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Odontology Oct 2021The purpose is to evaluate the effect of photo-thermal acceleration on in-office bleaching efficiency using a bleaching agent without photocatalysts in vitro....
The purpose is to evaluate the effect of photo-thermal acceleration on in-office bleaching efficiency using a bleaching agent without photocatalysts in vitro. Artificially discolored bovine lower incisors were prepared, and the mixed in-office bleaching material contained hydrogen peroxide 23% was applied by following treatment for 10 min: high-(HI group) and low-intensity LED lights (LI group), oven at 38 °C (OV group), and room temperature at 23 °C (RT group). Color was measured before and after bleaching and color difference (∆E*) was calculated. The data were statistically analyzed using a two-way ANOVA and Tukey's post hoc test. The temperature change (∆T) of applied bleaching agent in HI and LI groups was measured using a thermography and was analyzed using a T test. The bleaching procedures were repeated 6 times. Irradiation in the HI group resulted in the highest ΔE, followed by the LI group whose ΔE was significantly lower. Both irradiated modes exhibited higher ΔE compared to non-irradiated OV and RT groups which were not significantly different from each other. The average temperature rise of bleaching agents in HI and LI groups after 10 min irradiation was 15.00 °C and 11.80 °C, respectively. The effect of photo-thermal acceleration was proved for an in-office bleaching agent without photocatalysts in vitro.
Topics: Acceleration; Animals; Cattle; Color; Hydrogen Peroxide; Tooth Bleaching; Tooth Bleaching Agents
PubMed: 33991277
DOI: 10.1007/s10266-021-00612-5 -
Infection and Immunity Jun 2020Neutrophils kill invading microbes and therefore represent the first line of defense of the innate immune response. Activated neutrophils assemble NADPH oxidase to... (Review)
Review
Neutrophils kill invading microbes and therefore represent the first line of defense of the innate immune response. Activated neutrophils assemble NADPH oxidase to convert substantial amounts of molecular oxygen into superoxide, which, after dismutation into peroxide, serves as the substrate for the generation of the potent antimicrobial hypochlorous acid (HOCl) in the phagosomal space. In this minireview, we explore the most recent insights into physiological consequences of HOCl stress. Not surprisingly, Gram-negative bacteria have evolved diverse posttranslational defense mechanisms to protect their proteins, the main targets of HOCl, from HOCl-mediated damage. We discuss the idea that oxidation of conserved cysteine residues and partial unfolding of its structure convert the heat shock protein Hsp33 into a highly active chaperone holdase that binds unfolded proteins and prevents their aggregation. We examine two novel members of the chaperone holdase family, RidA and CnoX, whose thiol-independent activation mechanism differs from that of Hsp33 and requires N-chlorination of positively charged amino acids during HOCl exposure. Furthermore, we summarize the latest findings with respect to another bacterial defense strategy employed in response to HOCl stress, which involves the accumulation of the universally conserved biopolymer inorganic polyphosphate. We then discuss sophisticated adaptive strategies that bacteria have developed to enhance their survival during HOCl stress. Understanding bacterial defense and survival strategies against one of the most powerful neutrophilic oxidants may provide novel insights into treatment options that potentially compromise the ability of pathogens to resist HOCl stress and therefore may increase the efficacy of the innate immune response.
Topics: Bacteria; Bacterial Infections; Bacterial Physiological Phenomena; Defense Mechanisms; Humans; Hypochlorous Acid; Microbial Viability; Molecular Chaperones; Neutrophils; Oxidants; Oxidation-Reduction; Oxidative Stress; Protein Binding; Respiratory Burst; Structure-Activity Relationship
PubMed: 32152198
DOI: 10.1128/IAI.00964-19 -
F1000Research 2019Hypochlorous acid (HOCl; bleach) is a powerful weapon used by our immune system to eliminate invading bacteria. Yet the way HOCl actually kills bacteria and how they... (Review)
Review
Hypochlorous acid (HOCl; bleach) is a powerful weapon used by our immune system to eliminate invading bacteria. Yet the way HOCl actually kills bacteria and how they defend themselves from its oxidative action have only started to be uncovered. As this molecule induces both protein oxidation and aggregation, bacteria need concerted efforts of chaperones and antioxidants to maintain proteostasis during stress. Recent advances in the field identified several stress-activated chaperones, like Hsp33, RidA, and CnoX, which display unique structural features and play a central role in protecting the bacterial proteome during HOCl stress.
Topics: Bacteria; Bacterial Infections; Bacterial Proteins; Humans; Hypochlorous Acid; Molecular Chaperones; Oxidants; Oxidation-Reduction; Proteolysis; Stress, Physiological
PubMed: 31583082
DOI: 10.12688/f1000research.19517.1 -
Minerva Medica Jun 2022Chronic inhalation of cigarette smoke is a prominent cause of chronic obstructive pulmonary disease (COPD) and provides an important source of exogenous oxidants. In...
Chronic inhalation of cigarette smoke is a prominent cause of chronic obstructive pulmonary disease (COPD) and provides an important source of exogenous oxidants. In addition, several inflammatory and structural cells are a source of endogenous oxidants in the lower airways of COPD patients, even in former smokers. This suggests that oxidants play a key role in the pathogenesis of COPD. This oxidative stress is counterbalanced by the protective effects of the various endogenous antioxidant defenses of the lower airways. A large amount of data from animal models and patients with COPD have shown that both the stable phase of the disease, and during exacerbations, have increased oxidative stress in the lower airways compared with age-matched smokers with normal lung function. Thus, counteracting the increased oxidative stress may produce clinical benefits in COPD patients. Smoking cessation is currently the most effective treatment of COPD patients and reduces oxidative stress in the lower airways. In addition, many drugs used to treat COPD have some antioxidant effects, however, it is still unclear if their clinical efficacy is related to pharmacological modulation of the oxidant/antioxidant balance. Several new antioxidant compounds are in development for the treatment of COPD.
Topics: Animals; Antioxidants; Humans; Oxidants; Oxidative Stress; Pulmonary Disease, Chronic Obstructive; Smokers
PubMed: 35142479
DOI: 10.23736/S0026-4806.22.07972-1 -
Molecules (Basel, Switzerland) Feb 2022Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) primarily formed by burning of fossil fuels, wood and other organic materials. BaP as group I carcinogen... (Review)
Review
Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) primarily formed by burning of fossil fuels, wood and other organic materials. BaP as group I carcinogen shows mutagenic and carcinogenic effects. One of the important mechanisms of action of (BaP) is its free radical activity, the effect of which is the induction of oxidative stress in cells. BaP induces oxidative stress through the production of reactive oxygen species (ROS), disturbances of the activity of antioxidant enzymes, and the reduction of the level of non-enzymatic antioxidants as well as of cytokine production. Chemical compounds, such as vitamin E, curcumin, quercetin, catechin, cyanidin, kuromanin, berberine, resveratrol, baicalein, myricetin, catechin hydrate, hesperetin, rhaponticin, as well as taurine, atorvastatin, diallyl sulfide, and those contained in green and white tea, lower the oxidative stress induced by BaP. They regulate the expression of genes involved in oxidative stress and inflammation, and therefore can reduce the level of ROS. These substances remove ROS and reduce the level of lipid and protein peroxidation, reduce formation of adducts with DNA, increase the level of enzymatic and non-enzymatic antioxidants and reduce the level of pro-inflammatory cytokines. BaP can undergo chemical modification in the living cells, which results in more reactive metabolites formation. Some of protective substances have the ability to reduce BaP metabolism, and in particular reduce the induction of cytochrome (CYP P450), which reduces the formation of oxidative metabolites, and therefore decreases ROS production. The aim of this review is to discuss the oxidative properties of BaP, and describe protective activities of selected chemicals against BaP activity based on of the latest publications.
Topics: Animals; Antioxidants; Benzo(a)pyrene; Biomarkers; Disease Susceptibility; Energy Metabolism; Gene Expression Regulation; Humans; Lipid Peroxidation; Molecular Structure; Oxidants; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species
PubMed: 35209168
DOI: 10.3390/molecules27041379 -
Molecular Metabolism Jan 2024Energy-intensive kidney reabsorption processes essential for normal whole-body function are maintained by tubular epithelial cell metabolism. Although tubular metabolism...
OBJECTIVE
Energy-intensive kidney reabsorption processes essential for normal whole-body function are maintained by tubular epithelial cell metabolism. Although tubular metabolism changes markedly following acute kidney injury (AKI), it remains unclear which metabolic alterations are beneficial or detrimental. By analyzing large-scale, publicly available datasets, we observed that AKI consistently leads to downregulation of the mitochondrial pyruvate carrier (MPC). This investigation aimed to understand the contribution of the tubular MPC to kidney function, metabolism, and acute injury severity.
METHODS
We generated tubular epithelial cell-specific Mpc1 knockout (MPC TubKO) mice and employed renal function tests, in vivo renal C-glucose tracing, mechanistic enzyme activity assays, and tests of injury and survival in an established rhabdomyolysis model of AKI.
RESULTS
MPC TubKO mice retained normal kidney function, displayed unchanged markers of kidney injury, but exhibited coordinately increased enzyme activities of the pentose phosphate pathway and the glutathione and thioredoxin oxidant defense systems. Following rhabdomyolysis-induced AKI, compared to WT control mice, MPC TubKO mice showed increased glycolysis, decreased kidney injury and oxidative stress markers, and strikingly increased survival.
CONCLUSIONS
Our findings suggest that decreased renal tubular mitochondrial pyruvate uptake hormetically upregulates oxidant defense systems before AKI and is a beneficial adaptive response after rhabdomyolysis-induced AKI. This raises the possibility of therapeutically modulating the MPC to attenuate AKI severity.
Topics: Mice; Animals; Monocarboxylic Acid Transporters; Acute Kidney Injury; Oxidation-Reduction; Rhabdomyolysis; Oxidants
PubMed: 38056691
DOI: 10.1016/j.molmet.2023.101849 -
Frontiers in Cellular and Infection... 2019The toxicity of oxygen and nitrogen reactive species appears to be merely the tip of the iceberg in the world of redox homeostasis. Now, oxidative stress can be seen as... (Review)
Review
The toxicity of oxygen and nitrogen reactive species appears to be merely the tip of the iceberg in the world of redox homeostasis. Now, oxidative stress can be seen as a two-sided process; at high concentrations, it causes damage to biomolecules, and thus, trypanosomes have evolved a strong antioxidant defense system to cope with these stressors. At low concentrations, oxidants are essential for cell signaling, and in fact, the oxidants/antioxidants balance may be able to trigger different cell fates. In this comprehensive review, we discuss the current knowledge of the oxidant environment experienced by along the different phases of its life cycle, and the molecular tools exploited by this pathogen to deal with oxidative stress, for better or worse. Further, we discuss the possible redox-regulated processes that could be governed by this oxidative context. Most of the current research has addressed the importance of the trypanosomes' antioxidant network based on its detox activity of harmful species; however, new efforts are necessary to highlight other functions of this network and the mechanisms underlying the fine regulation of the defense machinery, as this represents a master key to hinder crucial pathogen functions. Understanding the relevance of this balance keeper program in parasite biology will give us new perspectives to delineate improved treatment strategies.
Topics: Animals; Antioxidants; Antiparasitic Agents; Chagas Disease; Glutathione; Homeostasis; Humans; Insect Vectors; Nitrosative Stress; Oxidants; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species; Signal Transduction; Spermidine; Trypanosoma cruzi
PubMed: 31921709
DOI: 10.3389/fcimb.2019.00435 -
Turkish Journal of Medical Sciences Jun 2023Hepayocyte loss may develop secondary to liver surgery and at this point liver regeneration plays a significant act in terms of liver reserve. The purpose of this...
BACKGROUND
Hepayocyte loss may develop secondary to liver surgery and at this point liver regeneration plays a significant act in terms of liver reserve. The purpose of this research was to investigate the efficacy of apocynin on liver regeneration and preservation after partial hepatectomy in rats.
METHODS
A total of 32 rats, have been divided into 4 groups (n: 8) for hepatectomy model. Inflammatory and antiinflammatory parameters were measured from blood and liver tissue samples. In addition, the effects of apocynin were examined immunohistochemically and histopathologically from liver tissue.
RESULTS
In liver tissue samples, a significant difference has been found in glutathione peroxidase, total nitrite, catalase, oxidative stress index, total antioxidant and total oxidant status between sham and hepatectomy groups. A significant difference has been achieved between hepatectomy and posthepatectomy-Apocynin in terms of glutathione peroxidase and oxidative stress index. Total antioxidant status, oxidative stress index, and total oxidant status were significantly different only between the sham and the hepatectomy groups. Statistical differences were found between sham and hepatectomy groups and between hepatectomy and pre+post-hepatectomy-Apocynin groups in terms of serum glutathione, malondialdehyde, total nitrite, and L-Arginine. There were significant differences between the sham and hepatectomy groups, between hepatectomy and posthepatectomy-apocynin groups, between posthepatctomy-apocynin and pre+posthepatectomy-apocynin groups in terms of sinusoidal dilatation, intracytoplasmic vacuolization and glycogen loss (p < 0.001), in all histopathologic parameters except sinusoidal dilatation (p < 0.05). However, significant Ki-67 increases have been elaborated in hepatectomy, posthepatectomy-apocynin, and pre+posthepatectomy-apocynin groups compared to sham group (p < 0.001), in pre+posthepatectomy apocynin group compared to hepatectomy and posthepatectomy-apocynin groups (p < 0.001).
DISCUSSION
Histopathology, immunohistochemistry, and biochemistry results of this study revealed that apocynin has a protective effect on enhancing liver regeneration in partial hepatectomy cases in rats.
Topics: Rats; Animals; Hepatectomy; Liver Regeneration; Antioxidants; Nitrites; Liver; Oxidants; Glutathione Peroxidase
PubMed: 37476910
DOI: 10.55730/1300-0144.5627 -
Journal of Hazardous Materials Jun 2023Harmful algal blooms (HABs) in coastal areas similarly impact both ecosystems and human health. The translocation of phytoplankton species via maritime transport can... (Review)
Review
Harmful algal blooms (HABs) in coastal areas similarly impact both ecosystems and human health. The translocation of phytoplankton species via maritime transport can potentially promote the growth of HABs in coastal systems. Accordingly, ballast water must be disinfected. The main goal of this study is to assess the effectiveness of different emerging biocides, including HO, peracetic acid (PAA), peroxymonosulfate (PMS), and peroxydisulfate (PDS). The effectiveness of these biocides is compared with that of conventional chlorination methods. Their effects on two ichthyotoxic microalgae with worldwide distribution, i.e., Prymnesium parvum and Heterosigma akashiwo, are examined. To ensure the prolonged effectiveness of the different reagents, their concentration-response curves for 14 days are constructed and examined. The results suggest a strong but shorter effect by PMS (EC50 = 0.40-1.99 mg·L) and PAA (EC50 = 0.32-2.70 mg·L), a maintained effect by HO (EC50 = 6.67-7.08 mg·L), and a negligible effect by PDS. H. akashiwo indicates higher resistance than P. parvum, except when HO is used. Based on the growth inhibition performance and consumption of the reagents as well as a review of important aspects regarding their application, using HO, PAA, or PMS can be a feasible alternative to chlorine-based reagents for inhibiting the growth of harmful phytoplankton.
Topics: Humans; Phytoplankton; Oxidants; Hydrogen Peroxide; Herbicides; Ecosystem; Harmful Algal Bloom; Disinfectants
PubMed: 36989795
DOI: 10.1016/j.jhazmat.2023.131279 -
Molecules (Basel, Switzerland) Dec 2021Covalent crosslinks within or between proteins play a key role in determining the structure and function of proteins. Some of these are formed intentionally by either... (Review)
Review
Covalent crosslinks within or between proteins play a key role in determining the structure and function of proteins. Some of these are formed intentionally by either enzymatic or molecular reactions and are critical to normal physiological function. Others are generated as a consequence of exposure to oxidants (radicals, excited states or two-electron species) and other endogenous or external stimuli, or as a result of the actions of a number of enzymes (e.g., oxidases and peroxidases). Increasing evidence indicates that the accumulation of unwanted crosslinks, as is seen in ageing and multiple pathologies, has adverse effects on biological function. In this article, we review the spectrum of crosslinks, both reducible and non-reducible, currently known to be formed on proteins; the mechanisms of their formation; and experimental approaches to the detection, identification and characterization of these species.
Topics: Animals; Cross-Linking Reagents; Disulfides; Enzymes; Humans; Oxidants; Oxidation-Reduction; Oxidative Stress; Peptides; Protein Aggregates; Proteins; Tandem Mass Spectrometry; Tryptophan; Tyrosine
PubMed: 35011250
DOI: 10.3390/molecules27010015