Expression Of Antioxidant-related Genes Research Articles

Zinc nanoparticles ameliorate oxidative stress and apoptosis induced by silver nanoparticles in the brain of male rats

The current study was conducted to investigate the possible ameliorative role of zinc nanoparticles (Zn NPs) against silver nanoparticles (Ag NPs)-induced oxidative and apoptotic brain damage in adult male rats. Twenty-four mature Wistar rats were randomly and equally divided into four groups: control group, Ag NPs group, Zn NPs group, and Ag NPs + Zn NPs group. Rats were exposed to Ag NPs (50 mg/kg) and/or Zn NPs (30 mg/kg) daily by oral gavage for 12 weeks. The results revealed that exposure to Ag NPs significantly increased malondialdehyde (MDA) content, decreased catalase and reduced glutathione (GSH) activities, downregulated the relative mRNA expression of antioxidant-related genes (Nrf-2 and SOD), and upregulated the relative mRNA expression of apoptosis-related genes (Bax, caspase 3 and caspase 9) in the brain tissue. Furthermore, severe neuropathological lesions with a substantial increase in the caspase 3 and glial fibrillary acidic protein (GFAP) immunoreactivity were observed in the cerebrum and cerebellum of Ag NPs-exposed rats. Conversely, co-administration of Zn NPs with Ag NPs significantly ameliorated most of these neurotoxic effects. Collectively, Zn NPs can be used as a potent prophylactic agent against Ag NPs-induced oxidative and apoptotic neural damage.

The presence of microplastics (MPs) reduces the toxicity of cadmium (Cd) to Cirrhinus mrigala larva

Cumulative studies have shown that microplastics (MPs) and cadmium (Cd) co-exist widely, but their combined toxic effects on aquatic organisms are still not well understood. In this study, Cirrhinus mrigala larvae were exposed to single and binary combinations for 7 days, and the growth performance, survival, intestinal contaminant migration, intestinal histopathology, enzyme activity, and expression of antioxidant-related and detoxification-related genes were measured. The results showed that PS-MPs, Cd, and their combined exposure cause intestinal tissue damage, which in turn affects the growth and survival of C. mrigala larvae, and combined exposure of PS-MPs and Cd reduces stagnant growth and death caused by single Cd exposure. Under both single and binary exposure, PS-MPs can accumulate in the intestine of C. mrigala larvae, but Cd-induced damage to intestinal tissues can increase the accumulation of PS-MPs in the intestine of C. mrigala larvae. PS-MPs, Cd and their combined exposure can cause abnormalities in enzyme activity and expression of antioxidant genes and detoxification genes. The results of continuous 7-day dynamic monitoring showed that the relative expression of cat in the Cd exposure group was significantly higher than that of the control group on days 1, 2 and 4; the relative expression of gpx was significantly higher than that of the control group on days 3, 4 and 7; the relative expression of mnsod was significantly higher than that of the control group on days 1, 3 and 7; and the relative expression of cusod was significantly higher than that of the control group on days 4, 6 and 7. These results indicated that the presence of MPs acted as an antagonist, reducing the toxicity of Cd to aquatic organisms. Overall, this study contributes to further understanding of the inter-regulatory relationship between MPs and Cd and the combined toxic effects on aquatic organisms.

Antibacterial, Antifungal, and Anticancer Effects of Camel Milk Exosomes: An In Vitro Study

Camel milk (CM) has potent antibacterial and antifungal effects and camel milk exosomes (CM-EXO) have been shown to inhibit the proliferation of a large variety of cancer cells including HepaRG, MCF7, Hl60, and PANC1. However, little is known regarding the effects of CM-EXO on bacteria, fungi, HepG2, CaCo2, and Vero cells. Therefore, this study aimed to evaluate the antibacterial, antifungal, and anticancer effects of CM-EXO. EXOs were isolated from CM by ultracentrifugation and characterized by transmission electron microscope and flow cytometry. Unlike CM, CM-EXO (6 mg/mL) had no bactericidal effects on Gram-positive bacteria (Staphylococcus aureus, Micrococcus luteus, and Enterococcus feacalis) but they had bacteriostatic effects, especially against Gram-negative strains (Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis), and fungistatic effects on Candida albicans. HepG2, CaCo2, and Vero cells were respectively treated with CM-EXOs at low (6.17, 3.60, 75.35 μg/mL), moderate (12.34, 7.20, 150.70 μg/mL), and high (24.68, 14.40, 301.40 μg/mL) doses and the results revealed that CM-EXOs triggered apoptosis in HepG2 and CaCo2 cells, but not in normal Vero cells, as revealed by high Bax expression and caspase 3 activities and lower expression of Bcl2. Interestingly, CM-EXOs also induced the elevation of intracellular reactive oxygen species and downregulated the expression of antioxidant-related genes (NrF2 and HO-1) in cancer cells but not in normal cells. CM-EXOs have antibacterial and antifungal effects as well as a selective anticancer effect against HepG2 and CaCo2 cells with a higher safety margin on normal cells.

Exogenous melatonin enhances Cd stress tolerance in Platycladus orientalis seedlings by improving mineral nutrient uptake and oxidative stress

The development of agriculture and industry has led to a gradual increase in the levels of cadmium (Cd) in the soil, which, due to its high mobility in soil, makes Cd deposition in plants a serious threat to the health of animals and humans. The important role of melatonin (MT) in regulating plant growth and adaptation to environmental stress has become a pertinent research topic, but the mechanisms of action of MT in Cd-stressed Platycladus orientalis seedlings are unclear. Here, we investigated the mitigation mechanism of exogenous MT application on P. orientalis seedlings under Cd stress. Cd stress significantly inhibited the growth of P. orientalis seedlings by disrupting photosynthetic pigments, mineral balance, osmotic balance, and oxidative balance. In contrast, the application of exogenous MT significantly increased the growth parameters of P. orientalis seedlings, reduced Cd accumulation and transfer in the seedlings, increased the content of iron, manganese, zinc, copper, chlorophyll, soluble protein, soluble sugar, and proline, reduced the content of glutathione, increased the activities of superoxide dismutase and peroxidase, and significantly enhanced the expression of antioxidant-related genes (POD, GST, and APX). It also effectively reduced the content of hydrogen peroxide and malondialdehyde to inhibit the production of reactive oxygen species, thus alleviating Cd-induced oxidative stress. In addition, MT significantly upregulated the expression of the ethanol dehydrogenase (ADH) gene, which is effective in removing the acetaldehyde produced by anaerobic respiration in seedlings under stress, thereby reducing the toxic effects on P. orientalis. The results showed that exogenous MT enhanced the tolerance of P. orientalis seedlings to Cd stress by regulating photosynthesis, mineral balance, osmotic balance, and the antioxidant system and that the optimal concentration of MT was 200 μmol·L−1.

G-Quadruplex Structures as a "Switch" Regulate ATF4 Expression in Ferroptotic HepG2 Cells.

G-quadruplex (G4) is a noncanonical structure folded in a widespread manner by guanine-rich tandem repeated sequences. As a key response factor, activating transcription factor 4 (ATF4) has dual functions in managing iron-dependent ferroptosis by regulating amino acid synthesis and antioxidant-related gene expression. In our study, the activity of ATF4 expression was elevated in HepG2 cells induced by erastin. Based on preliminary bioinformatics analyses, the G-tract region, named WT, had high potential to form G4, and it was found that PDS could markedly weaken the increase of ATF4 expression by reducing the sensitivity of HepG2 cells toward erastin. In circular dichroism spectra, WT oligonucleotides showed characteristic molar ellipticity at specific wavelengths of parallel G4 structures, while corresponding single-base mutants possessed a weaker ability to form G4, which were consistent with immunostaining results. In addition, endogenous G4 formed by the WT motif was significantly destroyed in HepG2 cells treated with erastin. After being transfected with WT oligonucleotides, the levels of ATF4 mRNA decreased significantly regardless of being treated with erastin or not. Meanwhile, mutations of G-tracts could advantageously impact the luciferase expression downstream of an ATF4 promoter in reporter assays, manifesting that the decrease of endogenous G4 in the ATF4 promoter was positively associated with the expression enhanced by erastin in HepG2 cells.

Mechanism of nephrotoxicity induced by chronic exposure of bisphenol A in mice based on oxidative stress and cell apoptosis

Bisphenol A (BPA) is widely used to produce epoxy resin and polycarbonate plastic products. In severe cases, these plastics may release BPA, which then infiltrates into the environment. Various concentrations of BPA have been found in most biological fluid. Its presence has been well shown to be closely related to many chronic diseases, including chronic kidney disease (CKD). However, little is known regarding the adverse effects of BPA exposure and its succedent cellular events on CKD. Hence, in the current in vivo study, we aimed to assess the effects of chronic exposure to BPA on animal nephrotoxicity through investigating oxidative stress and apoptosis. Upon exposure to BPA at 0.01, 0.1, and 1 mg/L via drinking water for four weeks, the mated and pregnant females were continuously exposed to BPA until weaning. Subsequently, three weeks old F1-male neonates were also orally challenged with the same three doses of BPA for ten weeks. The results showed that the kidneys of 0.1 and 1 mg/L BPA-treated mice were seriously damaged; the contents of serum renal function indexes and lipid peroxidation products were significantly increased, including urea nitrogen, creatinine, uric acid, and thiobarbituric acid reactive substances; the morphological structure of mouse kidneys was impaired; the expressions of antioxidant-related genes at mRNA and protein levels from mouse kidneys were markedly diminished, including glutathione-S-transferase, superoxide dismutase, and catalase; the expressions of genes and proteins related to apoptosis index (ratio of Bax/Bcl-1 and Caspase-3) were significantly enhanced. The data manifested that cumulative oxidative stress and apoptosis might play an essential role in the animal nephrotoxicity induced by chronic exposure to BPA.

Ginsenoside Rg1 and Re alleviates inflammatory responses and oxidative stress of broiler chicks challenged by lipopolysaccharide

Previous study showed that ginsenoside Rg1 (Rg1) and ginsenoside Re (Re) alleviated growth inhibition of broiler chicks with immune stress. The aim of this study was to investigate the effect of Rg1 and Re on inflammatory responses, oxidative stress, and apoptosis in liver of broilers with immune stress induced by lipopolysaccharide (LPS). Forty broiler chicks were randomly divided into 4 groups, each group consisting of 10 chickens. The model group, Rg1 group, and Re group were received continuously interval injection of 250 μg/kg body weight LPS at the age of 12, 14, 33, and 35 days to induce immune stress. Control group was injected with an equivalent amount of sterile saline. Then broilers in Rg1 group and Re group were given 1mg/kg body weight Rg1 and Re intraperitoneally 2 h after the LPS challenge respectively. Blood samples were collected for the detection of hormone levels, inflammatory mediators, and antioxidant parameters. Hepatic tissues were taken for pathological observation. Total RNA was extracted from the liver for real-time quantitative polymerase chain reaction analysis. Our results showed that Rg1 or Re could alleviate histological changes of liver, reduce production of stress-related hormones, inhibit inflammatory responses, and enhance antioxidant capacity in broilers challenged by immune stress. In addition, Rg1 or Re treatment upregulated mRNA expression of antioxidant-related genes and downregulated mRNA expression of inflammation-related factors and apoptosis-related genes in the liver of immune-stressed broilers. The results suggest that the plant extracts containing Rg1 and Re can be used for ameliorating hepatic oxidative stress and inflammation and controlling immune stress in broiler chicks.

Isorhamnetin improves in vitro maturation of oxidative stress-exposed porcine oocytes and subsequent embryo development.

This study investigated the effect of the flavonoid-based compound isorhamnetin (ISO) on maturation and developmental competence in oxidative stress-exposed porcine oocytes in vitro. Treatment with 2 μM ISO (2 ISO) increases the developmental rate of oxidative stress-exposed porcine oocytes during in vitro maturation (IVM). The glutathione level and mRNA expression of antioxidant-related genes (NFE2L2 and SOD2) were increased in the 2 ISO-treated group, whereas the reactive oxygen species level was decreased. Treatment with 2 ISO increased mRNA expression of a cumulus cell expansion-related gene (SHAS2) and improved chromosomal alignment. mRNA expression of maternal genes (CCNB1, MOS, BMP15 and GDF9) and mitogen activated protein kinase (MAPK) activity were increased in the 2 ISO-treated group. The total cell number per blastocyst and percentage of apoptotic cells were increased and decreased in the 2 ISO-treated group, respectively. Treatment with 2 ISO increased mRNA expression of development-related genes (SOX2, NANOG, and POU5F1) and anti-apoptotic genes (BCL2L1 and BIRC5) and decreased that of pro-apoptotic genes (CASP3 and FAS). These results demonstrate that 2 ISO improves the quality of porcine oocytes by protecting them against oxidative stress during IVM and enhances subsequent embryo development in vitro. Therefore, we propose that ISO is a useful supplement for IVM of porcine oocytes.

Involvement of Nrf2 in the immune regulation of Litopenaeus vannamei against Vibrio harveyi infection

NF-E2-related factor-like-2 (Nrf2) is a transcription factor that belongs to the Cap'n'Collar transcription factor family and plays a role in regulating inflammation, autophagy, metabolism, proteostasis, and cancer prevention. However, its influence on Vibrio spp infection in L. vannamei remains uncertain. In this study, the effects of Nrf2 on the immune response in Vibrio spp infection was determined by RT-PCR and histopathological analysis. The results showed that RNAi of Nrf2 significantly decreased the expression of antioxidant-related genes (CAT, SOD and GST; p < 0.05), and significantly up-regulated inflammation-related genes (IMD, pro-PO, P38, Toll, Hsp70, NFκB and RAB6A; p < 0.05) and the apoptosis gene (caspase3). Under the infection of V. harveyi, histopathological analysis showed that after RNAi of Nrf2, the hepatopancreas of shrimp has an abnormal arrangement of hepatic tubules and vacuolization of hepatocyte; The basement membrane is peeled off and the epithelial cells are massively necrotic. Compared with the RNAi of Nrf2 group, the tissue damage in the SFN group was much lessened, and there were fewer apoptosis signals in the TUNEL assay. In conclusion, this experiment indicated that Nrf2 is involved in the regulation of inflammatory response, oxidative stress,and apoptosis induced by V. harveyi in L. vannamei.

Effects of Dietary Epidermal Growth Factor Supplementation on Liver Antioxidant Capacity of Piglets with Intrauterine Growth Retardation.

The present experiment was conducted to study the effects of dietary epidermal growth factor (EGF) supplementation on the liver antioxidant capacity of piglets with intrauterine growth retar-dation (IUGR). The present study consists of two experiments. In experiment 1, six normal-birth-weight (NBW) and six intrauterine growth retardation (IUGR) newborn piglets were slaughtered within 2 to 4h after birth to compare the effects of IUGR on the liver antioxidant capacity of new-born piglets. The results showed that compared with NBW piglets, IUGR piglets had a lower birth weight and liver relative weight; IUGR piglets had a higher serum malondialdehyde (MDA) level, liver MDA level and hydrogen peroxide (H2O2) level, and had a lower liver total antioxidant capacity (T-AOC) level and glutathione peroxidase (GSH-Px) activity; IUGR trended to increase se-rum alanine aminotransferase (ALT) activity, aspartate aminotransferase (AST) activity, and H2O2 level, and trended to decrease liver total superoxide dismutase (SOD) activity. In experiment 2, six NBW piglets, and 12 IUGR piglets weaned at 21 days of age were randomly divided into the NC group (NBW piglets fed with basal diet); IC group (IUGR piglets fed with basal diet), and IE group (IUGR piglets fed with basal diet plus 2mg/kg EGF), and feeding for 14 days. Organ index, serum parameters, liver antioxidant capacity, and liver antioxidant-related genes expression were measured. The results showed that compared to the IC group, dietary EGF supplementation (IE group) significantly reduced serum MDA level and H2O2 level, and liver protein carbonyl (PC) level and 8-hydroxydeoxyguanosine (8-OHDG) level of piglets with IUGR; dietary EGF supplementation (IE group) significantly increased serum T-AOC level, liver T-AOC level and GSH-Px activity; dietary supplemented with EGF (IE group) enhanced liver Nrf2, NQO1, HO1, and GPX1 mRNA expression compared to IC group. Pearson's correlation analysis further showed that EGF can alleviate liver oxidative injury caused by IUGR and improve the performance of IUGR piglets. In conclusion, EGF exhibited potent protective effects on IUGR induced liver oxidative injury, by activating the Nrf2 signaling pathway to mediate the expression of downstream antioxidant enzymes and phase II detoxification enzymes (NQO1 and HO1), thereby alleviating liver oxidative damage and promoting the growth performance of IUGR piglets.

Dietary astaxanthin (Lucantin® Pink) mitigated oxidative stress induced by diazinon in rainbow trout (Oncorhynchus mykiss).

The potential of commercial astaxanthin on growth, biochemical factors, and antioxidant-related gene expression following a challenge with diazinon were studied in rainbow trout (Oncorhynchus mykiss). Fish (~ 20.70 g) were fed diets containing commercial astaxanthin (ASX) at 0.00 (CTR and ASX0), 0.50 (ASX1), 2.00 (ASX2), and 5.00 (ASX3) g kg-1 for 60 days. Afterwards, the treated fish (ASX1, ASX2, ASX3) as well as the fish in ASX0 group were challenged with diazinon (0.11 mg L-1) for 96 hr whereas fish in the CTR group was not challenged with diazinon. Results showed that growth pattern improved significantly with all enriched diets compared to the ASX0 group. Metabolic enzyme activities, including alanine aminotransferase and alkaline phosphatase decreased in ASX2 and ASX3 groups with respect to the ASX0 group. Serum antioxidant status also showed the same pattern with enhancement in the fish fed with the ASX2 and ASX3 supplemented diets. Feeding the fish with astaxanthin, particularly in the ASX3 group, up-regulated the expression of some antioxidant-relevant genes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and nuclear factor erythroid-2 related factor 2 (Nrf2) in the kidney and liver. Besides, the histopathological damages in kidneys and liver induced by diazinon were less pronounced in the ASX2 and ASX3 groups compared to the ASX0 group. In conclusion, commercial astaxanthin, especially at 5.00 g kg-1, enhanced the growth performance and ameliorated the oxidative stress induced by diazinon in rainbow trout.

An alternative pathway to plant cold tolerance in the absence of vacuolar invertase activity.

To cope with cold stress, plants have developed antioxidation strategies combined with osmoprotection by sugars. In potato (Solanum tuberosum) tubers, which are swollen stems, exposure to cold stress induces starch degradation and sucrose synthesis. Vacuolar acid invertase (VInv) activity is a significant part of the cold-induced sweetening (CIS) response, by rapidly cleaving sucrose into hexoses and increasing osmoprotection. To discover alternative plant tissue pathways for coping with cold stress, we produced VInv-knockout lines in two cultivars. Genome editing of VInv in 'Désirée' and 'Brooke' was done using stable and transient expression of CRISPR/Cas9 components, respectively. After storage at 4°C, sugar analysis indicated that the knockout lines showed low levels of CIS and maintained low acid invertase activity in storage. Surprisingly, the tuber parenchyma of vinv lines exhibited significantly reduced lipid peroxidation and reduced H2 O2 levels. Furthermore, whole plants of vinv lines exposed to cold stress without irrigation showed normal vigor, in contrast to WT plants, which wilted. Transcriptome analysis of vinv lines revealed upregulation of an osmoprotectant pathway and ethylene-related genes during cold temperature exposure. Accordingly, higher expression of antioxidant-related genes was detected after exposure to short and long cold storage. Sugar measurements showed an elevation of an alternative pathway in the absence of VInv activity, raising the raffinose pathway with increasing levels of myo-inositol content as a cold tolerance response.

Effects of blueberry anthocyanins on perfluorooctane sulfonate-induced oxidative stress and mitochondrial dysfunction in dugesia japonica

The effects of blueberry anthocyanins against perfluorooctane sulfonate on antioxidant-related gene expression levels, antioxidase activities, malondialdehyde content, glutathione/oxidized glutathione ratios, mitochondrial metabolic enzyme activities, and mitochondrial permeability transition pore opening rates were examined in the planarian Dugesia japonica. Glutathione reductase, glutathione peroxidase, and glutathione S-transferase gene expression levels were up-regulated on day 1 and then down-regulated following exposure to 5 mg/L perfluorooctane sulfonate with those of the control. The activities of the three corresponding enzymes were inhibited by perfluorooctane sulfonate and activated by anthocyanins. Malondialdehyde contents and mitochondrial permeability transition pore opening rates as well as the activities of mitochondrial metabolic enzymes, also increased and the glutathione/oxidized glutathione ratio decreased. Anthocyanin treatments have an alleviating effect on the disorder caused by perfluorooctane sulfonate.

Evaluation of Garlic Juice Processing Waste Supplementation in Juvenile Black Rockfish (Sebastes schlegelii) Diets on Growth Performance, Antioxidant and Digestive Enzyme Activity, Growth- and Antioxidant-Related Gene Expression, and Disease Resistance against Streptococcus iniae.

An 8-week feeding trial was conducted to evaluate the effects of various dietary levels of garlic juice processing waste (GJPW) on the growth, feed utilization, digestive and antioxidant enzyme activity, growth- and antioxidant-related gene expression, and resistance to Streptococcus iniae infection of juvenile black rockfish (Sebastes schlegelii). A total of 450 juvenile rockfish were randomly distributed into 30 L rectangular tanks (30 fish per tank). Five experimental diets were prepared in triplicate. The fish were fed experimental diets supplemented with GJPW at concentrations of 0 (GJPW0, control), 2.5 (GJPW2.5), 5 (GJPW5), 7.5 (GJPW7.5), and 10 g kg-1 (GJPW10) diet. All of the GJPW-supplemented treatments (2.5, 5, 7.5, and 10 g kg-1) significantly enhanced weight gain (WG), specific growth rate (SGR), feed efficiency (FE), protein efficiency ratio (PER), and digestive enzyme activity (amylase, trypsin, and lipase). A decreasing trend was seen in plasma aspartate aminotransferase (ALT), alanine aminotransferase (AST), and glucose (GLU) content with increasing dietary levels of GJPW. In contrast, plasma lysozyme and antioxidant enzyme activities were significantly increased with increasing dietary GJPW levels. Furthermore, GJPW administration significantly upregulated the expression of insulin-like growth factor-1 (IGF-1), superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) in the liver of rockfish. A challenge test with S. iniae showed significantly higher resistance in the GJPW-supplemented treatments than in the control. In short, dietary supplementation GJPW enhanced growth performance and antioxidant response in juvenile black rockfish, with suitable effects in fish fed with 2.5 g kg-1 GJPW for 8 weeks.

Mangosteen Pericarp Extract Supplementation Boosts Antioxidant Status via Rebuilding Gut Microbiota to Attenuate Motor Deficit in 6-OHDA-Induced Parkinson's Disease.

Oxidative stress and gut dysbiosis have been known to precede Parkinson's disease (PD). An antioxidant-rich product, mangosteen pericarp (MP), has the ability to counterbalance excessive free radicals and the imbalanced gut microbiota composition, suggesting the MP's capacity to delay PD progression. In this study, we explored the effects of two doses of MP extract in a unilateral 6-hydroxydopamine (6-OHDA)-induced PD rat model. We revealed that the 8-week supplementation of a low dose (LMP) and a high dose of the MP extract (HMP) improved motor function, as observed in decreased contralateral rotation, improved time spent on rod, and higher dopamine binding transporter (DAT) in the substantia nigra pars compacta (SNc). The MP extract, especially the HMP, also increased antioxidant-related gene expressions, restored muscle mitochondrial function, and remodeled fecal microbiota composition, which were followed by reduced reactive oxygen species levels in brain and inflammation in plasma. Importantly, bacterial genera Sutterella, Rothia, and Aggregatibacter, which were negatively correlated with antioxidant gene expressions, decreased in the HMP group. It is imperative to note that in addition to directly acting as an antioxidant to reduce excessive free radicals, MP extract might also increase antioxidant state by rebuilding gut microbiota, thereby enhanced anti-inflammatory capacity and restored mitochondrial function to attenuate motor deficit in 6-OHDA-induced PD-like condition. All in all, MP extract is a potential candidate for auxiliary therapy for PD.

Blue light exposure intensifies leaf red pigmentation and enhances oxidative stress tolerance in the ornamental bromeliad Neoregelia ‘Fireball’

Neoregelia is a genus of attractive, eye-catching foliage plants in the family Bromeliaceae. Blue light globally regulates multiple biological processes and secondary metabolism in plants. Recently, addition of blue light to the spectrum was reported to intensify pigmentation in some ornamental pot plants. Nevertheless, how blue light influences leaf red pigmentation and oxidative stress tolerance in Neoregelia is unclear. In this study, we performed RNA-seq analysis and a series of assays related to biological, physiological, and phenotypic characteristics. We found that exposure to blue light not only inhibits chlorophyll biosynthesis and accelerates the degradation of chlorophylls, but also up-regulates several flavonoid biosynthesis genes and significantly increases the accumulation of anthocyanins in Neoregelia ‘Fireball’ plants. Ultimately, this response leads to the presence of pure dark red leaves. We also found that blue light enhances oxidative stress tolerance in Neoregelia by promoting the expression of antioxidant-related genes and the accumulation of more proanthocyanidins (PAs). Our results also showed that blue light plays a positive role in lignin biosynthesis by activating the transcription of lignin biosynthesis-related genes in Neoregelia plants exposed to blue light. Furthermore, co-expression network analyses of RNA-seq data indicated that NfWRKY70 may be a key gene involved in the intensified leaf red pigmentation and enhanced oxidative tolerance caused by blue light exposure. Our findings provide novel insights into the regulatory mechanisms underlying blue light-induced leaf red pigmentation and oxidative tolerance, and offer new clues for the coordination between flavonoid and lignin biosynthesis in the plant phenylpropanoid biosynthetic pathway.

Evaluation of Taraxacum mongolicum flavonoids in diets for Channa argus based on growth performance, immune responses, apoptosis and antioxidant defense system under lipopolysaccharide stress

To ascertain the effects of Taraxacum mongolicum flavonoids (TMF) on the growth performance, digestive enzyme activity, immune indices, inflammatory response and antioxidant capacity of Channa argus, 400 C. argus with an average body weight of (8.08 ± 0.21) g were selected and divided randomly into four groups. They were fed with four experimental diets supplemented with TMF of 0 (control), 25, 50 and 100 mg/kg for 56 d, and then challenged with lipopolysaccharide (LPS) for 96 h, afterwards indices were detected. The results manifested that the addition of TMF above 50 mg/kg in the dietary could significantly improve the final body weight, WGR, SGR and PER of C. argus, while decreased FCR (P < 0.05). Similarly, the 50 mg/kg group had the highest activity of digestive enzymes (protease, lipase, amylase) in intestine and hepatopancreas, which were notably higher than those in the control group (P < 0.05). Nevertheless, 100 mg/kg group could effectively inhibit the liver and gut injury caused by LPS and reduce the contents of ALT and AST, LPS and LBP in serum. In the immune (LY, AKP, ACP, IgM, C3) and antioxidant (T-AOC, SOD, CAT, GSH-PX, GR, ASA, MDA) systems, 100 mg/kg groups were the optimal group, which were remarkably higher than those of the control group (P < 0.05). Additionally, the expression of genes revealed that 100 mg/kg group could noteworthy restrain the expression of pro-inflammatory factors (tnf-α, il-1β, il-8) and pro-apoptosis (cas-3,8,9, p53, bax, bcl-2) related genes, up-regulate the expression of anti-inflammatory (il-10, tgf-β) factors, antioxidant-related (nrf2, gpx, gst, cat) genes and heat shock proteins (hsp70, hsp90). Simultaneously, the survival rate of C. argus in the 100 mg/kg TMF-supplemented group was the highest after LPS challenge. Our results elucidate that dietary supplementation TMF protects C. argus from LPS-induced inflammatory injury, to ameliorate digestion, immune response, antioxidant status and apoptosis, implying that TMF could be regarded as an anti-inflammatory and antioxidant agent adding to aquatic animal feed.

Effects of dietary Plantago ovata seed extract administration on growth performance and immune function of common carp (Cyprinus carpio) fingerling exposed to ammonia toxicity.

Medicinal plants are powerful antioxidants which can improve well-being and suppress oxidative stress caused by environmental toxins in aquatic animals. In this regard, the present research was designed to show the potential effects of psyllium (Plantago ovata) seed extract (PSE) on the growth, and immune responses of common carp Cyprinus carpio exposed to acute ammonia toxicity. To perform the study, fish were fed with diets containing 0 (T0), 0.25 (T1), 0.5 (T2), and 1% (T3) PSE for 60days, and then exposed to ammonia (0.5mg L-1) for 3h. The findings showed that fish given the T1 diet outperformed the T3 and control groups in terms of ultimate weight, weight increase, and food conversion ratio. Additionally, the T1 group showed a significantly higher level of total protein and serum lysozyme activity than the other treatment groups. Moreover, the highest serum total immunoglobulin values were recorded in T1 and T2 groups. The results showed that PSE, especially at moderate levels, could successfully upregulate the transcription of immune-related genes (IFN-γ, Hsp70, TNF-ɑ, IL-1ß, IL-10, and IgE) compared to the control group after exposure to ammonia. Furthermore, improving ammonia-induced down regulations of antioxidant-related gene expressions (CYP1A, SOD, and GPX) was observed in fish fed with PSE-included diets compared to the control one. However, PSE-supplemented diets did not affect the mRNA expression level ofCAT. Regarding tight junction-associated genes, the higher mRNA expression level of occludin was observed in the T1 group, whereas the downregulation of CLD3 gene occurred in all experimental groups. Conversely, significant upregulation of osmoregulation-associated gene (NKA) was recorded in all experimental groups compared to the control one. Therefore, the administration of PSE (0.25% of the diet) for 60days is recommended to increase growth performance, improve health, and increase the resistance of common carp to oxidative stress caused by ammonia.

Nano‑copper enhances thermal efficiency and stimulates gene expression in response to multiple stresses in Pangasianodon hypophthalmus (Striped catfish)

Climate change and pollution are the major contributors to the aquatic system degradation. These factors also affect the existence and suitability of the aquatic animals. These abiotic factors affect the thermal tolerance of the Pangasianodon hypophthalmus. In the above backdrop, an experiment was conducted to delineate the role of nano‑copper (Cu-NPs) in the enhancement of thermal efficiency, anti-oxidative gene expression, and immunity of the P. hypophthalmus reared under arsenic (As), high temperature (34 °C) and low pH (6.5) stress for 110 days. Four isocaloric and isonitrogenous diets containing Cu-NPs at 0, 1.0, 1.5, and 2.0 mg kg−1 were formulated and prepared. The thermal efficiency study was conducted at the end of 110 days feeding trial and determined the critical thermal minima (CTmin), lethal thermal maxima (LTmax) and lethal thermal minima (LTmin), and critical thermal maxima (CTmax). The cortisol, heat shock protein (HSP 70) gene, and neurotransmitter enzymes were noticeably affected by As, As+T and As+pH+T, whereas it improved by dietary Cu-NPs during LTmin and LTmax. The genes related to immunological index viz. tumor necrosis factor (TNFα), interleukin (IL1b), inducible nitric oxide synthase (iNOS), immunoglobulin (Ig) and toll like receptor (TLR) in liver were noticeably altered with stressors. Whereas dietary Cu-NPs at 1.5 mg kg−1 diet improved the immune systems by improving gene expression during LTmin and LTmax. The anti-oxidative related gene expression SOD, CAT, and GPx were significantly enhanced with As, As+T, and As+pH+T, whereas Cu-NPs remarkably reduced the oxidative stress. The bioaccumulation and concentration of arsenic in P. hypophthalmus muscle and water were significantly reduced using dietary Cu-NPs. It also protects the tissues against DNA damage during LTmax. The present investigation revealed that supplementation of Cu-NPs at 1.5 mg kg-1 diet improves thermal efficiency and gene regulation related to anti-oxidative and immunity of the P. hypophthalmus.

Alleviative effects of astragaloside IV on cyclophosphamide-induced oxidative damage and immunosuppression in tilapia (Oreochromis niloticus)

Astragaloside IV (ASIV) has effects of antioxidation and immunologic enhancement. However, there are few reports on the application and potential mechanism of ASIV in aquaculture. In this study, we investigated the effect of ASIV on growth, antioxidation, and immune function of tilapia. Tilapia were fed a diet containing 0.1, 0.2, and 0.5 g·kg−1 ASIV for 60 days, followed by an intrapleural injection of 50 mg·kg−1 cyclophosphamide (CTX) to induce oxidative damage and immunosuppression. Then tilapia were weighed and blood, liver, spleen, kidney, and intestinal were collected. The results showed ASIV increased the final weight, relative weight rate, and specific growth rate of tilapia, reduce conversion ratio, and reduced the morphological lesions of tissues. Meanwhile, ASIV alleviated CTX-induced oxidative damage by improving antioxidant activity in serum and tissues and inhibiting lipid peroxidation. Additionally, ASIV attenuated the immunosuppression of tilapia caused by CTX, regulated immunochemical indexes in serum, increased the viability of peripheral blood leukocytes and head kidney macrophages, and restored respiratory burst activity (O2−) in head kidney macrophages and splenocytes. Furthermore, qPCR data showed ASIV up-regulated antioxidant-related gene expression of nrf2, ho-1, gpx3, and cat and immune-related gene expression including C3 and igm. In conclusion, ASIV as a feed additive can not only improve the growth performance but also enhance the antioxidant capacity and immune function of tilapia, which may be associated with the ability of ASIV to scavenge free radicals, reduce lipid peroxidation levels, and stabilize numbers of immune cells.