Superoxide Reduction Research Articles

Photoprotective sulfated mannogalactan from heterotrophic Bacillus velezensis blocks UV-A mediated matrix metalloproteinase expression and nuclear DNA damage in human dermal fibroblast

Prolonged exposure of human dermal fibroblasts (HDF) to ultraviolet (UV) radiation triggers the production of reactive oxygen species by upregulating the expression of matrix metalloproteinases (MMPs), causing type-I collagen degradation and photoaging. A sulfated (1 → 3)/(1 → 4) mannogalactan exopolysaccharide (BVP-2) characterized as [→3)-α-Galp-{(1 → 4)-α-6-O-SO3-Manp}-(1 → 3)-α-6-O-SO3-Galp-(1→] was isolated from seaweed-associated heterotrophic bacterium Bacillus velezensis MTCC13097. Whole genome analysis of B. velezensis MTCC13097 (Accession number JAKYLL000000000) revealed saccharine biosynthetic gene clusters for exopolysaccharide production. BVP-2 administered cells showed noteworthy reduction in mitochondrial superoxide (∼85 %, p < 0.05) and ROS production (62 %) than those exhibited by UV-A irradiated HDF cells. Oxidative imbalance in HDF cells (after UV-A exposure) was recovered with BVP-2 treatment by significantly downregulating nitric oxide (NO) production (98.6 μM/mL, 1.9-fold) and DNA damage (⁓67 %) in comparison with UV-A induced cells (191.8 μM/mL and 98.7 %, respectively). UV-irradiated HDF cells showed a ∼30-50 % downregulation in the expression of MMPs (1, 2, and 9) following treatment with BVP-2. Considerable amount of sulfation (18 %) along with (1 → 3)/(1 → 4) glycosidic linkages in BVP-2 could be pivotal factors for down-regulation of the intracellular MMP-1, which was further supported by molecular docking and structure-activity studies. The (1 → 3)/(1 → 4)-linked bacterial exopolysaccharide (BVP-2) might be used as prospective natural lead to attenuate and mitigate UV-A-induced photoaging.

Involvement of BcNAC083 in 1-MCP-induced delayed yellowing of pak choi (Brassica rapa subsp. Chinensis) through the regulation of reactive oxygen species metabolism and inhibition of major chlorophyll catabolic genes

Leaf yellowing is a typical senescence feature in postharvest pak choi. Plant-specific NAC transcription factors (TFs) are crucial regulators of plant senescence. In this study, a senescence-related NAC TF, BcNAC083, was investigated to identify its transcriptional regulation effects on the yellowing of pak choi by treatment with 1-methylcyclopropene (1-MCP). Applying 5.0 µL L–1 1-MCP alleviated yellowing and maintained a low respiration rate, high chlorophyll content, and relatively complete chloroplast structure in pak choi during storage. However, 10 μL L–1 ethylene accelerated yellowing, as demonstrated by the higher respiration rate, lower chloroplast structural integrity and chlorophyll content. In contrast to ethylene treatment, 1-MCP suppressed the activity of the reactive oxygen species (ROS) metabolism-related enzymes superoxide dismutase (SOD), catalase (CAT), ascorbic peroxidase (APX), and lipoxygenase (LOX), and correspondingly reduced superoxide anion (O2·–), hydrogen peroxide (H2O2), and malondialdehyde (MDA) accumulation. 1-MCP treatment also suppressed the transcript levels of ROS metabolic genes, including BcRBOHC, BcRBOHD, BcSOD, BcCAT, BcAPX, and BcLOX, and inhibited the activity of the chlorophyll catabolic enzymes chlorophyllase (CLH), Mg-de-chelatase, and pheophytin pheophorbide hydrolase (PPH) and transcript levels of associated genes, including BcCLH1/2, BcPPH1/2, BcPAO, BcNYC1, BcSGR1/2, BcHCAR, BcRCCR, and BcCAO. The expression of BcNAC083 was probably induced by ROS and was downregulated by 1-MCP and upregulated by ethylene. Molecular biology experiments determined that BcNAC083 bound directly to and activated the promoters of the chlorophyll metabolism-related genes BcCLH1, BcPPH1, BcNYC1, and BcHCAR. Importantly, transient overexpression of BcNAC083 stimulated the endogenous genes (NbCLH1, NbPPH1, NbNYC1, and NbHCAR) expression in tobacco leaves, resulting in rapid chlorophyll breakdown and leaf degreening. Treatment with 1-MCP may alleviated the yellowing of pak choi by inhibiting ROS accumulation and the transcriptional regulation of BcNAC083, which had positive regulatory effects on major chlorophyll metabolic genes.

β-Hydroxybutyrate Improves the Redox Status, Cytokine Production and Phagocytic Potency of Glucose-Deprived HMC3 Human Microglia-like Cells.

Brain glucose deprivation is a component of the pathophysiology of ischemia, glucose transporter1 (GLUT1) deficiency, neurological disorders and occurs transiently in diabetes. Microglia, the neuroimmune cells must function effectively to offer immune defence and debris removal in low-energy settings. Brain glucose deprivation may compromise microglial functions further escalating the disease pathology and deteriorating the overall mental health. In the current study, HMC3 human microglia-like cells were culturedin vitro and exposed to glucose deprivation to investigate the effects of glucose deprivation on phenotypic state, redox status, secretion of cytokines and phagocytic capabilities of HMC3 cells. However, HMC3 cells were able to proliferate in the absence of glucose but showed signs of redox imbalance and mitochondrial dysfunction, as demonstrated by decreased MTT reduction and Mito Tracker™ staining of cells, along with a concomitant reduction in NOX2 protein, superoxide, and nitrite levels. Reduced levels of secreted TNF and IL-1β were the signs of compromised cytokine secretion by glucose-deprived HMC3 microglia-like cells. Moreover, glucose-deprived HMC3 cells also showed reduced phagocytic activity as assessed by fluorescently labelled latex beads-based functional phagocytosis assay. β-hydroxybutyrate (BHB) supplementation restored the redox status, mitochondrial health, cytokine secretion, and phagocytic activity of glucose-deprived HMC3 microglia-like cells. Overall, impaired brain glucose metabolism may hinder microglia's capacity to release diffusible immune factors and perform phagocytosis. This could escalate the mental health issues in neurological diseases where brain glucose metabolism is compromised. Moreover, nutritional ketosis or exogenous ketone supplementation such as BHB may be utilized as a potential metabolic therapies for these conditions.

Inositol-6-phosphate mitigates deoxynivalenol nephrotoxicity in pig kidney explants

Abstract Deoxynivalenol (DON) is a mycotoxin that frequently contaminates food crops and negatively impacts human and animal health. While inositol-6-phosphate (IP6) is known to counteract DON-induced intestinal damage, inflammation, and oxidative stress, its ability to alleviate DON-caused kidney injury is yet unexplored. This study assessed DON’s kidney effects and IP6’s protective capability using an ex vivo renal explants model. From 360 explants taken from six pigs, four groups were formed: control (culture medium), DON (10 μM equivalent to 3 mg/kg of feed), IP6 group (5 mM), and DON + IP6 (10 μM + 5 mM). DON elevated creatinine levels and γ-glutamyl transferase activity in the culture medium. It led to cytoplasmic vacuolation in convoluted tubular epithelial cells and tubular necrosis, a drop in antioxidant potential (ABTS) and a rise in interleukin (IL)-8 mRNA. The introduction of IP6 restored renal histological and functional parameters, bolstered antioxidant status, enhanced IL-10 gene expression, and reduced superoxide anion levels. These results indicate that within the model of renal explants, IP6 significantly alleviates the nephrotoxic effects of DON while efficiently regulating the antioxidative and anti-inflammatory response within the kidneys.

Clinical pharmacology and tolerability of REC-994, a redox-cycling nitroxide compound, in randomized phase 1 dose-finding studies.

Cerebral cavernous malformation (CCM) has variable clinical symptoms, including potentially fatal hemorrhagic stroke. Treatment options are very limited, presenting a large unmet need. REC-994 (also known as tempol), identified as a potential treatment through an unbiased drug discovery platform, is hypothesized to treat CCMs through a reduction in superoxide, a reactive oxygen species. We investigated the safety, tolerability, and pharmacokinetic profile of REC-994 in healthy volunteers. Single- and multiple-ascending dose (SAD and MAD, respectively) studies were conducted in adult volunteers (ages 18-55). SAD study participants received an oral dose of REC-994 or placebo. MAD study participants were randomized 3:1 to oral doses of REC-994 or matching placebo, once daily for 10 days. Thirty-two healthy volunteers participated in the SAD study and 52 in the MAD study. Systemic exposure increased in proportion to REC-994 dose after single doses of 50-800 mg and after 10 days of dosing over the 16-fold dose range of 50-800 mg. Median Tmax and mean t1/2 were independent of dose in both studies, and the solution formulation was more rapidly absorbed. REC-994 was well tolerated. Treatment-emergent adverse effects across both studies were mild and transient and resolved by the end of the study. REC-994 has a favorable safety profile and was well tolerated in single and multiple doses up to 800 mg with no dose-limiting adverse effects identified. Data support conducting a phase 2 clinical trial in patients with symptomatic CCM.

Bone marrow-derived mesenchymal stem cells mitigate chronic colitis and enteric neuropathy via anti-inflammatory and anti-oxidative mechanisms

Current treatments for inflammatory bowel disease (IBD) are often inadequate due to limited efficacy and toxicity, leading to surgical resection in refractory cases. IBD’s broad and complex pathogenesis involving the immune system, enteric nervous system, microbiome, and oxidative stress requires more effective therapeutic strategies. In this study, we investigated the therapeutic potential of bone marrow-derived mesenchymal stem cell (BM-MSC) treatments in spontaneous chronic colitis using the Winnie mouse model which closely replicates the presentation and inflammatory profile of ulcerative colitis. The 14-day BM-MSC treatment regimen reduced the severity of colitis, leading to the attenuation of diarrheal symptoms and recovery in body mass. Morphological and histological abnormalities in the colon were also alleviated. Transcriptomic analysis demonstrated that BM-MSC treatment led to alterations in gene expression profiles primarily downregulating genes related to inflammation, including pro-inflammatory cytokines, chemokines and other biomarkers of inflammation. Further evaluation of immune cell populations using immunohistochemistry revealed a reduction in leukocyte infiltration upon BM-MSC treatment. Notably, enteric neuronal gene signatures were the most impacted by BM-MSC treatment, which correlated with the restoration of neuronal density in the myenteric ganglia. Moreover, BM-MSCs exhibited neuroprotective effects against oxidative stress-induced neuronal loss through antioxidant mechanisms, including the reduction of mitochondrial-derived superoxide and attenuation of oxidative stress-induced HMGB1 translocation, potentially relying on MSC-derived SOD1. These findings suggest that BM-MSCs hold promise as a therapeutic intervention to mitigate chronic colitis by exerting anti-inflammatory effects and protecting the enteric nervous system from oxidative stress-induced damage.

Effects of hypoxia in the diabetic corneal stroma microenvironment

Corneal dysfunctions associated with Diabetes Mellitus (DM), termed diabetic keratopathy (DK), can cause impaired vision and/or blindness. Hypoxia affects both Type 1 (T1DM) and Type 2 (T2DM) surprisingly, the role of hypoxia in DK is unexplored. The aim of this study was to examine the impact of hypoxia in vitro on primary human corneal stromal cells derived from Healthy (HCFs), and diabetic (T1DMs and T2DMs) subjects, by exposing them to normoxic (21% O2) or hypoxic (2% O2) conditions through 2D and 3D in vitro models. Our data revealed that hypoxia affected T2DMs by slowing their wound healing capacity, leading to significant alterations in oxidative stress-related markers, mitochondrial health, cellular homeostasis, and endoplasmic reticulum health (ER) along with fibrotic development. In T1DMs, hypoxia significantly modulated markers related to membrane permeabilization, oxidative stress via apoptotic marker (BAX), and protein degradation. Hypoxic environment induced oxidative stress (NOQ1 mediated reduction of superoxide in T1DMs and Nrf2 mediated oxidative stress in T2DMs), modulation in mitochondrial health (Heat shock protein 27 (HSP27), and dysregulation of cellular homeostasis (HSP90) in both T1DMs and T2DMs. This data underscores the significant impact of hypoxia on the diabetic cornea. Further studies are warranted to delineate the complex interactions.

Exogenous hydrogen sulphide alleviates senescence of postharvest pakchoi through regulating antioxidant system, endogenous hydrogen sulphide and nitric oxide metabolism

Previous studies showed that hydrogen sulphide (H2S) fumigation retarded the yellowing of detached pakchoi leaves. However, whether H2S regulated specific metabolic pathways and gene expression levels in this process remained unclear. In this study, the effect of H2S, DL-propargylglycine (PAG, H2S synthetic inhibitor) on antioxidant capacity, endogenous H2S synthesis, and endogenous NO synthesis in pakchoi was investigated. After H2S fumigation (40 L L−1, 6 h), the pakchoi stored at 20 °C ± 1 °C with 90–95% relative humidity exhibited the best quality, with the highest chlorophyll content and the lowest respiration rate and malondialdehyde content. Contrarily, PAG accelerated pakchoi senescence. H2S treatment reduced superoxide anion and hydrogen peroxide by increasing the activities of superoxide dismutase, catalase, ascorbate peroxidase, and peroxidase, partially up-regulating the expression of enzyme genes. The increased expression of BcLCD, BcDCD and BcCAS C1 activated L- and D-cysteine desulfhydrase activities so that more endogenous H2S were retained in the pakchoi. Meanwhile, H2S treatment increased cysteine content in pakchoi via up-regulating BcSAT5 expression and enhancing the activities of sulfite reductase and serine acetyltransferase. Moreover, H2S increased endogenous NO primarily by preserving the activities of nitrate reductase and nitrite reductase instead of NO synthase (NOS)-like activity and decreased nitrate and nitrite as well. Overall, exogenous H2S alleviated the senescence of postharvest pakchoi via positively regulating antioxidant system, endogenous H2S and NO metabolism. Moreover, this work described a putative regulatory mechanism and provided some relevant information for future research into the interaction of H2S and NO in this process.

Role of reactive oxygen species and antioxidative enzymes in the loss and re-establishment of desiccation tolerance in germinated pea seeds

This study highlights the regulatory function of ROS and its detoxifying enzymes during the loss and re-establishment of desiccation tolerance (DT) in PEG pretreated and untreated germinated pea (Pisum sativum L.) seeds with 2 mm long radicles. Dehydration of untreated pea seedlings to initial water content (IWC; 0.11 gH2O g−1 DM) and below IWC (0.06 gH2O g−1 DM) reduced the DT to 60 and 20 %, respectively. Significant amelioration in DT was observed in PEG pretreated seedlings by ∼100 % and 70 % following dehydration at IWC and below IWC, respectively. Rendering DT in the PEG pretreated seedlings was negatively associated with an extensive reduction in superoxide (∼2.3 folds) and H2O2 (∼1.8 folds) levels compared to the untreated seedlings. Enhanced expression, levels (quantitative) and number (isoenzyme) of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) in the PEG pretreated seedlings negatively correlated with the lowering ROS levels and its associated oxidative damage. It is concluded that the re-induction of increased antioxidative capacity is a key factor in the re-establishment of DT in PEG-pretreated pea seedlings. Additionally, PEG pretreatment resulted in 50 % disappearance of superoxide in the sub-apical zone (SZ) of the radicle compared to the radicle of untreated seedlings dehydrated below IWC. Further, in situ detection of superoxide accumulation in the apical zone (AZ) was NADPH-oxidase dependent but in the SZ it was independent of NADPH-oxidase. Our results showed that the osmotic stress induced the expression of antioxidative enzymes in germinated pea seeds and made them desiccation tolerant against oxidative stress caused by desiccation/drought.

Se Ameliorates Cd Toxicity in Oilseed rape (Brassica napus L.) Seedlings by Inhibiting Cd Transporter Genes and Maintaining root Plasma Membrane Integrity.

Se (Selenium) has been reported to be an important protective agent to decreases Cd (Cadmium) induced toxic in plants. However, it remains unclear how Se mitigates the uptake of Cd and increased the resistance to Cd toxicity. Hydroponic experiments were arranged to investigate the changes of physiological properties, root cell membrane integrity and Cd-related transporter genes in rape seedlings. Comparison of the biomass between the addition of Se and the absence of Se under Cd exposure showed that the Cd-induced growth inhibition of rape seedlings was alleviated by Se. Cd decreased the photosynthetic rate (Pn), stomatal conductance (Gs) and photosynthetic pigment content including chlorophyll a, chlorophyll b and carotenoid. However, all these parameters were all significantly improved by Se addition. Moreover, exposure to Se resulted in a decrease in Cd concentration in both shoot and root, ranging from 4.28 to 27.2%. Notably, the application of Se at a concentration of 1 µmol L- 1 exhibited the best performance. Furthermore, Se enhanced cell membrane integrity and reduced superoxide anion levels, thereby contributing to the alleviation of cadmium toxicity in plants. More critically, Se decreased the expression levels of root Cd-related transporter genes BnIRT1, BnHMA2 and BnHMA4 under Cd stress, which are responsible for Cd transport and translocation. These results are important to increase crop growth and reduce Cd load in the food chain from metal toxicity management and agronomical point of view.

Resveratrol Reverses Endothelial Colony-Forming Cell Dysfunction in Adulthood in a Rat Model of Intrauterine Growth Restriction.

Individuals born after intrauterine growth restriction (IUGR) are at risk of developing cardiovascular diseases (CVDs). Endothelial dysfunction plays a role in the pathogenesis of CVDs; and endothelial colony-forming cells (ECFCs) have been identified as key factors in endothelial repair. In a rat model of IUGR induced by a maternal low-protein diet, we observed an altered functionality of ECFCs in 6-month-old males, which was associated with arterial hypertension related to oxidative stress and stress-induced premature senescence (SIPS). Resveratrol (R), a polyphenol compound, was found to improve cardiovascular function. In this study, we investigated whether resveratrol could reverse ECFC dysfunctions in the IUGR group. ECFCs were isolated from IUGR and control (CTRL) males and were treated with R (1 μM) or dimethylsulfoxide (DMSO) for 48 h. In the IUGR-ECFCs, R increased proliferation (5'-bromo-2'-deoxyuridine (BrdU) incorporation, p < 0.001) and improved capillary-like outgrowth sprout formation (in Matrigel), nitric oxide (NO) production (fluorescent dye, p < 0.01), and endothelial nitric oxide synthase (eNOS) expression (immunofluorescence, p < 0.001). In addition, R decreased oxidative stress with reduced superoxide anion production (fluorescent dye, p < 0.001); increased Cu/Zn superoxide dismutase expression (Western blot, p < 0.05); and reversed SIPS with decreased beta-galactosidase activity (p < 0.001), and decreased p16ink4a (p < 0.05) and increased Sirtuin-1 (p < 0.05) expressions (Western blot). No effects of R were observed in the CTRL-ECFCs. These results suggest that R reverses long-term ECFC dysfunctions related to IUGR.

PacC mediated ammonia synthesis contributes to the pathogenicity of Trichothecium roseum by regulating reactive oxygen species and extracellular enzymes

The Pal signaling pathway plays an important role in the adaptation of pathogenic fungi to environmental pH fluctuations and consists of PalA, PalB, PalC, PalF, PalI, PalH and Pac C in filamentous fungi. As a key regulator of the Pal signaling pathway, the transcription factor PacC is involved in the regulation of ammonia synthesis, extracellular enzyme activity and pathogenicity of fungi. However, the effect of PacC on the Pal signaling pathway and the production of reactive oxygen species (ROS) in fungi is unknown. It is also unclear whether PacC is involved in the synthesis and transport of ammonia, the alkalinization of environmental pH and the regulation of extracellular enzyme gene expression in Trichothecium roseum. In this study, the wild-type strain, ΔPacC mutant and ΔPacC-C complement strains of T. roseum were used as material to analyze the role of TrPacC in the Pal pathway, ammonia accumulation and environmental pH regulation. Meanwhile, the effect of TrPacC on the pathogenicity of T. roseum was investigated by determining the production of ROS and the expression of extracellular enzyme genes. The results showed that deletion of TrPacC enhanced the pH signal perception and transduction by upregulating the expression of TrPalF and TrPalH, but downregulated the expression of TrPalC, TrPalA and TrPalB, which are involved in PacC activation. Deletion of TrPacC inhibited ammonia synthesis and secretion by downregulating the expression of TrGDH2, TrAMET, TrMEPB and TrGLT1, resulting in reduced ammonia accumulation and attenuated alkalization ability at ambient pH in vivo and in vitro. Deletion of TrPacC also reduced superoxide anion and hydrogen peroxide levels by downregulating TrNoxA expression, but had no significant effect on TrNoxB expression. In addition, deletion of TrPacC downregulated the expression of TrPG, TrPMG, TrPME, TrPL, TrPAL and TrCx and inhibited the lesion expansion of T. roseum on muskmelon and apple fruit. Taken together, deletion of TrPacC attenuated the pathogenicity of T. roseum in muskmelon and apple fruit by reducing the accumulation of ammonia and ROS and inhibiting the expression of extracellular enzyme genes.

Carnosic acid inhibits reactive oxygen species-dependent neutrophil extracellular trap formation and ameliorates acute respiratory distress syndrome

AimsInfiltration of activated neutrophils into the lungs is a hallmark of acute respiratory distress syndrome (ARDS). Neutrophilic inflammation, particularly neutrophil extracellular traps (NETs), is proposed as a useful target for treating ARDS. Carnosic acid (CA) is a food additive; however, its anti-neutrophilic activity in the treatment of ARDS has not been well established. The hypothesis of present study is to confirm that CA alleviates ARDS by suppressing neutrophilic inflammation and oxidative damage. Main methodsGeneration of superoxide anions and reactive oxygen species (ROS), induction of elastase degranulation, and formation of NETs by human neutrophils were assayed using spectrophotometry, flow cytometry, and immunofluorescent microscopy. Immunoblotting was performed to determine the cellular mechanisms involved. Cell-free radical systems were used to test antioxidant activities. The therapeutic effect of CA was evaluated in a lipopolysaccharide (LPS)-induced ARDS mouse model. Key findingsCA greatly reduced superoxide anion production, ROS production, elastase release, cluster of differentiation 11b expression, and cell adhesion in activated human neutrophils. Mechanistic studies have demonstrated that CA suppresses phosphorylation of extracellular regulated kinase and c-Jun N-terminal kinase in activated neutrophils. CA effectively scavenges reactive oxygen and nitrogen species, but not superoxide anions. This is consistent with the finding that CA is effective against ROS-dependent NET formation. CA treatment significantly improved pulmonary neutrophil infiltration, oxidative damage, NET formation, and alveolar damage in LPS-induced mice. SignificanceOur data suggested the potential application of CA for neutrophil-associated ARDS therapy.

Fucoidan treatment alleviates chilling injury in cucumber by regulating ROS homeostasis and energy metabolism.

Chilling injury is a major hindrance to cucumber fruit quality during cold storage. In this study, we evaluated the effects of fucoidan on fruit quality, reactive oxygen species homeostasis, and energy metabolism in cucumbers during cold storage. The results showed that, compared with the control cucumber fruit, fucoidan-treated cucumber fruit exhibited a lower chilling injury index and less weight loss, as well as reduced electrolyte leakage and malondialdehyde content. The most pronounced effects were observed following treatment with fucoidan at 15 g/L, which resulted in increased 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging rates and reduced superoxide anion production rate and hydrogen peroxide content. The expression and activity levels of peroxidase, catalase, and superoxide dismutase were enhanced by fucoidan treatment. Further, fucoidan treatment maintained high levels of ascorbic acid and glutathione, and high ratios of ascorbic acid/dehydroascorbate and glutathione/oxidized glutathione. Moreover, fucoidan treatment increased the activities of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase and their gene expression. Fucoidan treatment significantly delayed the decrease in ATP and ADP, while preventing an increase in AMP content. Finally, fucoidan treatment delayed the decrease of energy charge and the activities and gene expression of H+-ATPase, Ca2+-ATPase, cytochrome c oxidase, and succinate dehydrogenase in cucumber fruits. Altogether, our findings indicate that fucoidan can effectively enhance antioxidant capacity and maintain energy metabolism, thereby improving cucumber cold resistance during cold storage.

Protective effect of Hovenia dulcis Thunb. leaf extracts against ethanol-induced DNA damage in SH-SY5Y cells

Ethnopharmacological relevanceHovenia dulcis Thunb. has been used as a medicinal herb for the treatment of hepatic diseases and alcohol intoxication.Aim of the study: The genotoxic effect and the antigenotoxic potential of ethanolic extract of H. dulcis leaves and its methanolic fraction were evaluated against ethanol-induced damages in SH-SY5Y cells. Materials and methodsThe phytochemical analysis and antioxidant activity of H. dulcis extracts were also assessed. In addition, a systems biology analysis was performed to investigate the molecular pathway of action of the H. dulcis leaves compounds. ResultsThe ethanolic extract and its methanolic fraction presented genotoxicity through comet assay at 0.5 and 0.25 mg/mL. On the other hand, both extracts showed protective action against ethanol at all concentrations. Additionally, an NBT assay was performed and demonstrated an ability of the extracts to reduce superoxide anion formation when SH-SY5Y cells were challenged with ethanol. HPLC analysis indicated the presence of quercitrin, isoquercitrin, and rutin. Further, system biology assays indicated a molecular action pathway, where the compounds from the leaves of H. dulcis, in addition to performing free radical scavenging activity, activate PP2A, and may inhibit the apoptosis pathway activated by ethanol-induced oxidative stress. ConclusionsThis work is important to indicate potential antigenotoxic and antioxidant properties of H. dulcis leaves, and its use can be investigated against DNA damage induced by ethanol.

MS/MS Molecular Networking Unveils the Chemical Diversity of Biscembranoid Derivatives, Neutrophilic Inflammatory Mediators from the Cultured Soft Coral Sarcophyton trocheliophorum

Biscembranoids are the distinctive tetraterpenoids owing a 14/6/14 membered tricyclic scaffold that have been mainly discovered in the soft corals, especially the genera Sarcophyton, Lobophytum and Sinularia. Recent findings have demonstrated the great anti-inflammatory potential of biscembranoid analogues in human neutrophils, motivating more chemical and biological explorations targeting these marine-derived natural products. In the current study, the chemical diversity of biscembranoids derived from the cultured-type Sarcophyton trocheliophorum von Marenzeller was illustrated through MS/MS molecular networking (MN) profiling approach. Based on the MN patterns, the prioritization of unknown biscembranoid derivatives was putatively analyzed. As a result, the biscembrane targeting isolation afforded two new metabolites, sarcotrochelides A (1) and B (2), along with six known analogues (3-8). Their structures and relative configurations were determined by spectroscopic methods. In vitro neutrophil inflammatory inhibition was further investigated for all isolates based on reduced superoxide anion (O2•-) generation detections. Compounds 5-8 showed significant dose-dependently inhibitory effects, suggesting the cruciality of 6,7-dihydrooxepin-2(5H)-one moiety and saturated γ-lactone ring in their reactive oxygen species (ROS)-dependent anti-inflammatory properties.

UV-C delays senescence in ‘Lingwu long’ jujube fruit by regulating ROS and phenylpropanoid metabolism

Ultraviolet (UV–C), a no residual environmentally friendly physical treatment, plays an important role in delaying the senescence in fruit. In this study, ‘Lingwu long’ jujubes were treated with UV-C (5 kJ m−2) to investigate the impacts of cell wall degrading enzymes (CWDEs) activities, reactive oxygen species (ROS) metabolism, and phenylpropanoid metabolism under storage at 4 ± 1 °C for 30 d. UV-C treatment reduced respiration rate and decay index. Treated fruit exhibited lower polygalacturonase (PG), pectinate lyases (PL), cellulase (Cel), and β-galactosidase (β-gal) activities which ultimately delayed the reduction of firmness. UV-C treatment increased hydrogen peroxide (H2O2), free radical scavenging ability, and superoxide dismutase (SOD) and catalase (CAT) activities, reduced superoxide anion (O2−) and malondialdehyde (MDA) content. In addition, ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) activities were activated by UV-C treatment, leading to glutathione (GSH) and ascorbic acid (AsA) increased. Besides, phenolic compounds of jujube fruit treated with UV-C were also increased, which might be due to the enhanced phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), and 4-coumarate-CoA ligase (4CL) activities. In conclusion, UV-C was recommended for improving overall quality and alleviating senescence in jujube fruit.

Synergistic effects of dietary oxolinic acid combined with oxytetracycline on nonspecific immune responses and resistance against Vibrio parahaemolyticus infection of white shrimp (Penaeus vannamei)

This study investigated the synergistic effects of oxolinic acid (OA) combined with oxytetracycline (OTC) on white shrimp (Penaeus vannamei). Disk diffusion susceptibility testing was performed to analyze the sensitivity of Vibrio alginolyticus and Vibrio parahaemolyticus to different concentrations of OA and OTC. The results revealed that 50 mg OA/L combined with 50 mg OTC/L exhibited stronger antibacterial effects on V. alginolyticus and V. parahaemolyticus. The results of in vitro tests indicated that cotreatment with OA and OTC significantly reduced superoxide anion production and phenoloxidase activity, but not phagocytic activity. Subsequently, feeding trials were performed to investigate the immunomodulatory effects and bioaccumulation of dietary OA combined with OTC on shrimp. The healthy shrimp (15.13 ± 1.02 g) were divided into four groups: control, 100 mg OA/kg combined with 50 mg OTC/kg, 50 mg OA/kg combined with 100 mg OTC/kg, and 50 mg OA/kg combined with 50 mg OTC/kg. The shrimp were sampled to determine innate immunity parameters and residual OA and OTC levels in the muscle during a 28-day feeding regimen; the shrimp were fed the experimental diet from day 1 to day 5 and a commercial diet from day 6 to day 28. Residual OA levels were considerably higher in the group fed 100 mg OA/kg combined with 50 mg OTC/kg compared with the other groups and peaked on day 4. The residual OA levels of all the groups were below the detection limit after without providing OA. The residual OTC levels of the group fed 50 mg OA/kg combined with 100 mg OTC/kg were considerably higher from day 1 to day 4. The residual OTC levels in all the groups decreased rapidly and could not be detected on day 28. The administration of 50 mg OA/kg combined with 100 mg OTC/kg exerted the least effect on the white shrimp. Moreover, the survival rates of the treatment groups after the V. parahaemolyticus challenge were higher than those of the control group, especially the group fed 50 mg OA/kg combined with 100 mg OTC/kg. This result indicated that the synergistic effects of dietary OA and OTC are safe and effective. Combination therapy is a new method of antibiotic use in aquaculture.

Impact of Roux-en-Y Gastric Bypass on Mitochondrial Biogenesis and Dynamics in Leukocytes of Obese Women.

The chronic low-grade inflammation widely associated with obesity can lead to a prooxidant status that triggers mitochondrial dysfunction. To date, Roux-en-Y gastric bypass (RYGB) is considered the most effective strategy for obese patients. However, little is known about its molecular mechanisms. This interventional study aimed to investigate whether RYGB modulates oxidative stress, inflammation and mitochondrial dynamics in the leukocytes of 47 obese women at one year follow-up. We evaluated biochemical parameters and serum inflammatory cytokines -TNFα, IL6 and IL1β- to assess systemic status. Total superoxide production -dHe-, mitochondrial membrane potential -TMRM-, leucocyte protein expression of inflammation mediators -MCP1 and NF-kB-, antioxidant defence -GPX1-, mitochondrial regulation—PGC1α, TFAM, OXPHOS and MIEAP- and dynamics -MFN2, MNF1, OPA1, FIS1 and p-DRP1- were also determined. After RYGB, a significant reduction in superoxide and mitochondrial membrane potential was evident, while GPX1 content was significantly increased. Likewise, a marked upregulation of the transcription factors PGC1α and TFAM, complexes of the oxidative phosphorylation chain (I–V) and MIEAP and MFN1 was observed. We conclude that women undergoing RYGB benefit from an amelioration of their prooxidant and inflammatory status and an improvement in mitochondrial dynamics of their leukocytes, which is likely to have a positive effect on clinical outcome.

Superoxide Reduction by Cu‐Amyloid Beta Peptide Complexes: A Density Functional Theory Study

AbstractOxidative stress and copper dyshomeostasis are well established factors in the course of Alzheimer's disease (AD). Indeed, the pathological interaction of copper with the amyloid peptide is able to induce reactive oxygen species (ROS) production through a three‐step cycle in which O2 is gradually reduced to superoxide, oxygen peroxide and finally to highly neurotoxic OH⋅ radicals. The purpose of this study has been to investigate at a computational level, by Density Functional Theory (DFT) and molecular mechanics techniques, the final two steps of O2 reduction to OH− +OH radical i.e the superoxide and hydroperoxide reduction by ascorbate, on different Cu(II) ⋅ Aβ coordination models. At variance with the first step of O2 reduction to O2.− characterized by high energy barrier, the successive O2.− and O2H− reductions are low energy barriers processes and that the OH⋅ radical formation is further favored by the possibility of Cu(II) ⋅ Aβ to form the Asp1 amino terminal radical. We discuss the results obtained from the perspective of the recent findings in the Aβ redox chemistry in AD pathology.