Antioxidant Enzyme Activities Research Articles

Replacing Inorganic Source of Zinc with Zinc Hydroxy Chloride: Effects on Health Status, Hemato-biochemical Attributes, Antioxidant Status, and Immune Responses in Pre-ruminant Crossbred Calves.

The current research aimed to assess the feasibility of using Zn hydroxy chloride (ZnOHCl) as an alternative to ZnSO4 in pre-ruminant crossbred calves. Twenty-four male crossbred calves (Tharparkar × Holstein Friesian) were categorized into four groups according to body weight and age (body weight 31kg; age 10days). Experimental calves were kept on a similar feeding regimen except that different groups were supplemented with either 0mg Zn/kg DMI (Zn-0), 80mg Zn/kg DMI as ZnSO4 (ZnS-80), 40mg Zn/kg DMI as ZnOHCl (ZnH-40), or 80mg Zn/kg DMI as ZnOHCl (ZnH-80). All the calves were fed for 90days as per ICAR (2013) feeding standard to fulfill their nutrient requirements for growth rate of500g/day. The study observed the influence of different sources and varying levels of Zn supplementation over a 90-day experimental period on health status, hemato-biochemical attributes, antioxidant status, immune responses, and plasma minerals and erythrocyte Zn concentrations. The data was examined using a randomized complete block design (RCBD) with fixed effects of treatment, period, and their interaction. The results indicated that irrespective of the sources and levels of Zn, supplementation did not lead to significant changes in health status as assessed by fecal score, nasal score, ear score, and eye score. Hematological parameters remained unchanged following supplementation with different sources and levels of Zn. Zn-supplemented groups showed higher levels of total protein, globulin, and alkaline phosphates (ALP) compared to the non-supplemented group. However, no significant variations were detected within the Zn-supplemented groups. Zinc supplementation significantly increased total antioxidant capacity (TAC), antioxidant enzyme activity, total immunoglobulin (Ig), immunoglobulin G (IgG), cell-mediated immunity (CMI), and humoral immunity (HI); however, no significant variations were detected among Zn-supplemented groups. Zn supplementation enhanced plasma and RBC Zn concentration without affecting the plasma concentration of other minerals. However, among the Zn-supplemented groups, 80mg Zn/kg DMI as ZnOHCl resulted in the highest RBC Zn concentration. The study results demonstrate that Zn supplementation enhanced biomarkers of zinc status, antioxidant levels, and immune responses in pre-ruminant crossbred calves. Nevertheless, no significant variations were observed between the different Zn sources (ZnSO4 and ZnOHCl) utilized in this study. Research suggests that ZnOHCl could be a feasible alternative to ZnSO4 in the diet of pre-ruminant crossbred calves.

Copper oxide nanoparticles mitigate cadmium toxicity in rice seedlings through multiple physiological mechanisms.

Heavy metal pollution poses a serious threat to crops growth and yield. Recently, nanoparticles (NPs) have emerged as a promising strategy to mitigate the negative effect of heavy metal on crop growth. This study investigated the beneficial effects of copper oxide nanoparticles (CuO NPs) on the morphological and physiological-biochemical traits of rice seedlings (Oryza sativa L.) under cadmium (Cd) stress. The results demonstrated that the application of CuO NPs increased the contents of nutrition elements in shoots and roots as well as photosynthetic pigments, consequently improving the growth of rice seedlings under Cd stress, especially at low level of Cd stress. Meanwhile, CuO NPs obviously decreased the Cd accumulation in the rice seedlings and immobilized Cd in less toxic chemical forms and subcellular compartments. Moreover, CuO NPs modulated the antioxidant system, ameliorating oxidative damage and membrane injury caused by Cd. Multivariate analysis established correlations between physio-biochemical parameters and further revealed the mitigation of Cd damage to rice seedlings by CuO NPs was associated with inhibition Cd accumulation, altering Cd chemical form and subcellular distribution, increasing the contents of mineral nutrients, photosynthetic pigments and secondary metabolites and antioxidant enzyme activities, and reducing oxidative damage. Overall, the present study indicated that CuO NPs could effectively reduce the Cd toxicity to rice seedlings, demonstrating their potential application in agricultural production.

Prefeeding of berberine alleviates waterborne copper-induced hepatic oxidative stress, lipid deposition, and intestinal microbiota dysbiosis in yellow catfish (Pelteobagrus fulvidraco)

Copper (Cu) contamination is a common issue in aquaculture and normally leads to hepatic and intestinal damage in fish. Due to the effective lipid-lowering, antioxidative, and intestinal microbiota-maintaining properties of berberine (BBR), it has the potential to be a feed additive to diminish Cu toxicity in fish. This study aimed to determine whether berberine could alleviate hepatic and intestinal damage in yellow catfish (Pelteobagrus fulvidraco) caused by waterborne Cu2+ exposure. The fish with the same weight (2.65 ± 0.25 g) were assigned to four groups: a control group (Con) that received a control diet for nine weeks; a Cu group, a BBR100 group, and a BBR400 group that received the control diet, 100 mg/kg berberine, and 400 mg/kg berberine for eight weeks, respectively, and after that, they were exposed to 0.8 mg/L Cu2+ for an additional week. The BBR100 and BBR 400 groups had significantly higher weight gain than the Cu group, but significantly lower hepatic and serum total cholesterol and triglyceride levels, and berberine treatment significantly improved intestinal and hepatic histological damage (P < 0.05). Berberine treatment significantly increased intestinal complement 3 and complement 4 levels but distinctly regulated hepatic and intestinal antioxidant enzyme activities while significantly reducing malondialdehyde levels compared to those in the Cu group. In addition, pretreatment with berberine significantly increased the expression levels of intestinal farnesoid X receptor (fxr) and fibroblast growth factor 19, as well as hepatic fxr, and downregulated the expression of its downstream lipogenesis genes (srebp1c, fas, and pparγ). Based on 16S rDNA analysis, the abundances of some probiotic bacteria (e.g., Lactobacillus) were elevated, but the abundances of some pathogenic bacteria (e.g., Morganella) decreased in the BBR400 group. At KEGG level 3, the pathway related to “Pathogenic Escherichia coli infection” was significantly enriched in the Cu group but significantly lower enriched in the BBR100 group. These findings indicated that berberine alleviated waterborne copper-induced hepatic and intestinal damage mainly by activating the FXR pathway, reducing oxidative stress and lipid deposition, and maintaining intestinal microbiota homeostasis in yellow catfish.

Strategies of invasive snail Pomacea canaliculata during hibernation in rice fields of south China: effects of body size, sex, and soil depth.

The invasive freshwater snail Pomacea canaliculata is an agricultural pest with a certain level of tolerance to abiotic stress. After the harvest of late rice, the snails usually burrow themselves into the soil surface layers to overwinter and pose a renewed threatto rice production in the following year. Revealing the response of snails to environmental stresses is crucial for developing countermeasures to control their damage and spread. In this study, we conducted a 120-day in situ experiment during the winter to investigate the survival and physiological changes of hibernating snails in 0-5 and 5-10 cmsoil depths, aiming to explore their overwintering strategies. Our results showed that 73.61%, 87.50%, and 90.28% of male, female, and juvenile snails survived after hibernation for 120 days in 0-10 cm soil depth, respectively. The differences in survival rates based on sex and size of snailspotentially reflect the countermeasures of snails to rapidly reproduce after hibernation. Simultaneously, the hibernating snails exhibited the ability to maintain a certain level of body weight. During this period, the snails increased their antioxidant enzyme activities to cope with oxidative stress, and enhanced their lipid storage. The hibernation survival of snails was not significantly affected by different soil depths, indicating that they have the potential to hibernate into deeper soils. Furthermore, snails were capable of increasing their contents of bound water and glycerol to cope with sudden cold spells during hibernation. Our findings emphasize the adaptive changes of P. canaliculata snails overwintering in paddy soils. In future studies, the vulnerabilitiesof P. canaliculata during hibernation (e.g. shell characteristics, nutrient reserves, and dehydration tolerance, etc.,) should be investigated to develop effective control methods for this period. © 2024 Society of Chemical Industry.

Linagliptin mitigates cisplatin-induced kidney impairment via mitophagy regulation in rats, with emphasis on SIRT-3/PGC-1α, PINK-1 and Parkin-2

Cisplatin (CDDP) often leads to kidney impairment, limiting its effectiveness in cancer treatment. The lack of mitophagy in proximal tubules exacerbates this issue. Hence, targeting SIRT-3 and PGC1-α shows promise in mitigating CDDP-induced kidney damage. The potential renoprotective effects of linagliptin, however, remain poorly understood. This study represents the first exploration of linagliptin's impact on CDDP-induced kidney impairment in rats, emphasizing its potential role in mitophagic pathways. The experiment involved four rat groups: Group (I) received saline only, Group (II) received a single intraperitoneal injection of CDDP at 6 mg/kg. Groups (III) and (IV) received linagliptin at 6 and 10 mg/kg p.o., respectively, seven days before CDDP administration, continuing for an additional four days. Various parameters, including renal function tests, oxidative stress, TNF-α, IL-1β, IL-6, PGC-1α, FOXO-3a, p-ERK1, and the gene expression of SIRT-3 and P62 in renal tissue, were assessed. Linagliptin improved renal function, increased antioxidant enzyme activity, and decreased IL-1β, TNF-α, and IL-6 expression. Additionally, linagliptin significantly upregulated PGC-1α and PINK-1/Parkin-2 expression while downregulating P62 expression. Moreover, linagliptin activated FOXO-3a and SIRT-3, suggesting a potential enhancement of mitophagy. Linagliptin demonstrated a positive impact on various factors related to kidney health in the context of CDDP-induced impairment. These findings suggest a potential role for linagliptin in improving cancer treatment outcomes. Clinical trials are warranted to further investigate and validate its efficacy in a clinical setting.

Integrating network pharmacology and experimental verification to explore the pharmacological mechanisms of phlorizin against osteoarthritis.

To study the pharmacological effects and mechanisms of phlorizin in the treatment of osteoarthritis (OA) through network pharmacological analysis, molecular docking, and experimental validation. First, we screened out the relevant targets related to phlorizin and OA from the public database. The key targets, biological processes, and signaling pathways of phlorizin against OA were identified by protein-protein interaction (PPI) network, Gene Ontology (GO), and Encyclopedia of Kyoto Genes and Genomes (KEGG) pathway enrichment analysis. Subsequently, molecular docking was performed to predict the binding activity between phlorizin and key targets. Finally, we evaluated the effects of phlorizin on hydrogen peroxide-induced OA in rats and validated its possible mechanism of action based on the findings of the network pharmacology analysis. Network pharmacology revealed a total of 235 cross-targets involved in the treatment of OA. Phlorizin's anti-OA effect was found to be primarily mediated through oxidoreductase activity, with JAK-STAT and NF-κB signaling pathways playing a regulating role, according to pathway enrichment analysis. Phlorizin demonstrated a strong affinity for NF-κB1 targets through molecular docking. Moreover, in vitro experiments demonstrated that phlorizin could enhance intracellular antioxidant enzyme activities with good ROS scavenging ability and significantly reduce the expression of NF-κB1 and inflammatory cytokines. Phlorizin can inhibit the progression of OA. The potential underlying mechanism involves inhibiting the NF-κB pathway to reduce inflammation and promote intracellular antioxidant action.

Tenofovir alafenamide compared to tenofovir disoproxil fumarate, induces dysglycemia, and dyslipidemia in Wistar rats.

To determine the metabolic effects of tenofovir alafenamide (TAF) compared to tenofovir disoproxil fumarate (TDF) in vivo. Male Wistar rats (Rattus novergicus, 250-300 g body weight) were divided into 3 groups (n = 8) and orally treated daily with 1.0 ml distilled water (group 1), TAF (0.42 mg/kg) (group 2), or TDF (5.0 mg/kg) (group 3), respectively, for 56 days. Glucose tolerance tests were done before the animals were sacrificed by halothane overdose, and blood was collected by cardiac puncture for the analysis of plasma lipids, electrolytes, and insulin. The kidney and pancreatic tissues were excised and homogenized to measure oxidative stress. Compartmentation of TAF and TDF was determined in NRK-52 and Peripheral Blood Mononuclear Cells (PBMC). There were no significant differences in weight gain among controls, TAF- or TDF-treated rats. TAF-treated rats had significantly increased fasting blood glucose (FBG), fasting plasma insulin (FPI), insulin resistance, impaired glucose tolerance, and dyslipidemia compared to control or TDF-treated rats, respectively. There was increased lipid peroxidation in the pancreas of TAF-treated compared to TDF-treated or control animals, respectively. TDF- treated rats presented with symptoms of Fanconi syndrome compared to TAF-treated or control animals, respectively. Kidney homogenates from TDF-treated animals had significantly reduced antioxidant enzyme activity compared to TAF-treated animals or controls, respectively. Intracellular concentrations of TAF were significantly higher than TDF in both NRK-52E cells and PBMC, respectively. TAF treatment is weight-neutral and causes dysglycemia, and dyslipidemia but not Fanconi syndrome compared to TDF.

Waterborne atenolol disrupts neurobehavioral and neurochemical responses in adult zebrafish.

Environmental contamination by pharmaceuticals from industrial waste and anthropogenic activities poses adverse health effects on non-target organisms. We evaluated the neurobehavioral and biochemical responses accompanying exposure to ecological relevant concentrations of atenolol (0, 0.1, 1.0, and 10µg/L) for seven uninterrupted days in adult zebrafish (Danio rerio). Atenolol-exposed fish exhibited anxiety-like behavior, characterized by significant bottom-dwelling with marked reduction in vertical exploration. Atenolol-exposed fish exhibited marked increase in the duration and frequency of aggressive events without altering their preference for conspecifics. Biochemical data using brain samples indicated that atenolol disrupted antioxidant enzyme activities and induced oxidative stress. Exposure to atenolol markedly decreased ATP and AMP hydrolysis without affecting ADP hydrolysis and acetylcholinesterase (AChE) activity. Atenolol significantly upregulated tryptophan hydroxylase 1 (tph1) mRNA expression but downregulated brain-derived neurotrophic factor (bdnf) mRNA. Collectively, waterborne atenolol elicits aggressive and anxiety-like responses in adult zebrafish, accompanied by oxidative stress, reduced nucleotide hydrolysis, altered tph1 and bdnf mRNA expression, which may impact the survival and health of fish in aquatic environment.

Microplastics predominantly affect gut microbiota by altering community structure rather than richness and diversity: A meta-analysis of aquatic animals

The impacts of microplastics on the gut microbiota, a crucial component of the health of aquatic animals, remain inadequately understood. This phylogenetically controlled meta-analysis aims to identify general patterns of microplastic effects on the alpha diversity (richness and Shannon index), beta diversity, and community structure of gut microbiota in aquatic animals. Data from 63 peer-reviewed articles on the Web of Science were synthesized, encompassing 424 observations across 31 aquatic species. The analysis showed that microplastics significantly altered the community structure of gut microbiota, with between-group distances being 87.75% higher than within-group distances. This effect was significant even at environmentally relevant concentrations (≤1 mg L−1). However, their effects on richness, Shannon index, and beta diversity (community variation) were found to be insignificant. The study also indicated that the effects of microplastics were primarily dependent on their concentration and size, while the phylogeny of tested species explained limited heterogeneity. Furthermore, variations in gut microbiota alpha diversity, beta diversity, and community structure were correlated with changes in antioxidant enzyme activities from the liver and hepatopancreas. This implies that gut microbiota attributes of aquatic animals may provide insights into host antioxidant levels. In summary, this study illuminates the impacts of microplastics on the gut microbiota of aquatic animals and examines the implications of these effects for host health. It emphasizes that microplastics mainly alter the community structure of gut microbiota rather than significantly affecting richness and diversity.

Comparative role of calcium oxide nanoparticles and calcium bulk fertilizer to alleviate cadmium toxicity by modulating oxidative stress, photosynthetic performance and antioxidant-defense genes expression in alfalfa

Cadmium (Cd) toxicity poses a significant threat to soil health and sustainable food production. Its bioaccumulation in plant tissues induces phytotoxicity by affecting physiological and biochemical attributes, leading to a reduction in plant biomass and production. Recently, nanotechnology has emerged as a promising approach for addressing heavy metal toxicity in an eco-friendly manner to enhance crop production. However, the comparative role of foliar applied calcium oxide nanoparticles (CaO-NPs) and bulk calcium fertilizer under Cd stress in alfalfa remains unexplored. Herein, we studied the ameliorative role of CaO-NPs and bulk calcium (50 and 100 mg L−1) to alleviate Cd stress (30 mg kg−1) in alfalfa seedlings. Plants exposed to Cd exhibited significant decreases in morpho-physiological traits, gas exchange attributes, and pigment contents as well as increase in Cd bioaccumulation in plant tissues. Notably, exogenous application of CaO-NPs ameliorates the toxic impact of Cd by enhancing plant biomass (45%), fluorescence efficiency and gaseous exchange attributes. The maximum dose of CaO-NPs induced Cd-tolerance response accompanied by a significant increase in antioxidative enzyme activities, such as superoxide dismutase (SOD; 29%), peroxidase (POD; 41%), catalase (CAT; 36%) and ascorbate peroxidase (APX; 49%), which play positive roles in ROS scavenging. TEM examination further revealed the protective role of these NPs in averting Cd-induced damage to leaf ultrastructure and mesophyll cells. Furthermore, CaO-NPs had a substantial influence on both Cd and Ca2+ accumulation in plant tissues, while qRT‒PCR analysis demonstrated higher expression of antioxidant defense genes viz. Cu/ZnSOD (0.38 fold change (FC)), MtPOD (0.51 FC), MtCAT (0.61 FC) and MtAPX (0.79 FC) under CaO-NPs application, over Cd control. Overall, our findings suggested that exogenous CaO-NPs could be effective in alleviating the adverse effects of Cd on alfalfa seedlings to ensure food safety and support sustainable agriculture.

Pharmacological Activities and Molecular Mechanisms of Sinapic Acid in Neurological Disorders.

Sinapic acid (SA) is a phenylpropanoid derivative found in various natural sources that exhibits remarkable versatile properties, including antioxidant, anti-inflammatory, and metal-chelating capabilities, establishing itself as a promising candidate for the prevention and treatment of conditions affecting the central nervous system, such as Alzheimer's disease (AD), Parkinson's disease (PD), ischemic stroke, and other neurological disorders. These effects also include neuroprotection in epilepsy models, as evidenced by a reduction in seizure-like behavior, cell death in specific hippocampal regions, and lowered neuroinflammatory markers. In AD, SA treatment enhances memory, reverses cognitive deficits, and attenuates astrocyte activation. SA also has positive effects on cognition by improving memory and lowering oxidative stress. This is shown by lower levels of oxidative stress markers, higher levels of antioxidant enzyme activity, and better memory retention. Additionally, in ischemic stroke and PD models, SA provides microglial protection and exerts anti-inflammatory effects. This review emphasizes SA's multifaceted neuroprotective properties and its potential role in the prevention and treatment of various brain disorders. Despite the need for further research to fully understand its mechanisms of action and clinical applicability, SA stands out as a valuable bioactive compound in the ongoing quest to combat neurodegenerative diseases and enhance the quality of life for affected individuals.

Antioxidant Activities and Laxative Effect of Bioactive Compounds from Cynara cardunculus var. sylvestris

The present study aims to investigate the antioxidant and anti-constipation activities of the derived phenolic extracts in ribs wild cardoon (Cynara sylvestris). Analysed extracts (acetone, methanol and aqueous) exhibited high level of phenolic compounds and excellent antioxidant activities with significant IC50 values (p ≤0.05), as assessed by the DPPH radical-scavenging activity (0.84±0.08 - 2.44±0.007 μg/mL), ABTS cationic radical test (0.96 ±0.01- 136.67±6.75 μg/mL) and β-carotene bleaching assay (2.09±0.02-51.12±1.32 μg/mL). Also, higher levels of insoluble dietary fibers were found (56.18 ± 0.91% DW of neutral detergent fiber). The in vivo investigation was performed on Wistar rats to explore the ability of C. sylvestris aqueous extract (CSAE) in the enhancement of the gastrointestinal transit and the treatment of induced constipation by Loperamide (commercialized as Idium). A significant increase of 15, 24.5 and 32.4% in gastrointestinal motility was recordedwhen doses of CSAE increased (75, 150 and 300 mg/kg b.w, respectively). Food intake, water consumption, number and weight of stools were also increased in a dose-dependent manner, compared to the positive control (untreated). Moreover, CSAE provided significantly (p ≤0.05) and dose-dependently protection against oxidative stress by preserving normal antioxidant enzymes activities (SOD and GPx) in intestinal and colonic mucosa, and resorted hepatic enzymes (AST and ALT) and renal (urea and creatinine) levels to normal values. These results can be explained by the abundance of phenolic compounds and insoluble fibers in this plant. Therefore, its use can be encouraged in alimentary and pharmaceutical applications as antioxidant and laxative food supplements.

Role of Quaternary Aminoacid Derivatives and Ion Homeostasis in Amelioration of Salinity Stress

Salinity is a detriment to plant production throughout the world. Salinity impacts the quality of irrigation water. Understanding salt stress in plants necessitates complex physiological and metabolic stages. Preserving turgescent cells and regulating the water potential to maintain a proper water balance among the key responsibilities of osmoprotectants, long-term, high salt doses can slow down plant growth and development by interfering with physiological processes like nutrient imbalance, membrane damage, enzyme inhibition and metabolic dysfunctions like photosynthesis, hormone production and ion homeostasis, all of which can result in plant death. Hyperionic and hyperosmotic stress are also caused by prolonged, high salt doses. Osmolytes (such as proline and glycine betaine) accumulate under different salt levels, antioxidant enzyme activities increase and eventually some of the negative effects of NaCl toxicity on plants are mitigated. Plants under salt stress may have higher concentrations of reactive oxygen species (ROS) such as superoxide radicals (O2) and hydrogen peroxide (H2O2). Ion homeostasis is crucial for plants during abiotic stress conditions.

Chitosan stabilized lemon essential oil nanoemulsion controls black mold rot and maintains quality of table grapes

Aspergillus carbonarius infection leads to black mold rot in table grapes, causes grape decay, reduces fruit quality and marketability, which produces significant economic losses. This study investigated the antifungal efficacy of chitosan-stabilized lemon essential oil nanoemulsion (LO-CNE) against A. carbonarius and black mold rot of table grapes. LO-CNE was prepared with a mean diameter of 130.01 ± 8.34 nm. LO-CNE exhibited superior antifungal activity, reduced spore germination and germ tube elongation, decreased the antioxidant enzyme activities in A. carbonarius; the minimal inhibitory concentration of LO-CNE was determined to be 30 mg/mL. LO-CNE reduced the occurrence of black mold rot by 63 % and lesion diameter by 56.78 % in table grapes compared to the control. At their peak activity level, the grapes treated with LO-CNE exhibited significantly enhanced antioxidant and defense-related enzyme activities. Specifically, polyphenol oxidase activity increased by 2.27-fold, peroxidase activity by 2.22-fold, superoxide dismutase activity by 0.68-fold, catalase activity by 1.61-fold, phenylalanine ammonia-lyase activity by 3.38-fold, and ascorbate peroxidase activity by 2.36-fold. The LO-CNE application reduced natural decay by 95 %, weight loss by 15 % compared to the control, and effectively maintained the quality parameters of table grapes. Therefore, LO-CNE can be considered an alternative disease-control agent for grape preservation.

Combined transcriptomics and metabolomics analysis reveals salinity stress specific signaling and tolerance responses in the seagrass Zostera japonica.

Multiple regulatory pathways of Zostera japonica to salt stress were identified through growth, physiological, transcriptomic and metabolomic analyses. Seagrasses are marine higher submerged plants that evolved from terrestrial monocotyledons and have fully adapted to the high saline seawater environment during the long evolutionary process. As one of the seagrasses growing in the intertidal zone, Zostera japonica not only has the ability to quickly adapt to short-term salt stress but can also survive at salinities ranging from the lower salinity of the Yellow River estuary to the higher salinity of the bay, making it a good natural model for studying the mechanism underlying the adaptation of plants to salt stress. In this work, we screened the growth, physiological, metabolomic, and transcriptomic changes of Z. japonica after a 5-day exposure to different salinities. We found that high salinity treatment impeded the growth of Z. japonica, hindered its photosynthesis, and elicited oxidative damage, while Z. japonica increased antioxidant enzyme activity. At the transcriptomic level, hypersaline stress greatly reduced the expression levels of photosynthesis-related genes while increasing the expression of genes associated with flavonoid biosynthesis. Meanwhile, the expression of candidate genes involved in ion transport and cell wall remodeling was dramatically changed under hypersaline stress. Moreover, transcription factors signaling pathways such as mitogen-activated protein kinase (MAPK) were also significantly influenced by salt stress. At the metabolomic level, Z. japonica displayed an accumulation of osmolytes and TCA mediators under hypersaline stress. In conclusion, our results revealed a complex regulatory mechanism in Z. japonica under salt stress, and the findings will provide important guidance for improving salt resistance in crops.

Elucidation of the Role of L-Arginine and Nω-Nitro-L-Arginine in the Treatment of Rats with Different Levels of Hypoxic Tolerance and Exposure to Lead Nitrate

Background/Aims: Individual resistance to hypoxia is an important feature of the physiological profile of an organism, particularly in relation to lead-induced toxicity. Methods: Our study focused on evaluating parameters of mitochondrial oxygen consumption, microsomal oxidation, intensity of lipoperoxidation processes and antioxidant defences in the liver of rats with low (LR) and high (HR) resistance to hypoxia to elucidate the mechanisms of action of L-arginine and the NO synthase inhibitor L-NNA before or after exposure to lead nitrate. Results: Our study suggests that the redistribution of oxygen-dependent processes towards mitochondrial processes under the influence of the nitric oxide precursor amino acid L-arginine is an important mechanism for maintaining mitochondrial respiratory chain function during per os lead nitrate exposure (3.6 mg lead nitrate/kg bw per day for 30 days). Animals were given L-arginine at a dose of 600 mg/kg bw (i.p., 30 min) before and after exposure to lead nitrate or the NO synthase inhibitor Nω-nitro-L-arginine (L-NNA) at a dose of 35 mg/kg bw (i.p., 30 min) before and after exposure to lead nitrate. Our experiments demonstrated the efficacy of using lead nitrate to simulate lead-related toxic processes via Pb levels in liver tissue; we demonstrated significantly reduced levels of nitrites and nitrates, i.e. stable metabolites of the nitric oxide system, in both LR and HR animals. The effect of the amino acid L-arginine stabilised the negative effects of lead nitrate exposure in both groups of LR and HR rats. We observed the efficiency of mitochondrial energy supply processes and showed a greater vulnerability of NADH-dependent oxidation during lead nitrate exposure in the liver of HR rats. Conclusion: L-arginine initiated the processes of oxidation of NADH-dependent substrates in the LR group, whereas in the HR group this directionality of processes was more effective when the role of the nitric oxide system was reduced (use of L-NNA). Our study of key antioxidant enzyme activities in rat liver tissue during lead nitrate exposure revealed changes in the catalase-peroxidase activity ratio. We found different activities of antioxidant enzymes in the liver tissue of rats treated with lead nitrate and L-arginine or L-NNA, with a significant increase in GPx activity in the LR group when L-arginine was administered both before and after exposure to lead nitrate.

Insights into response of seagrass (Zostera marina) to sulfide exposure at morphological, physiochemical and molecular levels in context of coastal eutrophication and warming.

Sulfide in sediment porewaters, is toxic to rooted macrophytes in both marine and freshwater environments. Current research on sulfide stress in seagrasses primarily focuses on morphological and physiological aspects, with little known about the molecular response and resistance mechanisms. This study first investigated the damage caused by sulfide to eelgrass (Zostera marina L.) using transcriptomic, metabolomic, and other physiological and biochemical indicators and explored the potential resistance of eelgrass at molecular level through laboratory simulated and in-situ sulfide stress experiments. Comprehensive results showed that sulfide stress severely inhibited the growth, photosynthesis, and antioxidant enzyme activities of eelgrass. Importantly, transcriptome analysis revealed significant activation of pathways related to carbohydrate and sulfur metabolism. This activation served a dual purpose: providing an energy source for eelgrass stress response and achieving detoxification through accelerated sulfur metabolism-a potential resistance mechanism. The toxicity of sulfide increased with rising temperature as evidenced by a decrease in EC50. Results from recovery experiments indicated that when Fv/Fm reduced to about 0 under sulfide stress, the growth and photosynthesis of eelgrass recovered to normal level after timely removal of sulfide. However, prolonged exposure to sulfide resulted in failure to recover, leading ultimately to plant death. This study not only enhances our understanding of the molecular-level impacts of sulfide on seagrasses but also provides guidance for the management and ecological restoration of seagrass meadows under sulfide stress.

Rational design of ROS scavenging and fluorescent gold nanoparticles to deliver siRNA to improve plant resistance to Pseudomonas syringae

Bacterial diseases are one of the most common issues that result in crop loss worldwide, and the increasing usage of chemical pesticides has caused the occurrence of resistance in pathogenic bacteria and environmental pollution problems. Nanomaterial mediated gene silencing is starting to display powerful efficiency and environmental friendliness for improving plant disease resistance. However, the internalization of nanomaterials and the physiological mechanisms behind nano-improved plant disease resistance are still rarely understood. We engineered the polyethyleneimine (PEI) functionalized gold nanoparticles (PEI-AuNPs) with fluorescent properties and ROS scavenging activity to act as siRNA delivery platforms. Besides the loading, protection, and delivery of nucleic acid molecules in plant mature leaf cells by PEI-AuNPs, its fluorescent property further enables the traceability of the distribution of the loaded nucleic acid molecules in cells. Additionally, the PEI-AuNPs-based RNAi delivery system successfully mediated the silencing of defense-regulated gene AtWRKY1. Compared to control plants, the silenced plants performed better resistance to Pseudomonas syringae, showing a reduced bacterial number, decreased ROS content, increased antioxidant enzyme activities, and improved chlorophyll fluorescence performance. Our results showed the advantages of AuNP-based RNAi technology in improving plant disease resistance, as well as the potential of plant nanobiotechnology to protect agricultural production.

Comprehensive analysis of pepper (Capsicum annuum) RAV genes family and functional identification of CaRAV1 under chilling stress

BackgroundDespite its known significance in plant abiotic stress responses, the role of the RAV gene family in the response of Capsicum annuum to chilling stress remains largely unexplored.ResultsIn this study, we identified and characterized six members of the CaRAV gene subfamily in pepper plants through genome-wide analysis. Subsequently, the CaRAV subfamily was classified into four branches based on homology with Arabidopsis thaliana, each exhibiting relatively conserved domains within the branch. We discovered that light response elements accounted for the majority of CaRAVs, whereas low-temperature response elements were specific to the NGA gene subfamily. After pepper plants were subjected to chilling stress, qRT‒PCR analysis revealed that CaRAV1, CaRAV2 and CaNGA1 were significantly induced in response to chilling stress, indicating that CaRAVs play a role in the response to chilling stress. Using virus-induced gene silencing (VIGS) vectors, we targeted key members of the CaRAV gene family. Under normal growth conditions, the MDA content and SOD enzyme activity of the silenced plants were slightly greater than those of the control plants, and the REC activity was significantly greater than that of the control plants. The levels of MDA and electrolyte leakage were greater in the silenced plants after they were exposed to chilling stress, and the POD and CAT enzyme activities were significantly lower than those in the control, which was particularly evident under repeated chilling stress. In addition, the relative expression of CaPOD and CaCAT was greater in V2 plants upon repeated chilling stress, especially CaCAT was significantly greater in V2 plants than in the other two silenced plants, with 3.29 and 1.10 increases within 12 and 24 h. These findings suggest that CaRAV1 and CaNGA1 positively regulate the response to chilling stress.ConclusionsSilencing of key members of the CaRAV gene family results in increased susceptibility to chilling damage and reduced antioxidant enzyme activity in plants, particularly under repeated chilling stress. This study provides valuable information for understanding the classification and putative functions of RAV transcription factors in pepper plants.

Cardiotoxicity risk induced by sanitary insecticide Dimefluthrin

Dimefluthrin (DIM) is a commonly utilized sanitary insecticide, predominantly employed for indoor pest management within residential and public environments directly interacting with human habitation. However, the usage of DIM is escalating with increasing mosquito resistance, prompting concerns about its health risks. Here, using zebrafish as a research model, we systematically evaluated DIM's impact on human health. Findings revealed significant health hazards during embryonic development, including reduced hatching rates, shortened body lengths, and organ malformations, notably affecting the heart. It was explored the mechanism of DIM-induced cardiotoxicity in zebrafish, and histopathological analyses revealed that DIM resulted in ventricular linearization in zebrafish embryos. Antioxidant enzyme activities were reduced and cardiac reactive oxygen species (ROS) accumulated after DIM exposure, suggesting clear signs of oxidative stress. Additionally, acridine orange (AO) staining and caspase-3 immunofluorescence demonstrated cardiac apoptosis in Tg (kdrl: EGFP) zebrafish. qPCR analysis implied that DIM induced apoptosis via the p53/Caspase pathway by up-regulating the expression levels of p53, cytochrome C (cyto-C), caspase-9, and caspase-3. Together, our work provided a systematic perspective on the cardiotoxicity of sanitary pesticides, which could offer opportunities for future risk management.