A microtiter plate assay for superoxide dismutase using a water-soluble tetrazolium salt (WST-1)

A GPx-mimetic copper vanadate nanozyme mediates the release of nitric oxide from S-nitrosothiols

Although reactive oxygen and nitrogen species (ROS/RNS), such as hydrogen peroxide (H₂O₂), nitric oxide (NO), hydroxyl radicals (OH˙), superoxide (O₂^-) etc., play crucial roles in redox biology and cellular signaling, higher concentrations of these species lead to oxidative and nitrosative stress, which are associated with various pathophysiological conditions like neurodegeneration, cardiovascular diseases and cancer. There is growing evidence that functional impairment of the endothelium is one of the first recognizable signs of the development of atherosclerotic cardiovascular disease. A decreased bioavailability of NO and increased generation of ROS are the two major molecular changes associated with endothelial dysfunction. Therefore, it is a viable strategy to increase the bioavailability of NO while reducing the amount of ROS to prevent the progression of cardiovascular diseases. In this paper, we discuss for the first time that copper vanadate (CuV₂O₆) can not only release NO from S-nitrosothiols but can also control the ROS levels by functionally mimicking the antioxidant enzyme glutathione peroxidase (GPx) at physiological pH. We used several imaging techniques and spectroscopic measurements to understand the catalysis on the surface of the material during the reactions. The denitrosylation, as well as GPx-like activity, by CuV₂O₆ can be carried out multiple times without affecting the catalytic activity.

Mechanistic insights into primary biotransformation of diethyl phthalate in earthworm and significant SOD inhibitory effect of esterolytic products

Phthalic acid esters (PAEs) are used as plasticizer or modifier in artificially-manufactured products. Though the rapid biotransformation of phthalates in microbes and plants have been well documented, it is less studied yet in terrestrial animals, e.g. earthworm. In this study, the major biotransformation of diethyl phthalate (DEP) in Eisenia fetida was illustrated using in vitro incubation of earthworm crude enzymes. DEP could be substantially biotransformed into phthalate monoester (MEP) and a small amount of phthalic acid (PA) through esterolysis, which was verified to be driven by endogenous carboxylesterase. Despite the inferior contribution, the oxidation of DEP might also occur under the initiated electron transfer by NADPH coenzyme. The dominant metabolite MEP showed a higher inhibition of superoxide dismutase (SOD) activity than DEP with EC₅₀ of 0.0082 ± 0.0016 mmol/L, so the higher ecological risks of MEP would be marked. The inhibition effect of PA was validated to be even stronger than MEP though it was slightly generated. The direct binding interaction with SOD was proved to be an important molecular event for regulation of SOD activity. Besides the static quenching mechanism, the caused conformational changes including despiralization of α-helix and spatial reorientation of tryptophan were spectrally believed to affect binding and underlie inhibition efficiency of SOD activity.

Decoyinine Induced Resistance in Rice against Small Brown Planthopper Laodelphax striatellus

Induced resistance against SBPH via microbial pesticides is considered as an eco-friendly and promising management approach. In this study, the induced resistance against SBPH in rice seedling by a new potential microbial pesticide, decoyinine (DCY), a secondary metabolite produced by Streptomyces hygroscopicus, was evaluated to investigate the effects of DCY on SBPH's biological and population parameters along with defense-related physiological and biochemical indices in rice against SBPH feeding. We found that DCY has potential to improve rice resistance and significantly reduced the fecundity of SBPH. Laboratory results revealed that DCY treated rice significantly changed SBPH's fecundity and population life table parameters. The concentrations of hydrogen peroxide (H2O2), soluble sugars and malondialdehyde (MDA) were significantly lower in DCY treated rice plants against SBPH infestation at 24, 48 and 96 hours post infestation (hpi), respectively. The concentrations of antioxidant enzymes, catalase (CAT) was significantly higher at 72 hpi, while super oxidase dismutase (SOD) and peroxidase (POD) concentrations were recorded higher at 96 hpi. The concentrations of synthases enzymes, phenyl alanine ammonia-lyase (PAL) was higher at 48 hpi, whereas polyphenol oxidase (PPO) concentration was maximum at 72 hpi against SBPH infestation. The results imply that DCY has unique properties to enhance rice resistance against SBPH by stimulating plant defensive responses. Microbial pesticides may be developed as an alternative to chemical pest control.

In Vivo and Ex Vivo Evaluation of 1,3-Thiazolidine-2,4-Dione Derivatives as Euglycemic Agents

Thiazolidinediones (TZDs), used to treat type 2 diabetes mellitus, act as full agonists of the peroxisome proliferator-activated receptor gamma. Unfortunately, they produce adverse effects, including weight gain, hepatic toxicity, and heart failure. Our group previously reported the design, synthesis, in silico evaluation, and acute oral toxicity test of two TZD derivatives, compounds 40 (C40) and 81 (C81), characterized as category 5 and 4, respectively, under the Globally Harmonized System. The aim of this study was to determine whether C40, C81, and a new compound, C4, act as euglycemic and antioxidant agents in male Wistar rats with streptozotocin-induced diabetes. The animals were randomly divided into six groups (n = 7): the control, those with diabetes and untreated, and those with diabetes and treated with pioglitazone, C40, C81, or C4 (daily for 21 days). At the end of the experiment, tissue samples were collected to quantify the level of glucose, insulin, triglycerides, total cholesterol, and liver enzymes, as well as enzymatic and nonenzymatic antioxidant activity. C4, without a hypoglycemic effect, displayed the best antioxidant activity. Whereas C81 could only attenuate the elevated level of blood glucose, C40 generated euglycemia by the end of the treatment. All compounds produced a significant decrease in triglycerides.

Key considerations when using the sulforhodamine B assay for screening novel anticancer agents

Anticancer drug discovery programmes use a large number of in-vitro assays to screen the potency of compound libraries. The accuracy and reliability of these in-vitro assays are vital in selecting potent lead candidates for further (pre)clinical studies. Among the commonly used cell viability assays, the sulforhodamine B (SRB) assay has been a popular choice due to its simplicity, accuracy, reliability and reproducibility. SRB dye interacts with protein's basic amino acids and viable cell number is determined based on the cellular protein content. In this study, the cytotoxic potency of the novel hydroxythiopyridone derivatives towards A549 and H522 cells was determined using the SRB assay. The known drugs oxaliplatin and vorinostat were also examined. The resulting EC50 values were accurate, reliable and reproducible. However, all EC50 values calculated in 6-well plates were higher compared to those determined from 96-well plates. Furthermore, results from 6-well plates were also more variable compared to 96-well plates. Our results confirm that SRB assay is a reliable technique in screening the potency of anticancer drug candidates but plating conditions need to be carefully considered.

Immunotoxicity of polychlorinated biphenyls (PCBs) to the marine crustacean species, Scylla paramamosain

Polychlorinated biphenyls (PCBs) are persistent organic pollutants in environments, and they can negatively affect aquatic animal health. After 7 days of PCBs exposure, the activities of catalase, phenoloxidase, and superoxide dismutase and the total hemocyte count in the haemolymph were significantly decreased and the reactive oxygen species (ROS) content and phagocytic rate of hemocytes were significantly increased in mud crab Scylla paramamosain. Additionally, serum lysozyme, glutathione, glutathione-S-transferase, and glutathione peroxidase activities were significantly down-regulated in mud crab after PCBs exposure. The survival rate of crab hemocytes significantly declined as the PCBs concentration increased, indicating that PCBs had a cytotoxic effect on hemocytes. Exposure to increasing concentrations of PCBs also increased the degree of DNA damage in crab hemocytes. After PCBs exposure, the expression levels of P53 and caspase-3 in hemocytes were significantly up-regulated, which suggests that apoptosis was occurring. The apoptosis rate of hemocytes was up-regulated as the PCBs concentration increased, indicating that apoptosis was induced by the PCBs-activated caspase-3 pathway. These data suggest that exposure to PCBs hampered the immune response of mud crabs, most likely by (1) inducing ROS, causing DNA damage, and reducing the viability of hemocytes, (2) reducing the activities of antioxidant enzymes, and (3) inducing phagocytosis and apoptosis of hemocytes. And the final result of PCBs-induced immunotoxicity to mud crabs is the reduced bacterial disease resistance and survival rate of crabs under Vibrio alginolyticus challenge.

Identifying Chemical Composition, Safety and Bioactivity of Thai Rice Grass Extract Drink in Cells and Animals

Rice grass has been reported to contain bioactive compounds that possess antioxidant and free-radical scavenging activities. We aimed to assess rice grass extract (RGE) drink by determining catechin content, free-radical scavenging and iron-binding properties, as well as toxicity in cells and animals. Young rice grass (Sukhothai-1 strain) was dried, extracted with hot water and lyophilized in a vacuum chamber. The resulting extract was reconstituted with deionized water (260 mg/40 mL) and served as Sukhothai-1 rice grass extract drink (ST1-RGE). HPLC results revealed at least eight phenolic compounds, for which the major catechins were catechin, epicatechin and epigallocatechin-3-gallate (EGCG) (2.71-3.57, 0.98-1.85 and 25.47-27.55 mg/40 mL serving, respectively). Elements (As, Cu, Pb, Sn and Zn) and aflatoxin (B1, B2, G1 and G2) contents did not exceed the relevant limits when compared with WHO guideline values. Importantly, ST1-RGE drink exerted radical-scavenging, iron-chelating and anti-lipid peroxidation properties in aqueous and biological environments in a concentration-dependent manner. The drink was not toxic to cells and animals. Thus, Sukhothai-1 rice grass product is an edible drink that is rich in catechins, particularly EGCG, and exhibited antioxidant, free radical scavenging and iron-binding/chelating properties. The product represents a functional drink that is capable of alleviating conditions of oxidative stress and iron overload.

Recent Advances in Multicellular Tumor Spheroid Generation for Drug Screening

Multicellular tumor spheroids (MCTs) have been employed in biomedical fields owing to their advantage in designing a three-dimensional (3D) solid tumor model. For controlling multicellular cancer spheroids, mimicking the tumor extracellular matrix (ECM) microenvironment is important to understand cell-cell and cell-matrix interactions. In drug cytotoxicity assessments, MCTs provide better mimicry of conventional solid tumors that can precisely represent anticancer drug candidates' effects. To generate incubate multicellular spheroids, researchers have developed several 3D multicellular spheroid culture technologies to establish a research background and a platform using tumor modelingvia advanced materials science, and biosensing techniques for drug-screening. In application, drug screening was performed in both invasive and non-invasive manners, according to their impact on the spheroids. Here, we review the trend of 3D spheroid culture technology and culture platforms, and their combination with various biosensing techniques for drug screening in the biomedical field.

Inherited Selenocysteine Transfer RNA Mutation: Clinical and Hormonal Evaluation of 2 Patients

INTRODUCTION

Iodothyronine deiodinases are selenoproteins with the amino acid selenocysteine (Sec) introduced into the position of a TGA stop codon by a complex machinery involving tRNA^[Ser]Sec when a cis-acting Sec-insertion sequence element is present in the 3' end of the mRNA. Recently, a variant in the TRU-TCA1-1 gene encoding for tRNA^[Ser]Sec was reported, which resulted in reduced expression of stress-related selenoproteins. The proband presented with multisystem symptoms, euthyroid hyperthyroxinemia, and selenium deficiency. Here, we describe 2 new members of a family harboring the same tRNA^[Ser]Sec variant.

CASE PRESENTATION

A 13-year-old patient was seen for Hashimoto's disease with high FT3 (4.6 pg/mL, normal range 2-4.2 pg/mL) and normal FT4 and TSH concentrations. He had no clinical complaints. During a 6-year clinical and hormonal follow-up, the index patient was not treated, FT3 decreased, FT4 increased, and serum TSH stayed in the normal range resulting in a euthyroid hyperthyroxinemia. Reverse T3 concentration was significantly increased at the last visit (19 years and 4 months). At the last evaluation, the total selenium level was low (91 μg/L, normal range 95-125). DNA sequencing identified a germinal homozygous variant (C65G) in the TRU-TCA1-1 gene. During follow-up, no additional clinical symptom was observed in the absence of any treatment. The same germinal tRNA^[Ser]Sec variant was identified at heterozygous state in his father, who had normal thyroid function tests except a moderately increased reverse T3 concentration, with increased total selenium (143 μg/L) level. In both patients, the expression of stress-related selenoprotein GPX3 was in the low-normal range (168 and 180 IU/L, respectively, normal range: 150-558 IU/L). We did not find any significant biological abnormalities evocative of other selenoprotein deficiencies.

DISCUSSION/CONCLUSION

We report on 2 members of a family with a variant in the TRU-TCA1-1 gene encoding for tRNA^[Ser]Sec. Our study suggests that this tRNA^[Ser]Sec variant is not exclusively causative of disruption in selenoprotein synthesis.

Study on active response of superoxide dismutase and relevant binding interaction with bioaccumulated phthalates and key metabolites in Eisenia fetida

Phthalic acid esters (PAEs) are a group of widespread persistent organic pollutants in the environment. Though the harmful effect of PAEs including activity inhibition of superoxide dismutase (SOD) to arouse oxidative stress were well documented, the deep insights into mechanisms that are relevant with SOD activity are still lacking. By 7d-cultivation of Eisenia fetida in artificially-polluted soil, the different active responses of SOD in earthworm were shown to PAE congeners. Despite the less bioaccumulation and bioavailability, the di-butyl phthalate (DBP) etc. structurally coupled with longer ester-chains appeared more effective to trigger the up-regulation and then the slight decline of SOD activity. Given the remarkable biotransformation especially for short-chain PAEs, the SOD activity response in earthworm should be regarded as joint effect with their metabolites, e.g. monophthalates (MAEs) and phthalic acid (PA). The in vitro SOD activity was shown with the obvious inhibition of 21.31% by DBP, 88.93% by MBP, and 58.57% by PA respectively when the concentrations were elevated up to 0.03 mM. The SOD activity inhibition confirmed the molecular binding with pollutants as an essential event besides the biological regulation for activity. The binding interaction was thermodynamically exothermic, spontaneous and strengthened primarily by Van der Waals force and hydrogen bonds, and was spectrally diagnosed with the conformational changes including diminution of α-helix content and spatial reorientation of fluorophore tryptophan. As coherently illustrated with the larger fluorescence quenching constants (3.65*10⁴-4.47*10⁴/mol) than DBP, the metabolites should be the priority concern due to stronger activity inhibition and toxicological risks.

Longitudinal evidence for immunosenescence and inflammaging in free-living great tits

The first-line effector mechanisms of immune defence, including inflammation and oxidative burst, contribute significantly to host-pathogen resistance. Whether these immune responses undergo age-related changes in birds remains unknown. Here, we tracked selected inflammatory parameters in 54 free-living great tits (Parus major) of known age, captured repeatedly over three consecutive years, with the aims to investigate long-term repeatability and age-dependent changes in cellular oxidative burst responsiveness upon in vitro stimulation with bacterial lipopolysaccharide (LPS), and to identify its relationships with leukotriene B4 (LTB4) levels and haematological traits. In addition, we linked these immunological traits to selected physiological markers (antioxidants and oxidative stress markers). LTB4 levels increased with age and we have shown a similar non-significant tendency also for absolute granulocyte counts, indicating propagating chronic inflammation over the bird's lifetime, consistent with the inflammaging hypothesis. In contrast, cellular oxidative burst followed a quadratic trend of dependency on age with a peak in midlife individuals, in line with the immunosenescence hypothesis. Interestingly, LTB4 levels were positively associated with general oxidative damage, but negatively with antioxidant glutathione peroxidase activity, indicating links to redox balance. This longitudinal study demonstrates the contrasting patterns of age-related changes in background and acute markers of pro-inflammatory immunity contributing to immunosenescence in birds and thus provides basis for interpretation of the tested inflammatory markers in cross-cohort datasets.

Nobiletin-loaded composite penetration enhancer vesicles restore the normal miRNA expression and the chief defence antioxidant levels in skin cancer

Skin cancer is one of the most dangerous diseases, leading to massive losses and high death rates worldwide. Topical delivery of nutraceuticals is considered a suitable approach for efficient and safe treatment of skin cancer. Nobiletin; a flavone occurring in citrus fruits has been reported to inhibit proliferation of carcinogenesis since 1990s, is a promising candidate in this regard. Nobiletin was loaded in various vesicular systems to improve its cytotoxicity against skin cancer. Vesicles were prepared using the thin film hydration method, and characterized for particle size, zeta potential, entrapment efficiency, TEM, ex-vivo skin deposition and physical stability. Nobiletin-loaded composite penetration enhancer vesicles (PEVs) and composite transfersomes exhibited particle size 126.70 ± 11.80 nm, 110.10 ± 0.90 nm, zeta potential + 6.10 ± 0.40 mV, + 9.80 ± 2.60 mV, entrapment efficiency 93.50% ± 3.60, 95.60% ± 1.50 and total skin deposition 95.30% ± 3.40, 100.00% ± 2.80, respectively. These formulations were selected for cytotoxicity study on epidermoid carcinoma cell line (A431). Nobiletin-loaded composite PEVs displayed the lowest IC50 value, thus was selected for the in vivo study, where it restored skin condition in DMBA induced skin carcinogenesis mice, as delineated by histological and immuno-histochemical analysis, biochemical assessment of skin oxidative stress biomarkers, in addition to miRNA21 and miRNA29A. The outcomes confirmed that nobiletin- loaded composite PEVs is an efficient delivery system combating skin cancer.

Effects of cyclophosphamide on antioxidative and immune functions of Nile tilapia (Oreochromis Niloticus) via the TLR-NF-κB signaling pathway

Intensive aquaculture often results in immunosuppression in fish, which may cause a series of diseases. In this study, to investigate the immunosuppressive mechanisms in fish, tilapia were intrapleural injected cyclophosphamide (CTX) at the doses of 10, 25, 50, 75 and 100 mg·kg^-1 to induce immunosuppression. We determined the viability of immune cells, the content of lysozyme (LZM) and immunoglobulin M (IgM), the levels of nitric oxide (NO) and antioxidant parameters. Meanwhile, the mRNA levels of complement C3 (c3), igm and the genes associated with the TLR-NF-κB signaling pathway in the head kidney (HK) and spleen were also determined. The results showed that CTX had a significant cytotoxic effect on peripheral blood leukocytes, HK macrophages and spleen cells in a dose-dependent manner. The protein and mRNA levels of C3 and IgM were down-regulated with the increase of CTX concentrations in serum, HK and/or spleen. The NO and LZM contents decreased significantly in HK and spleen after CTX treatments with 75 and 100 mg·kg^-1. CTX treatments with 50, 75 and/or 100 mg·kg^-1 markedly decreased the antioxidant ability and enhanced lipid peroxidation in HK and spleen. Furthermore, qPCR data showed that CTX treatments with 50-100 mg·kg^-1 clearly down-regulated the mRNA levels of tlr2, myd88, irak1, traf6, nfκb1, nfκb2, il-6, il-10 and tnf-α in the HK and/or spleen. Overall results suggested that CTX treatment had a cytotoxic effect on immune cells, induced lipid peroxidation, decreased the antioxidant capacity and inhibited immune function. The immunosuppressive mechanisms of CTX may be associated with the TLR-NF-κB signaling pathway.

Transcriptome Analysis Provides Insights into Hepatic Responses to Trichloroisocyanuric Acid Exposure in Goldfish (Carassius auratus)

Simple Summary

Trichloroisocyanuric acid (TCCA) has been widely used in public health and aquaculture for the prevention and treatment of diseases. As a strong oxidative disinfectant, TCCA may cause adverse influences on aquatic organisms and further poses a threat to the aquatic ecosystems. Nonetheless, the toxicological influences of TCCA on aquatic animals are still scarce and the mechanisms of the toxicity at the molecular levels in goldfish (Carassius auratus) have not been illustrated. The current study investigated the influences of sublethal concentration of TCCA on transcriptomic responses, the molecular indices of oxidative stress, and histopathological alterations in the hepatic and gill tissues of goldfish. The results indicated that TCCA exposure induced the disturbance of energy metabolism and the detoxification process. Furthermore, TCCA exposure also induced oxidative stress in the liver and caused pathological damage in gills. These findings could be useful to help understand the toxicological influences of TCCA on goldfish.

Abstract

In this study, goldfish (Carassius auratus) were exposed to 0 (control group) and 0.81 mg/L TCCA for four consecutive days. The liver transcriptome, the molecular indices of oxidative stress, and gills histopathology were investigated. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that energy metabolism-related pathways such as glycolysis/gluconeogenesis were significantly enriched, suggesting their perturbation in the liver of goldfish. Additionally, TCCA exposure also caused pathological damage in gills, which compromised physiological function and decreased oxygen intake capacity of gills, thus leading to the enhancement of anaerobic metabolism. This finding was confirmed by the significant upregulation of lactate dehydrogenase in the liver of goldfish. Moreover, many phase I and phase II metabolic enzymes might be activated to alleviate TCCA-induced toxicity in goldfish, and glutathione S-transferases (GSTs) and cytochrome P450s (CYPs) play a crucial role in the metabolism of TCCA in the liver of goldfish. Furthermore, the antioxidant enzyme analysis showed that TCCA exposure induced oxidative damage in the liver and partially impaired the antioxidant defense system of goldfish, evidenced by decreased superoxide dismutase (SOD) and catalase (CAT), and increased malondialdehyde (MDA) level. In summary, this study will improve our understanding of the molecular mechanisms of the TCCA-induced toxicity in goldfish.

Effects of subcutaneous injection of λ/κ-carrageenin on the immune and liver antioxidant status of gilthead seabream (Sparus aurata)

This study investigated the acute inflammatory response induced by subcutaneous injection of carrageenin (1%) or phosphate-buffered saline (control) in gilthead seabream (Sparus aurata). Skin mucus, serum, head kidney (HK) and liver were sampled at 1.5, 3 and 6 hr post-injection (p.i.) to determine the immune and antioxidant status of this fish species. The skin mucus of the carrageenin group showed increased superoxide dismutase and peroxidase activities, lysozyme abundance, bactericidal activity against Vibrio anguillarum and Photobacterium damselae, and total immunoglobulins compared with those of the control group. However, the carrageenin-injected fish sampled at 6 hr p.i. showed decreased protease activity in the skin mucus and peroxidase activity in the HK leucocytes compared with the control. Moreover, the carrageenin injection had no effects on the systemic immune system, but it reduced the liver catalase activities at both 3 and 6 hr in the carrageenin group relative to those in the control group. The expression levels of several proinflammatory and cell marker genes in the HK and liver were also determined. In the HK, the expression levels of interleukin-1β and prostaglandin D synthase 1 were upregulated at 1.5 and 3 hr, respectively, in the carrageenin group compared with those in the control group. Contrarily, the expression of the NADPH oxidase subunit phox40 (an acidophilic granulocyte marker) in the carrageenin group at 6 hr was downregulated compared with that in the control group. These results suggested that subcutaneous injection of κ/λ-carrageenin in gilthead seabream triggered an acute skin inflammation characterized by the rapid recruitment of acidophilic granulocytes and the release of humoral mediators into the skin mucus.

Does the Anionic Surfactant Isopropylamine Dodecylbenzene Sulfonate Induce Hepatic Oxidative Stress and Impairment in Carassius auratus gibelio?

Isopropylamine dodecylbenzene sulfonate (IDS) is a new kind of anionic surfactant (ANS). To preliminarily evaluate the aquatic toxicity of IDS, this study took gibel carp (Carassius auratus gibelio) as the research object. The well-acclimatized fish were divided into six groups and exposed to 0 mg/L, 0.5 mg/L, 1.0 mg/L, 2.0 mg/L, 4.0 mg/L, or 8.0 mg/L of IDS for 7, 14, 21 or 28 days. Our results showed that the superoxide dismutase (SOD) activity and malondialdehyde (MDA) content of the liver were unaffected by IDS exposure, while glutathione peroxidase (GSH-Px) activity was significantly inhibited. Hepatic tissue exhibited pathological damage, characterized by nuclear migration and dissolution and cell boundary blurring. The results suggest that IDS does not cause oxidative stress in the liver, but cause hepatic histopathological damage. GSH-Px can be considered as a biomarker of IDS exposure in gibel carp.

Modulation of Inflammatory Pathways and Adipogenesis by the Action of Gentisic Acid in RAW 264.7 and 3T3-L1 Cell Lines

Gentisic acid (GA), a benzoic acid derivative present in various food ingredients, has been shown to have diverse pharmaceutical activities such as anti-carcinogenic, antioxidant, and hepatoprotective effects. In this study, we used a co-culture system to investigate the mechanisms of the anti-inflammatory and anti-adipogenic effects of GA on macrophages and adipocytes, respectively, as well as its effect on obesity-related chronic inflammation. We found that GA effectively suppressed lipopolysaccharide-stimulated inflammatory responses by controlling the production of nitric oxide and pro-inflammatory cytokines and modulating inflammation-related protein pathways. GA treatment also inhibited lipid accumulation in adipocytes by modulating the expression of major adipogenic transcription factors and their upstream protein pathways. Furthermore, in the macrophage-adipocyte co-culture system, GA decreased the production of obesity-related cytokines. These results indicate that GA possesses effective anti-inflammatory and anti-adipogenic activities and may be used in developing treatments for the management of obesity-related chronic inflammatory diseases.

Antioxidant Effects of Anthocyanin-Rich Riceberry™ Rice Flour Prepared Using Dielectric Barrier Discharge Plasma Technology on Iron-Induced Oxidative Stress in Mice

Redox-active iron generates reactive oxygen species that can cause oxidative organ dysfunction. Thus, the anti-oxidative systems in the body and certain dietary antioxidants, such as anthocyanins, are needed to control oxidative stress. We aimed to investigate the effects of dielectric barrier discharge (DBD) plasma technology in the preparation of Riceberry™ rice flour (PRBF) on iron-induced oxidative stress in mice. PRBF using plasma technology was rich in anthocyanins, mainly cyanidine-3-glucoside and peonidine-3-glucoside. PRBF (5 mg AE/mg) lowered WBC numbers in iron dextran (FeDex)-loaded mice and served as evidence of the reversal of erythrocyte superoxide dismutase activity, plasma total antioxidant capacity, and plasma and liver thiobarbituric acid-reactive substances in the loading mice. Consequently, the PRBF treatment was observed to be more effective than NAC treatment. PRBF would be a powerful supplementary and therapeutic antioxidant product that is understood to be more potent than NAC in ameliorating the effects of iron-induced oxidative stress.

Plasma redox and inflammatory patterns during major depressive episodes: a cross-sectional investigation in elderly patients with mood disorders

BACKGROUND

While both depression and aging have been associated with oxidative stress and impaired immune response, little is known about redox patterns in elderly depressed subjects. This study investigates the relationship between redox/inflammatory patterns and depression in a sample of elderly adults.

METHODS

The plasma levels of the advanced products of protein oxidation (AOPP), catalase (CAT), ferric reducing antioxidant power (FRAP), glutathione transferase (GST), interleukin 6 (IL-6), superoxide dismutase (SOD), total thiols (TT), and uric acid (UA) were evaluated in 30 patients with mood disorders with a current depressive episode (depressed patients, DP) as well as in 30 healthy controls (HC) aged 65 years and over. Subjects were assessed with the Hamilton Depression Rating Scale (HAM-D), the Hamilton Rating Scale for Anxiety (HAM-A), the Geriatric Depression Rating Scale (GDS), the Scale for Suicide Ideation (SSI), the Reason for Living Inventory (RFL), the Activities of Daily Living (ADL), and the Instrumental Activity of Daily Living (IADL).

RESULTS

DP showed higher levels than HC of AOPP and IL-6, while displaying lower levels of FRAP, TT, and CAT. In the DP group, specific correlations were found among biochemical parameters. SOD, FRAP, UA, and TT levels were also significantly related to psychometric scale scores.

CONCLUSION

Specific alterations of redox systems are detectable among elderly DP.

Assessment of toxicity and environmental behavior of chiral ethiprole and its metabolites using zebrafish model

Ethiprole is effective against a wide range of insects and has been used throughout the world. In this work, the toxicity, bioaccumulation and elimination of ethiprole and its main metabolites (ethiprole sulfone (M1), ethiprole sulfide (M2), ethiprole amide (M3), ethiprole sulfone amide (M4) and desethylsulfinyl ethiprole (M5)) in zebrafish Danio rerio were investigated at enantiomeric level. Rac-ethiprole showed high toxicity (96 h LC₅₀ = 708 μg L^-1) and M2 was six times more toxic than ethiprole (111 μg L^-1). Enantioselective toxicity was observed, with the S-ethiprole (924 μg L^-1) being more toxic than R-ethiprole (2195 μg·L^-1). Rac-ethiprole and M2 could induce oxidative stress in the liver of adult zebrafish and developmental toxicity in zebrafish embryos. Zebrafish were exposed to 100 μg L^-1 rac-/R-/S-ethiprole and the bioaccumulation was monitored during a 21 d period followed by a 7 d metabolism. The bioconcentration factor (BCF) of rac-ethiprole was 17, and the half-lives of rac-ethiprole and metabolites varied between 0.44 and 2.99 d. R-ethiprole was preferentially accumulated and metabolized in zebrafish. Besides, the metabolic pathways of R- and S-ethiprole were found to be different. This study indicated assessment of metabolites and enantioselectivity should be taken into consideration in evaluating environmental risks of ethiprole.

Hypoxia-induced oxidative stress and transcriptome changes in the mud crab (Scylla paramamosain)

Mud crab (Scylla paramamosain) is an economically important cultured species in China. Hypoxia is a major environmental stressor during mud crab culture. In the present study, we investigated the oxidative stress and transcriptome changes in the gills of mud crab after intermediate hypoxia stress with dissolved oxygen (DO) 3.0 ± 0.2 mg/L (named as "DO3") and acute hypoxia stress with DO 1.0 ± 0.2 mg/L (named as "DO1") for 0, 3, 6, 12 and 24 h. The superoxide dismutase (SOD) activity of DO1 increased significantly at 3, 6 and 24 h after hypoxia stress, while SOD activity of DO3 increased significantly at 6 and 24 h. The total antioxidant capacity (T-AOC) increased significantly at 6, 12 and 24 h after hypoxia stress. The malondialdehyde (MDA) concentration of DO1 increased significantly at 6, 12 and 24 h after hypoxia stress, while MDA concentration of DO3 only increased significantly at 6 h. The lactate dehydrogenase (LDH) activity of DO1 increased significantly at 3, 6, 12 and 24 h after hypoxia stress, while LDH activity of DO3 increased significantly at 12 and 24 h. Transcriptomic analysis was conducted at 24 h of gill tissues after hypoxia stress. A total of 1052 differentially expressed genes (DEGs) were obtained, including 394 DEGs between DO1 and DO3, 481 DEGs between DO1 and control group, 177 DEGs between DO3 and control group. DEGs were enriched in the pathways related to metabolism, immune functions, ion transport, and signal transduction. Transcriptional analysis showed that glycolysis and tricarboxylic acid cycle genes were the key factors in regulating the adaptation of mud crab to hypoxia stress.

One Week of CDAHFD Induces Steatohepatitis and Mitochondrial Dysfunction with Oxidative Stress in Liver

The prevalence of nonalcoholic fatty liver disease (NAFLD) has been rapidly increasing worldwide. A choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) has been used to create a mouse model of nonalcoholic steatohepatitis (NASH). There are some reports on the effects on mice of being fed a CDAHFD for long periods of 1 to 3 months. However, the effect of this diet over a short period is unknown. Therefore, we examined the effect of 1-week CDAHFD feeding on the mouse liver. Feeding a CDAHFD diet for only 1-week induced lipid droplet deposition in the liver with increasing activity of liver-derived enzymes in the plasma. On the other hand, it did not induce fibrosis or cirrhosis. Additionally, it was demonstrated that CDAHFD significantly impaired mitochondrial respiration with severe oxidative stress to the liver, which is associated with a decreasing mitochondrial DNA copy number and complex proteins. In the gene expression analysis of the liver, inflammatory and oxidative stress markers were significantly increased by CDAHFD. These results demonstrated that 1 week of feeding CDAHFD to mice induces steatohepatitis with mitochondrial dysfunction and severe oxidative stress, without fibrosis, which can partially mimic the early stage of NASH in humans.

An Antioxidant Nanoparticle Enhances Exercise Performance in Rat High-intensity Running Models

Although the adverse effects of excessively generated reactive oxygen species (ROS) on the body during aerobic exercise have been debated, there are few reports on the remarkable effects of the application of conventional antioxidants on exercise performance. The conventional antioxidants could not enhance exercise performance due to their rapid excretion from the body and serious adverse effects on the cellular respiratory system. In this study, impact of the original antioxidant self-assembling nanoparticle, redox-active nanoparticle (RNP), is investigated on the exercise performance of rats during running experiments. With an increase in the dose of the administered RNP, the all-out time of the rat running extends in a dose-dependent manner. In contrast, with an increase in the dose of the low-molecular-weight (LMW) antioxidant, the all-out running time of the rats decreases. The control group and LMW antioxidant treated group decrease in the number of red blood cells (RBCs) and increase oxidative stress after running. However, the RNP group maintains a similar RBC level and oxidative stress as that of the sedentary group. The results suggest that RNP, which shows long-blood circulation without disturbance of mitohormesis, effectively removes ROS from the bloodstream to suppresses RBC oxidative stress and damage, thus improving exercise performance.

Efficiency of Deoxynivalenol Detoxification by Microencapsulated Sodium Metabisulfite Assessed via an In Vitro Bioassay Based on Intestinal Porcine Epithelial Cells

Deoxynivalenol (DON) contamination occurs in feeds and causes a reduction in growth performance, damage to the intestinal epithelial cells, and increased susceptibility to enteric pathogen challenge. Sodium metabisulfite (SMBS) has shown promise in reducing DON; however, SMBS quickly degrades under aqueous acidic conditions such as the environment within a stomach. Thus, protection of SMBS is required for effective delivery to the small intestine to detoxify DON. This study was to encapsulate SMBS into hydrogenated palm oil-based microparticles for its delivery to the small intestine and to evaluate its efficacy on DON detoxification in simulated intestinal fluids using IPEC-J2 cells in vitro. The diameter of the SMBS containing microparticles was 511 ± 135 μm, and the loading capacity of SMBS in the microparticles was 45.50%; 1.41% of the encapsulated SMBS (ES) was released into the simulated gastric fluid, and 66.39% of ES was progressively released into the simulated intestinal fluid within 4 h at 37 °C. In IPEC-J2 cells, when DON was treated with the simulated gastric fluid containing 0.5% ES for 2 h, then mixed with the simulated intestinal fluid (1:1) and incubated for 2 h, cytotoxicity was not observed. DON treated with 0.5 ES decreased the gene expression of inflammatory cytokines in the cells compared with DON alone and maintained the cell integrity. To conclude, the SMBS containing microparticles were stable in the simulated gastric fluid and allowed a progressive release of SMBS in the simulated intestinal fluid. The released SMBS in the simulated intestinal fluid effectively detoxified DON.

Aggravated behavioral and neurochemical deficits and redox imbalance in mice with enhanced neonatal iron intake: improvement by biochanin A and role of microglial p38 activation

Objectives: We aim to investigate the joint effect of iron (enhanced neonatal iron intake), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and biochanin A (BA, oral administration) and possible mechanisms for action on behavioral and neurochemical indicators in the mice. Methods: Rotarod test, pole test and swim test were used to evaluate animal behavior. The neurochemical analysis was conducted by HPLC-ECD. Oxidative stress was determined in this study. Further mechanism was investigated through in vitro experiments. Results: Iron and MPTP co-administration significantly induced behavioral deficits and decreased striatal dopamine content in the male and female mice. The co-administration of iron and MPTP also significantly induced redox imbalance in the substantia nigra (SN) of mice. Furthermore, BA significantly improved behavioral deficits and increased striatal dopamine content in the mice co-treated with iron and MPTP. BA also significantly improved redox imbalance in the SN of mice co-administered with iron and MPTP. Finally, we showed that iron and 1-Methyl-4-phenylpyridinium (MPP+) co-treatment significantly increased superoxide production in microglial cultures by inducing p38 mitogen-activated protein kinase (MAPK) activation. BA also significantly decreased superoxide production and p38 MAPK phosphorylation in the cultures co-treated with iron and MPP+. Conclusion: Iron and MPTP co-treatment may result in worsened behavioral and neurochemical deficits and aggravated redox imbalance through inducing microglial p38 MAPK activation. BA may improve behavioral and neurochemical deficits and redox imbalance through repressing microglial p38 MAPK activation.

Marine cyanobacterium Spirulina maxima as an alternate to the animal cell culture medium supplement

Serum is a stable medium supplement for in vitro cell culture. Live cells are used in stem cell research, drug toxicity and safety testing, disease diagnosis and prevention, and development of antibiotics, drugs, and vaccines. However, use of serum in culture involves concerns such as an ethical debate regarding the collection process, lack of standardized ingredients, and high cost. Herein, therefore, we evaluated the possibility of using edible cyanobacterium (Spirulina maxima), which is a nutrient-rich, sustainable, and ethically acceptable source, as a novel substitute for fetal bovine serum (FBS). H460 cells were cultured to the 10th generation by adding a mixture of spirulina animal cell culture solution (SACCS) and FBS to the culture medium. Cell morphology and viability, cell cycle, apoptosis, proteomes, and transcriptomes were assessed. We observed that SACCS had better growth-promoting capabilities than FBS. Cell proliferation was promoted even when FBS was replaced by 50-70% SACCS; there was no significant difference in cell shape or viability. There were only slight differences in the cell cycle, apoptosis, proteomes, and transcriptomes of the cells grown in presence of SACCS. Therefore, SACCS has the potential to be an effective, low-cost, and eco-friendly alternative to FBS in in vitro culture.

Manganese(II) complexes derived from acyclic ligands having flexible alcohol arms: structural chracterization and SOD and catalase mimetic studies

In this work, a series of seven MnII complexes of noncyclic flexible ligands derived from 2,6-diformylpyridine and ethanolamine or alkyl-substituted ethanolamines were prepared and characterized, six structurally by single-crystal X-ray diffraction studies. The complexes are dichlorido{2,2′-[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]diethanol}manganese(II), [MnCl2(C11H15N3O2)] or [MnCl2(L1)], (2), bis{μ-2,2′-[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]diethanol}bis[dithiocyanatomanganese(II)], [Mn2(NCS)4(C11H15N3O2)2] or [Mn2(NCS)4(L1)2], (3), chlorido{1,1′-[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]bis(propan-2-ol)}manganese(II) chloride monohydrate, [MnCl(C13H19N3O2)(H2O)]Cl·H2O or [MnCl(L2)(H2O)]Cl·H2O, (4), {1,1′-[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]bis(propan-2-ol)}dithiocyanatomanganese(II), [Mn(NCS)2(C13H19N3O2)] or [Mn(NCS)2(L2)], (5), aquadichlorido{2,2′-dimethyl-2,2′-[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]bis(propan-1-ol)}manganese(II) 0.3-hydrate, [MnCl2(C15H23N3O2)(H2O)]·0.3H2O or [MnCl2(L3)(H2O)]·0.3H2O, (6), (dimethylformamide){2,2′-dimethyl-2,2′-[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]bis(propan-1-ol)}dithiocyanatomanganese(II), [Mn(NCS)2(C15H23N3O2)(C3H7NO)] or [Mn(NCS)2(L3)(DMF)], (7), and (dimethylformamide){2,2′-[(pyridine-2,6-diyl)bis(nitrilomethanylylidene)]bis(butan-1-ol)}dithiocyanatomanganese(II) dimethylformamide monosolvate, [Mn(NCS)2(C15H23N3O2)(C3H7NO)]·C3H7NO or [Mn(NCS)2(L4)(DMF)]·DMF, (8). The crystal structure of ligand L1 is also reported, but that of (5) is not. All four ligands (L1–L4) have five potential donor atoms in an N3O2 donor set, i.e. three N (pyridine/diimine donors) and two alcohol O atoms, to coordinate the MnII centre. The N3O2 donor set coordinates to the metal centre in a pentagonal planar arrangement; seven-coordinated MnII complexes were obtained via coordination of two auxiliary ligands (anions or water molecules) at the axial positions. However, in some cases, the alcohol O-atom donors remain uncoordinated, resulting in five- or six-coordinated MnII complexes. The structurally characterized complexes were tested for their catalytic scavenging of superoxide and peroxide. The results indicated that the complexes with coordinated exogenous water or chloride ligands showed higher SOD activity than those with exogenous thiocyanate ligands.

Effects of dietary baicalin supplementation on growth performance, antioxidative status and protection against oxidative stress-induced liver injury in GIFT tilapia (Oreochromis niloticus)

Baicalin, a main bioactive compound of Scutellaria baicalensis, has a variety of pharmacological activities including antioxidation, anti-inflammation and hepatoprotection. However, there are few reports on these biological activities in fish. Therefore, the aim of this study was to assess the effects of baicalin on growth performance, antioxidative status and hepatoprotection in tilapia. The fish were fed on different doses of baicalin (0, 0.4, 0.8 and 1.6 g/kg diet). After feeding 60 days, parts of fishes were netted, and the blood, liver, gills and muscle tissues were collected to analyze the antioxidative effect. The remaining fishes were injected with saline or hydrogen peroxide (H₂O₂) for challenge test. The results showed that the specific growth rate of fish was slightly increased in three baicalin treatments, and the feed efficiency was clearly improved in 0.4 g/kg baicalin treatment. Meanwhile, the antioxidative capacity in blood, liver and/or gill was enhanced in treatments with 0.4, 0.8 and/or 1.6 g/kg baicalin. After challenge test, the pre-treatments with baicalin effectively alleviated H₂O₂-induced liver injury. In serum and liver, pre-treatments with 0.8 and/or 1.6 g/kg baicalin suppressed the oxidative damage induced by H₂O₂, as evidenced by improvement of the levels of SOD, T-AOC and GSH and the decline of MDA level. More important, pre-treatments with 0.4, 0.8 and/or 1.6 g/kg baicalin blocked the upregulation of mRNA levels of tlr1, myd88, irak4, rela, tnf-α and il-1β in H₂O₂-induced liver injury. In summary, dietary baicalin supplementation could improve feed efficiency, enhance antioxidative ability and alleviate oxidative stress-induced hepatotoxicity in tilapia.

Dysregulation of Catalase by a Sulphamoylated Estradiol Analogue Culminates in Antimitotic Activity and Cell Death Induction in Breast Cancer Cell Lines

Recent findings revealed that 2-ethyl-17-oxoestra-1,3,5(10)-trien-3-yl sulfamate (ESE-one) induces antiproliferative activity and cell rounding dependent on the generation of superoxide anion, hydrogen peroxide and peroxyl radical. In the current study, the role of these reactive oxygen species was assessed in the activity exerted by ESE-one on cell cycle progression, mitochondrial membrane potential and cell death induction in breast tumorigenic cells. The influence of ESE-one was also investigated on superoxide dismutase and catalase activity. ESE-one induced a time-dependent accumulation of cells in the G₁ phase and G₂/M phase that is partially impaired by tiron and trolox and N,N′-dimethylthiourea suggesting that superoxide anion, hydrogen peroxide and peroxyl radical are required for these effects exerted by ESE-one. Flow cytometry data in MCF-7 cells demonstrated that tiron decreased depolarization of the membrane potential in ESE-one exposed cells, indicating that superoxide anion plays a role in the depolarization effects induced by ESE-one. Spectrophotometry data showed that ESE-one decreased catalase activity in both cell lines. This study contributes towards pertinent information regarding the effects of an in silico-designed sulfamoylated compound on antioxidant enzymes leading to aberrant quantities of specific reactive oxygen species resulting in antimitotic activity culminating in the induction of cell death in breast cancer cell lines.

Comparative transcriptome analysis uncovers roles of hydrogen sulfide for alleviating cadmium toxicity in Tetrahymena thermophila

Background

Cadmium (Cd) is a nonessential heavy metal with potentially deleterious effects on different organisms. The organisms have evolved sophisticated defense system to alleviate heavy metal toxicity. Hydrogen sulfide (H₂S) effectively alleviates heavy metal toxicity in plants and reduces oxidative stress in mammals. However, the function of H₂S for alleviating heavy metal toxicity in aquatic organisms remains less clear. Tetrahymena thermophila is an important model organism to evaluate toxic contaminants in an aquatic environment. In this study, the molecular roles of exogenously H₂S application were explored by RNA sequencing under Cd stress in T. thermophila.

Results

The exposure of 30 μM Cd resulted in T. thermophila growth inhibition, cell nigrescence, and malondialdehyde (MDA) content considerably increase. However, exogenous NaHS (donor of H₂S, 70 μM) significantly alleviated the Cd-induced toxicity by inhibiting Cd absorbtion, promoting CdS nanoparticles formation and improving antioxidant system. Comparative transcriptome analysis showed that the expression levels of 9152 genes changed under Cd stress (4658 upregulated and 4494 downregulated). However, only 1359 genes were differentially expressed with NaHS treatment under Cd stress (1087 upregulated and 272 downregulated). The functional categories of the differentially expressed genes (DEGs) by gene ontology (GO) revealed that the transcripts involved in the oxidation–reduction process, oxidoreductase activity, glutathione peroxidase activity, and cell redox homeostasis were the considerable enrichments between Cd stress and NaHS treatment under Cd stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the carbon metabolism, glutathione metabolism, metabolism of xenobiotics by cytochrome P450, and ABC transporters were significantly differentially expressed components between Cd stress and NaHS treatment under Cd stress in T. thermophila. The relative expression levels of six DEGs were further confirmed through quantitative real-time polymerase chain reaction (qRT-PCR).

Conclusion

NaHS alleviated Cd stress mainly through inhibiting Cd absorbtion, promoting CdS nanoparticles formation, increasing oxidation resistance, and regulation of transport in free-living unicellular T. thermophila. These findings will expand our understanding for H₂S functions in the freshwater protozoa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-020-07337-9.

Comparative study on the effect of dietary β-carotene and phycocyanin extracted from Spirulina platensis on immune-oxidative stress biomarkers, genes expression and intestinal enzymes, serum biochemical in Nile tilapia, Oreochromis niloticus

The current trial investigated the roles of β-carotene and phycocyanin extracted from Spirulina platensis on growth, serum biochemical, digestive enzymes, antioxidant defense, immune responses, and immune gene expression in Nile tilapia (Oreochromis niloticus). Fish (1.52 ± 0.10 g) were randomly stocked to three treatments with three replicates (12 fish per replicate) in nine aquaria (60 L glass aquarium for each), and reared for 70-days. Three tested diets were formulated to be isonitrogenous and isolipidic, and were offered for experimental fish until ad-libitum three times daily at 09:00 a.m., 11.00 a.m. and 3:00 p.m. The first diet (control) was without supplementation. About 50 mg β-carotene and 50 mg phycocyanin kg^-1 were supplemented to the other experimental diets, respectively. Results indicated that feed intake was not (P > 0.05) differ among experimental diets. Compared to control diet wight gain and specific growth rate were significantly (P < 0.05) in fish fed diet containing β-carotene, while, the highest weight gain and the best FCR were detected in phycocyanin diet. Survival fish among treatments was significantly (P < 0.05) differ and the highest survival rate was showed in fish fed diet supplemented with phycocyanin. Either β-carotene or phycocyanin significantly (P < 0.05) improved the intestinal digestive enzymes compared with control diet, where the highest values of chymotrypsin, trypsin, lipase and amylase were noticed in fish fed phycocyanin. Diets supplemented with β-carotene and phycocyanin significantly (P < 0.05) improved hematology parameters contents compared with to the control diet, and the best contents were detected in fish fed diet supplemented with phycocyanin. The highest significant (P < 0.05) phagocytic, lysozyme, immunoglobulin M (IgM), superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and total antioxidant capacity (T-AOC) activities were recorded in diet supplemented with phycocyanin. The transcripts of interferon gamma and interleukin 1β genes were (P < 0.05) up-regulated in the liver of fish fed diet supplemented with β-carotene and phycocyanin, but expression of HSP70 gene down-regulated in fish fed β-carotene and phycocyanin containing diet compared control. The highest gene expression of the interferon gamma and interleukin 1β was observed in fish fed phycocyanin.

Renalase is localized to the small intestine crypt and expressed upon the activation of NF-κB p65 in mice model of fasting-induced oxidative stress

AIMS

Renalase expression is regulated by Nuclear Factor (NF)-κB and hypoxia inducible factor (HIF)-1α, and antioxidative stress function in renal cells were reported. However, dynamics of renalase and localizes in intestine were remain unknown. We evaluated the effects of oxidative stress on renalase expression and localization using model of fasting induced oxidative stress and Caco-2 cell, and examined the its physiological effects.

MAIN METHODS

24 male mice were divided into three groups: Control (Con), 72 h fasting (Fast), and 24 h refeeding after fasting (Refeed). Jejunum and ileum were collected respectively. The structure of jejunum and ileum were observed by hematoxylin and eosin (HE) stain. The expression levels of carbonylated protein, renalase, NF-κB p65 and HIF-1α were measured by immunoblotting. Localization of renalase was observed by immunofluorescent. in vitro assay was performed using Caco-2 cell. Renalase was overexpressed using adenovirus. After that, Caco-2 cell was treated with 2 mM H₂O₂ for 30 min or 24 h.

KEY FINDINGS

Renalase was increased in Fast and it was localized in crypt. HIF-1α did not increase, but NF-κB p65 increased in Fast. Renalase overexpression protects the Caco-2 cells against H₂O₂ induced oxidative stress.

SIGNIFICANCE

Renalase was localized in crypt and increased in Fast. This increase suggested protect response to oxidative stress because undifferenced cells were localized in crypt and need to be protected. Actually, renalase protected Caco-2 cells against H₂O₂ induced oxidative stress. Small intestinal renalase expression was regulated by NF-κB p65 and was considered to be a defense mechanism against oxidative stress.

A Cerium Vanadate Nanozyme with Specific Superoxide Dismutase Activity Regulates Mitochondrial Function and ATP Synthesis in Neuronal Cells

Nanoparticles that functionally mimic the activity of metal-containing enzymes (metallo-nanozymes) are of therapeutic importance for treating various diseases. However, it is still not clear whether such nanozymes can completely substitute the function of natural enzymes in living cells. In this work, we show for the first time that a cerium vanadate (CeVO₄ ) nanozyme can substitute the function of superoxide dismutase 1 and 2 (SOD1 and SOD2) in the neuronal cells even when the natural enzyme is down-regulated by specific gene silencing. The nanozyme prevents the mitochondrial damage in SOD1- and SOD2-depleted cells by regulating the superoxide levels and restores the physiological levels of the anti-apoptotic Bcl-2 family proteins. Furthermore, the nanozyme effectively prevents the mitochondrial depolarization, leading to a significant improvement in the cellular levels of ATP under oxidative stress.

Chronic exposure of hydrogen peroxide alters redox state, apoptosis and endoplasmic reticulum stress in common carp (Cyprinus carpio)

Hydrogen peroxide (H₂O₂) appears to be ubiquitous in natural water. Higher level of H₂O₂ can cause physiological stress, immunosuppression and even death in aquatic animals, but the physiological and molecular mechanisms of H₂O₂ toxicity are not well studied. Thus, the aim of the present study was to exposure potential toxic mechanisms of H₂O₂ via assessing the effects on redox state, apoptosis and endoplasmic reticulum (ER) stress in common carp. The fish were subjected to four concentrations of H₂O₂ (0, 0.25, 0.5 and 1 mM) for 14 days. And then, the tissues including blood, liver, muscle, gills, intestines, heart, kidney and spleen were collected to measure biochemical parameter and gene expression. The results showed that H₂O₂ exposure suppressed the majority antioxidative parameters in serum, liver, muscle and intestines, but enhanced T-SOD, CAT and T-AOC levels in gills. In all tested tissues, the MDA content was significantly promoted by H₂O₂ exposure. The oxidative stress-related genes including nrf2, gstα, sod, cat and/or gpx1 were upregulated in liver, gills, muscle, intestines, and/or kidney, but downregulated in heart after H₂O₂ exposure. Moreover, the ho-1 mRNA level was inhibited by H₂O₂ exposure in all tissues except intestines and spleen. After 14 days of exposure, H₂O₂ induced ER stress and initiated IRE1 and PERK pathways, which activated downstream genes, including chop, grp78 and/or xbp1s, to regulate UPR in liver, gills, muscle and/or heart. Meanwhile, H₂O₂ exposure activated MAPK pathway to regulate mitochondria-related genes including bcl-2, bax and cytc, which further triggered cas-8, cas-9 and cas-3, and accelerated apoptosis in liver, gills, muscle and heart. Importantly, in different tissues, the genes associated with oxidative stress, ER stress and apoptosis showed a different influence, and more significant influence was observed in the muscle, gills and liver. Overall results suggested that long-term H₂O₂ exposure induced oxidative stress, ER stress and apoptosis in the majority of tested tissues of common carp. The Nrf2, IRE1, PERK and MAPK pathways played important roles in H₂O₂-induced toxicity in fish. These data enriched the toxicity mechanism of H₂O₂ in fish, which might contribute to the risk assessment of H₂O₂ in aquatic environment.

Hepatoprotective effect of Moringa oleifera leaves aquatic extract against lead acetate-induced liver injury in male Wistar rats

Current research was performed to explore the hepatoprotective potential of Moringa oleifera leaves extract on lead acetate-induced hepatic injury. Twenty-four male Wistar rats were divided equally into 4 groups. The first group was control, while the second, third, and fourth groups were given 200 mg/kg aqueous Moringa extract only, 100 mg/kg lead only, and 100 mg/kg lead plus 200 mg/kg aqueous Moringa leaves extract, respectively, via oral gavage for 4 weeks. Weight gain and feed efficiency ratio were recorded. Serum lipid profiles, liver enzyme activities, and proteins beside hepatic superoxide dismutase activity, reduced glutathione, tumor necrosis factor alpha (TNF-α), and deoxyribonucleic acid fragmentation were assessed. Liver histopathological examination and nuclear factor kappa B (NF-kB) immunohistochemistry were performed. Administration of lead lowered (P < 0.05) weight gain, feed efficiency ratio, and perturbed lipid profile than control. Lead increased liver enzyme activities and TNF-α, while reduced serum proteins and hepatic antioxidant markers compared to control. Lead aggravated hepatic DNA fragmentation beside the presence of histopathological lesions. Co-administration of aqueous Moringa extract with lead significantly alleviated lead-induced adverse effects. The administration of aqueous Moringa extract with its antioxidant significantly restored the lead perturbations through reduction of oxidative stress-induced DNA damage via amelioration of NF-kB and TNF-α which kept hepatocyte integrity and reduced serum hepatic enzyme activities.

Highly Stable Pyrimidine Based Luminescent Copper Nanoclusters with Superoxide Dismutase Mimetic and Nitric Oxide Releasing Activity

Copper nanoclusters (CuNCs) are emerging as an interesting class of materials for various biomedical applications. In this work, we have designed highly stable nucleobase-capped luminescent CuNCs and studied the effect of substituents on the cluster composition and photophysical properties. The NCs exhibit exceptional stability in ambient atmosphere and show significant variation in the emission properties with a change in position of substituents on the ligand, thiouracil. This study represents the first example of a nanocluster that functionally mimics the activity of a major antioxidant enzyme, superoxide dismutase (SOD). In addition to their enzyme-mimetic activity, the CuNCs evince controlled release of nitric oxide (NO), a key gaseous molecule of endothelial system from S-nitrosothiol, S-nitrosoglutathione (GSNO). Further, to a greater significance, these luminescent CuNCs are readily taken up by the mammalian cells and exhibit low toxicity. The superoxide dismutase and NO releasing activity of the fluorescent, biocompatible copper nanoclusters suggest their potential application in both therapeutics and bioimaging.

Spectrophotometric method for superoxide anion radical detection in a visible light (400-780 nm) system

A method was developed that used hydroxylamine hydrochloride as a probe in a superoxide anion radical-generating visible light system for determining superoxide anion radicals. An Azure I solution with hydroxylamine hydrochloride was illuminated, after which a ferric iron solution was added to the sample solution and the remaining hydroxylamine hydrochloride in solution reduced from ferric to ferrous ions. Then, 1,10-phenanthroline solution was added and spectrophotometrically measured at 510 nm, which indirectly indicated the hydroxylamine hydrochloride content. The yields of superoxide anion radicals were indirectly expressed by the hydroxylamine hydrochloride decrement. Under optimal experimental conditions, the linear range was 0.0-1.5 × 10^-5 M and the limit of detection and limit of quantification were obtained to be 8.37 × 10^-7 and 2.54 × 10^-6 M with an R² of 0.9993. The method was simple and feasible and could be used for the stable measurement of superoxide anion radicals produced by photosensitizers that produce color under acidic conditions in visible light systems.

Pharmacokinetics and Protective Effects of Tartary Buckwheat Flour Extracts against Ethanol-Induced Liver Injury in Rats

The grains of Tartary buckwheat (Fagopyrum esculentum) are traditionally consumed on a daily basis and are used in the preparation of diverse processed foods owing to the high concentration of rutin, an antioxidant compound. However, rutin is highly concentrated in hull and bran, but not in edible flour fractions. Rutin-enriched TB flour extracts (TBFEs) were obtained by hydrothermal treatment (autoclaving, boiling, or steaming) and their pharmacokinetic profiles were evaluated following a single-dose oral administration in rats. The antioxidant and protective activities of the extracts against alcoholic liver disease (ALD) were investigated after repetitive oral administration of TBFEs for 28 days prior to ethanol ingestion. The results demonstrated that rutin-enriched TBFEs had better oral absorption and was retained longer in the bloodstream than native TBFE or standard rutin. The activities of antioxidant enzymes and intracellular antioxidant levels increased in ALD rats following TBFE treatments, especially following the administration of rutin-enriched TBFEs. The antioxidant activity of TBFEs consequently contributed toward protecting the liver against injury caused by repetitive ethanol administration, as confirmed by analyzing relative liver weight, liver injury markers, lipid peroxidation, and calcium permeability. These results suggest the promising potential of TBFEs as antioxidant-enriched functional foods for human health.

Catalase and superoxide dismutase response and the underlying molecular mechanism for naphthalene

Naphthalene, a naturally-occurring polyaromatic hydrocarbon, pose potential threats to health for its wide exposures in environment. Naphthalene could disrupt the redox equilibrium resulting in oxidative damage. Antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) are considered to be the efficient defense barriers to protect organisms from negative impacts of toxicants. Limited information is available regarding the underlying molecular mechanism between antioxidant enzymes and naphthalene. In this paper, structural and functional alterations of CAT and SOD for low dose (1.6-25.6 mg/L) naphthalene exposure have been investigated at the molecular and cellular levels. The enzyme activity responses of CAT and SOD in hepatocytes for naphthalene were consistent with the molecular, in which the activity of CAT increased and the activity of SOD slightly inhibited. Spectroscopy methods and molecular docking were carried out to investigate the underlying binding mechanisms. Naphthalene exposure significantly changed the conformation of CAT with secondary structure alteration (α-helix increase) but only changed the skeleton structure of SOD without secondary structure alteration. Naphthalene could bind to CAT and SOD primarily via H-binding force accompanied with the particle size of CAT/SOD agglomerates decreasing. Naphthalene preferentially bound to the surface of CAT and SOD. Besides, naphthalene could also bind directly to the active center of CAT with the key residues Arg364 and Tyr 357 for activity. This paper provides a combined cellular and molecular strategy to research biomarker responses for toxicants exposure. Besides, this study offers detailed basic data for the comprehensive understanding of naphthalene toxicity.

TIGAR reduces smooth muscle cell autophagy to prevent pulmonary hypertension

Yamanaka R, Hoshino A, Fukai K, Urata R, Minami Y, Honda S, Fushimura Y, Hato D, Iwai-Kanai E, Matoba S. TIGAR reduces smooth muscle cell autophagy to prevent pulmonary hypertension. Am J Physiol Heart Circ Physiol 319: H1087-H1096, 2020. First published September 18, 2020; doi:10.1152/ajpheart.00314.2020.-Pulmonary arterial hypertension (PAH) is a refractory disease. Its prognosis remains poor; hence, establishment of novel therapeutic targets is urgent. TP53-induced glycolysis and apoptosis regulator (TIGAR) is a downstream target of p53 and exhibits functions inhibiting autophagy and reactive oxygen species (ROS). Recently, p53 was shown to suppress PAH progression. Because inhibition of autophagy and ROS is known to improve PAH, we examined the effect of TIGAR on PAH progression. We compared pulmonary hypertension (PH) development between TIGAR-deficient knockout (KO) and wild-type (WT) mice using a hypoxia-induced PH model. Human pulmonary artery smooth muscle cells (PASMCs) were used for in vitro experiments with small interfering RNA (siRNA) to investigate the possible molecular mechanisms. From the analysis of right ventricular pressure, right ventricular weight, and mortality rate, we concluded that the hypoxia-induced PH development was remarkably higher in TIGAR KO than in WT mice. Pathological investigation revealed that medial thickening of the pulmonary arterioles and cell proliferation were increased in TIGAR KO mice. Autophagy and ROS activity were also increased in TIGAR KO mice. TIGAR knockdown by siRNA increased cell proliferation and migration, exacerbated autophagy, and increased ROS generation during hypoxia. Autophagy inhibition by chloroquine and ROS inhibition by N-acetylcysteine attenuated the proliferation and migration of PASMCs caused by TIGAR knockdown and hypoxia exposure. TIGAR suppressed the proliferation and migration of PASMCs via inhibiting autophagy and ROS and, therefore, improved hypoxia-induced PH. Thus, TIGAR might be a promising therapeutic target for PAH.NEW & NOTEWORTHY Pulmonary arterial hypertension is a refractory disease. TP53-induced glycolysis and apoptosis regulator (TIGAR) is a downstream target of p53 and exhibits functions inhibiting autophagy and reactive oxygen species (ROS). By using TIGAR-deficient knockout mice and human pulmonary artery smooth muscle cells, we found that TIGAR suppressed the proliferation and migration of PASMCs via inhibiting autophagy and ROS and, therefore, improved hypoxia-induced PH. TIGAR will be a promising therapeutic target for PAH.

5-(N-Trifluoromethylcarboxy)aminouracil as a Potential DNA Radiosensitizer and Its Radiochemical Conversion into N-Uracil-5-yloxamic Acid

Hypoxia-a hallmark of solid tumors-dramatically impairs radiotherapy, one of the most common anticancer modalities. The adverse effect of the low-oxygen state can be eliminated by the concomitant use of a hypoxic cell radiosensitizer. In the present paper, we show that 5-(N-trifluoromethylcarboxy) aminouracil (CF3CONHU) can be considered as an effective radiosensitizer of DNA damage, working under hypoxia. The title compound was synthesized in the reaction of 5-aminouracil and trifluoroacetic anhydride in trifluoroacetic acid. Then, an aqueous and deoxygenated solution of the HPLC purified compound containing tert-butanol as a hydroxyl radical scavenger was irradiated with X-rays. Radiodegradation in a 26.67 ± 0.31% yield resulted in only one major product-N-uracil-5-yloxamic acid. The mechanism that is possibly responsible for the formation of the observed radioproduct has been elucidated with the use of DFT calculations. The cytotoxic test against the PC3 prostate cancer cell line and HDFa human dermal fibroblasts confirmed the low cytotoxicity of CF3CONHU. Finally, a clonogenic assay and flow cytometric analysis of histone H2A.X phosphorylation proved the radiosensitization in vitro.

Prooxidation and Cytotoxicity of Selenium Nanoparticles at Nonlethal Level in Sprague-Dawley Rats and Buffalo Rat Liver Cells

The effects of selenium nanoparticles (SeNPs) on the antioxidant capacity in Sprague-Dawley (SD) rats were investigated. The rats were given intragastric administration of an SeNP suspension at doses of 0, 2, 4, and 8 mg Se/kg BW for two weeks. The antioxidant capacity in serum and organic tissues (liver, heart, and kidney) and the gene expression levels of glutathione peroxidase 1 (GPX1) and glutathione peroxidase 4 (GPX4) in the liver were measured. Buffalo rat liver (BRL) cell lines were further constructed to explore the cytotoxicity mechanism induced by SeNPs through the determination of antioxidant capacity; cell activity; apoptosis; and Caspase-3, Caspase-8, and Caspase-9 family activities. The results showed that SeNP administration over 4.0 mg Se/kg BW decreased the antioxidant capacities in the serum, liver, and heart and downregulated mRNA expression of GPX1 and GPX4 in the liver. The BRL cell line experiments showed that treatment with over 24 μM SeNPs decreased the viability of the cells and damaged the antioxidant capacity. Flow cytometry analysis showed that decreased cell viability induced by SeNPs is mainly due to apoptosis, rather than cell necrosis. Caspase-3 and Caspase-8 activities were also increased when BRL cells were treated with 24 μM and 48 μM SeNPs. Taken together, a nonlethal level of SeNPs could impair the antioxidant capacity in serum and organic tissues of rats, and the liver is the most sensitive to the toxicity of SeNPs. A pharmacological dose of SeNPs could lead to cytotoxicity and induce cell death through apoptosis and extrinsic pathways contributing to SeNP-induced apoptosis in BRL cells.

Time-Resolved Fluorescence Detection of Superoxide Anions Based on an Enzyme-Integrated Lanthanide Coordination Polymer Composite

In this work, we proposed a new strategy of fabricating time-resolved fluorescent nanoprobes by using an enzyme-integrated lanthanide coordination polymer (CP) composite for the detection of superoxide anions (O₂^•-). This CP composite was constructed with terbium ions (Tb³⁺) as a metal node, adenosine triphosphate (ATP) as a bridge ligand, and carboxyphenylboronic acid (CPBA) as a sensitizer in which superoxide dismutase (SOD) was encapsulated by a self-adaptive inclusion process. The as-prepared SOD@ATP/Tb-CPBA displays both catalytic and fluorescence properties. Benefiting from the shielding effect of ATP/Tb CP, greatly enhanced catalytic activity and stability against harsh environments can be obtained in the loaded SOD. Meanwhile, the loaded SOD can remove the water molecules on the coordination sphere of Tb³⁺, leading to a significant increase in the fluorescence intensity and lifetime of SOD@ATP/Tb-CPBA. However, upon the addition of O₂^•-, the fluorescence of SOD@ATP/Tb-CPBA was quenched significantly. This is because SOD can convert O₂^•- into H₂O₂ to induce the deboronation of CPBA, resulting in an intramolecular charge transfer process. On this basis, by taking advantage of Tb³⁺ in long lifetime emission, a time-resolved fluorescence method was developed for the detection of O₂^•-, and satisfactory results have been achieved in both buffered aqueous solutions and serum samples. We believe that the presented study will open up a new avenue to develop enzyme-involved fluorescent nanoprobes.

Emulsified silicone oil is taken up by and induces pro-inflammatory response in primary retinal microglia

Purpose

Silicone oil is used as endotamponade in combination with vitrectomy. Thinning of retinal layers and loss of retinal cells under silicone oil use have been found. Here, we investigate the influence of silicone oil on primary microglia cells.

Methods

Primary microglia cells were prepared from the porcine retina. Microglia identity was assessed with Iba1 staining. Silicone oil was emulsified by sonification. Cell morphology and silicone oil uptake were evaluated by light microscopy after Coomassie blue staining. Cytokine secretion was evaluated with ELISA. Toxicity of silicone oil on microglia and toxic effect of silicone oil–treated microglia on neuronal cell line PC12 were evaluated by MTT or WST assay, respectively.

Results

Microglia took up silicone oil droplets after 72 h of incubation. Silicone oil induced no toxicity but increased the metabolism in microglial cells. In addition, the secretion of IL-6 and IL-8, but not of IL-1ß or TNF-α, was induced. Silicone oil–treated microglia did not exert any neurotoxic effect on differentiated PC12 cells but induced an increase in metabolism.

Conclusion

Emulsified silicone oil changes the activity level of microglia and induces the secretion of IL-6 and IL-8. Neurotoxicity is not induced. Further experiments are required to investigate the long-term effect of silicone oil on microglia and their consequent effect on neuronal cells.

Enhanced type I photoreaction of indocyanine green via electrostatic-force-driven aggregation

Owing to the strong NIR absorbance, indocyanine green (ICG) has attracted new attention in emerging photo-theranostics. However, ICG has a very low ROS production efficiency and mainly works through the type II photoreaction via its monomer. The aggregation tendency of ICG in aqueous milieus further worsens the scenario. Herein, ICG aggregates show an enhanced type I photoreaction pathway and have much better photooxidizing capability than its monomer, which improves the performance of ICG in the photodynamic inactivation of bacteria. This finding provides a feasible way to tackle the contradiction of ROS generation and ICG aggregation. Finally, the photodynamic effect of ICG aggregates was combined with the photothermal effect of gold nanorods to achieve an effective treatment of bacterial infection.