Search Results (140)

This study establishes a murine model of corticosteroid-associated osteonecrosis of the femoral head (ONFH) using a sustained-release prednisolone pellet and evaluates mitochondrial stress using ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and changes in key histologic markers of bone over a 6-week period. Sixteen 12-week-old Balb/C mice were divided into two groups: a prednisolone group (PRED) and a control group (SHAM). The PRED group received a subcutaneous 60-day sustained-release pellet containing 2.5 mg of prednisolone, while the SHAM group received placebo pellets. PET/CT imaging was performed at 1, 3, and 6 weeks. Bone mineral density (BMD) measurements, and histomorphological analyses for the number of empty lacunae, osteoblasts, osteoclasts, and NADPH oxidase (NOX) 2, a marker for oxidative stress, were conducted at 4 or 6 weeks. PET/CT imaging demonstrated increased uptake in the femoral head at 3 weeks in the PRED group. This was accompanied by increased numbers of empty lacunae and osteoclasts, increased oxidative stress, and decreased alkaline phosphatase staining at 4 weeks in the PRED group. We have successfully established and validated a small murine model of ONFH. The findings of this preclinical study suggest a critical timeline for potential interventions to mitigate the early adverse effects of continuous corticosteroid exposure on bone. Full article

Oxidative stress is a key driver of chronic inflammatory diseases. Anodendron affine is a native Formosan plant species in Taiwan that remains largely underexplored phytochemically and bioactivity. To reveal the bioactive constituents and assess its potential as a source of anti-inflammatory antioxidants, we performed bioactivity-guided fractionation and evaluated the inhibition of superoxide anion (O₂^•−) generation in formyl-L-methionyl-L-leucyl-L-phenylalanine-stimulated human neutrophils. Molecular docking simulations were employed to model interactions with Formyl peptide receptor 1 (FPR1) and the Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex, including neutrophil cytosol factor 1 (p47phox) and NADPH oxidase 2 (NOX2), to propose a theoretical mechanism of action. Phytochemical investigation led to the isolation of two new compounds, methyl 4,5-O-diferuloyl-3-methoxyquinate (1) and 16-pregnen-3,12,20-trione (2), together with four known compounds. Notably, 4-hydroxy-3-prenylbenzoic acid (5) exhibited potent inhibitory activity (IC₅₀ = 17.65 ± 0.97 μM), surpassing the activity of the positive control, ibuprofen (IC₅₀ = 27.85 ± 3.56 μM). Docking studies suggested that anodendrosin H (4) and 4-hydroxy-3-prenylbenzoic acid (5) exhibit high predicted binding affinity to p47phox and NOX2. Based on these results, compounds 1, 4, and 5 from A. affine were identified as potential lead candidates for the development of novel anti-inflammatory therapeutics. Full article

Skeletal muscle atrophy underlies sarcopenia, frailty, and muscular dystrophies, but the molecular mechanisms linking oxidative stress to muscle degeneration remain incompletely understood. We previously identified protein complex formation between transient receptor potential canonical 3 (TRPC3) and NADPH oxidase 2 (Nox2) as a key driver of anthracycline-induced myocardial atrophy. Here, we investigated whether this complex also contributes to skeletal muscle wasting. In skeletal muscle from sciatic nerve transection model mice and Duchenne muscular dystrophy (mdx) mice, TRPC3-Nox2 complex formation was enhanced. TRPC3 deletion significantly attenuated denervation-induced soleus atrophy and reduced reactive oxygen species (ROS) production. TRPC3-Nox2 complex formation was upregulated in the soleus muscle (SM) of mdx mice. Pharmacological disruption of the TRPC3-Nox2 interaction improved muscle size and strength and reduced plasma creatine kinase in mdx mice. A recombinant adeno-associated virus (AAV) encoding a TRPC3 C-terminal peptide was used to suppress TRPC3-Nox2 complex formation in vivo. AAV-mediated expression of TRPC3 C-terminal peptide mitigated muscle wasting (CSA) in mdx mice, while muscle strength and plasma CK were not significantly improved. Thus, TRPC3-Nox2 complex formation may be a pivotal driver of oxidative stress-mediated skeletal muscle atrophy. Targeting this protein–protein interaction represents a promising therapeutic strategy for Duchenne muscular dystrophy (DMD) and other intractable muscle-wasting disorders. Full article

Colorectal cancer (CRC) incidence is a significant cancer globally, and radiotherapy resistance is a serious problem. Cucurbitacin D (CBD), extracted from many plants such as the tubers of Trichosanthes kirilowii and the fruits of Ecballium elaterium (squirting cucumber), has various therapeutic effects, such as anti-cancer, -inflammation, -diabetes, and -viral infection effects. Since reports have indicated that CBD exhibits effective anti-cancer activity across various cancer types, our hypothesis is that CBD will overcome radioresistance in CRC radiotherapy. In the present study, we identified that CBD, a triterpenoid compound isolated from Trichosanthes kirilowii and Ecballium elaterium, has an anti-cancer and anti-inflammatory effect in vivo and in vitro. In LPS-induced murine models, CBD suppresses LPS-mediated cytokines, including TNFα, IL-6, IL-1β, and COX-2. In CRC xenograft mouse models, CBD treatment results in significantly smaller tumor volumes than the control. In HCT116 and HT29 cells, CBD treatment suppresses cell viability and increases LDH cytotoxicity and caspase-3 activity and cleavage. However, combined treatment of CBD and Z-VAD-FMK inhibits caspase-dependent apoptosis and cell death. Since CBD induces intracellular calcium (Ca²⁺) and reactive oxygen species (ROS) generation, it mediates ER stress-induced apoptotic cell death through the PERK-ATF4-CHOP axis. Moreover, ER stress inducer thapsigargin (TG) mediates synergistic apoptotic cell death in CBD-treated HCT116 and HT29 cells. However, PERK or CHOP knockdown suppresses ER stress-mediated apoptosis in CBD-treated HCT116 and HT29 cells. CBD treatment induces oxidative stress through the NADPH Oxidase 4 (NOX4) and also increases ROS generation. However, NOX4 knockdown and ROS inhibitor NAC or DPI block ER stress-induced apoptotic cell death by inhibiting the suppression of cell viability and the elevation of caspase-3 activity, LDH cytotoxicity, and intracellular ROS activity in CBD-mediated HCT116 and HT29 cells. We established radioresistant CRC models (HCT116R and HT29R); subsequently, radiation (2 Gy) in combination with CBD treatment overcame radioresistance via the modulation of the epithelial–mesenchymal transition (EMT) phenomenon, including the increase in N-cadherin and vimentin and the reduction in E-cadherin. Thus, these results show that CBD may be a new powerful therapeutic approach for CRC radiotherapy. Full article

Objective: Although the etiologies and pathogenesis of common hearing disorders—noise-induced hearing loss (NIHL), age-related hearing loss (ARHL), and idiopathic sudden sensorineural hearing loss (ISSNHL)—are diverse, accumulating evidence indicates that reactive oxygen species (ROS) contribute to hearing loss and that antioxidants may help prevent or treat it. We conducted a literature review to examine the relationship between hearing loss and ROS/free radicals in both humans and animal models. Methods: We performed a comprehensive literature search of PubMed/MEDLINE, Embase, the Cochrane Library, Scopus, and Google Scholar to evaluate the induction and role of ROS in the development and treatment of hearing loss. Results: We synthesized evidence across NIHL, ARHL, and ISSNHL. Factors and reactive species implicated in hearing loss included cytomegalovirus infection, genetic polymorphisms, NADPH oxidase 4 (NOX4), NOX transgenic models (NOX-Tg), lipid hydroperoxides (LOOH), and malondialdehyde (MDA). Antioxidant strategies examined for prevention or treatment included vitamins A, C, and E with magnesium; rebamipide; α-lipoic acid; LLY-283; edaravone; melatonin; glutathione peroxidase; superoxide dismutase; glucose; hydrogen-saturated saline; activation of nuclear factor erythroid 2-related factor 2 (Nrf2); inhaled hydrogen gas; and caffeic acid. Conclusions: Elevated ROS and free radicals appear to contribute to the pathogenesis of hearing loss. Although definitive conclusions cannot yet be drawn, current evidence suggests that antioxidant approaches may aid in prevention and treatment. Further studies are needed to elucidate underlying mechanisms, refine therapeutic targets and dosing, and validate efficacy in rigorously designed clinical trials. Full article

Neuroinflammation and oxidative stress are key drivers of various ocular diseases. Experimental hypoxia, modeled using cobalt chloride (CoCl₂), induces hypoxia-inducible factor 1-alpha (HIF-1α) stabilization, mitochondrial dysfunction, and excessive reactive oxygen species (ROS) production, primarily via the NADPH oxidase 2 (Nox2)–voltage-gated proton channel Hv1 axis. Although Botulinum neurotoxin type A (BoNT/A) is classically recognized for SNAP-25 cleavage, recent studies suggest broader anti-inflammatory and neuroprotective effects. We evaluated BoNT/A in R28 retinal precursor cells and ex vivo retinal explants subjected to CoCl₂-induced hypoxic stress. BoNT/A pretreatment attenuated CoCl₂-induced upregulation of HIF-1α, Hv1, Nox2, NOD-like receptor protein 3 (NLRP3), COX2, and nuclear factor kappa B (NF-κB), while enhancing protective mediators including suppressor of cytokine signaling 3 (SOCS3), Growth Associated Protein 43 (Gap43), and Syntaxin12. Brn3a expression and retinal architecture were preserved, apoptotic cell death reduced, and glial activation suppressed. Moreover, BoNT/A decreased mitochondrial ROS accumulation, restored voltage-dependent anion channel 1 (VDAC1) distribution, and partially stabilized intracellular pH. These findings indicate that BoNT/A mitigates oxidative stress and inflammation in hypoxia-driven retinal injury, at least in part, via modulation of the Nox2–Hv1–ROS axis, and support its potential as a therapeutic candidate for ocular disorders associated with hypoxia and neuroinflammation. Full article

Background: Exposure to tobacco smoke, from conventional tobacco cigarettes (CTC) or heated tobacco products (HTPs), increases oxidative stress, causing endothelial dysfunction and higher cardiovascular risk. It is unclear whether smoke exposure also promotes low-grade endotoxemia, potentially activating NADPH oxidase and further impairing endothelial function. This study assessed serum lipopolysaccharide (LPS) levels in children and adults actively or passively exposed to conventional cigarette smoke or HTPs, compared with non-exposed controls. Methods: We conducted a cross-sectional study comprising 26 children passively exposed to HTPs, 26 children exposed to CTC, and 26 unexposed controls, as well as 20 adult chronic HTP users, 20 chronic CTC, and 20 non-smoking adults. Circulating LPS was measured alongside oxidative stress markers (NOX2, H₂O₂), endothelial function, intestinal permeability (zonulin), and nicotine exposure (serum cotinine). Results: Exposed children had higher cotinine, LPS, and zonulin than controls, with no differences between HTP and CTC groups. Multiple linear regression analysis identified cotinine (β = 0.343; p = 0.005) and zonulin (β = 0.441; p < 0.001) as independent LPS predictors. In adults, LPS and zonulin were higher in both smoker groups versus controls; zonulin (β = 0.477; p < 0.001) and nitric oxide bioavailability (β = −0.307; p = 0.007) independently predicted LPS. Conclusions: Passive and active exposure to CTC or HTPs increases low-grade endotoxemia and zonulin, potentially driving NOX2-mediated oxidative stress. Full article

Background/Objectives: The Eustachian tube (ET) is a physiological channel connecting the middle ear with the external atmosphere. The ET plays a role in maintaining the pressure balance of the middle ear, protecting it from pathogen invasion, and cleaning secretions. Eustachian tube dysfunction (ETD) can lead to middle ear diseases in animals. The ET morphological structure are different across species. Therefore, we aim to compare the anatomical and morphological of ET across species. Methods: The combined skull base–nasal approach was used to anatomy ET. Hematoxylin-eosin, luxol fast blue myelin and immunohistochemical Staining were used to observe the morphology of ET. Results: There were significant differences in the size and structure of ET among species: the rodents ET (mouse: 1.152 ± 0.084 mm; rat: 3.738 ± 0.04355 mm) is characterized by cartilage and obvious bubbles; while the miniature pigs ET (32.34 ± 2.157 mm) has a chondroid conical structure similar to that of humans. ET inflammation model was built by intro-tympanic injection of lipopolysaccharide (LPS). NADPH oxidase 2 (NOX2) significantly increased by 38.6% in inflamed mice, causing ET oxidative stress. The expressions of inflammatory factors interleukin-1β (IL-1β) and cyclooxygenase-2 (COX2) increased by 28.4% and 30.8%, resulting in thickening of the ET mucosa and infiltration of inflammatory cells. Conclusions: The combined skull base–nasal approach was an effective method to anatomy ET across species. The morphology of ET varied across species and NOX2 might play an important role in ET inflammation. Full article

In recent decades, chemotherapy has significantly improved cancer survival, yet its adverse effects on non-cancerous tissues raise increasing concerns. In this context, growing attention has been focused on natural compounds that may be useful in mitigating the undesirable effects of chemotherapeutic agents. Here, we aimed to demonstrate that Cytosporone B (CsnB) is a potent agent for counteracting the cardiovascular effects induced by Imatinib. To this end, 12-week-old male Wistar rats were studied; they were divided into three groups as follows: (1) control, (2) Imatinib-treated (Imatinib: 60 mg/kg/day, per os), (3) Imatinib + CsnB-treated (CsnB: 5 mg/kg/day, i.p.). After the two-week-long experimental period, rats were euthanized. Their hearts were used for the following biochemical measurements: NADPH oxidase (NOX4), high mobility group box 1 (HMGB1), peptidylarginine deiminase 4 (PAD4), inducible nitric oxide synthase (iNOS) expression, tumor necrosis factor-alpha (TNF-α) level, and myeloperoxidase (MPO) activity. Imatinib caused a marked upregulation of key inflammatory and oxidative markers, including HMGB1, TNF-α, MPO, iNOS, PAD4, and NOX4 in cardiac tissue; however, CsnB treatment mitigated these elevations, implying its role in opposing Imatinib-induced inflammatory and oxidative processes in the heart. Our findings suggest that CsnB holds promise as a cardioprotective agent capable of modulating Imatinib-induced adverse cardiac effects. Full article

While Moringa oleifera Lam. (MO) extracts are known to have various bioactive properties, including anti-inflammatory properties, the components responsible still remain to be identified. This study explores the protective effects of the MO component, 7-octenoic acid (7OCT) in LPS-stimulated THP-1 macrophage inflammatory responses. The compound significantly downregulated the production of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6, as well as the expression of inflammation-related genes NFKB1, PTGS2, and NOS2. Additionally, it inhibited the nuclear translocation of NF-κB p65, a key transcription factor of inflammatory signaling cascade. Effects on oxidative stress showed that 7OCT inhibited LPS-induced NADPH oxidase 2 (NOX2) component genes including CYBB, CYBA, NCF1, NCF2, and NFE2L2, along with phosphorylated NOX2 and p47^phox proteins. The compound reduced the expression of TP53, BAX, CASP3, and CASP7, while enhancing BCL2 expression and Bcl-2 protein levels, suggesting an effect on apoptosis. Decreased levels of BAX, caspase-3, and cleaved caspase-3 proteins further confirmed its anti-apoptotic effect. Our findings suggest that 7OCT exhibits strong anti-inflammatory, antioxidant, and anti-apoptotic properties. Full article

The relationship between periodontitis and cardiovascular diseases (CVDs) extends beyond epidemiological associations, as demonstrated by meta-analyses showing a significantly increased risk for coronary heart disease development. At the core of this association lies systemic inflammation, where periodontal pathogens initiate cascades of pro-inflammatory cytokines. This inflammatory response manifests through substantial elevations in interleukin-1 beta (IL-1β), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in periodontitis patients. Oxidative stress plays a crucial role, with Nicotinamide Adenine Dinucleotide Phosphate (NADPH) Oxidase 2 (NOX2) activation leading to markedly increased superoxide production compared to healthy controls. The peroxynitrite formed via NO–superoxide interaction accumulates in affected vascular tissues, substantially reducing nitric oxide (NO) bioavailability. Molecular mimicry mechanisms are evidenced by P. gingivalis heat shock protein sharing significant sequence homology with human HSP60, triggering autoimmune responses that affect cardiovascular tissues. Epigenetic modifications show specific alterations, with Nrf2 target gene expression substantially downregulated in chronic periodontal inflammation, particularly affecting heme oxygenase-1 (HO-1) and NAD(P)H:Quinone Oxidoreductase 1 (NQO1) expression. These molecular pathways create a complex network of interactions that fundamentally link periodontal and cardiovascular pathologies. Full article

Nanoceria is a multifaceted enzyme-like catalyst of ROS-mediated (reactive oxygen species) reactions, which results in its multiple biomedical applications. Biodegradable polysaccharide coatings improve biocompatibility, while the effects of these coatings on the ROS-related activity of nanoceria in cells need thorough studies. Here, we used human embryonic lung fibroblasts to study the effects of maltodextrin and chitosan coatings on cellular oxidative metabolism of nanoceria by examining cell viability, mitochondrial potential, accumulation of nanoparticles in cells, intracellular ROS, expression of NOX4 (NADPH oxidase 4), NRF2 (nuclear factor erythroid 2-related factor 2), NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), and STAT3 (signal transducer and activator of transcription 3) proteins as well as the expression of biomarkers of DNA damage/repair, cell proliferation, and autophagy. Both types of polysaccharide-coated nanoceria were non-toxic up to millimolar concentrations. For maltodextrin-coated nano-CeO₂, in contrast to bare nanoparticles, there was no oxidative DNA damage/repair with moderate activation of NOX4 expression. Like bare nanoceria, maltodextrin-coated nanoparticles demonstrate the proliferative impact and do not activate autophagy. However, maltodextrin-coated nanoparticles have an activating impact on mitochondrial potential and the NF-κB pathway. Chitosan-coated nanoceria causes short-term intracellular oxidative stress, activation of the expression of NOX4, STAT3, and NRF2, oxidative DNA damage, and double-strand breaks accompanied by activation of DNA repair systems. In contrast to maltodextrin-coated nanoparticles, chitosan-coated nanoceria inhibits the NF-κB pathway and activates autophagy. These findings would be useful in the development of advanced nanoceria-based pharmaceuticals and contribute to the understanding of the biochemical properties of nanoceria as a modulator of ROS-dependent signaling pathways. Full article

Alzheimer’s disease (AD) is associated with an abnormal accumulation of amyloid β (Aβ) fibrils in the brain parenchyma and cerebrovasculature, which leads to cognitive impairment and cerebrovascular dysfunction. Cerebrovascular endothelial cells play a crucial role in regulating cerebral blood flow, vascular permeability, and neurovascular function. Reactive oxygen species (ROS), particularly those generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), contribute to vascular dysfunction and amyloid deposition in the Alzheimer’s disease (AD) brain. However, the role of the NOX4 isoform in AD pathogenesis remains to be examined. In the present study, we found that NOX4 among the NOX isoforms is predominantly expressed in bEnd.3 mouse brain endothelial cells. Treatment with Aβ₄₀ significantly enhanced the release of H₂O₂ and NO, and increased the endothelial cell viability. To test the involvement of NOX4 in Aβ₄₀-induced H₂O₂ production, we utilized pharmacological inhibitors of NOX isoforms. Aβ₄₀-induced H₂O₂ production was attenuated in the presence of the pan-NOX inhibitor, apocynin, or the NOX1/4-selective inhibitors, setanaxib and GKT136901. Since only the NOX4 isoform is expressed in bEnd.3 cells, these results indicate that NOX4 is responsible for the release of H₂O₂ stimulated by Aβ₄₀. Taken together, the present study demonstrated that Aβ₄₀ peptide exerts beneficial effects in bEnd.3 endothelial cells via the NOX4-dependent mechanism. Full article

The NADPH oxidase 2 (NOX2) complex is a critical regulator of immune homeostasis. It is utilized by phagocytic leukocytes including neutrophils, monocytes, and macrophages to generate reactive oxygen species (ROS) that drive microbe clearance and modulate inflammatory responses. Within NOX2, the essential scaffold protein p47phox plays a pivotal role in orchestrating enzyme activation and facilitating the assembly and membrane translocation of cytosolic components of the complex. Tight regulation of p47phox activity is crucial, and its disruption is linked to a number of pathological conditions. Conversely, its hyperactivity contributes to oxidative stress, tissue damage, the progression of cardiovascular diseases, neurodegenerative disorders, inflammatory conditions, metabolic syndromes, and cancer. In this review, we detail the structural and functional roles of p47phox, mechanisms of its regulation, and its multifaceted contributions to disease pathogenesis. We explore the latest advances in p47phox-targeted therapeutic strategies, discuss current challenges in the field, highlight p47phox’s potential as a transformative target in redox biology and propose future directions to unlock its clinical utility. Full article

Inorganic arsenic [As(III) and As(V)] is a pervasive environmental contaminant in groundwater systems, early-life exposure to which is associated with an impaired cognitive ability and an increased risk of neurobehavioral disorders. Although the effect of As(III) on the neurons is well studied, the involvement of the microglia remains unclear. In this study, the effects of sodium arsenite (NaAsO₂) on microglial activation and the underlying NLRP3 inflammasome mechanism were determined. Pregnant rats were gavaged with NaAsO₂ (0, 1, 4, and 10 mg/kg body weight), which dissociates in aqueous solutions into bioactive arsenite species [As(OH)₃], from gestational day 1 (GD1) to postnatal day 21 (PND21). The results showed that As(III) induces learning and memory impairments and microglial activation in the hippocampus of offspring rats (PND21). Increased expression of NLRP3, the activation of caspase-1, and the production of interleukin-1β were observed in both the hippocampus of As(III)-exposed offspring rats and As(III)-exposed microglial BV2 cells under culture conditions. Interestingly, blocking the NLRP3 inflammasome using MCC950 mitigated its activation. Furthermore, inhibition of NADPH oxidase 2 (NOX2) using apocynin or specific siRNA significantly reduced As(III)-induced microglial NLRP3 inflammasome activation. In addition, inactivation of the microglial NLRP3 inflammasome or NOX2 markedly rescued As(III)-induced neurotoxicity in the hippocampal HT22 cells. Taken together, this study reveals that NOX2/NLRP3-inflammasome-dependent microglial activation promotes As(III)-induced learning and memory impairments in developmental rats. Full article