenoids, terpenes and vitamins) as natural therapeuticals to inhibit health damages via inhibition of AGEs in vitro and in vivo. Methods: This manuscript reviewed publications available in the PubMed and Science Direct databases dated from the last 20 years on the uses of phytochemicals to inhibit the AGEs in vitro and in vivo. Also, recent patents on the use of anti-glycant drugs were reviewed using the Google Advanced Patents database. Results and Discussion: Phenolic compounds have been mostly studied to inhibit AGEs. Food phytochemicals derived from agroindustry wastes, including peanut skins, and the bagasses derived from citrus and grapes are promising antiglycant agents via scavenging of free radicals, metal ions, the suppression of metabolic pathways that induces inflammation, the activation of pathways that promote antioxidant defense, the blocking of AGE connection with the receptor for advanced glycation endproducts (RAGE). Conclusion: Phytochemicals derived from agroindustry are promising anti-glycants, which can be included to replace synthetic drugs for AGE inhibition, and consequently to act as a therapeutical strategy to prevent and treat diseases caused by AGEs, including diabetes, ovarian cancer, osteoporosis, and Alzheimer’s disease.


Sign in / Sign up

Export Citation Format

Share Document