Superoxide Dismutase Research Articles

Potential anxiolytic therapeutics from Hybanthus enneaspermus (L.) F. Muell. - mitigate anxiety by plausibly modulating the GABAA-Cl- channel

Anxiety is a commonly prevailing psychological disorder that requires effective treatment, wherein phytopharmaceuticals and nutraceuticals could offer a desirable therapeutic profile. Hybanthus enneaspermus (L.) F. Muell. is a powerful medicinal herb, reportedly effective against several ailments, including psychological disorders. The current research envisaged evaluating the anxiolytic potential of the ethanolic extract of Hybanthus enneaspermus (EEHE) and its toluene insoluble biofraction (ITHE) employing experimental and computational approaches. Elevated Plus Maze, Light and Dark Transition, Mirror Chamber, Hole board and Open field tests were used as screening models to assess the antianxiety potential of 100, 200 and 400 mg/kg body weight of EEHE and ITHE in rats subjected to social isolation, using Diazepam as standard. The brains of rats exhibiting significant anxiolytic activity were dissected for histopathological and biochemical studies. Antioxidant enzymes like catalase, superoxide dismutase, glutathione-S-transferase, glutathione peroxidase, glutathione reductase; and neurotransmitters viz. monoamines (serotonin, noradrenaline, dopamine), Gamma-aminobutyric acid (GABA), and glutamate were quantified in the different regions of rats’ brain (cortex, hippocampus, pons, medulla oblongata, cerebellum). Chromatographic techniques were used to isolate phytoconstituents from the fraction exhibiting significant activity that were characterized by spectroscopic methods and subjected to in silico molecular docking. ITHE at 400 mg/kg body weight significantly mitigated anxiety in all the screening models (p < 0.05), reduced the inflammatory vacuoles and necrosis (p < 0.05) and potentiated the antioxidant enzymes (p < 0.05). It enhanced the monoamines and GABA levels while attenuating glutamate levels (p < 0.01) in the brain. Three significant flavonoids viz. Quercitrin, Rutin and Hesperidin were isolated from ITHE. In silico docking studies of these flavonoids revealed that the compounds exhibited substantial binding to the GABAA receptor. ITHE displayed a promising pharmacological profile in combating anxiety and modulating oxidative stress, attributing its therapeutic virtues to the flavonoids present.

Physiology, Biochemistry, and Transcriptomics Jointly Reveal the Phytotoxicity Mechanism of Acetochlor on Pisum sativum L.

Acetochlor, as a commonly used pre-emergent herbicide, can be toxic to crops and affect production if used improperly. However, the toxic mechanism of acetochlor on plants is not fully understood. The present study used a combination of transcriptomic analysis and physiological measurements to investigate the effects of short-term (15-day) exposure to different concentrations of acetochlor (1, 10, 20 mg/kg) on the morphology, physiology, and transcriptional levels of pea seedlings, aiming to elucidate the toxic response and resistance mechanisms in pea seedlings under herbicide stress. The results showed that the toxicity of acetochlor to pea seedlings was dose-dependent, manifested as dwarfing and stem base browning with increasing concentrations, especially at 10 mg/kg and above. Analysis of the antioxidant system showed that from the 1 mg/kg treatment, malondialdehyde, superoxide dismutase, peroxidase, and glutathione peroxidase in peas increased with increasing concentrations of acetochlor, indicating oxidative damage. Analysis of the glutathione (GSH) metabolism system showed that under 10 mg/kg treatment, the GSH content of pea plants significantly increased, and GSH transferase activity and gene expression were significantly induced, indicating a detoxification response in plants. Transcriptomic analysis showed that after acetochlor treatment, differentially expressed genes in peas were significantly enriched in the phenylpropane metabolic pathway, and the levels of key metabolites (flavonoids and lignin) were increased. In addition, we found that acetochlor-induced dwarfing of pea seedlings may be related to gibberellin signal transduction. Environ Toxicol Chem 2024;00:1-15. © 2024 SETAC.

Synergistic toxic effects and mechanistic insights of beta-cypermethrin and pyraclostrobin exposure on hook snout carp (Opsariichthys bidens): A biochemical, transcriptional, and molecular approach

The extensive utilization of pesticides results in their frequent detection in aquatic environments, often as complex mixtures, posing risks to aquatic organisms. The hook snout carp (Opsariichthys bidens) serves as a valuable bioindicator for evaluating the impacts of environmental pollutants in aquatic ecosystems. However, few studies examined the toxic effects of pesticides on O.bidens, let alone the characterization of the combined effects resulting from their mixtures. This study aims to elucidate the toxic effects of beta-cypermethrin and pyraclostrobin on O.bidens, individually and in combination, focusing on biochemical, transcriptional, and molecular responses. By organizing and analyzing the toxicogenomic databases, both pesticides were identified as a contributor to processes such as apoptosis, oxidative stress, and inflammatory responses. The acute toxicity test revealed comparable acute toxicity of beta-cypermethrin and pyraclostrobin on O.bidens, with LC50 being 0.019 and 0.027 mg/L, respectively, whereas the LC50 decreased to 0.0057 and 0.0079 mg/L under the combined exposure, indicating potential synergistic effects. The activities of enzymes involved in oxidative stress and detoxification were significantly altered after exposure, with superoxide dismutase (SOD) and catalase (CAT) increasing, while malondialdehyde (MDA) levels decreased. The activity of CYP450s was significantly changed. Likewise, the expression levels of genes (mn-sod, p53, esr, il-8) associated with oxidative stress, apoptosis, endocrine and immune systems were significantly increased. Combined exposure to the pesticides significantly exacerbated the aforementioned biological processes in O.bidens. Furthermore, both pesticides can modify protein activity by binding to the surface of SOD molecules and altering protein conformation, contributing to the elevated enzyme activity. Through the investigation of the synergistic toxic effects of pesticides and molecular mechanisms in O.bidens, our findings highlight the importance of assessing the combined effects of pesticide mixtures in aquatic environments.

Mitigating Ni and Cu ecotoxicity in the ecological restoration material and ornamental Primula forbesii Franch. with exogenous 24-epibrassinolide and melatonin

Nickel (Ni) and copper (Cu) contamination have become major threats to plant survival worldwide. 24-epibrassinolide (24-EBR) and melatonin (MT) have emerged as valuable treatments to alleviate heavy metal-induced phytotoxicity. However, plants have not fully demonstrated the potential mechanisms by which these two hormones act under Ni and Cu stress. Herein, this study investigated the impact of individual and combined application of 24-EBR and MT on the growth and physiological traits of Primula forbesii Franch. subjected to stress (200 μmol L–1 Ni and Cu). The experiments compared the effects of different mitigation treatments on heavy metal (HM) stress and the scientific basis and practical reference for using these exogenous substances to improve HM resistance of P. forbesii in polluted environments. Nickel and Cu stress significantly hindered leaf photosynthesis and nutrient uptake, reducing plant growth and gas exchange. However, 24-EBR, MT, and 24-EBR + MT treatments alleviated the growth inhibition caused by Ni and Cu stress, improved the growth indexes of P. forbesii, and increased the gas exchange parameters. Exogenous MT effectively alleviated Ni stress, and 24-EBR + MT significantly alleviated the toxic effects of Cu stress. Unlike HM stress, MT and 24-EBR + MT activated the antioxidant enzyme activity (by increasing superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), significantly reduced reactive oxygen species (ROS) accumulation, and regulated ascorbate and glutathione cycle (AsA-GSH) efficiency. Besides, the treatments enhanced the ability of P. forbesii to accumulate HMs, shielding plants from harm. These findings conclusively illustrate the capability of 24-EBR and MT to significantly bolster the tolerance of P. forbesii to Ni and Cu stress.

Treatment with walnut peptide ameliorates memory impairment in zebrafish and rats: promoting the expression of neurotrophic factors and suppressing oxidative stress.

Walnut peptide, a low molecular weight peptide separated from walnuts by enzymatic hydrolysis, is considered as a potential nutraceutical with a variety of biological activities. In this study, we characterized the walnut peptide prepared by alkaline protease hydrolysis and evaluated its neuroprotective effect in zebrafish and rat models of memory disorders. Series of concentrations of the walnut peptide were orally administered to zebrafish and rats to examine its impact on the behavior and biochemical indicators. The results showed that the oral administration of walnut peptide significantly ameliorated the behavioral performance in zebrafish exposed to bisphenol AF (1 μg mL-1) and rats exposed to alcohol (30% ethanol, 10 mL kg-1). Furthermore, the walnut peptide upregulated the expression of neurotrophic-related molecules in zebrafish, such as the brain-derived neurotrophic factor (BDNF) and the glial cell-derived neurotrophic factor (GDNF). In the rat brain, the walnut peptide increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), while dramatically reduced malondialdehyde (MDA) level. Together, these findings elucidated that the walnut peptide might partially offset the declarative memory deficits via regulation of neurotrophic-related molecule expression and promotion of the antioxidant defense ability. Therefore, walnut peptide holds the potential for development into functional foods as a nutritional supplement for the management of certain neurodegenerative disorders.

Protective effect of tert-butylhydroquinone against cisplatin-induced hepatorenal injury via modulating oxidative stress, inflammation, and apoptosis

Context Cisplastin (CDDP) is a chemotherapeutic drug frequently used to manage a variety of cancers. However, its use is associated with hepatorenal toxicity resulting from elevated reactive oxygen species production. Objective Herein, the hepatorenal protective effect of tert-butylhydroquinone (tBHQ) in cisplatin (CDDP)-treated rats was examined. Methods Wistar male rats randomly divided into four groups: normal control, tBHQ, CDDP and tBHQ + CDDP received 50 mg/kg b.w./day of tBHQ orally for 14 days while 7 mg/kg b.w of CDDP was administered intraperitoneally on Day 8. Results CDDP increased serum biomarkers of hepatic (AST, ALP, ALT, GGT) and renal (creatinine, urea, uric acid, kidney injury molecule 1) function. The levels of nuclear factor erythroid-2-related factor 2 protein and the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities were decreased in liver and kidney. Also, CDDP increased hepatic and renal levels of NF-κB, TNFα, Bax and caspase-3 proteins and decreased hepatorenal levels of Bcl-2 protein in the liver and kidney. Pre-treatment with tBHQ prevented these negative effects. Significance Pre-intervention with tBHQ attenuates hepatorenal toxicity of CDDP by dampening oxidative stress, inflammation and apoptosis.

Induction of necrosis symptoms by potato virus X in AGO2-silenced tomato plants associates with reduced transcript accumulation of copper chaperon for superoxide dismutase gene

RNA silencing is a prominent antiviral defense mechanism in plants. When infected with a virus, RNA silencing–deficient plants tend to show exacerbated symptoms along with increased virus accumulation. However, how symptoms are exacerbated is little understood. Here, we investigated the role of the copper chaperon for superoxide dismutase (CCS) 1, in systemic necrosis observed in Argonaute (AGO)2-silenced tomato plants infected with potato virus X (PVX). While infection with the UK3 strain of PVX induced mosaic symptoms in tomato plants, systemic necrosis occurred when AGO2 was silenced. The CCS1 mRNA level was reduced and micro RNA398 (miR398), which potentially target CCS1, was increased in AGO2-knockdown tomato plants infected with PVX-UK3. Ectopic expression of CCS1 using recombinant PVX attenuated necrosis, suggesting that CCS1 alleviates systemic necrosis by activating superoxide dismutases to scavenge reactive oxygen species. Previous reports have indicated a decrease in the levels of CCS1 and superoxide dismutases along with an increased level of miR398 in plants infected with other viruses and viroids, and thus might represent shared regulatory mechanisms that exacerbate symptoms in these plants.

Mitigating drought-induced oxidative stress in wheat (Triticum aestivum L.) through foliar application of sulfhydryl thiourea

Drought stress is a major abiotic stress affecting the performance of wheat (Triticum aestivum L.). The current study evaluated the effects of drought on wheat phenology, physiology, and biochemistry; and assessed the effectiveness of foliar-applied sulfhydryl thiourea to mitigate drought-induced oxidative stress. The treatments were: wheat varieties; V1 = Punjab-2011, V2 = Galaxy-2013, V3 = Ujala-2016, and V4 = Anaaj-2017, drought stress; D1 = control (80% field capacity [FC]) and D2 = drought stress (40% FC), at the reproductive stage, and sulfhydryl thiourea (S) applications; S0 = control-no thiourea and S1 = foliar thiourea application @ 500 mg L−1. Results of this study indicated that growth parameters, including height, dry weight, leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), net assimilation rate (NAR) were decreased under drought stress-40% FC, as compared to control-80% FC. Drought stress reduced the photosynthetic efficiency, water potential, transpiration rates, stomatal conductances, and relative water contents by 18, 17, 26, 29, and 55% in wheat varieties as compared to control. In addition, foliar chlorophyll a, and b contents were also lowered under drought stress in all wheat varieties due to an increase in malondialdehyde and electrolyte leakage. Interestingly, thiourea applications restored wheat growth and yield attributes by improving the production and activities of proline, antioxidants, and osmolytes under normal and drought stress as compared to control. Thiourea applications improved the osmolyte defense in wheat varieties as peroxidase, superoxide dismutase, catalase, proline, glycine betaine, and total phenolic were increased by 13, 20, 12, 17, 23, and 52%; while reducing the electrolyte leakage and malondialdehyde content by 49 and 32% as compared to control. Among the wheat varieties, Anaaj-2017 showed better resilience towards drought stress and also gave better response towards thiourea application based on morpho-physiological, biochemical, and yield attributes as compared to Punjab-2011, Galaxy-2013, and Ujala-2016. Eta-square values showed that thiourea applications, drought stress, and wheat varieties were key contributors to most of the parameters measured. In conclusion, the sulfhydryl thiourea applications improved the morpho-physiology, biochemical, and yield attributes of wheat varieties, thereby mitigating the adverse effects of drought. Moving forward, detailed studies pertaining to the molecular and genetic mechanisms under sulfhydryl thiourea-induced drought stress tolerance are warranted.

Evaluation of Antimicrobial and Antioxidant Potential of Oxalis corymbosa Extracts.

This work aimed to assess the antioxidant and antimicrobial properties of Oxalis corymbosa extracts. Biochemical analyses were conducted on various plant parts, utilizing enzymatic and non-enzymatic assays. Parameters such as total soluble protein, chlorophyll, and carotenoid contents were also evaluated to elucidate the role of bioactive chemical compounds. The antimicrobial screening of extracts was performed against the bacterial and fungal strains Escherichia coli, Staphylococcus aureus, and Candida albicans, respectively. Results indicated that chlorophyll a, chlorophyll b, total chlorophyll, carotenoid content, anthocyanin content, catalase, peroxidase, and superoxide dismutase were most abundant in the O. corymbosa leaves. Moreover, total ascorbate peroxidase content, total phenolic content, and total flavonoid content were found to be higher in the roots compared to other parts. High-performance liquid chromatography analysis identified chlorogenic acid as the major component, followed by gallic acid, caffeic acid, quercetin, and salicylic acid. Regarding antibacterial potential, each extract exhibited significant activity, with methanolic and ethyl acetate extracts demonstrating the maximum inhibition zone against S. aureus and E. coli, respectively. These findings highlight the substantial antioxidant and antibacterial potential of different parts of O. corymbosa, suggesting their promising applications as ingredients in various nutraceutical products.

Flavonoids for treating pulmonary fibrosis: Present status and future prospects.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with an unknown underlying cause. There is no complete cure for IPF; however, two anti-fibrotic agents (Nintedanib and pirfenidone) are approved by the USFDA to extend the patient's life span. Therefore, alternative therapies supporting the survival of fibrotic patients have been studied in recent literature. The abundance of phenolic compounds, particularly flavonoids, has gathered attention due to their potential health benefits. Various flavonoids, like naringin, quercetin, baicalin, baicalein, puerarin, silymarin, and kaempferol, exhibit anti-inflammatory and anti-oxidant properties, which help decrease lung fibrosis. Various databases, including PubMed, EBSCO, ProQuest, and Scopus, as well as particular websites, such as the World Health Organisation and the National Institutes of Health, were used to conduct a literature search. Several mechanisms of action of flavonoids are reported with the help of in vivo and cell line studies emphasizing their ability to modulate oxidative stress, inflammation, and fibrotic processes in the lungs. They are reported for the restoration of biomarkers like hydroxyproline, cytokines, superoxide dismutase, malondialdehyde and others associated with IPF and for modulating various pathways responsible for the progression of pulmonary fibrosis. Yet, flavonoids have some drawbacks, such as poor solubility, challenging drug loading, stability issues, and scarce bioavailability. Therefore, novel formulations of flavonoids are explored, including liposomes, solid lipid microparticles, polymeric nanoparticles, nanogels, and nanocrystals, to enhance the therapeutic efficacy of flavonoids in pulmonary fibrosis. This review focuses on the role of flavonoids in mitigating idiopathic pulmonary fibrosis, their mode of action and novel formulations.

The Protective Effect of Melatonin on LPS-Induced Myocardial Injury via the Caspase-11/GSDMD Pathway.

Melatonin (MT) has been demonstrated to have cardioprotective effects. Nevertheless, the precise mechanism through which MT provides protection against the etiology of LPS-induced myocardial injury remains uncertain. In this investigation, our objective was to explore the impact of MT on LPS-induced myocardial injury in an in vitro setting. H9C2 cells were categorized into four groups: a control group (H9C2 group), an MT group, an LPS group, and an MT + LPS group. The H9C2 group received treatment with sterile saline solution, the LPS group was exposed to 5 μg/mL LPS for 24 hours, the MT + LPS group underwent pretreatment with 150 μmol/L MT for 2 hours, followed by exposure to 5 μg/mL LPS for 24 hours, and the MT group received only 150 μmol/L MT for 2 hours. Cell viability and lactate dehydrogenase (LDH) release were assessed using the CCK-8 assay and LDH activity assay, respectively. The levels of reactive oxygen species (ROS) were quantified in each group of cells, and the percentage of propidium iodide (PI)-stained apoptotic cells was determined by flow cytometry. The mRNA levels of caspase11, GSDMD, and IL-18 in each group of cells were quantified. MT treatment significantly protected H9C2 cells from LPS-induced damage, as evidenced by decreased LDH release. LPS treatment markedly increased ROS levels in H9C2 cells, which were subsequently reduced by MT. LPS caused a substantial decrease in superoxide dismutase (SOD) activity and a significant increase in malondialdehyde (MDA) levels, while MT treatment significantly reversed these effects. Additionally, MT markedly enhanced the proportion of viable H9C2 cells compared to LPS-treated controls, as evidenced by the PI staining assay. LPS upregulated both mRNA levels and protein levels of IL-18 in H9C2 cells. However, MT treatment effectively mitigated this LPS-induced increase. Furthermore, MT significantly decreased LPS-induced protein levels of cleaved-caspase 11 and GSDMD-N in H9C2 cells. Overall, our findings suggest that MT inhibits the Caspase11-GSDMD signaling pathway via pyroptosis-related proteins (caspase-11 and GSDMD-N) and reduces the expression of inflammation-related cytokines (IL-18), thereby exerting a protective effect on H9C2 cells after LPS injury.

Effects of tea infusion on selenium uptake in grapevine

Increased selenium (Se) content in fruits can supply Se in human body, but the effects of teas on the Se uptake in fruit trees are unknown. The effects of infusions of four teas (green, black, dark, and white) on the Se uptake of grapevine were studied to promote the Se uptake in fruit trees in this study. However, only black tea infusion increased the biomass, photosynthetic pigment content, superoxide dismutase (SOD) activity, peroxidase (POD) activity, and soluble protein content of grapevine. Except for white tea infusion, other tea infusions also increased the catalase (CAT) activity of grapevine. Furthermore, the tea infusions increased the activities of adenosine triphosphate sulfurase (ATPS) and adenosine 5’-phosphosulfate reductase (APR), and decreased the activities of serine acetyltransferase (SAT) and selenocysteine methyltransferase (SMT). Only the dark and white tea infusions increased the shoot total Se content by 86.53% and 23.32%, respectively (compared with the control), and also increased the shoot inorganic Se content and shoot organic Se content. Notably, four tea infusions decreased the organic Se proportion and increased the inorganic Se proportion in grapevine. Correlation and grey relational analyses showed that the root total Se content, ATPS activity, and ARP activity were closely associated with the shoot total Se content. The principal component and cluster analyses also showed that the ATPS activity, APR activity, root total Se content, and shoot total Se content were classified into one category. These findings show that black tea infusion can promote grapevine growth, while dark and white tea infusions can promote the Se uptake in grapevine.

Multifunctional cerium oxide nanozymes with high ocular surface retention for dry eye disease treatment achieved by restoring redox balance

Dry eye disease (DED) is a kind of multifactorial ocular surface disease that displays ocular discomfort, visual disturbance, and tear film instability. Oxidative stress is a fundamental pathogenesis in DED. An imbalance between the reactive oxygen species (ROS) level and protective enzyme action will lead to oxidative stress, cell dysfunction, tear hyperosmolarity, and inflammation. Herein, a multifunctional cerium oxide nanozyme with high ocular surface retention property was designed to neutralize over-accumulated ROS and restore redox balance. Cerium oxide nanozymes were fabricated via branched polyethylenimine-graft-poly (ethylene glycol) nucleation and dispersion, followed by phenylboronic acid (PBA) functionalization (defined as Ce@PB). Due to the dynamic chemical bonding formation between the PBA segment and the cis-diol groups in the mucin layer of the tear film, Ce@PB nanozymes possess good adhesive capability to the ocular surface, thus extending the drug's retention time. On the other hand, Ce@PB nanozymes could mimic the cascade processes of superoxide dismutase and catalase to maintain intracellular redox balance. In vitro and in vivo studies suggest that such multifunctional nanozymes possess good biocompatibility and hemocompatibility. More importantly, Ce@PB nanozymes treatment in the animal model could repair corneal epithelial defect, increase the number of goblet cells and promote tear secretion, thus achieving an effective treatment for DED. Statement of Significance• PBA-functionalized bPEI-g-PEG-based cerium oxide (Ce@PB) nanozymes were designed and fabricated.• The Ce@PB nanozymes have superoxide dismutase (SOD) and catalase (CAT) enzyme-like activity scavenging excessive intracellular reactive oxygen species (ROS).• The Ce@PB nanozymes demonstrate extended retention on the ocular surface and can effectively treat dry eye disease.

Unravelling drought and salinity stress responses in barley genotypes: physiological, biochemical, and molecular insights

In the face of escalating environmental challenges, understanding crop responses to abiotic stress is pivotal for sustainable agriculture. The present study meticulously investigates the intricate interplay between drought and salinity stress in barley (Hordeum vulgare L.). Employing three distinct barley genotypes—Traveller, Prunella, and Zahna—we scrutinize their physiological, biochemical, and molecular adaptations under stress conditions. Our findings underscore genotype-specific responses, unravelling the multifaceted mechanisms that govern stress tolerance. Chlorophyll content, a vital indicator of photosynthetic efficiency, exhibits significant variations across genotypes. Salinity stress induces a decline in chlorophyll levels, while drought stress triggers a more nuanced response. Stomatal conductance, a key regulator of water loss, also diverges among the genotypes. Traveller displays remarkable stomatal closure under drought, conserving water, whereas Prunella and Zahna exhibit contrasting patterns. Antioxidant enzyme activities, crucial for combating oxidative stress, fluctuate significantly. Activities of superoxide dismutase (SOD) and catalase (CAT) surge under salinity stress, while drought predominantly impacts SOD. Gene expression profiling reveals genotype-specific signatures, with stress-responsive genes modulating adaptive pathways. Correlation analyses revealed the intricate interplay of the physiological and biochemical parameters. Genotype-specific adaptations, coupled with dynamic physiological and molecular responses, underscore the plasticity of barley’s stress tolerance mechanisms. Throughout the study, the Zahna genotype demonstrated notable tolerance in terms of performance. These insights hold promise for breeding resilient cultivars, bolstering food security in an increasingly unpredictable climate. By deciphering the barley stress symphony, we contribute to the harmonious orchestration of sustainable agricultural practices.

Improving blueberry cold storage quality: the effect of preharvest hexanal application on chilling injuries and antioxidant defense mechanisms.

Blueberries are vulnerable to chilling injury (CI). This can lead to limited longevity when they are subjected to cold storage conditions. This study investigated the effectiveness of a preharvest spray containing 0.02% hexanal in reducing CI and improving the postharvest storage quality of 'Star' and 'Biloxi' blueberries. The blueberries were stored for a period of 5 weeks at 2 °C and in 90% relative humidity (RH). The findings revealed that the preharvest hexanal spraying of both cultivars delayed senescence by mitigating CI, as evidenced by the bolstering of the antioxidant defense system through increased superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT), and phenylalanine ammonia lyase (PAL) enzyme activity. The treated fruit also maintained elevated levels of total phenol content (TPC), total flavonoids (TFC), and vitamin C, demonstrating enhanced free radical scavenging capacity (FRSC), while exhibiting reduced polyphenoloxidase (PPO) activity, and reduced malondialdehyde (MDA), and H2O2 content in comparison with the control group. The preharvest hexanal treatment also suppressed fruit softening by maintaining greater firmness and higher membrane stability index (MSI) scores, inhibiting the activity of polygalacturonase (PG), pectinmethylesterase (PME), xylanase, and α-amylase, and reducing microbial counts (MC) and incidence of decay (DI) in comparison with the control. Preharvest hexanal treatment also improved the overall storage quality by reducing weight loss, total soluble solids (TSS), pH, and the TSS/acid ratio, while increasing titratable acidity (TA) in comparison with the control during cold storage. The findings suggest that hexanal, as a preharvest application, delays senescence effectively and preserves overall quality by enhancing cold tolerance through antioxidant defense mechanisms in blueberry storage under cold conditions. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Adaptive traits of Planctomycetota bacteria to thrive in macroalgal habitats and establish mutually beneficial relationship with macroalgae

AbstractBacteria and macroalgae share an inseparable relationship, jointly influencing coastal ecosystems. Within macroalgae habitats, Planctomycetota, a group of bacteria notoriously challenging to cultivate, often dominate. However, the mechanisms facilitating their persistence in this environment remain unclear. Here, we successfully isolated a novel Planctomycetota bacterium, Stieleria sp. HD01, from the surface of kelp. We demonstrated that HD01 possesses a robust ability to metabolize fucoidan, which constitutes half of the kelp‐derived organic carbon and exhibits resistance to attack by most microorganisms. Moreover, HD01 can utilize a broad spectrum of other organics, indicating its metabolic versatility and competitive prowess within algal environments. Additionally, HD01 can secrete antagonistic substances against other bacteria, form biofilms, and employ superoxide dismutase and catalase to resist oxidative stress, further consolidating its ecological fitness. Comparative metagenomics analysis suggested that Planctomycetota may have a mutually beneficial relationship with kelp.

Temperature acclimation and response to acute thermal stress in the adults of the snow crab Chionoecetes opilio Fabricius, 1788 (Decapoda: Brachyura: Oregoniidae)

ABSTRACT Ectothermic marine animals vary widely in their tolerance to temperature changes, and polar stenothermal species seem to have poor ability to compensate for a rise in water temperature. The sub-Arctic snow crab (Chionoecetes opilioFabricius, 1788) lives in the northwestern Atlantic Ocean and northern Pacific Ocean at temperatures ranging from about −1.5 °C to 4 °C. Since the metabolic costs overtake caloric intake above 7 °C, the snow crab appears to be energetically restricted to cold water. We investigated thermal stress responses in adult male crabs exposed to a sudden temperature increase to 9.5 °C for 24 hr after four weeks of acclimation at 2.5 °C or 5.5 °C. Heart-rate loggers implanted in a limited number of crabs showed 60% increase in cardiac activity during the thermal stress. Surplus oxygen supply in all crabs was inferred by the low hemolymph lactate and unchanged glucose levels, but only the crabs acclimated at 5.5 °C were still active at the elevated temperature. Low heat shock and oxidative stress responses were suggested by the missing upregulation of the genes encoding four heat shock proteins (Hsp70a, Hsc71, Hsp90a2, Hsp60) and the antioxidative enzymes superoxide dismutase and catalase. The trend towards inverse temperature-dependent on the expression of the hsp genes may be related to increased protein damage at low temperatures, or possible trade-offs between costs and benefits of producing heat shock proteins at elevated temperature. Although adult snow crabs seem to be able to cope with short-term heat stress, the tolerance to chronic elevated temperatures should be further examined using a larger number of individuals.

Genome-wide identification and expression analysis of the SOD gene family under biotic and abiotic stresses in sweet orange

Genome-wide identification and expression analysis of the SOD gene family under biotic and abiotic stresses in sweet orange

Ecotoxicological Research on the Toxic Impact of Zinc Oxide and Silver Nanoparticles on Oreochromis mossambicus.

Silver nanoparticles (AgNPs) and Zinc oxide nanoparticles (ZnONPs) have been widely used and are eventually been discharged into the natural aquatic ecosystem. The current study examined and correlated the toxicity of AgNPs and ZnONPs on the Mozambique tilapia, Oreochromis mossambicus. Lethal concentration (LC50) was determined with four different concentrations (0.05, 0.10, 0.15, and 0.20 mg/L) of AgNPs and ZnONPs; subsequently, the fishes were exposed to sublethal concentrations for a period of 21 days, and the oxidative stress and antioxidant and nonantioxidant parameters were studied. Results revealed oxidative stress evinced by increased lipid peroxidation (LPO) protein carbonyl activity (PCA), glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) activity, metallothionein (MT) activity, and reduced glutathione in chronic exposure compared with acute exposure. Nonspecific immunological characteristics such as lysozyme (LYZ), myeloperoxidase (MPO), and respiratory burst activity (RBA) were also noticed in the serum. Furthermore, severe histological damages including damages in telangiectasia and epithelial cell hyperplasia were found in the combined treated group with Ag and ZnONPs than in individual treatments. When Ag and ZnONPs were combined, a reduction in the accumulation of Ag was observed in the liver, which increased drastically in individual exposure. The current findings highlight the importance of taking into account the combined exposure and correlation of NPs, their bioavailability, and toxicity in the aquatic ecosystem.

Ecotoxicological Research on the Toxic Impact of Zinc Oxide and Silver Nanoparticles on Oreochromis mossambicus.

Silver nanoparticles (AgNPs) and Zinc oxide nanoparticles (ZnONPs) have been widely used and are eventually been discharged into the natural aquatic ecosystem. The current study examined and correlated the toxicity of AgNPs and ZnONPs on the Mozambique tilapia, Oreochromis mossambicus. Lethal concentration (LC50) was determined with four different concentrations (0.05, 0.10, 0.15, and 0.20 mg/L) of AgNPs and ZnONPs; subsequently, the fishes were exposed to sublethal concentrations for a period of 21 days, and the oxidative stress and antioxidant and nonantioxidant parameters were studied. Results revealed oxidative stress evinced by increased lipid peroxidation (LPO) protein carbonyl activity (PCA), glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) activity, metallothionein (MT) activity, and reduced glutathione in chronic exposure compared with acute exposure. Nonspecific immunological characteristics such as lysozyme (LYZ), myeloperoxidase (MPO), and respiratory burst activity (RBA) were also noticed in the serum. Furthermore, severe histological damages including damages in telangiectasia and epithelial cell hyperplasia were found in the combined treated group with Ag and ZnONPs than in individual treatments. When Ag and ZnONPs were combined, a reduction in the accumulation of Ag was observed in the liver, which increased drastically in individual exposure. The current findings highlight the importance of taking into account the combined exposure and correlation of NPs, their bioavailability, and toxicity in the aquatic ecosystem.