Inhibition Of Reactive Oxygen Species Generation Research Articles

Targeting lncRNA16 by GalNAc-siRNA conjugates facilitates chemotherapeutic sensibilization via the HBB/NDUFAF5/ROS pathway.

Chemoresistance is a significant barrier to effective cancer treatment. Potential mechanisms for chemoresistance include reactive oxygen species (ROS) accumulation and expression of chemoresistance-promoting genes. Here, we report a novel function of lncRNA16 in the inhibition of ROS generation and the progression of chemoresistance. By analyzing the serum levels of lncRNA16 in a cohort of 35 patients with non-small cell lung cancer (NSCLC) and paired serum samples pre- and post-treatment from 10 NSCLC patients receiving neoadjuvant platinum-based chemotherapy, performing immunohistochemistry (IHC) assays on 188 NSCLC tumor samples, using comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS) assays, as well as RNA immunoprecipitation (RIP) and RNA pull-down analyses, we discovered that patients with increased serum levels of lncRNA16 exhibited a poor response to platinum-based chemotherapy. The expression of hemoglobin subunit beta (HBB) and NDUFAF5 significantly increases with the development of chemoresistance. LncRNA16 binds to HBB and promotes HBB accumulation by inhibiting autophagy. LncRNA16 can also inhibit ROS generation via the HBB/NDUFAF5 axis and function as a scaffold to facilitate the colocalization of HBB and NDUFAF5 in the mitochondria. Importantly, preclinical studies in mouse models of chemo-resistant NSCLC have suggested that lncRNA16 targeting by trivalent N-acetylgalactosamine (GalNAc)-conjugated siRNA restores chemosensitivity and results in tumor growth inhibition with no detectable toxicity in vivo. Overall, lncRNA16 is a promising therapeutic target for overcoming chemoresistance, and the combination of first-line platinum-based chemotherapy with lncRNA16 intervention can substantially enhance anti-tumor efficacy.

The erythromycin polyketide compound TMC-154 stimulates ROS generation to exert antibacterial effects against Streptococcus pyogenes

The erythromycin polyketide compound TMC-154 is a secondary metabolite that is isolated from the rhizospheric fungus Clonostachys rogersoniana associated with Panax notoginseng, which possesses antibacterial activity. However, its antibacterial mechanism has not been investigated thus far. In this study, proteomics coupled with bioinformatics approaches was used to explore the antibacterial mechanism of TMC-154. KEGG pathway enrichment analysis indicated that eight signaling pathways were associated with TMC-154, including oxidative phosphorylation, cationic antimicrobial peptide (CAMP) resistance, benzoate degradation, heme acquisition systems, glycine/serine and threonine metabolism, beta-lactam resistance, ascorbate and aldarate metabolism, and phosphotransferase system (PTS). Cell biology experiments confirmed that TMC-154 could induce reactive oxygen species (ROS) generation in Streptococcus pyogenes; moreover, TMC-154-induced antibacterial effects could be blocked by the inhibition of ROS generation with the antioxidant N-acetyl L-cysteine. In addition, TMC-154 combined with ciprofloxacin or chloramphenicol had synergistic antibacterial effects. These findings indicate the potential of TMC-154 as a promising drug to treat S. pyogenes infections. SignificanceStreptococcus pyogenes is a nearly ubiquitous human pathogen that causes a variety of diseases ranging from mild pharyngitis and skin infection to fatal sepsis and toxic heat shock syndrome. With the increasing incidence of known antibiotic resistance, there is an urgent need to find novel drugs with good antibacterial activity against S. pyogenes. In this study, we found that TMC-154, a secondary metabolite from the fungus Clonostachys rogersoniana, inhibited the growth of various bacteria, including Staphylococcus aureus, S. pyogenes, Streptococcus mutans, Pseudomonas aeruginosa and Vibrio parahemolyticus. Proteomic analysis combined with cell biology experiments revealed that TMC-154 stimulated ROS generation to exert antibacterial effects against S. pyogenes. This study provides potential options for the treatment of S. pyogenes infections in the future.

Carpesii fructus extract exhibits neuroprotective effects in cellular and Caenorhabditis elegans models of Parkinson's disease.

Parkinson's disease (PD) is a debilitating neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Despite extensive research, no definitive cure or effective disease-modifying treatment for PD exists to date. Therefore, the identification of novel therapeutic agents with neuroprotective properties is of utmost importance. Here, we aimed to investigate the potential neuroprotective effects of Carpesii fructus extract (CFE) in both cellular and Caenorhabditis elegans (C. elegans) models of PD. The neuroprotective effect of CFE in H2O2- or 6-OHDA-induced PC-12 cells and α-synuclein-overexpressing PC-12 cells were investigated by determining the cell viability, mitochondrial damage, reactive oxygen species (ROS) production, apoptosis, and α-synuclein expression. In NL5901, BZ555, and N2 worms, the expression of α-synuclein, motive ability, the viability of dopaminergic neurons, lifespan, and aging-related phenotypes were investigated. The signaling pathway was detected by Western blotting and validated by employing small inhibitors and RNAi bacteria. In cellular models of PD, CFE significantly attenuated H2O2- or 6-OHDA-induced toxicity, as evidenced by increased cell viability and reduced apoptosis rate. In addition, CFE treatment suppressed ROS generation and restored mitochondrial membrane potential, highlighting its potential as a mitochondrial protective agent. Furthermore, CFE reduced the expression of α-synuclein in wide type (WT)-, A53T-, A30P-, or E46K-α-synuclein-overexpressing PC-12 cells. Our further findings reveal that CFE administration reduced α-synuclein expression and improved its induced locomotor deficits in NL5901 worms, protected dopaminergic neurons against 6-OHDA-induced degeneration in BZ555 worms, extended lifespan, delayed aging-related phenotypes, and enhanced the ability of stress resistance in N2 worms. Mechanistic studies suggest that the neuroprotective effects of CFE may involve the modulation of the MAPK signaling pathway, including ERK, JNK, and p38, whereas the interference of these pathways attenuated the neuroprotective effect of CFE invitro and invivo. Overall, our study highlights the potential therapeutic value of CFE as a neuroprotective agent in the context of PD. Furthermore, elucidation of the active compounds of CFE will provide valuable insights for the development of novel therapeutic strategies for PD.

Protective Effect of Mycosporine-like Amino Acids Isolated from an Antarctic Diatom on UVB-Induced Skin Damage.

Although it is well recognized that mycosporine-like amino acids (MAAs) are ultraviolet (UV) protective agents that can reduce UV damage, the specific biological mechanism of its role in the skin remains unclear. In this study, we investigated the effect of MAAs extracted from Antarctic diatom Phaeodactylum tricornutum ICE-H on UVB-induced skin damage using a mice model. The MAAs components identified by liquid chromatography-tandem mass spectrometry included 4-deoxygadusol, shinorine, and porphyra-334, which were purified using a Supledean Carboxen1000 solid phase extraction column. The antioxidant activities of these MAA compounds were tested in vitro. For UVB-induced skin photodamage in mice, MAAs alleviated skin swelling and epidermal thickening in this study. We detected the content of reactive oxygen species (ROS), malondialdehyde, and collagen in skin tissue. In addition, quantitative real-time polymerase chain reaction was used to detect nuclear factor-κB (NF-κB), tumor necrosis factor α, interleukin-1β, cyclooxygenase-2, mitogen activated protein kinase (MAPK) family (extracellular signal-regulated kinase, c-Jun amino-terminal kinase, and p38 kinase), and matrix metalloproteinases. The expression of these cytokines and enzymes is related to inflammatory responses and collagen degradation. In comparison to the model group without MAA treatment, the MAA component decreased the concentration of ROS, the degree of oxidative stress in the skin tissue, and the expression of genes involved in the NF-κB and MAPK pathways. In summary, these MAA components extracted from Phaeodactylum tricornutum ICE-H protected against UVB-induced skin damage by inhibiting ROS generation, relieving skin inflammation, and slowing down collagen degradation, suggesting that these MAA components are effective cosmetic candidate molecules for the protection and therapy of UVB damage.

The Effects of Flavonol and Flavone Glucuronides from Potentilla chinensis Leaves on TNF-α-Exposed Normal Human Dermal Fibroblasts.

Skin aging is a complex biological process influenced by a variety of factors, including UV radiation. UV radiation accelerates collagen degradation via the production of reactive oxygen species (ROS) and cytokines, including TNF-α. In a prior investigation, the inhibitory properties of flavonol and flavone glucuronides derived from Potentilla chinensis on TNF-α-induced ROS and MMP-1 production were explored. Consequently, we verified the skin-protective effects of these flavonol and flavone glucuronides, including potentilloside A, from P. chinensis, and conducted a structure-activity relationship analysis as part of our ongoing research. We investigated the protective effects of the extract and its 11 isolates on TNF-α-stimulated normal human dermal fibroblasts (NHDFs). Ten flavonol and flavone glucuronides significantly inhibited ROS generation (except for 7) and suppressed MMP-1 secretion, except for 2. In contrast, six isolates (1, 5, 6, 11, 9, 10, and 11) showed a significant reverse effect on COLIA1 secretion. Comparing the three experimental results of each isolate, potentilloside A (1) showed the most potent skin cell-protective effect among the isolates. Evaluation of the signaling pathway of potentilloside A in TNF-α-stimulated NHDF revealed that potentilloside A inhibits the phosphorylation of ERK, JNK, and c-Jun. Taken together, these results suggest that compounds isolated from P. chinensis, especially potentilloside A, can be used to inhibit skin damage, including aging.

Phthalocyanine aggregates in the photodynamic therapy: dogmas, controversies, and future prospects.

Photodynamic therapy (PDT), a rapidly developing method for the treatment of cancer and bacterial diseases, is based on the photosensitization of oxygen to generate reactive oxygen species (ROS) that destroy specific biological targets. Among the various photosensitizers, phthalocyanines (Pc) have attracted particular attention due to their excellent photophysical properties, most of which meet the therapeutic requirements. The statement that aggregation of Pc-based photosensitizers is undesirable because it suppresses ROS generation has become commonplace in PDT. In this review, we have collected and discussed a number of works whose results refute this well-established axiom and show that aggregated forms of phthalocyanines can still exhibit photodynamic activity, in some cases in synergy with the photothermal and optoacoustic effects. In addition, ROS generation can be induced by aggregates under the conditions of sonodynamic therapy.

Six Functions of Respiration: Isn't It Time to Take Control over ROS Production in Mitochondria, and Aging Along with It?

Cellular respiration is associated with at least six distinct but intertwined biological functions. (1) biosynthesis of ATP from ADP and inorganic phosphate, (2) consumption of respiratory substrates, (3) support of membrane transport, (4) conversion of respiratory energy to heat, (5) removal of oxygen to prevent oxidative damage, and (6) generation of reactive oxygen species (ROS) as signaling molecules. Here we focus on function #6, which helps the organism control its mitochondria. The ROS bursts typically occur when the mitochondrial membrane potential (MMP) becomes too high, e.g., due to mitochondrial malfunction, leading to cardiolipin (CL) oxidation. Depending on the intensity of CL damage, specific programs for the elimination of damaged mitochondria (mitophagy), whole cells (apoptosis), or organisms (phenoptosis) can be activated. In particular, we consider those mechanisms that suppress ROS generation by enabling ATP synthesis at low MMP levels. We discuss evidence that the mild depolarization mechanism of direct ATP/ADP exchange across mammalian inner and outer mitochondrial membranes weakens with age. We review recent data showing that by protecting CL from oxidation, mitochondria-targeted antioxidants decrease lethality in response to many potentially deadly shock insults. Thus, targeting ROS- and CL-dependent pathways may prevent acute mortality and, hopefully, slow aging.

Laricitrin 3-Rutinoside from Ginkgo biloba Fruits Prevents Damage in TNF-α-Stimulated Normal Human Dermal Fibroblasts.

Human skin comprises the epidermis and dermis, which perform interactive functional activities with each other in order to maintain the skin's tensile strength. In particular, the dermal layer is crucial for skin protection. However, skin aging destroys collagen and elastin fibers, causing wrinkles, pigments, and sagging. Skin aging-related factors, such as tumor necrosis factor-α (TNF-α), promote the generation of intercellular reactive oxygen species (ROS). These are known to stimulate the hypersecretion of matrix metalloproteinase-1 (MMP-1), which degrades collagen and inhibits collagen synthesis. In this study, as part of our ongoing discovery of natural products, we investigated potential natural products derived from ginkgo fruit (Ginkgo biloba fruit) with protective effects against TNF-α-induced skin aging. Phytochemical investigation of the MeOH extract of G. biloba fruits, aided by liquid chromatography-mass spectrometry, led to the isolation of 14 compounds (1-14) from the n-butanol-soluble fraction. These were structurally determined to be: (E)-coniferin (1), syringin (2), 4-hydroxybenzoic acid 4-O-β-D-glucopyranoside (3), vanillic acid 4-O-β-D-glucopyranoside (4), glucosyringic acid (5), (E)-ferulic acid 4-O-β-D-glucoside (6), (E)-sinapic acid 4-O-β-D-glucopyranoside (7), ginkgotoxin-5-glucoside (8), ginkgopanoside (9), (Z)-4-coumaric acid 4-O-β-D-glucopyranoside (10), (1'R,2'S,5'R,8'S,2'Z,4'E)-dihydrophaseic acid 3'-O-β-D-glucopyranoside (11), eucomic acid (12), rutin (13), and laricitrin 3-rutinoside (L3R) (14). Biological evaluation of the isolated compounds for their effects on intracellular ROS generation showed that, of these 14 compounds, L3R (14) inhibited TNF-α-stimulated ROS generation (p < 0.001 at 100 μM). Inhibition of ROS generation by L3R led to the suppression of MMP-1 secretion and protection against collagen degradation. The inhibitory effect of L3R was mediated by the inhibition of extracellular signal regulated kinase (ERK) phosphorylation. Furthermore, L3R diminished the secretion of pro-inflammatory cytokines interleukin 6 (IL-6) and interleukin 8 (IL-8). Based on these experimental results, L3R is a potential bioactive natural product that can be used to protect against skin damage, including aging, in cosmetics and pharmaceuticals.

β-Asarone Alleviates High-Glucose-Induced Oxidative Damage via Inhibition of ROS Generation and Inactivation of the NF-κB/NLRP3 Inflammasome Pathway in Human Retinal Pigment Epithelial Cells.

Diabetic retinopathy (DR) is the leading cause of vision loss and a major complication of diabetes. Hyperglycemia-induced accumulation of reactive oxygen species (ROS) is an important risk factor for DR. β-asarone, a major component of volatile oil extracted from Acori graminei Rhizoma, exerts antioxidant effects; however, its efficacy in DR remains unknown. In this study, we investigated whether β-asarone inhibits high-glucose (HG)-induced oxidative damage in human retinal pigment epithelial (RPE) ARPE-19 cells. We found that β-asarone significantly alleviated cytotoxicity, apoptosis, and DNA damage in HG-treated ARPE-19 cells via scavenging of ROS generation. β-Asarone also significantly attenuated the excessive accumulation of lactate dehydrogenase and mitochondrial ROS by increasing the manganese superoxide dismutase and glutathione activities. HG conditions markedly increased the release of interleukin (IL)-1β and IL-18 and upregulated their protein expression and activation of the nuclear factor-kappa B (NF-κB) signaling pathway, whereas β-asarone reversed these effects. Moreover, expression levels of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome multiprotein complex molecules, including thioredoxin-interacting protein, NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain, and cysteinyl aspartate-specific proteinase-1, were increased in ARPE-19 cells under HG conditions. However, their expression levels remained similar to those in the control group in the presence of β-asarone. Therefore, β-asarone protects RPE cells from HG-induced injury by blocking ROS generation and NF-κB/NLRP3 inflammasome activation, indicating its potential as a therapeutic agent for DR treatment.

Reduction of high glucose-induced oxidative injury in human retinal pigment epithelial cells by sarsasapogenin through inhibition of ROS generation and inactivation of NF-κB/NLRP3 inflammasome pathway.

Hyperglycemia-induced accumulation of reactive oxygen species (ROS) is a major risk factor for diabetic retinopathy (DR). Sarsasapogenin is a natural steroidal saponin that is known to have excellent antidiabetic effects and improve diabetic complications, but its potential efficacy and mechanism for DR are unknown. The current study was designed to explore whether sarsasapogenin inhibits hyperglycemia-induced oxidative stress in human retinal pigment epithelial (RPE) ARPE-19 cells and to elucidate the molecular mechanisms. To mimic hyperglycemic conditions, ARPE-19 cells were cultured in medium containing high glucose (HG). The suppressive effects of sarsasapogenin on HG-induced cell viability reduction, apoptosis and ROS production were investigated. In addition, the relevance of the nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathway was explored to investigate the mechanism of antioxidant and anti-inflammatory activity of sarsasapogenin. Sarsasapogenin significantly alleviated cytotoxicity and apoptosis in HG-treated ARPE-19 cells through inhibition of intracellular ROS generation. Sarsasapogenin also effectively attenuated HG-induced excess accumulation of mitochondrial superoxide, reduction of glutathione content, and inactivation of manganese superoxide dismutase and glutathione peroxidase. The HG condition markedly increased the expression and maturation of interleukin (IL)-1β and IL-18 through the activation of the NF-kB signaling pathway, whereas sarsasapogenin reversed these effects. Moreover, although the expression of NLRP3 inflammasome multiprotein complex molecules was increased in ARPE-19 cells cultured under HG conditions, their levels remained similar to the control group in the presence of sarsasapogenin. Sarsasapogenin could protect RPE cells from HG-induced injury by inhibiting ROS generation and NF-κB/NLRP3 inflammasome pathway, suggesting its potential as a therapeutic agent to improve the symptoms of DR.

TiO2 nanoparticles affect spermatogenesis and adhesion junctions via the ROS-mediated mTOR signalling pathway in Eriocheir sinensis testes

Recent findings found that TiO2 nanoparticles (TiO2-NPs) have male reproductive toxicity. However, few reports have studied the toxicity of TiO2-NPs in crustaceans. In this study, we first chose the freshwater crustacean Eriocheir sinensis (E. sinensis) to explore the male toxicity of TiO2-NP exposure and the underlying mechanisms. Three nm and 25 nm TiO2-NPs at a dose of 30 mg/kg bw induced apoptosis and damaged the integrity of the haemolymph-testis-barrier (HTB, a structure similar to the blood-testis-barrier) and the structure of the seminiferous tubule. The 3-nm TiO2-NPs caused more severe spermatogenesis dysfunction than the 25-nm TiO2-NPs. We initially confirmed that TiO2-NP exposure affected the expression patterns of adherens junctions (α-catenin and β-catenin) and induced tubulin disorganization in the testis of E. sinensis. TiO2-NP exposure caused reactive oxygen species (ROS) generation and an imbalance of mTORC1-mTORC2 (mTORC1/rps6/Akt levels were increased, while mTORC2 activity was not changed). After using the ROS scavenger NAC to inhibit ROS generation, both the mTORC1-mTORC2 imbalance and alterations in AJs were rescued. More importantly, the mTORC1 inhibitor rapamycin abolished mTORC1/rps6/Akt hyperactivation and partially restored the alterations in AJs and tubulin. Collectively, the mTORC1-mTORC2 imbalance induced by TiO2-NPs was involved in the mechanism of AJ and HTB disruption, resulting in spermatogenesis in E. sinensis.

Balloon Flower Root-Derived Extracellular Vesicles: In Vitro Assessment of Anti-Inflammatory, Proliferative, and Antioxidant Effects for Chronic Wound Healing.

Excessive reactive oxygen species (ROS) in wound lesions can lead to oxidative stress and failure of normal wound healing processes, eventually resulting in chronic skin wounds. A multitude of researchers have investigated various natural products with physiological activities, including antioxidant effects, for healing chronic skin wounds. Balloon flower root (BFR), which contains bioactive components such as platycodins, is known for its anti-inflammatory and antioxidant effects. In this study, we isolated BFR-derived extracellular vesicles (BFR-EVs) that possess anti-inflammatory, proliferative, and antioxidant activities via a combination of polyethylene glycol-based precipitation and ultracentrifugation. Our objective was to investigate the potential of BFR-EVs in treating chronic wounds caused by ROS. Despite efficient intracellular delivery, BFR-EVs showed no significant cytotoxicity. In addition, BFR-EVs inhibited the expression of pro-inflammatory cytokine genes in lipopolysaccharide-stimulated RAW 264.7 cells. Furthermore, water-soluble tetrazolium salt-8 assay showed that BFR-EVs had a proliferation-promoting effect on human dermal fibroblasts (HDFs). Scratch closure and transwell migration assays indicated that BFR-EVs could promote the migration of HDFs. When the antioxidant effect of BFR-EVs was evaluated through 2',7'-dichlorodihydrofluorescein diacetate staining and quantitative real-time polymerase chain reaction, the results revealed that BFR-EVs significantly suppressed ROS generation and oxidative stress induced by H2O2 and ultraviolet irradiation. Our findings suggest that BFR-EVs hold the potential as a natural candidate for healing chronic skin wounds.

HMG-CoA Reductase Inhibitors Suppress Monosodium Urate-Induced NLRP3 Inflammasome Activation through Peroxisome Proliferator-Activated Receptor-γ Activation in THP-1 Cells.

Peroxisome proliferator-activated receptor γ (PPAR-γ) is thought to negatively regulate NLRP3 inflammasome activation. The aim of this study was to identify the inhibitory effect of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) on monosodium urate (MSU) crystal-induced NLRP3 inflammasome activation through the regulation of PPAR-γ in THP-1 cells. The expression of PPAR-γ, NLRP3, caspase-1, and interleukin-1β (IL-1β) in human monocytic THP-1 cells transfected with PPAR-γ siRNA or not and stimulated with MSU crystals was assessed using quantitative a real time-polymerase chain reaction and Western blotting. The expression of those markers in THP-1 cells pretreated with statins (atorvastatin, simvastatin, and mevastatin) was also evaluated. Intracellular reactive oxygen species (ROS) were measured using H2DCF-DA and flow cytometry analyses. THP-1 cells treated with MSU crystals (0.3 mg/mL) inhibited PARR-γ and increased NLRP3, caspase-1, and IL-1β mRNA and protein expression, and all those changes were significantly reversed by treatment with atorvastatin, simvastatin, or mevastatin. PPAR-γ activity revealed that MSU crystals suppressed PPAR-γ activity, which was markedly augmented by atorvastatin, simvastatin, and mevastatin. Transfecting cells with PPAR-γ siRNA attenuated the inhibitory effect of statins on MSU crystal-mediated NLRP3 inflammasome activation. Statins also significantly reduced the intracellular ROS generation caused by stimulation with MSU crystals. The inhibitory effects of atorvastatin and simvastatin on intracellular ROS generation were reduced in THP-1 cells transfected with PPAR-γ siRNA. This study demonstrates that PPAR-γ is responsible for suppressing MSU-mediated NLRP3 inflammasome activation. The inhibitory effect of statins on MSU-induced NLRP3 inflammasome activation depends on PPAR-γ activity and production and the inhibition of ROS generation.

O-GlcNAcylation Is Required for the Survival of Cerebellar Purkinje Cells by Inhibiting ROS Generation.

Purkinje cells (PCs), as a unique type of neurons output from the cerebellar cortex, are essential for the development and physiological function of the cerebellum. However, the intricate mechanisms underlying the maintenance of Purkinje cells are unclear. The O-GlcNAcylation (O-GlcNAc) of proteins is an emerging regulator of brain function that maintains normal development and neuronal circuity. In this study, we demonstrate that the O-GlcNAc transferase (OGT) in PCs maintains the survival of PCs. Furthermore, a loss of OGT in PCs induces severe ataxia, extensor rigidity and posture abnormalities in mice. Mechanistically, OGT regulates the survival of PCs by inhibiting the generation of intracellular reactive oxygen species (ROS). These data reveal a critical role of O-GlcNAc signaling in the survival and maintenance of cerebellar PCs.

Anti-inflammatory efficacy of brown seaweed (Padina tetrastromatica) in 3T3-L1 adipocytes and low-dose LPS induced inflammation in C57BL6 mice

Chronic systemic inflammation is a central indicator of numerous diseases. Regulation of inflammation in adipose and liver is essential in mitigating obesity. SIRT1 is known to modulate inflammation and metabolic pathways. Brown algae Padina tetrastromatica possesses anti-oxidant and anti-inflammatory properties. However, the synergistic effects of P. tetrastromatica bioactives Fucoxanthin (Fx) and Total lipids (TL) to inhibit inflammation in SIRT1 silenced 3T3-L1 adipocytes remain unknown. Furthermore, the role of anti-inflammatory food supplements in mitigating systemic inflammation stays elusive. Therefore, here we studied the effects of P.tetrastromatica bioactives on cytokine production and activation of cell signals in SIRT1 silenced and LPS-induced inflammation in 3T3-L1 adipocytes and mice models. Preliminary in silico screening of Fx and its metabolites with target inflammatory markers was performed. The effects of Fx and TL on adipogenesis and reactive oxygen species (ROS) in silenced cells were detected by Oil Red O and DCFH-DA assay. Cytokine production and protein expression of NF-κB, COX-2, IL-10 and SIRT1 were determined by ELISA and western blotting. Fx and TL significantly inhibited adipogenesis, ROS, and Nitric oxide (NO), pro-inflammatory cytokine production (IL-6, IL-1ß, MCP-1, TNF-α) in SIRT1 silenced and LPS-challenged inflamed cells. Inflammatory marker (NF-κB, COX-2) expression was downregulated in Fx and TL treated cells compared to LPS and SIRT1 silenced cells indicating their modulating mechanistic ability to mitigate inflammation. Whereas, the expression of anti-inflammatory cytokine IL-10, adiponectin and NAD+ were upregulated significantly in Fx and TL treated cells compared to silenced and LPS insulted cells. These results were further validated by feeding seaweed and barley blended anti-inflammatory food (AIF) to LPS-treated mice. Results showed that AIF supplementation inhibited ROS generation, and pro-inflammatory cytokine, COX-2 and NF-κB expression. Whereas, feeding AIF upregulated adiponectin, NAD+, IL-10, and SIRT1 levels. Results suggest potential therapeutic food applications of P. tetrastromatica to manage inflammation and obesity.

DTPA-Bound Planar Catechin with Potent Antioxidant Activity Triggered by Fe3+ Coordination

In diseases related to oxidative stress, accumulation of metal ions at the site of pathogenesis results in the generation of reactive oxygen species (ROS) through the reductive activation of oxygen molecules catalyzed by the metal ions. If these metals can be removed and the generated ROS can be strongly scavenged, such diseases can be prevented and treated. Planar catechins exhibit stronger radical scavenging activity than natural catechins and can efficiently scavenge hydroxyl radicals generated by the Fenton reaction without showing pro-oxidant effects, even in the presence of iron ions. Hence, in the current study, we designed a compound in which diethylenetriaminepentaacetic acid (DTPA), a metal chelator, was bound to a planar catechin with enhanced radical scavenging activity by immobilizing the steric structure of a natural catechin to be planar. This compound showed almost no radical scavenging activity due to intramolecular hydrogen bonding of DTPA with the planar catechins; however, when coordinated with Fe3+, it showed more potent radical scavenging activity than planar catechins. Owing to its potent antioxidant activity triggered by metal coordination and its inhibition of ROS generation by trapping metal ions, this compound might exert excellent preventive and therapeutic effects against oxidative stress-related diseases.

Osthole attenuated cytotoxicity induced by 6-OHDA in SH-SY5Y cells through inhibition of JAK/STAT and MAPK pathways.

Natural coumarin called osthole is regarded as a medicinal herb with widespread applications in Traditional Chinese Medicine. It has various pharmacological properties, including antioxidant, anti-inflammatory, and anti-apoptotic effects. In some neurodegenerative diseases, osthole also shows neuroprotective properties. In this study, we explored how osthole protects human neuroblastoma SH-SY5Y cells from the cytotoxicity of 6-hydroxydopamine (6-OHDA). Using the MTT assay and DCFH-DA methods, respectively, the viability of the cells and the quantity of intracellular reactive oxygen species (ROS) were evaluated. Signal Transducers and Activators of Transcription (STAT), Janus Kinase (JAK), extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and caspase-3 activation levels were examined using western blotting. In SH-SY5Y cells, the results showed that a 24-hour exposure to 6-OHDA (200 µM) lowered cell viability but markedly elevated ROS, p-JAK/JAK, p-STAT/STAT, p-ERK/ERK, p-JNK/JNK ratio, and caspase-3 levels. Interestingly, osthole (100 µM) pretreatment of cells for 24 hr prevented 6-OHDA-induced cytotoxicity by undoing all effects of 6-OHDA. In summary, our data showed that osthole protects SH-SY5Y cells against 6-OHDA-induced cytotoxicity by inhibiting ROS generation and reducing the activity of the JAK/STAT, MAPK, and apoptotic pathways.

Systematic Exploration of the Potential Material Basis and Molecular Mechanism of the Mongolian Medicine Shudage-4 in Attenuating Stress-Induced Gastric Ulcer in Rat.

Shudage-4, an ancient and well-known formula in traditional Mongolian medicine comprising four different types of traditional Chinese medicine, is widely used in the treatment of gastric ulcers. However, the potential material basis and molecular mechanism of Shudage-4 in attenuating stress-induced gastric ulcers remain unclear. This study aimed to first explore the potential material basis and molecular mechanism of Shudage-4 in attenuating gastric ulcers in rats. The chemical constituents and transitional components in the blood of Shudage-4 were identified by ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS). The rat gastric ulcer model was induced by water immersion restraint stress (WIRS). The ulcer damage to gastric tissue was measured at the gross anatomical level and pathological level by hematoxylin-eosin (HE) staining of gastric tissue. RNA sequencing of gastric tissue and plasma metabolomics were performed to analyze the mechanism of Shudage-4 against gastric ulcers. A Pearson correlation analysis was performed to explore the association between serum metabolites and gene expression of gastric tissue. A total of 30 chemical constituents were identified in Shudage-4 by UPLC-TOF-MS. Among 30 constituents, 13 transitional components in the blood were considered as the potential material basis. Shudage-4 treatment had a significant effect on WIRS-induced gastric ulcers in rats. HE staining of gastric tissue illustrated that WIRS-induced ulcer damage was suppressed by Shudage-4 treatment. RNA sequencing of gastric tissue showed that 282 reversed expression genes in gastric tissue were related to Shudage-4 treatment, and gene set enrichment analysis revealed that Shudage-4 treatment significantly inhibited gene set expression related to reactive oxygen species (ROS), which was also validated by detecting rat gastric tissue MDA, GSH, SOD, GSH-Px, and CAT activities. The plasma metabolomic data demonstrated that 23 significantly differential metabolites were closely associated with the Shudage-4 treatment. The further multiomics joint analysis found that significantly upregulated 5 plasma metabolites in Shudage-4-treated rats compared to model rats were negatively correlated with gene set expression related to ROS in gastric tissue. Shudage-4 alleviated WIRS-induced gastric ulcers by inhibiting ROS generation, which was achieved by regulating plasma metabolites level.

Caveolin-1 ameliorates acetaminophen-aggravated inflammatory damage and lipid deposition in non-alcoholic fatty liver disease via the ROS/TXNIP/NLRP3 pathway.

The overuse of acetaminophen (APAP) may cause more severe hepatotoxicity in patients with non-alcoholic fatty liver disease (NAFLD). Caveolin-1 (CAV1), is an essential regulator of metabolic function, which can alleviate liver damage by scavenging reactive oxygen species (ROS). Evidence suggests that the NOD-like receptor family pyrin domain-containing 3 (NLRP3) -mediated pyroptosis is involved in the development of NAFLD. Moreover, thioredoxin-interactive protein (TXNIP) activation is a key event linking ROS to NLRP3 inflammasome. However, whether CAV1 alleviates APAP-aggravated hepatotoxicity in NAFLD via the ROS/TXNIP/NLRP3 pathway remains unclear. An in vivo fatty liver model was established by feeding mice a high-fat diet for 56days. Additionally, using in vitro approach, AML-12 cells were incubated with free fatty acids for 48h and APAP was added during the last 24h. We found that the overuse of APAP in NAFLD not only induced oxidative stress, but also increased TXNIP expression, NLRP3-mediated pyroptosis, and lipid deposition. In addition to inhibiting ROS generation and lipid deposition, overexpression of CAV1 reduced the elevated levels of TXNIP expression and NLRP3-mediated pyroptosis. However, the effect of CAV1 on TXNIP expression, NLRP3-mediated pyroptosis, and lipid deposition was reversed by CAV1 small interfering RNA (siRNA) intervention. Finally, N-acetyl cysteine (NAC) treatment reduced CAV1 siRNA-mediated changes in TXNIP expression and NLRP3-mediated pyroptosis levels. These results demonstrate that the inhibitory effect of CAV1 on NLRP3-mediated pyroptosis may be mediated through the ROS/TXNIP axis. Moreover, the current study provides novel mechanistic insights into the protective effects of CAV1 on APAP-aggravated hepatotoxicity in NAFLD.

Mild hypothermia alleviates oxygen-glucose deprivation/reperfusion-induced apoptosis by inhibiting ROS generation, improving mitochondrial dysfunction and regulating DNA damage repair pathway in PC12 cells.

The brain ischemia/reperfusion (I/R) injury has a great impact on human life and property safety. As far as we know, mild hypothermia (MH) is an effective measure to reduce neuronal injury after I/R. However, the precise mechanism is not extremely clear. The purpose of this study was to investigate whether mild therapeutic hypothermia can play a protective role in nerve cells dealing with brain I/R injury and explore its specific mechanism in vitro. A flow cytometer, cell counting kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) release assay were performed to detect apoptotic rate of cells, cell viability and cytotoxicity, respectively, reactive oxygen species (ROS) assay kit, JC-1 fluorescent methods, immunofluorescence and western blot were used to explore ROS, mitochondrial transmembrane potential (Δψm), mitochondrial permeability transition pore (MPTP) and protein expression, respectively. The result indicated that the cell activity was decreased, while the cytotoxicity and apoptosis rate were increased after treating with oxygen-glucose deprivation/reperfusion (OGD/R) in PC12 cells. However, MH could antagonize this phenomenon. Interestingly, treating with OGD/R increased the release of ROS and the transfer of Cytochrome C (Cyt-C) from mitochondria to cytoplasm. In addition, it up-regulated the expression of γH2AX, Bax and Clv-caspase3, down-regulated the expression of PCNA, Rad51 and Bcl-2, and inhibited the function of mitochondria in PC12 cells. Excitingly, the opposite trend was observed after MH treatment. Therefore, our results suggest that MH protects PC12 cells against OGD/R-induced injury with the mechanism of inhibiting cell apoptosis by reducing ROS production, improving mitochondrial function, reducing DNA damage, and enhancing DNA repair.