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Critical Reviews in Toxicology Sep 2023The mechanisms of particle-induced pathogenesis in the lung remain poorly understood. Neutrophilic inflammation and oxidative stress in the lung are hallmarks of... (Review)
Review
A review of pulmonary neutrophilia and insights into the key role of neutrophils in particle-induced pathogenesis in the lung from animal studies of lunar dusts and other poorly soluble dust particles.
The mechanisms of particle-induced pathogenesis in the lung remain poorly understood. Neutrophilic inflammation and oxidative stress in the lung are hallmarks of toxicity. Some investigators have postulated that oxidative stress from particle surface reactive oxygen species (psROS) on the dust produces the toxicopathology in the lungs of dust-exposed animals. This postulate was tested concurrently with the studies to elucidate the toxicity of lunar dust (LD), which is believed to contain psROS due to high-speed micrometeoroid bombardment that fractured and pulverized lunar surface regolith. Results from studies of rats intratracheally instilled (ITI) with three LDs (prepared from an Apollo-14 lunar regolith), which differed 14-fold in levels of psROS, and two toxicity reference dusts (TiO and quartz) indicated that psROS had no significant contribution to the dusts' toxicity in the lung. Reported here are results of further investigations by the LD toxicity study team on the toxicological role of oxidants in alveolar neutrophils that were harvested from rats in the 5-dust ITI study and from rats that were exposed to airborne LD for 4 weeks. The oxidants per neutrophils and all neutrophils increased with dose, exposure time and dust's cytotoxicity. The results suggest that alveolar neutrophils play a critical role in particle-induced injury and toxicity in the lung of dust-exposed animals. Based on these results, we propose an adverse outcome pathway (AOP) for particle-associated lung disease that centers on the crucial role of alveolar neutrophil-derived oxidant species. A critical review of the toxicology literature on particle exposure and lung disease further supports a neutrophil-centric mechanism in the pathogenesis of lung disease and may explain previously reported animal species differences in responses to poorly soluble particles. Key findings from the toxicology literature indicate that (1) after exposures to the same dust at the same amount, rats have more alveolar neutrophils than hamsters; hamsters clear more particles from their lungs, consequently contributing to fewer neutrophils and less severe lung lesions; (2) rats exposed to nano-sized TiO have more neutrophils and more severe lesions in their lungs than rats exposed to the same mass-concentration of micron-sized TiO; nano-sized dust has a greater number of particles and a larger total particle-cell contact surface area than the same mass of micron-sized dust, which triggers more alveolar epithelial cells (AECs) to synthesize and release more cytokines that recruit a greater number of neutrophils leading to more severe lesions. Thus, we postulate that, during chronic dust exposure, particle-inflicted AECs persistently release cytokines, which recruit neutrophils and activate them to produce oxidants resulting in a prolonged continuous source of endogenous oxidative stress that leads to lung toxicity. This neutrophil-driven lung pathogenesis explains why dust exposure induces more severe lesions in rats than hamsters; why, on a mass-dose basis, nano-sized dusts are more toxic than the micron-sized dusts; why lung lesions progress with time; and why dose-response curves of particle toxicity exhibit a hockey stick like shape with a threshold. The neutrophil centric AOP for particle-induced lung disease has implications for risk assessment of human exposures to dust particles and environmental particulate matter.
Topics: Cricetinae; Rats; Humans; Animals; Dust; Neutrophils; Lung; Lung Diseases; Cytokines; Oxidants; Particle Size
PubMed: 37850621
DOI: 10.1080/10408444.2023.2258925 -
International Journal of Toxicology Aug 2024The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of Hydrogen Peroxide for use in cosmetics. This ingredient is reported to function in... (Review)
Review
The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of Hydrogen Peroxide for use in cosmetics. This ingredient is reported to function in cosmetics as an antimicrobial agent, cosmetic biocide, oral health care agent, and oxidizing agent. The Panel reviewed the data relevant to the safety of this ingredient and concluded that Hydrogen Peroxide is safe in cosmetics in the present practices of use and concentration described in this safety assessment.
Topics: Hydrogen Peroxide; Cosmetics; Humans; Consumer Product Safety; Animals; Risk Assessment; Toxicity Tests; Oxidants
PubMed: 38469819
DOI: 10.1177/10915818241237790 -
Chemosphere May 2024Azo dyes are largely used in many industries and discharged in large volumes of their effluents into the aquatic environment giving rise to non-esthetic pollution and... (Review)
Review
Azo dyes are largely used in many industries and discharged in large volumes of their effluents into the aquatic environment giving rise to non-esthetic pollution and health-risk problems. Due to the high stability of azo dyes in ambient conditions, they cannot be abated in conventional wastewater treatment plants. Over the last fifteen years, the decontamination of dyeing effluents by persulfate (PS)-based advanced oxidation processes (AOPs) has received a great attention. In these methods, PS is activated to be decomposed into sulfate radical anion (SO), which is further partially hydrolyzed to hydroxyl radical (OH). Superoxide ion (O) and singlet oxygen (O) can also be produced as oxidants. This review summarizes the results reported for the discoloration and mineralization of synthetic and real waters contaminated with azo dyes covering up to November 2023. PS activation with iron, non-iron transition metals, and carbonaceous materials catalysts, heat, UVC light, photocatalysis, photodegradation with iron, electrochemical and related processes, microwaves, ozonation, ultrasounds, and other processes is detailed and analyzed. The principles and characteristics of each method are explained with special attention to the operating variables, the different oxidizing species generated yielding radical and non-radical mechanisms, the addition of inorganic anions and natural organic matter, the aqueous matrix, and the by-products identified. Finally, the overall loss of toxicity or partial detoxification of treated azo dye solutions during the PS-based AOPs is discussed.
Topics: Azo Compounds; Water Pollutants, Chemical; Iron; Oxidation-Reduction; Oxidants; Water
PubMed: 38527631
DOI: 10.1016/j.chemosphere.2024.141766 -
Water Research Aug 2023For decades, red tide control has been recognized as necessary for mitigating financial damage to fish farms. Chemical disinfectants, frequently used for water...
For decades, red tide control has been recognized as necessary for mitigating financial damage to fish farms. Chemical disinfectants, frequently used for water disinfection, can reduce the risk of red tides on inland fish farms. This study systematically evaluated four different chemical disinfectants (ozone (O), permanganate (MnO), sodium hypochlorite (NaOCl), and hydrogen peroxide (HO)) for their potential use in inland fish farms to control red tides by investigating their (i) inactivation efficacy regarding C. polykrikoides, (ii) total residual oxidant and byproduct formation, and (iii) toxicity to fish. The inactivation efficacy of C. polykrikoides cells by chemical disinfectants from highest to lowest followed the order of O > MnO > NaOCl > HO for different cell density conditions and disinfectant doses. The O and NaOCl treatments generated bromate as an oxidation byproduct by reacting with bromide ions in seawater. The acute toxicity tests of the disinfectants for juvenile red sea bream (Pagrus major) showed that 72-h LC values were 1.35 (estimated), 0.39, 1.32, and 102.61 mg/L for O, MnO, NaOCl, and HO, respectively. Considering the inactivation efficacy, exposure time of residual oxidants, byproduct formation, and toxicity toward fish, HO is suggested as the most practical disinfectant for controlling red tides in inland fish farms.
Topics: Animals; Harmful Algal Bloom; Dinoflagellida; Disinfectants; Hydrogen Peroxide; Seawater; Oxidants; Fishes
PubMed: 37392510
DOI: 10.1016/j.watres.2023.120230 -
Clinical Oral Investigations May 2024This randomized controlled trial aimed to evaluate the equivalence in the color change, adverse effects, self-perception (AS) and the impact on oral condition (IO) of... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
This randomized controlled trial aimed to evaluate the equivalence in the color change, adverse effects, self-perception (AS) and the impact on oral condition (IO) of participants submitted to different application protocols of in-office dental bleaching.
MATERIALS AND METHODS
165 participants were bleached with a 35% hydrogen peroxide gel (Total Blanc Office One-Step, DFL), according to the following protocols: (1) 2 applications of 20-min each (2 × 20 min); (2) 1 × 40-min and; (3) 1 × 30-min. The color change was evaluated with the Vita Easyshade spectrophotometer, Vita Classical and Vita Bleachedguide scales. The intensity and risk of tooth sensitivity (TS) and gingival irritation (GI) were recorded using a 0-10 visual analogue scale (VAS). AS and IO was assessed before and after the bleaching procedure using the Orofacial Aesthetic Scale and Oral Health Impact Profile-14, respectively.
RESULTS
Equivalent color change were observed (p < 0.001), with no significant difference between groups. The group 2 × 20 min presented the highest risk of TS (76%, 95% CI 63 to 85), compared to the 1 × 30 min (p < 0.04). The intensity of TS and GI and the risk of GI was similar between groups (p > 0.31). Irrespectively of the group (p = 0.32), significant improvements were observed for all items of AS and IO after bleaching (p < 0.02).
CONCLUSIONS
The 1 × 30 min protocol produced equivalent color change to the other bleaching protocols with reduced risk of TS and shorter application time.
CLINICAL RELEVANCE
A more simplified application regimen of a single application of 30 min yields effective bleaching and patient satisfaction while minimizing undesirable side effects and improving patient satisfaction.
Topics: Humans; Tooth Bleaching; Female; Hydrogen Peroxide; Tooth Bleaching Agents; Male; Adult; Single-Blind Method; Dentin Sensitivity; Spectrophotometry; Treatment Outcome; Middle Aged; Esthetics, Dental; Adolescent
PubMed: 38700548
DOI: 10.1007/s00784-024-05697-0 -
Environmental Science and Pollution... Sep 2023Arsenite is both more harmful and challenging to get out of water than arsenate. For enhanced As (III) removal, a ternary oxide nanoparticle (FCCTO) mainly composed of...
Arsenite is both more harmful and challenging to get out of water than arsenate. For enhanced As (III) removal, a ternary oxide nanoparticle (FCCTO) mainly composed of iron(Fe), with a small proportion of cerium(Ce) and copper(Cu) was created using a coprecipitation-calcination process. FCCTO was found to be effective in removing As (III) from water, with factors such as adsorbent dose, pH, temperature, and coexisting anions influencing its efficiency. The surface area of FCCTO reached 180.2 m/g and the doping significantly increased its pore volume and diameter. The adsorption process on FCCTO was endothermic and spontaneous. Ce and Cu in FCCTO were able to efficiently oxidize 81.3% As (III) to As(V). Abundant sites were provided by surface hydroxyl groups for arsenic adsorption. The maximal As(III) adsorption capacity of this adsorbent under the synergistic impact of oxidation and adsorption was 101.5 mg/g. After five cycles, the FCCTO's As(III) adsorption rate dropped to 60% as a result of tetravalent Ce consumption. Surface complexation, redox, and adsorption all had a significant impact on the adsorption process. Overall, FCCTO was an excellent adsorbent with benefits of being facile fabrication, environmentally, recyclable, and having a high As(III) adsorption capacity.
Topics: Oxides; Arsenites; Water Pollutants, Chemical; Water; Arsenic; Nanoparticles; Water Purification; Adsorption; Hydrogen-Ion Concentration
PubMed: 37552441
DOI: 10.1007/s11356-023-29082-8 -
Archives of Physiology and Biochemistry Jun 2024Diabetes in humans a chronic metabolic disorder characterised by hyperglycaemia, it is associated with an increased risk of cardiovascular disease, disruptions to... (Review)
Review
Diabetes in humans a chronic metabolic disorder characterised by hyperglycaemia, it is associated with an increased risk of cardiovascular disease, disruptions to metabolism and vascular functions. It is also linked to oxidative stress and its complications. Its role in vascular dysfunctions is generally reported without detailed impact on the molecular mechanisms. Potassium ion channel (K channels) are key regulators of vascular tone, and as membrane proteins, are modifiable by oxidant stress associated with diabetes. This review manuscript examined the impact of oxidant stress on vascular K channel functions in diabetes, its implication in vascular complications and metabolic and cardiovascular diseases.
Topics: Humans; Oxidative Stress; Potassium Channels; Diabetic Angiopathies; Animals; Oxidants
PubMed: 35757993
DOI: 10.1080/13813455.2022.2090578 -
Proceedings of the National Academy of... Mar 2024Apical cilia on epithelial cells defend the lung by propelling pathogens and particulates out of the respiratory airways. Ciliated cells produce ATP that powers cilia...
Apical cilia on epithelial cells defend the lung by propelling pathogens and particulates out of the respiratory airways. Ciliated cells produce ATP that powers cilia beating by densely grouping mitochondria just beneath the apical membrane. However, this efficient localization comes at a cost because electrons leaked during oxidative phosphorylation react with molecular oxygen to form superoxide, and thus, the cluster of mitochondria creates a hotspot for oxidant production. The relatively high oxygen concentration overlying airway epithelia further intensifies the risk of generating superoxide. Thus, airway ciliated cells face a unique challenge of producing harmful levels of oxidants. However, surprisingly, highly ciliated epithelia produce less reactive oxygen species (ROS) than epithelia with few ciliated cells. Compared to other airway cell types, ciliated cells express high levels of mitochondrial uncoupling proteins, UCP2 and UCP5. These proteins decrease mitochondrial protonmotive force and thereby reduce production of ROS. As a result, lipid peroxidation, a marker of oxidant injury, decreases. However, mitochondrial uncoupling proteins exact a price for decreasing oxidant production; they decrease the fraction of mitochondrial respiration that generates ATP. These findings indicate that ciliated cells sacrifice mitochondrial efficiency in exchange for safety from damaging oxidation. Employing uncoupling proteins to prevent oxidant production, instead of relying solely on antioxidants to decrease postproduction oxidant levels, may offer an advantage for targeting a local area of intense ROS generation.
Topics: Humans; Reactive Oxygen Species; Mitochondrial Uncoupling Proteins; Superoxides; Ion Channels; Oxidative Stress; Adenosine Triphosphate; Epithelial Cells; Oxidants; Oxygen; Mitochondrial Proteins
PubMed: 38416686
DOI: 10.1073/pnas.2318771121 -
Science China. Life Sciences Aug 2023
Topics: Oxidants; Oxidation-Reduction; Antioxidants; Oxidative Stress
PubMed: 37296347
DOI: 10.1007/s11427-023-2336-1 -
Advanced Healthcare Materials Apr 2024Drug-induced liver injury (DILI) is a severe condition characterized by impaired liver function and the excessive activation of ferroptosis. Unfortunately, there are...
Drug-induced liver injury (DILI) is a severe condition characterized by impaired liver function and the excessive activation of ferroptosis. Unfortunately, there are limited options currently available for preventing or treating DILI. In this study, MnO nanoflowers (MnONfs) with remarkable capabilities of mimicking essential antioxidant enzymes, including catalase, superoxide dismutase (SOD), and glutathione peroxidase are successfully synthesized, and SOD is the dominant enzyme among them by density functional theory. Notably, MnONfs demonstrate high efficiency in effectively eliminating diverse reactive oxygen species (ROS) such as hydrogen peroxide (HO), superoxide anion (O ), and hydroxyl radical (•OH). Through in vitro experiments, it is demonstrated that MnONfs significantly enhance the recovery of intracellular glutathione content, acting as a potent inhibitor of ferroptosis even in the presence of ferroptosis activators. Moreover, MnONfs exhibit excellent liver accumulation properties, providing robust protection against oxidative damage. Specifically, they attenuate acetaminophen-induced ferroptosis by inhibiting ferritinophagy and activating the P62-NRF2-GPX4 antioxidation signaling pathways. These findings highlight the remarkable ROS scavenging ability of MnONfs and hold great promise as an innovative and potential clinical therapy for DILI and other ROS-related liver diseases.
Topics: Manganese Compounds; Ferroptosis; Oxides; Animals; Chemical and Drug Induced Liver Injury; Mice; Reactive Oxygen Species; Oxidation-Reduction; Humans; Male; Acetaminophen; Liver; Antioxidants; Superoxide Dismutase; Catalase; Hydrogen Peroxide; Mice, Inbred C57BL
PubMed: 38238011
DOI: 10.1002/adhm.202302556