mRNA Levels Of Antioxidant Enzymes Research Articles

Mechanisms of PM10 Disruption of the Nrf2 Pathway in Cornea.

We have previously shown that PM10 exposure causes oxidative stress and reduces Nrf2 protein levels, and SKQ1 pre-treatment protects against this damage in human corneal epithelial cells (HCE-2). The current study focuses on uncovering the mechanisms underlying acute PM10 toxicity and SKQ1-mediated protection. HCE-2 were pre-treated with SKQ1 and then exposed to 100 μg/mL PM10. Cell viability, oxidative stress markers, programmed cell death, DNA damage, senescence markers, and pro-inflammatory cytokines were analyzed. Nrf2 cellular location and its transcriptional activity were determined. Effects of the Nrf2 inhibitor ML385 were similarly evaluated. Data showed that PM10 decreased cell viability, Nrf2 transcriptional activity, and mRNA levels of antioxidant enzymes, but increased p-PI3K, p-NFκB, COX-2, and iNOS proteins levels. Additionally, PM10 exposure significantly increased DNA damage, phosphor-p53, p16 and p21 protein levels, and β-galactosidase (β-gal) staining, which confirmed the senescence. SKQ1 pre-treatment reversed these effects. ML385 lowered the Nrf2 protein levels and mRNA levels of its downstream targets. ML385 also abrogated the protective effects of SKQ1 against PM10 toxicity by preventing the restoration of cell viability and reduced oxidative stress. In conclusion, PM10 induces inflammation, reduces Nrf2 transcriptional activity, and causes DNA damage, leading to a senescence-like phenotype, which is prevented by SKQ1.

Effects of the Complex of Panicum miliaceum Extract and Triticum aestivum Extract on Hair Condition.

Proso millet (Panicum miliaceum L.) and common wheat (Triticum aestivum L.) have been used as major crops in multiple regions since ancient times, and they contain various nutrients that can affect human hair health. This study investigated the various biological effects of a complex of millet extract and wheat extract (MWC) on hair health. Human immortalized dermal papilla cells (iDPCs) for an in vitro study and an anagen-synchronized mouse model for an in vivo study were employed. These findings revealed that the application of the MWC in vitro led to an increase in the mRNA levels of antioxidant enzymes (catalase and SOD1), growth factors (IGF-1, VEGF, and FGF7), and factors related to hair growth (wnt10b, β-catenin) while decreasing inflammatory cytokine mRNA levels (IL-6 and TNFα). The mRNA levels of hair follicles (HFs) in the dorsal skin of the mouse model in the early and late telogen phases were also measured. The mRNA levels in the in vivo study showed a similar alteration tendency as in the in vitro study in the early and late telogen phases. In this model, MWC treatment elongated the anagen phase of the hair cycle. These findings indicate that the MWC can suppress oxidative stress and inflammation and may elongate the anagen phase by enhancing the growth factors involved in the wnt10b/β-catenin signaling pathway. This study suggests that the MWC might have significant potential as a functional food for maintaining hair health.

Redox Profile of Skeletal Muscles: Implications for Research Design and Interpretation.

Mammalian skeletal muscles contain varying proportions of Type I and II fibers, which feature different structural, metabolic and functional properties. According to these properties, skeletal muscles are labeled as 'red' or 'white', 'oxidative' or 'glycolytic', 'slow-twitch' or 'fast-twitch', respectively. Redox processes (i.e., redox signaling and oxidative stress) are increasingly recognized as a fundamental part of skeletal muscle metabolism at rest, during and after exercise. The aim of the present review was to investigate the potential redox differences between slow- (composed mainly of Type I fibers) and fast-twitch (composed mainly of Type IIa and IIb fibers) muscles at rest and after a training protocol. Slow-twitch muscles were almost exclusively represented in the literature by the soleus muscle, whereas a wide variety of fast-twitch muscles were used. Based on our analysis, we argue that slow-twitch muscles exhibit higher antioxidant enzyme activity compared to fast-twitch muscles in both pre- and post-exercise training. This is also the case between heads or regions of fast-twitch muscles that belong to different subcategories, namely Type IIa (oxidative) versus Type IIb (glycolytic), in favor of the former. No safe conclusion could be drawn regarding the mRNA levels of antioxidant enzymes either pre- or post-training. Moreover, slow-twitch skeletal muscles presented higher glutathione and thiol content as well as higher lipid peroxidation levels compared to fast-twitch. Finally, mitochondrial hydrogen peroxide production was higher in fast-twitch muscles compared to slow-twitch muscles at rest. This redox heterogeneity between different muscle types may have ramifications in the analysis of muscle function and health and should be taken into account when designing exercise studies using specific muscle groups (e.g., on an isokinetic dynamometer) or isolated muscle fibers (e.g., electrical stimulation) and may deliver a plausible explanation for the conflicting results about the ergogenic potential of antioxidant supplements.

Natural astaxanthin enhanced antioxidant capacity and improved semen quality through the MAPK/Nrf2 pathway in aging layer breeder roosters

BackgroundNatural astaxanthin (ASTA) has strong antioxidant properties and has been widely used as a health product to improve human health. However, the effects of ASTA on the reproductive performance of aging roosters have been poorly studied. We aimed to investigate the effects of dietary ASTA on semen quality and antioxidant capacity in aging roosters and to explore the potential mechanism of semen quality change via anti-oxidation defense system.MethodsIn the present study, 96 53-week-old Jinghong No. 1 layer breeder roosters were fed a corn-soybean meal basal diet containing 0, 25, 50, or 100 mg/kg ASTA for 6 weeks.ResultsSemen quality in the ASTA groups remarkably improved than that in the control group, and antioxidant activities, the abilities to scavenge hydroxyl radicals and superoxide anions, increased gradually with ASTA addition (P < 0.05). In addition, the mRNA levels of antioxidant enzymes as well as the mRNA and protein levels of the mitogen-activated protein kinase (MAPK) and nuclear factor-erythroid 2-related factor 2 (Nrf2) were markedly increased in the 50–100 mg/kg ASTA group (P < 0.05).ConclusionsCollectively, these results demonstrate that dietary ASTA may improve semen quality by increasing antioxidant enzyme activities and the ability to scavenge hydroxyl radicals, which may be related to upregulation of the MAPK/Nrf2 pathway.

Effects of Flutriafol Fungicide on the Lipid Accumulation in Human Liver Cells and Rat Liver.

Flutriafol (FTF) is a triazole fungicide that can cause liver toxicity through the ingestion of its residues in food and water. However, little is known about the liver toxicity of FTF, particularly nonalcoholic fatty liver disease (NAFLD) in humans. Therefore, the purpose of this study was to investigate whether FTF induces NAFLD in human liver cells and animal liver. HepG2 cells and Sprague Dawley (SD) rats were treated with FTF at doses of 0–640 µM for 24 h and 0–150 mg/kg bw/day for 28 days, respectively. FTF (80, 160, and 320 µM) treatment to cells induced lipid accumulation. FTF (80 and 160 µM)-treated cells had higher levels of cytochrome P450 enzymes and reactive oxygen species and increased mitochondrial membrane potential loss than the control. FTF also increased the mRNA levels of antioxidant enzymes through oxidative stress and nuclear factor erythroid 2-related factor 2 pathways in HepG2 cells. However, a higher level of FTF (320 µM) induced apoptosis. The treatment of SD rats with FTF (2.5–150 mg/kg bw/day) induced fatty infiltration in the liver by impairing liver metabolism and inducing apoptosis. Therefore, our data suggest that human exposure to FTF residues may be a risk factor for liver diseases, such as NAFLD.

SOD2 mRNA as a potential biomarker for exercise: interventional and cross-sectional research in healthy subjects.

The health-promoting effects of exercise are explained by the biological adaptation to oxidative stress via maintenance of mitochondrial function especially in muscles. Although the induction of antioxidant enzymes in muscle is a useful indicator of exercise, it is not widely used due to the invasiveness of muscle biopsies. To explore more suitable biomarkers for exercise, we examined mRNA levels of antioxidant enzymes in peripheral blood mono­nuclear cells of 14 volunteers in an exercise intervention study. These results were validated in a cross-sectional study of 392 healthy individuals, and we investigated the association between exercise habits, smoking, alcohol consumption, mitochondrial DNA, malondialdehyde, and various clinical features. The 2-week exercise increased superoxide dismutase 1 at the end of exercise and superoxide dismutase 2 from week 4 onwards. In the cross-sectional study, superoxide dismutase 2 correlated positively with exercise habits and number of mitochondrial DNA, and negatively with malondialdehyde levels. Multivariate binominal regression analysis showed that superoxide dismutase 2 was positively associated with exercise habits in nonsmoking individuals. These results suggest that mRNA levels of superoxide dismutase 2 in blood might be a potentially useful biomarker for exercise in healthy individuals. This study was registered with University Hospital Medical Information Network (No: 000038034).

High dietary starch impairs intestinal health and microbiota of largemouth bass, Micropterus salmoides

This study focused on the effects of starch levels on growth performance, intestinal dysbiosis and health of Micropterus salmoides. Three isonitrogenous and isolipidic diets containing different corn starch levels (5%, 10%, 15%) were fed to experimental fish (initial body weight: 8.66 ± 0.04g) for 8 weeks, respectively. The results showed that the 15% starch levels suppressed the growth, decreased the height and width of villus and number of goblet cell in midgut compared with the other groups (P < 0.05). Moreover, plasma endotoxin (PE) and diamine oxidase (DAO) increased significantly with dietary starch levels (P < 0.05). Notably, 15% starch diets up-regulated the expression of Claudin-1 and down-regulated the expression of ZO-1, Claudin-4 and Claudin-5 in intestine (P < 0.05). Meanwhile, fish fed 15% starch diets decreased antioxidant enzyme mRNA levels (Nrf2, CAT and SOD) and activities (SOD and CAT) compared to the other groups (P < 0.05). The increased dietary starch levels upregulated the expression of pro-inflammatory cytokines (IL-8, IL-1β and TNFα) and anti-inflammatory cytokines (IL-10 and TGF-β1) (P < 0.05). Additionally, the abundance of intestinal probiotics (such as Lactobacillus) decreased with the increase of dietary starch level (P < 0.05), while abundance of intestinal potentially pathogenic bacteria (such as Brevundimonas and Ralstonia) increased (P < 0.05). Fish fed 15% starch diet had less concentrations of acetate and butyrate in intestinal digesta than the 5% starch group (P < 0.05). These results suggested that 15% starch diets would impair the intestinal health, suppress immune and antioxidant capacity and finally reduced growth of Micropterus salmoides. The imbalances in intestinal microbiota and the reduced production of short-chain fatty acids (SCFA) may be partly responsible for the loss of intestinal function.

Impact of dietary zinc oxide nanoparticles on selected serum biomarkers, lipid peroxidation and tissue gene expression of antioxidant enzymes and cytokines in Japanese quail

BackgroundThe use of zinc oxide in the form of nanoparticles (ZnO-NPs) is of great benefit due to its potent effectiveness and higher bioavailability compared to zinc oxide. This study aimed to investigate the impact of dietary inclusion of different doses of ZnO-NPs on selected serum biomarkers, lipid peroxidation and tissue gene expression of antioxidant enzymes and cytokines in Japanese quail. Eighty Japanese quails (Coturnix japonica) (45 days old) were randomly divided into four groups (20 birds for each) with 4 replicates (5 birds each). Birds in the first group were fed a basal diet alone and served as a control (C). Birds in groups 2–4 were fed the basal diet supplemented with ZnO-NPs at doses of 15 mg/kg, 30 mg/kg and 60 mg/kg for a period of 60 days. At the end of the experiment, all birds were sacrificed to collect blood in a plain vacutainer, whereas liver and brain tissues were stored frozen at -80 °C. The obtained sera were used for the analysis of selected biochemical parameters, whereas tissue homogenates were used for the estimation of zinc, oxidative stress biomarkers and gene expression of selected antioxidant enzymes and cytokines.ResultsZnO-NPs (30 and 60 mg/kg) induced a significant decrease in serum triacylglycerol (TAG) compared to the control. ZnO-NPs did not affect the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein, albumin, globulin and tissue zinc concentrations but reduced the malondialdehyde (MDA) levels compared to the control. The liver retained a higher zinc concentration than that of brain tissue. In a dose-dependent manner, ZnO-NPs upregulated the mRNA levels of antioxidant enzymes (superoxide dismutase: SOD1; catalase: CAT; glutathione peroxidase-1: GPX 1) and pro-inflammatory cytokines (interferon α: IFN-α; interleukin 6: IL-6) in liver and brain tissues.ConclusionThe current study suggests the inclusion of ZnO-NPs, particularly 60 mg/kg, in the diet of Japanese quails to improve antioxidant and immune status.

Effects of dietary mulberry leaf powder on growth performance, blood metabolites, meat quality, and antioxidant enzyme-related gene expression of fattening Hu lambs

This study was conducted to investigate the effects of the mulberry [Morus alba var. multicaulis (Perrott.) Loud.] leaf powder (MLP) supplementation in dietary concentrates on growth performance, blood metabolites, meat quality, and antioxidant enzyme (AOE) gene expression in fattening Hu lambs. Forty approximately 3-mo-old Hu lambs (16.5 ± 0.6 kg) were randomly allocated to five groups and fed with concentrates containing 0%, 15%, 30%, 45%, or 60% MLP (control, T15, T30, T45, and T60, respectively). The results showed that 15%–30% MLP supplementation maintained growth and carcass performance, and the weight of total stomach, especially of rumen in T15 and T30, were higher than those of the control. Dietary MLP supplementation decreased serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, cholesterol, and triglyceride levels, but increased the high-density lipoprotein levels. Moreover, MLP supplementation improved the longissimus lumborum muscle color (redness), tenderness, and water-holding capacity. It was further observed that 15% MLP supplementation enhanced all AOE mRNA levels apart from that of EPHX1. In summary, dietary MLP supplementation could partially improve the blood metabolites, meat quality, and AOE mRNA levels in the liver of fattening Hu lamb, and the level of 15% supplementation was the most promising.

Hydrogen sulfide is required for salicylic acid-induced chilling tolerance of cucumber seedlings.

Salicylic acid (SA) and hydrogen sulfide (H2S) have been proved to be multifunctional signal molecules to participate in the response of plants to abiotic stresses. However, it is still unclear whether there is interaction between SA and H2S in response to chilling intensity of cucumber seedlings. Here, we found SA was sensitive to chilling intensity. Under normal condition, NaHS (H2S donor) or removing endogenous H2S with hypotaurine (HT, a specific scavenger of H2S) and DL-propargylglycine (PAG, a specific inhibitor of H2S) has no effect on endogenous SA level; however, SA induced endogenous H2S content and activated the activities and mRNA level of L-/D-cysteine desulfhydrase (L-/D-CD), and inhibiting endogenous SA with paclobutrazol (PAC) or 2-aminoindan-2-phosphonic acid (AIP) blocked this effect, implying H2S may play a role after SA signal. Further studies showed that both SA and NaHS notably alleviated chilling injury, which was evidenced by lower electrolyte leakage (EL), MDA content, and ROS accumulation, compared with H2O treatment. Of note, SA and H2S improved the activities and mRNA level of antioxidant enzymes (SOD, POD, CAT, APX, and GR) as well as the contents of AsA and GSH. Additionally, the chilling-response genes (ICE, CBF1, and COR) were obviously upregulated by exogenous SA and NaHS. However, the positive effect of SA on chilling tolerance was inhibited by HT, whereas PAC or AIP did not affect NaHS-induced chilling tolerance. Taken together, the data reveals that H2S acts as a downstream signal of SA-induced chilling tolerance of cucumber via modulating antioxidant system and chilling-response genes.

Hydrostatic Pressure Regulates Oxidative Stress through microRNA in Human Osteoarthritic Chondrocytes.

Hydrostatic pressure (HP) modulates chondrocytes metabolism, however, its ability to regulate oxidative stress and microRNAs (miRNA) has not been clarified. The aim of this study was to investigate the role of miR-34a, miR-146a, and miR-181a as possible mediators of HP effects on oxidative stress in human osteoarthritis (OA) chondrocytes. Chondrocytes were exposed to cyclic low HP (1–5 MPa) and continuous static HP (10 MPa) for 3~h. Metalloproteinases (MMPs), disintegrin and metalloproteinase with thrombospondin motif (ADAMTS)-5, type II collagen (Col2a1), miR-34a, miR-146a, miR-181a, antioxidant enzymes, and B-cell lymphoma 2 (BCL2) were evaluated by quantitative real-time polymerase chain reaction qRT-PCR, apoptosis and reactive oxygen species ROS production by cytometry, and β-catenin by immunofluorescence. The relationship among HP, the studied miRNA, and oxidative stress was assessed by transfection with miRNA specific inhibitors. Low cyclical HP significantly reduced apoptosis, the gene expression of MMP-13, ADAMTS5, miRNA, the production of superoxide anion, and mRNA levels of antioxidant enzymes. Conversely, an increased Col2a1 and BCL2 genes was observed. β-catenin protein expression was reduced in cells exposed to HP 1–5 MPa. Opposite results were obtained following continuous static HP application. Finally, miRNA silencing enhanced low HP and suppressed continuous HP-induced effects. Our data suggest miRNA as one of the mechanisms by which HP regulates chondrocyte metabolism and oxidative stress, via Wnt/β-catenin pathway.

Safflower Yellow and Its Main Component HSYA Alleviate Diet-Induced Obesity in Mice: Possible Involvement of the Increased Antioxidant Enzymes in Liver and Adipose Tissue.

PurposeOxidative stress plays an important role in the pathogenesis of obesity and its associated disorders. Safflower yellow (SY) and hydroxysafflor yellow A (HSYA), the natural compounds isolated from Carthamus tinctorius L., has been found to possess antioxidative and anti-obesity properties. The purpose of the present study is to investigate whether SY and its main component HSYA alleviate obesity by the antioxidant effects.MethodsDiet-induced obese (DIO) mice were treated with 200 mg/kg/d SY or HSYA for 10 weeks. Body weight, fat mass, serum biochemical parameters and superoxide dismutase (SOD) activities were measured. Glucose and insulin tolerance tests were performed. The expression of antioxidant enzymes in liver and adipose tissue were measured. In vitro, H2O2-induced oxidative stress HepG2 cells and 3T3-L1 adipocytes were treated with SY and HSYA to investigate the direct effects of SY and HSYA on the expression of antioxidant enzymes.ResultsSY and HSYA significantly decreased the body weight gain of DIO mice, and decreased fat mass to 57.8% and 61.6% of the control mice, respectively (P < 0.05). The parameters of glucose metabolism and liver function were improved after SY and HSYA treatment. The hepatic SOD activities and the mRNA levels of antioxidant enzymes in liver and adipose tissue of SY and HSYA treated mice were increased (P < 0.05). Meanwhile, the administration of SY and HSYA on the H2O2-induced oxidative stress HepG2 cells and adipocytes also increased the expression of the antioxidant factor and antioxidant enzymes to 1.2~3.3 folds of the control cells (P < 0.05).ConclusionSY and its main component HSYA could significantly decrease the fat mass, and improve glucose metabolism and liver function in diet-induced obese mice. The beneficial effects of SY and HSYA on obesity and metabolism may be associated with the increased expression of antioxidant enzymes in liver and adipose tissue.

Effects of thermal manipulation of eggs on the response of jejunal mucosae to posthatch chronic heat stress in broiler chickens

In this study, the aim was to investigate effects of chronic heat stress (CHS) on the mRNA levels of proinflammatory cytokines (interleukin [IL]-6, IL-8, IL-1β, and tumor necrosis factor alpha [TNF-α]), toll-like receptors (TLR2 and TLR4), heat shock proteins (Hsp70, heat shock transcription factor [HSF]-1, and HSF3) and antioxidant enzymes (catalase, glutathione peroxidase, NADPH oxidase, and superoxide-dismutase) in the jejunal mucosae of broiler chickens subjected to thermal manipulation (TM) during embryogenesis. TM was carried out at 39°C and 65% relative humidity (RH) for 18 h daily from embryonic days 10 to 18. Control group was incubated at 37.8°C and 56% RH. CHS was induced by raising the temperature to 35°C for 7 D throughout posthatch days 28 to 35. On post-hatch-day 28 (day zero of CHS) and after 1, 3, 5, and 7 D of CHS, the jejunal mucosae were collected from both groups to evaluate the mRNA levels by real-time reverse transcription-PCR analysis. On day zero of CHS, the mRNA levels of antioxidant enzymes, TLRs, HSF3, IL-1β, and TNF-α were not significantly different between TM and control groups, while the levels of IL-6, IL-8, and HSF1 were lower and the level of Hsp70 was higher in TM. However, during CHS, the mRNA levels of antioxidant enzymes, IL-1β, TNF-α, TLR4, and HSF1 were significantly lower in TM than in controls, while the levels of TLR2 and IL-8 were significantly higher in TM than in controls. In addition, TM led to significant increase of mRNA levels of IL-6 and HSF3 after 1 D and Hsp70 after 3 D of CHS and to significant decrease of mRNA levels of IL-6 after 3 and 5 D, HSF3 after 7 D, and Hsp70 after 5 D of CHS. Results of this study suggest that TM led to altered posthatch antioxidant, immunological, and Hsp response to CHS in the jejunal mucosae of broiler chickens, probably indicating that TM may mitigate the adverse effects of CHS.

Spirulina Lipids Alleviate Oxidative Stress and Inflammation in Mice Fed a High-Fat and High-Sucrose Diet.

High-fat and high-sucrose diet (HFHSD)-induced obesity leads to oxidative stress and chronic inflammatory status. However, little is known about the beneficial effects of total lipids extracted from Spirulina. Hence, in the present study, Spirulina lipids were extracted with chloroform/methanol (SLC) or ethanol (SLE) and then their effects on oxidative stress and inflammation in the mice fed a HFHSD were investigated. The results show that the major lipid classes and fatty acid profiles of SLC and SLE were almost similar, but the gamma-linolenic acid (GLA) and carotenoid contents in SLE was a little higher than that in SLC. Dietary 4% SLC or SLE for 12 weeks effectively decreased the hepatic lipid hydroperoxide levels as well as increased the activities and mRNA levels of antioxidant enzymes in the mice fed a HFHSD. In addition, supplementation with SLC and SLE also markedly decreased the levels of serum pro-inflammatory cytokines and the mRNA expression of pro-inflammatory cytokines in the liver and epididymal white adipose tissue of mice fed a HFHSD, and the effects of SLC and SLE were comparable. These findings confirm for the first time that dietary Spirulina lipids could alleviate HFHSD-induced oxidative stress and inflammation.

The antioxidant status, apoptosis, intercellular integrity and immune function of grass carp (Ctenopharyngodon idella) head kidney and spleen fed different levels of pyridoxine

This study was carried out to investigate the effects of dietary pyridoxine (PN) on the antioxidant status, apoptosis, intercellular integrity and immune function of head kidney and spleen in young grass carp (Ctenopharyngodon idella). Results showed that compared with the optimal PN level, (a) PN deficiency decreased antioxidant enzyme activities and down-regulated the mRNA levels of antioxidant enzymes, NF-E2-related factor 2 (Nrf2), myeloid cell leukaemia-1 (Mcl-1) and tight junction proteins, whereas it increased the contents of reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl (PC), and up-regulated the mRNA levels of cysteinyl aspartic acid-protease (caspase), Fas ligand (FasL), p38 mitogen-activated protein kinase (p38MAPK) and myosin light chain kinase (MLCK) in the head kidney and spleen of fish (p < .05). (b) PN deficiency decreased lysozyme (LZ) and acid phosphatase (ACP) activities, and complement contents, and down-regulated the mRNA levels of antibacterial peptides, anti-inflammatory cytokines, inhibitor of κBα (IκBα) and target of rapamycin (TOR), whereas it up-regulated the mRNA levels of pro-inflammatory cytokines and nuclear factor kappa B p65 (NF-κBp65) in the head kidney and spleen of fish (p < .05). (c) Dietary PN requirements of grass carp based on the malondialdehyde content and lysozyme activity were estimated as 4.97 and 4.99 mg/kg diet, respectively.

Enzyme-treated soy protein supplementation in low protein diet improved flesh tenderness, juiciness, flavor, healthiness, and antioxidant capacity in on-growing grass carp (Ctenopharyngodon idella).

An 8-week feeding trial was conducted to investigate the effects of enzyme-treated soy protein (ETSP) supplementation in low protein diets on growth performance as well as flesh sensory quality and healthiness in on-growing grass carp. A total of 540 on-growing grass carp (initial average weight 325.72 ± 0.60 g) were fed six diets, which included a normal protein diet (28% crude protein) and five low protein diets (26% crude protein) supplemented with graded levels of ETSP (0.0, 0.8, 1.2, 1.6, and 2.0%). The results showed that reducing dietary protein by 2% decreased percentage weight gain, feed intake, and flesh flavor (aspartic acid, glutamic acid, histidine, and 5'-inosinic acid contents) and healthiness-related indices (linolenic acid (LA) and docosahexaenoic acid (DHA) contents and polyunsaturated fatty acids to saturated fatty acids ratio). Under the condition of reducing dietary protein by 2%, 0.8-1.2% ETSP supplementation restored above parameters to levels equal or superior to those in 28% crude protein diet group. Although reducing dietary protein by 2% did not deteriorate flesh tenderness and juiciness, 0.8-1.2% ETSP supplementation in low protein diets also improved the two indices compared with 28% crude protein diet. Moreover, ETSP-improved flesh quality was partly related to increased muscle antioxidant enzymes activities and their mRNA levels. In addition, ESTP-enhanced antioxidant enzyme mRNA levels were partly associated with the upregulation of NF-E2-related factor 2 (Nrf2) and target of rapamycin (TOR) signaling. Collectively, 0.8-1.2% ETSP supplementation in low protein diets improved growth performance as well as flesh sensory quality and healthiness in on-growing grass carp.

Pachypodol, a Methoxyflavonoid Isolated from Pogostemon cablin Bentham Exerts Antioxidant and Cytoprotective Effects in HepG2 Cells: Possible Role of ERK-Dependent Nrf2 Activation.

Oxidative stress has been implicated in the pathogenesis of many diseases including chronic liver diseases. Nrf2 is a master transcriptional factor regulating the induction of cellular antioxidant defense systems. Here, the Nrf2-activating effect of the crude methanol extract of dried leaves of Pogostemon cablin Bentham was demonstrated by measuring the antioxidant response element (ARE)-driven luciferase activity and pachypodol, 4′,5-dihydroxy-3,3′,7-trimethoxyflavone, was isolated by bioactivity-guided fractionation and further separation using chromatographic techniques. To our knowledge, this is the first study to evaluate the antioxidant and cytoprotective effects of pachypodol in HepG2 cells as well as the underlying molecular mechanisms. Indeed, pachypodol protected HepG2 cells from cell death caused by tert-butylhydroperoxide-induced oxidative stress and also attenuated ROS production. The ability of pachypodol to activate Nrf2/ARE pathway was further confirmed by observing Nrf2 expression in nuclear fraction, mRNA levels of Nrf2 target antioxidants, and cellular glutathione content in HepG2 cells. Extracellular signal-regulated kinase (ERK) is one of the important kinases involved in Nrf2 activation. Pachypodol increased ERK phosphorylation and ERK inhibition by PD98059 totally abrogated the increase in ARE luciferase activity, nuclear Nrf2 accumulation and mRNA levels of antioxidant enzymes by pachypodol. In conclusion, pachypodol isolated from P. cablin can protect hepatocytes from oxidative injury, possibly mediated by enhancing endogenous antioxidant defense system through ERK-dependent Nrf2 activation.

Piceatannol protects against cisplatin nephrotoxicity via activation of Nrf2/HO-1 pathway and hindering NF-κB inflammatory cascade.

This study investigates the molecular mechanisms of the nephroprotective effect of piceatannol (PIC) against cisplatin-induced nephrotoxicity in rats. PIC (10mg/kgi.p.) was given for 7days, starting 2days before cisplatin single injection (7mg/kgi.p.). Serum creatinine, blood urea nitrogen (BUN), kidney injury molecule 1, and neutrophil gelatinase-associated lipocalin were used as nephrotoxicity markers. Oxidative stress, inflammatory, and apoptotic markers were determined. In addition, the role of PIC in Nrf2 activation and its subsequent induction of antioxidant enzymes, as well as its potential cross talk with nuclear factor kappa-B, were addressed. PIC reversed cisplatin-induced elevation of nephrotoxicity markers and restored the normal kidney ultrastructure. PIC attenuated cisplatin-induced reduction in Nrf2 expression and the relative mRNA level of antioxidant enzymes: hemeoxygenase-1, cysteine ligase catalytic, and modifier subunits, as well as superoxide dismutase and glutathione-S-transferase activities. Cisplatin pro-inflammatory response was reduced by PIC treatment as evidenced by the suppression of nuclear factor kappa-B activation and the subsequent decreased tissue levels of interleukin-1β, tumor necrosis factor-α, cyclooxygenase-2, and inducible nitric oxide synthase. PIC suppressed cisplatin-induced apoptosis by decreasing p53 and cytochrome C expression and caspase-3 activity. Therefore, PIC may protect against cisplatin-induced nephrotoxicity by modulating Nrf2/HO-1 signaling and hindering the inflammatory and apoptotic pathways.

Effects of high-fat diet on muscle textural properties, antioxidant status and autophagy of Chinese soft-shelled turtle (Pelodiscus sinensis)

This research illustrates the effects of high-fat diet induced oxidative stress on muscle textural properties, oxidation status and autophagy of juvenile Chinese soft-shelled turtles (Pelodiscus sinensis) and explores the molecular regulatory mechanism. A total of 120 juvenile Chinese soft-shelled turtles with the average initial body weight of (38.60 ± 1.13) g were fed two diets that contained different lipid levels, 6.38% (normal diet, ND) and 13.89% (high-fat diet, HFD), for 8 weeks. The results indicated that: (1) the survival rate (SR) and feed conversion rate (FCR) were not significantly different (P > .05); the final body weight, weight gain rate (WGR), specific growth rate (SGR), and the hepatosomatic index (HIS) of groups that were fed with HFD were significantly higher than those fed with ND (P < .05). Moreover, the moisture and ash contents in the muscle and calipash were not significantly affected by the lipid level (P > .05), while the crude lipid content of the turtles increased, and the crude protein content decreased when the dietary lipid concentration increased (P < .05); (2) regarding the textural mechanical properties, no significant differences were observed in adhesiveness, cohesiveness and springiness (P > .05), but a significant decreases in hardness, gumminess and chewiness of muscle with HFD (P < .05); (3) the reactive oxygen species (ROS) and malondialdehyde (MDA) contents were increased in the HFD group (P < .05). It was significantly up-regulated the mRNA level of the signaling molecule Keap1 as well as down-regulated Nrf2 in the muscle (P < .05), meanwhile its downstream the activities of antioxidant enzymes of total superoxide dismutase (T-SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR) and the content of glutathione (GSH) and antioxidant gene expression were significantly decreased (P < .05); (4) the expressions of autophagy-related genes MAP1LC3A, MAP1LC3B, MAP1LC3C and ULK1 were significantly increased in the HFD group, while mTOR was significantly decreased as well as increased AMPK mRNA level (P < .05), and the transmission electron microscopy result showed that there were obviously more autophagosomes in muscle tissues of the HFD group than ND group. In summary, high-fat diet induced oxidative stress and autophagy in the juvenile Chinese soft-shelled turtles, which might be related to increased lipid content and ROS level by down-regulating the mRNA level of antioxidant enzymes, and inhibiting the Nrf2 and mTOR signaling pathways.

Effects of dietary dandelion extracts on growth performance, liver histology, immune-related gene expression and CCl4 resistance of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

The study investigated the effects of dietary supplementation with dandelion extracts (DE) on growth performance, feed utilization, body composition, serum biochemical, liver histology, immune-related gene expression and CCl4 resistance of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). A basal diet supplemented with DE at 0% (diet 0%), 0.1% (diet 0.1%), 0.2% (diet 0.2%), 0.4% (diet 0.4%) and 0.8% (diet 0.8%) were fed to hybrid grouper for 8 weeks. The results revealed that dietary DE had not a significant impact on growth performance and feed utilization (P > 0.05), but it could decrease the percent of crude lipids in whole body and increase the percent of crude protein in muscle (P < 0.05). Dietary DE increased the mRNA levels of antioxidant enzymes (catalase, glutathione peroxidase and glutathione reductase) and reduced inflammatory factor in the spleen and head-kidney of fish (P < 0.05), but reduced the expression of the liver antioxidant gene except for glutathione reductase (P < 0.05). Dietary supplementation with 0.2%–0.4% DE could effectively improve liver health. After injection of CCL4 by 72 h, fish fed Diet0.2% and Diet0.4% showed regular hepatocyte morphology while fish fed Diet 0%, Diet 0.1% and Diet 0.8% showed hepatocyte damage. Higher survival rate and total blood cell count was observed in fish fed 0.1%–0.4% dietary DE (P < 0.05). In conclusion, DE could be used as a functional feed additive to enhance liver function of farmed fish. The best level of it should be between 0.2% and 0.4%.