Hepatic Glutathione Peroxidase Research Articles

Physicochemical properties and hepatoprotective effects of glycated Snapper fish scale peptides conjugated with xylose via maillard reaction

The physicochemical properties and hepatoprotective effects of fish scales peptides (FSP) and the glycated peptides conjugated with xylose via Maillard reaction (FSP-MRPs) were investigated. Results showed that the FSP was rich in oligopeptides within 2–10 amino acids, the degree of grafting of FSP-MRPs was 52.97 ± 1.58% and the antioxidant activities in vitro of FSP were improved through Maillard reaction. In order to investigate the antioxidant activities of FSP-MRPs after digestion, the simulated gastrointestinal digestion experiments of FSP and FSP-MRPs in vitro were conducted. Results indicated that the antioxidant activities of FSP and FSP-MRPs remained as stronger as before even under the digestive conditions. Furthermore, FSP-MRPs could significantly reduce the elevated activities of serum aspartate aminotransferase and alanine aminotransferase, decrease the elevated the levels of hepatic malondialdehyde and triglyceride, and inhibit the decrease of hepatic superoxide dismutase, catalase and glutathione peroxidase caused by alcohol-induced liver damage. These findings suggest that the glycated peptides formed by FSP and xylose via Maillard reaction may be potential to be exploited as a potential functional ingredient in food industry.

Antioxidant and hepatoprotective effects of Korean ginseng extract GS-KG9 in a D-galactosamine-induced liver damage animal model.

BACKGROUND/OBJECTIVESThis study was designed to investigate the improvement effect of white ginseng extract (GS-KG9) on D-galactosamine (Ga1N)-induced oxidative stress and liver injury.SUBJECTS/METHODSSixty Sprague-Dawley rats were divided into 6 groups. Rats were orally administrated with GS-KG9 (300, 500, or 700 mg/kg) or silymarin (25 mg/kg) for 2 weeks. The rats of the GS-KG9- and silymarin-treated groups and a control group were then intraperitoneally injected Ga1N at a concentration of 650 mg/kg for 4 days. To investigate the protective effect of GS-KG9 against GalN-induced liver injury, blood liver function indicators, anti-oxidative stress indicators, and histopathological features were analyzed.RESULTSSerum biochemical analysis indicated that GS-KG9 ameliorated the elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) in GalN-treated rats. The hepatoprotective effects of GS-KG9 involved enhancing components of the hepatic antioxidant defense system, including glutathione, glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). In addition, GS-KG9 treatment inhibited reactive oxygen species (ROS) production induced by GalN treatment in hepatocytes and significantly increased the expression levels of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) proteins, which are antioxidant proteins. In particular, by histological analyses bases on hematoxylin and eosin, Masson's trichrome, α-smooth muscle actin, and transforming growth factor-β1 staining, we determined that the administration of 500 mg/kg GS-KG9 inhibited hepatic inflammation and fibrosis due to the excessive accumulation of collagen.CONCLUSIONSThese findings demonstrate that GS-KG9 improves GalN-induced liver inflammation, necrosis, and fibrosis by attenuating oxidative stress. Therefore, GS-KG9 may be considered a useful candidate in the development of a natural preventive agent against liver injury.

Comparative Analysis of Luteolin and Luteolin-7-O-Glucoside on anti-Atherogenesis in ApoE Knockout Mice with Hyperhomocysteinemia

AbstractLuteolin is a naturally occurring flavone that reportedly has anti-inflammatory effect. Flavones in plants are usually present in the form of glucosides, although occasionally they are found as aglycones. The bioavailability of flavones may differ when consumed as either aglycones or glucosides. Nonetheless, numerous studies focused on the biological activity of flavonoid aglycones or that in vitro. These findings are supporting reason to compare the anti-atherogenic effect of aglycone and glucoside forms of flavones in vivo. Male ApoE knockout mice (n = 28, 6-week-old) were divided randomly into 4 groups of 7 mice: negative control group, homocysteine control group, luteolin and luteolin7-O-glucoside groups with homocysteine. All animals were fed by a high-fat diet, modified by AIN-93, containing 0.5% of cholesterol and 45% of fat. Luteolin and luteolin-7-O-glycoside were given daily by gavage for 5 weeks (50 mg/kg BW, respectively). To induce hyperhomocysteinemia, homocysteine was provided as a drinking water (0.9g/L). Administration of homocysteine did not affect body weight gain, feed intake and feed efficiency ratio among groups. Homocysteine feeding sharply increased serum concentrations of homocysteine and triglyceride as well as adhesion molecules including monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1, which were attenuated by the administration of luteolin and luteolin-7-O-glucoside (p < 0.05). Homocysteine administration produced development of atherosclerotic process by the induction of hepatic inducible nitric oxide synthase and cyclooxygenase-2 as well as aortic intercellular adhesion molecule expressions along with diminished expressions of antioxidative enzymes, such as hepatic glutathione reductase (GR), aortic GR and glutathione peroxidase (p < 0.05). Administration of both flavones down-regulated expressions of inflammatory mediators and adhesion molecules as well as up-regulated expressions of antioxidative enzymes (p < 0.05). These data were in accordance with the histopathological observations which were analyzed by hematoxylin and eosin (H&E) stain and immunohistochemistry. In a comparison of both agents, luteolin more potently attenuated inflammation and oxidative stress than luteolin-7-O-glucoside. These results exhibit that luteolin and luteolin-7-O-glycoside ameliorated atherogenic processes through the regulation of inflammation and oxidative stress in ApoE knockout mice with hyperhomocysteinemia. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government of MOE (No 201704340001).

Differential hepatic oxidative status in steers with divergent residual feed intake phenotype

Oxidative stress occurs when oxidant production exceeds the antioxidant capacity to detoxify the reactive intermediates or to repair the resulting damage. Feed efficiency has been associated with mitochondrial function due to its impact on cell energy metabolism. However, mitochondria are also recognized as a major source of oxidants. The aim of this study was to determine lipid and protein oxidative stress markers, and gene and protein expression as well as activity of antioxidant enzymes in the liver of steers of divergent residual feed intake (RFI) phenotypes. Hereford steers (n = 111) were evaluated in post-weaning 70 days standard test for RFI. Eighteen steers exhibiting the greatest (n = 9; high-RFI) and the lowest (n = 9; low-RFI) RFI values were selected for this study. After the test, steers were managed together under grazing conditions until slaughter when they reached the slaughter body weight. At slaughter, hepatic samples were obtained, were snap-frozen in liquid nitrogen and stored at −80°C until analyses. Hepatic thiobarbituric acid reactive species and protein carbonyls were greater (P = 0.05) and hepatic 4-hydroxynonenal protein adducts tended (P = 0.10) to be greater for high- than low-RFI steers. Hepatic gene expression glutathione peroxidase 4, glutamate–cysteine ligase catalytic subunit and peroxiredoxin 5 mRNA was greater (P ≤ 0.05) and glutathione peroxidase 3 mRNA tended (P = 0.10) to be greater in low- than high-RFI steers. Hepatic protein expression and enzyme activity of manganese superoxide dismutase and glutathione peroxidase enzyme activity tended (P ≤ 0.10) to be greater for low- than high-RFI steers. High-efficiency steers (low-RFI) probably had better hepatic oxidative status which was strongly associated with greater antioxidant ability near to the oxidant production site and, therefore, reduced oxidative stress of the liver. Decreased hepatic oxidative stress would reduce maintenance requirements due to a lower protein and lipid turnover and better efficiency in the use of energy.

Effects of acclimation temperature on the thermal physiology in two geographically distinct populations of lake sturgeon (Acipenser fulvescens).

Temperature is one of the most important abiotic factors regulating development and biological processes in ectotherms. By 2050, climate change may result in temperature increases of 2.1-3.4°C in Manitoba, Canada. Lake sturgeon, Acipenser fulvescens, from both northern and southern populations in Manitoba were acclimated to 16, 20 and 24°C for 30days, after which critical thermal maximum (CTmax) trials were conducted to investigate their thermal plasticity. We also examined the effects of temperature on morphological and physiological indices. Acclimation temperature significantly influenced the CTmax, body mass, hepatosomatic index, metabolic rate and the mRNA expression of transcripts involved in the cellular response to heat shock and hypoxia (HSP70, HSP90a, HSP90b, HIF-1α) in the gill of lake sturgeon. Population significantly affected the above phenotypes, as well as the mRNA expression of Na+/K+ ATPase-α1 and the hepatic glutathione peroxidase enzyme activity. The southern population had an average CTmax that was 0.71 and 0.45°C higher than the northern population at 20 and 24°C, respectively. Immediately following CTmax trials, mRNA expression of HSP90a and HIF-1α was positively correlated with individual CTmax of lake sturgeon across acclimation treatments and populations (r = 0.7, r = 0.62, respectively; P < 0.0001). Lake sturgeon acclimated to 20 and 24°C had decreased hepatosomatic indices (93 and 244% reduction, respectively; P < 0.0001) and metabolic suppression (27.7 and 42.1% reduction, respectively; P < 0.05) when compared to sturgeon acclimated to 16°C, regardless of population. Glutathione peroxidase activity and mRNA expression Na+/K+ ATPase-α1 were elevated in the northern relative to the southern population. Acclimation to 24°C also induced mortality in both populations when compared to sturgeon acclimated to 16 and 20°C. Thus, increased temperatures have wide-ranging population-specific physiological consequences for lake sturgeon across biological levels of organization.

Growth and metabolic responses of juvenile grouper (Epinephelus coioides) to dietary methionine/cystine ratio at constant sulfur amino acid levels

An eight-week feeding trial was conducted to investigate the effects of dietary methionine/cystine (Met/Cys) ratio on juvenile grouper growth performance, hepatic metabolic enzymes, serum immune-related parameters, liver antioxidant indices, and relative expression of genes in the mTOR pathway. Six isonitrogenous, isocaloric experimental diets with a fixed Met and Cys level (1.78%) and variable Met/Cys ratio (0.76–4.50) were formulated. Each diet was randomly assigned to triplicate groups of 30 juvenile fish with an average initial weight of 11.66 g. The fish were fed twice daily for 2 months. Weight gain and specific growth rates, feed efficiency and intake, and protein efficiency ratio had positive linear and/or quadratic responses to the dietary Met/Cys ratio. In contrast, the variations in dietary Met/Cys ratio had no apparent effect on the hepatosomatic index, condition factor, whole-body moisture, protein, lipid or ash content, or hepatic betaine homocysteine methyltransferase or S-adenosylhomocysteine hydrolase. Hepatic methionine synthase, cystathionine β-synthase, glutathione peroxidase, superoxide dismutase, and catalase activity, serum acid phosphatase, alkaline phosphatase, and lysozyme activity, and serum IgM and C3 content had positive linear and/or quadratic responses to the dietary Met/Cys ratio. In contrast, the malondialdehyde content had negative linear and/or quadratic responses to the dietary Met/Cys ratio. Hepatic RagA/B, RagC/D, Raptor, and eIF4B mRNA levels were unaffected by the dietary Met/Cys ratio. On the contrary, muscular upstream and downstream mTOR signal pathway gene mRNA levels had positive linear and/or quadratic responses to the dietary Met/Cys ratio. However, the 4E-BP mRNA levels had negative linear and quadratic responses to the dietary Met/Cys ratio. Cys could replace up to 41% of the Met in the fish diets. The use of appropriate Met/Cys ratios (range 1.93–2.77) in the feed may help improve grouper growth performance, immune function, and antioxidant ability and positively regulate genes in the mTOR signaling pathway.

Sodium acetate protects against nicotine-induced excess hepatic lipid in male rats by suppressing xanthine oxidase activity

Fatty liver is the hepatic consequence of chronic insulin resistance (IR) and related syndromes. It is mostly accompanied by inflammatory and oxidative molecules. Increased activity of xanthine oxidase (XO) exerts both inflammatory and oxidative effects and has been implicated in metabolic derangements including non-alcoholic fatty liver disease. Short chain fatty acids (SCFAs) elicit beneficial metabolic alterations in IR and related syndromes. In the present study, we evaluated the preventive effects of a SCFA, acetate, on nicotine-induced dysmetabolism and fatty liver. Twenty-four male Wistar rats (n = 6/group): vehicle-treatment (p.o.), nicotine-treated (1.0 mg/kg; p.o.), sodium acetate-treated (200 mg/kg; p.o.) and nicotine + sodium acetate-treated groups. The treatments lasted for 8 weeks. IR was estimated by oral glucose tolerance test and homeostatic model assessment of IR. Plasma and hepatic free fatty acid, triglyceride (TG), glutathione peroxidase, adenosine deaminase (ADA), XO and uric acid (UA) were measured. Nicotine exposure resulted in reduced body weight, liver weight, visceral adiposity, glycogen content and glycogen synthase activity. Conversely, exposure to nicotine increased fasting plasma glucose, lactate, IR, plasma and hepatic TG, free fatty acid, TG/HDL-cholesterol ratio, lipid peroxidation, liver function enzymes, plasma and hepatic UA, XO and ADA activities. However, plasma and hepatic glucose-6-phosphate dehydrogenase-dependent antioxidant defense was not affected by nicotine. Concomitant treatment with acetate ameliorated nicotine-induced effects. Taken together, these results indicate that nicotine exposure leads to excess deposition of lipid in the liver by enhancing XO activity. The results also imply that acetate confers hepatoprotection and is accompanied by decreased XO activity.

Bisphenol A-induced oxidative damage in the hepatic and cardiac tissues of rats: The modulatory role of sesame lignans.

Bisphenol A (BPA) is an environmental pollutant that is widely produced throughout the world. It is primarily used in the manufacture of polycarbonate plastics, epoxy resins, paints and dental materials. BPA has been reported to promote hepatotoxicity and cardiotoxicity. The antioxidant activity of sesame lignans is well established. The current study assessed the protective efficiency of sesame lignans against BPA-induced hepatotoxicity and cardiotoxicity. Rats were divided into 4 groups: A control group, a BPA-treated group, a sesame lignans-treated group and a sesame lignans and BPA-treated group. Rats were orally administered their respective doses daily [30 mg/kg body weight (BW) BPA and/or 20 mg/kg BW sesame lignans] for 6 weeks. Liver function tests were performed using serum of all groups. Lipid profile and antioxidant status were also measured in liver tissue of the studied groups. The results were confirmed by histopathological examination of liver and heart tissues. The oral administration of BPA was revealed to elicit significant decreases in the activities of hepatic glutathione peroxidase, glutathione reductase, superoxide dismutase and glutathione. It also significantly increased levels of malondialdehyde. Furthermore, BPA-treatment resulted in lipid accumulation, elevated activities of alanine aminotransferase, creatine kinase MB and lactate dehydrogenase, and histological changes of liver and heart tissues. However, the co-administration of sesame lignans and BPA attenuated hepatotoxicity, cardiotoxicity and BPA-induced histological changes. The results of the current study indicated that sesame lignans may be helpful in the development of novel natural drugs to treat hepatic and cardiovascular disorders.

Benefits of thymol supplementation on performance, the hepatic antioxidant system, and energetic metabolism in grass carp.

Thymol is an herbal food additive used to improve animal performance. Thymol acts via its potential to enhance productive and reproductive performance, and by improving bioavailability of nutrients in fish. Nevertheless, the exact mechanisms associated with these phenomena remain poorly understood, although recent evidence has suggested the involvement of the phosphotransfer network and antioxidant status. Therefore, the aim of this study was to determine whether the improvement of the antioxidant/oxidant status and the phosphoryl transfer network may be involved in enhanced growth performance in grass carp (Ctenopharyngodon idella) fed with various levels of thymol (100, 200, and 300 mg/kg feed). Thymol-supplementation (100 mg/kg feed) produced higher body weight and weight gain for 60-day post-feeding compared to the control group. Specific growth rate was higher; while feed conversion ratio was lower in fish that consumed 100 mg of thymol/kg compared to other groups. Hepatic lactate dehydrogenase activity and lipid peroxidation levels were lower in the thymol-supplemented group (100 mg/kg feed) than in the control group, while reactive oxygen species were lower in all supplemented groups than in the control group. Hepatic superoxide dismutase (300 mg/kg feed) and glutathione peroxidase (100, 200, and 300 mg/kg feed) activities, as well as antioxidant capacity against peroxyl radicals (100 mg/kg feed) were higher in these groups than in the control group. Based on these data, we conclude that 100 mg thymol/kg dietary supplementation increased growth performance of fingerling grass carp. Finally, hepatic adenylate kinase activity was lower in the thymol supplemented group (100 mg/kg feed) than in the control group. Thymol supplementation (100 mg/kg feed) improved hepatic energy metabolism, while practically all tested concentrations of thymol enhanced hepatic antioxidant status, all of which may be pathways involved in increased growth performance in fingerling grass carp.

Effect of Illicium verum or Eucommia ulmoides leaf extracts on the anti-stress ability, and mRNA and protein expression of Nrf2 and TNF-α in Duroc×Landrace×Yorkshire and Chinese native Licha-black nursery piglets.

Plant extracts are considered to be an effective alternative to antibiotics in response to weaning stress in piglets. This study evaluated the effect of Illicium verum extracts (IVE) or Eucommia ulmoides leaf extracts (ELE) on growth performance, serum and liver antioxidant ability of nursery piglets, as well as the difference of IVE and ELE on Duroc×Landrace×Yorkshire (DLY) and Chinese native Licha-black (LCB) piglets. A total of 96 nursery piglets (48 DLY and 48 LCB piglets) with an average body weight of 11.22±0.32kg were randomly divided into four treatments in a 2×4 factorial design. Each treatment had four replicates with 3 DLY and 3 LCB piglets per replicate respectively. Treatments included: basal diet, basal diet+500mg/kg IVE, basal diet+250mg/kg ELE and basal diet+50mg/kg chlortetracycline (CHL). All piglets were housed individually for the 42days trial period after 7days adaptation. Results showed that there were significant interactions (p<.05) between piglets species and dietary treatments in average daily gain (ADG) and feed efficiency, serum and hepatic glutathione peroxidase (GSH-Px) and malondialdehyde (MDA), hepatic integral optical density (IOD) of α-tumour necrosis factor (TNF-α), hepatic relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2)/TNF-α and protein expression of TNF-α. Regardless of piglets species, supplementation with IVE and ELE increased (p<.05) ADG and feed efficiency, T-SOD and GSH-Px in serum and liver, hepatic IOD of Nrf2, hepatic mRNA and protein expression of Nrf2/TNF-α. However, CHL treatment resulted in lower (p<.05) serum GSH-Px and hepatic mRNA and protein expression of Nrf2/TNF-α, and higher hepatic MDA and IOD of TNF-α. Compared to LCB, DLY piglets had higher (p<.05) ADG and feed efficiency, serum and hepatic MDA, and protein expression of TNF-α, but lower (p<.05) ADFI, liver index, serum and hepatic GSH-Px, hepatic IOD of TNF-α, mRNA expressions of Nrf2/TNF-α were observed. In conclusion, Illicium verum (500mg/kg) and Eucommia ulmoides leaf (250mg/kg) extracts can increase the growth performance and antioxidant ability of DLY and LCB piglets, while chlortetracycline produces undesirable side-effects on the antioxidant ability of DLY and LCB piglets. Illicium verum and Eucommia ulmoides leaf extracts produced different antioxidant effects in DLY and LCB piglets with the Chinese native Licha-black pig responding better than Duroc×Landrace×Yorkshire.

The hepatoprotective activities of Kalimeris indica ethanol extract against liver injury in vivo.

Kalimeris indica (L.) Sch. Bip. is a traditional Chinese medicine (TCM) and a portion of food used for cooking in China. It has been demonstrated that an ethanol extract of K. indica has an anti‐inflammatory effect by inhibition of nitric oxide (NO) production on murine macrophage RAW264.7 cells after lipopolysaccharide (LPS) induction. In this study, the hepatoprotective effects of the total phenolics of K. indica (TPK), the total triterpenes of K. indica (TTK), and the total flavones of K. indica (TFK) from ethanol extracts of K. indica were evaluated in Bacille Calmette–Guerin (BCG)/LPS‐induced liver injury in vivo. The treatments of TPK, TTK, and TFK improved liver injury in mice. Additionally, all treatments significantly not only reduced the hepatic malondialdehyde (MDA) content and hepatic total nitric oxide synthase (tNOS) but also induced the hepatic superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) activity. The treatments of TPK and TTK significantly reduced the hepatic inducible nitric oxide synthase (iNOS). The treatments of TPK, TTK, and TFK reduced the serum total bilirubin (T‐Bil), and only TFK treatment reduced the serum alanine aminotransferase (ALT). Our results suggest that TPK, TTK, and TFK from ethanol extracts of K. indica might play an essential protective role against BCG/LPS‐induced liver injury in vivo.

Modulation of the Lipid Profile, Hepatic and Renal Antioxidant Activities, and Markers of Hepatic and Renal Dysfunctions in Alloxan-Induced Diabetic Rats by Virgin Coconut Oil.

Research studies that holistically investigated the effect of administration of Virgin Coconut Oil (VCO) on diabetic humans or animals are limited in literature. To investigate the effect of administration of VCO on lipid profile, markers of hepatic and renal dysfunction, and hepatic and renal antioxidant activities of alloxan induced diabetic rats. Twenty-four male albino rats were used, and they were divided into four groups of six rats each. Group 1 (Normal Control, NC) received distilled water (1 mL/kg); Group 2 (VCO Control) received VCO (5 mL/kg); Group 3 (Diabetic Control, DC) received distilled water (1 mL/kg); Group 4 (Test Group, TG) received 5 ml/kg of VCO. There were no significant differences in blood glucose, body weights, relative liver weights, relative kidney weights, hepatic and renal Superoxide Dismutase (SOD) activities, Malondialdehyde (MDA), albumin, aspartate Amino Transaminase (AST), alanine Amino Transaminase (ALT), Alkaline Phosphatase (ALP), urea, creatinine, uric acid, total cholesterol, triacylglycerol, Very Low Density Lipoprotein cholesterol (VLDL) and Low Density Lipoprotein cholesterol (LDL) concentrations; significant increases in renal Glutathione (GSH), hepatic catalase, Glutathione Peroxidase (GPx) and GSH but significant reduction in renal GPx and catalase activities of VCO control group compared with NC group. There were significant increases in blood glucose, relative liver and kidney weights, hepatic GPx, hepatic and renal MDA concentration, ALP, AST, ALT, urea, creatinine, uric acid, triacylglycerol, total cholesterol, LDL and VLDL concentrations; and significant decreases in body weight, hepatic SOD and GSH activities and albumin concentration but no significant difference in hepatic catalase activity of DC group compared with NC group. Administration of VCO to diabetic rats positively modulated these parameters compared with the diabetic control. The study showed the potentials of VCO in the management of hyperlipidemia, renal and hepatic dysfunctions imposed by hyperglycemia and by oxidative stress in diabetic rats.

Dietary Supplementation with Hazelnut Oil Reduces Serum Hyperlipidemia and Ameliorates the Progression of Nonalcoholic Fatty Liver Disease in Hamsters Fed a High-Cholesterol Diet.

Objective: Hazelnut oil (HO) is rich in monounsaturated fatty acids and polyunsaturated fatty acids. This study intended to analyze the effects of hazelnut oil supplementation on the serum lipid profile and nonalcoholic fatty liver disease in hamsters fed a high-cholesterol (HC) diet. Methods: Hamsters were fed a basic diet (control group) and an HC diet (HC group) for 16 weeks (n = 10 in each group). Hamsters were fed an HC diet for four weeks to induce hyperlipidemia and were then fed an HC diet enriched with 5% (low-dose HC + HO group; n = 10) and 10% HO (high-dose HC + HO group; n = 10) for 12 weeks. Serum lipid levels, hepatic changes (including steatosis, inflammation, and fibrosis), and hepatic prooxidant-antioxidant status (malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST)) were evaluated after the treatment period. Results: Hamsters in the control group showed normal serum lipid profiles, normal liver function, and moderate glycogen storage without hepatic steatosis. Hamsters in the HC group showed severe hyperlipidemia, severe hepatic steatosis, and moderate steatohepatitis (mononuclear cell and neutrophil infiltration, oval cell hyperplasia, and fibrosis). Compared to the HC group, both the low-dose and the high-dose HC + HO groups showed a significant reduction of hyperlipidemia (serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein cholesterol (VLDL-C levels)) and improved liver function (serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT)). Additionally, compared to the HC group, intrahepatic triglyceride accumulation (IHTC) was significantly higher in the HC + HO group, while the incidence of steatohepatitis was significantly lower. The intake of the HC diet was associated with a higher level of lipid peroxidation (malondialdehyde, MDA) and a lower concentration of hepatic antioxidant enzymes (SOD, GPx, and GST), and all these factors were partially improved in the low-dose and high-dose HC + HO groups. Conclusions: Our findings indicate that the intake of HO reduced serum hyperlipidemia and oxidative stress and ameliorated the progression of nonalcoholic fatty liver disease in hamsters fed a high-cholesterol diet.

Addition of l-carnitine to formulated feed improved growth performance, antioxidant status and lipid metabolism of juvenile largemouth bass, Micropterus salmoides

l-carnitine is essential for fatty acids transportation from cytosol into the mitochondrial matrix, and promotes the β-oxidation of long-chain fatty acids to provide energy for fish. The aim of this study was to research the effect of dietary l-carnitine on the growth performance, antioxidant capacity and lipid metabolism in juvenile largemouth bass, Micropterus salmoides. Four formulated diets (Diet 1, Diet 2, Diet 3 and Diet 4) were supplemented with graded levels (0, 0.1, 0.2 and 0.3 g/kg) of l-carnitine. The results showed dietary supplementation of 0.1 g/kg l-carnitine significantly increased weight gain, while 0.3 g/kg l-carnitine supplementation decreased viscerasomatic index and intraperitoneal ratio of largemouth bass. The Plasma high density lipoprotein cholesterol (HDL-C) content of the fish which fed Diet 2 and Diet 4 were significantly higher than the fish fed Diet 1. Fish fed Diet 1 had significantly lower hepatic glutathione peroxidase (GSH-Px) activity and mRNA expression than fish fed Diet 2, Diet 3 and Diet 4. Contrary, fish fed Diet 1 had significantly higher hepatic fatty acid synthetase (FAS) activity and the mRNA expression than fish fed Diet 2, Diet 3 and Diet 4. Fish fed Diet 2, Diet 3 and Diet 4 had significantly increased the activity of hepatic carnitine palmitoyltransferase (CPT1), but no significant effect on the expression of hepatic CPT1 gene than fish fed Diet 1. In conclusion, these results confirmed that dietary supplemented of l-carnitine was beneficial for promoting growth in largemouth bass and could improve the antioxidant capacity. Furthermore, l-carnitine could play an important role in fatty acids metabolism.

Passion fruit peel intake decreases inflammatory response and reverts lipid peroxidation and adiposity in diet-induced obese rats

This study investigated Passiflora edulis peel flour (PEPF) intake and its effect against high-fat diet–induced obesity. PEPF is a source of fiber and phenolic compounds, which can decrease oxidative stress and inflammatory cytokines, both linked to chronic inflammatory response and fat deposition in obesity. Therefore, we hypothesized that PEPF intake could decrease inflammatory cytokines and oxidative stress observed in obesity, leading to decrease of fatness and chronic inflammatory response. The aims of the study were to evaluate the lipid peroxidation, the expression of antioxidants enzymes, and inflammatory parameters in obese rats. Male Sprague-Dawley rats were divided into 3 groups (n = 8 per group) according to the diets: control (based on AIN-93G), high-fat (HF, 35% fat w/w), and HF with PEPF (HFPF), and the experiment lasted for 10 weeks. PEPF showed high dietary fiber content and bioactive compounds, such as ferulic acid, and β-carotene. PEPF intake was effective in reducing body weight gain (13.31%) and total body fat (22.58%). The lipid peroxidation in the liver and adipose tissue decreased in the HFPF group compared to HF-fed animals, whereas hepatic glutathione peroxidase and glutathione reductase activity and their expressions in the liver were higher in HFPF than HF. In addition, the PEPF intake decreased inflammatory cytokines in serum. These results suggest that PEPF intake decreases oxidative stress, possibly by the increase of antioxidant enzymes expression. Furthermore, PEPF decreases inflammatory response and protects from adiposity. Then, PEPF could act as an adjuvant to control of early parameters in obesity dysfunction.

Diet Supplemented With Synthetic Carotenoids: Effects on Growth Performance and Biochemical and Immunological Parameters of Yellow Perch (Perca flavescens).

The current study assessed the effect of dietary canthaxanthin and lycopene supplementation at different concentrations on growth performance and antioxidant status in yellow perch (Perca flavescens). In this regard, fish with initial weight (32 ± 1.0 g) were divided into five groups in triplicate, and fed on carotenoid-free diet (control), canthaxanthin (CTX) (50 and 100 mg/kg diet), and lycopene (200 and 400 mg/kg diet) for 60 days. Growth parameters and antioxidant enzymes were evaluated after 30 and 60 days post feeding. Tissue liver and intestine from six fish per treatment was collected for antioxidant and digestive enzymes analysis. The results revealed a significant increase (P < 0.05) of lipid content in the group fed lycopene at a dietary level 400 mg/kg for 60 days, compared to the control. Moreover, dietary carotenoids exhibited no significant effect on growth performance; this was evidenced by no significant up-regulation of growth hormone (gh) and insulin-like growth factor 1b (igf-1b) genes after 30 and 60 days post feeding. Intestinal lipase and trypsin activities were significantly improved with dietary lycopene especially at a dose of (400 mg/kg diet) for 60 days. Malondialdehyde (MDA) level in liver was also significantly decreased with dietary lycopene (400 mg/kg diet) for 60 days. Hepatic superoxide dismutase (SOD), catalase (CAT), and Glutathione peroxidase (GSH-Px) activities were significantly decreased with dietary CTX, especially at dose (100 mg/kg diet) and lycopene at a concentration of 200 and 400 mg/kg diet after 60 days feeding. Additionally, the immune-related gene interleukin-1 beta (il-1b) mRNA expression level revealed up-regulation in groups fed on CTX at different concentrations for 30 days, and fish fed lycopene at a concentration level 400 mg/kg diet for 60 days. The obtained results concluded that dietary supplementation of canthaxanthin and lycopene could enhance immune response and maintain antioxidants defense of fish. Therefore, it considered as a functional aquafeed ingredient for yellow perch.

Phytomodulatory effects of fresh and processed shoots of an edible bamboo Dendrocalamus hamiltonii Nees &amp; Arn. Ex Munro on antioxidant defense system in mouse liver

Bamboo shoots are highly nutritious and a potential rich source of antioxidants and bioactive compounds. Besides nutrients, shoots also contain an anti-nutrient, cyanogenic glucosides accounting for its acrid taste that needs to be removed by adequate processing prior to consumption. However, processing can alter the value of phytochemicals with either desirable or adverse effects on the therapeutic quality of shoots. To evaluate the effects of processing, we investigated the effect of fermented, brine preserved and boiled shoots of Dendrocalamus hamiltonii on antioxidant defense system in mouse liver. Glutathione content increased significantly in the liver tissues of all the groups administered with bamboo shoots extract except the mice that received brine preserved shoots extract, where content decreased by 19%. Glutathione reductase (21%), glutathione peroxidase (20%) and catalase (69%) activity decreased significantly in the group administered with the extract of fresh shoots. The fermentation process was recognized as the most valuable process to improve the activity of hepatic superoxide dismutase (23%), glutathione peroxidase (27%) and catalase (29%).

The effects of coenzyme Q10 supplement on blood lipid indices and hepatic antioxidant defense system in SD rats fed a high cholesterol diet

A total of 24 SD rats were allotted to four treatment groups such as the control (CON), 1% of cholesterol diet (CHO), 0.5% of coenzyme Q10 (COQ) and 1% of cholesterol plus 0.5% of coenzyme Q10 (CHCQ) groups to determine the effects of coenzyme Q10 (CoQ10) on the antioxidant defense system in rats. The body weight, weight gain, liver weight and abdominal fat pads were unaffected by 0.5% of CoQ10 supplement in the rats. The level of triglyceride and HDL-cholesterol levels in the blood was significantly increased (p < 0.05) by the 1% of cholesterol supplement (CHO), whereas 0.5% of CoQ10 supplement (COQ) did not alter these blood lipid indices. In the mRNA expression, there was a significant effect (P < 0.05) of the CoQ10 supplement on the mRNA expression of superoxide dismutase (SOD), although the mRNA expression of glutathione peroxidase (GPX) and glutathione S-transferase (GST) was unaffected by cholesterol or the CoQ10 supplement. Similar to mRNA expression of SOD, its activity was also significantly increased (P < 0.05) by CoQ10, but not by the cholesterol supplement effect. The activities hepatic GPX and GST were unaffected by CoQ10 and cholesterol supplements in rats. Lipid peroxidation in the CHO group resulted in a significant (p < 0.05) increase compared with that in the other groups, indicating that the CoQ10 supplement to 1% of cholesterol-fed rats alleviated the production of lipid peroxidation in the liver. In conclusion, 0.5% of the CoQ10 supplement resulted in positive effects on the hepatic antioxidant defense system without affecting blood lipid indices in 1% of cholesterol fed rats.

Dietary choline supplementation regulated lipid profiles of egg yolk, blood, and liver and improved hepatic redox status in laying hens

Five hundred and forty 19-wk-old HyLine Brown laying hens were randomly distributed to 6 dietary treatments and fed 1of 6 corn-soybean meal-based diets added into choline with 0, 425, 850, 1,700, 3,400, and 6,800mg/kg to investigate effects of dietary choline supplementation on lipid profiles of egg yolk, serum and liver, and hepatic redox status of laying hens. Yolk weight and total lipid, triglyceride, cholesterol and phosphatidylcholine, serum triglyceride, cholesterol, apolipoprotein B 100 (apoB 100), and very low density lipoprotein (VLDL), and liver relative weight, total lipid, triglyceride and apoB 100 as well as hepatic total superoxide dismutase and glutathione peroxidase (GSH-Px) activities, total antioxidant capacity (T-AOC), and malondialdehyde (MDA) in laying hens at weeks 58 and 68 of age were determined. The differences (P < 0.001) were caused by choline treatments in yolk phosphatidylcholine (at 850mg/kg or more choline), serum VLDL, and liver triglyceride (at 1,700 and 3,400mg/kg choline) of birds, at weeks 58 and 68 of age, and yolk total lipids were elevated (P < 0.05) by supplemental choline at 3,400mg/kg whereas liver total lipids were reduced (P < 0.05) by 1,700 and 3,400mg/kg choline addition. Hens fed diets supplemented choline had higher (P = 0.005) liver GSH-Px activity (with 3,400mg/kg choline) and greater (P = 0.014) T-AOC (with 1,700mg/kg choline) than those fed diets with 0 and 425mg/kg choline addition. Choline affected serum VLDL, liver total lipid, triglyceride and apoB 100 at weeks 58 and 68 of age and hepatic GSH-Px activity, T-AOC and MDA at week 68 of age quadratically (P < 0.05), whereas it influenced total lipid and phosphatidylcholine of egg yolk linearly (P < 0.05) and quadratically (P < 0.05). In conclusion, dietary choline supplementation elevated yolk total lipid and phosphatidylcholine and serum VLDL, reduced liver total lipid and triglyceride, and enhanced hepatic GSH-Px activity and T-AOC in laying hens.

Dietary supplementation with caffeine increases survival rate, reduces microbial load and protects the liver against Aeromonas hydrophila-induced hepatic damage in the grass carp Ctenopharyngodon idella

The indiscriminate use of antibiotics is a major concern for the aquaculture industry because of the increasing prevalence of bacterial resistance, including the emergence of multi-resistant strains of Aeromonas hydrophila. Therefore, alternative ecofriendly therapeutic or prophylactic approaches such as natural products have been suggested, including caffeine, a methylxanthine with potent bactericidal and antioxidant properties. The aims of this study were to evaluate whether dietary supplementation with caffeine exerted bactericidal effects against A. hydrophila, and to determine whether caffeine protected the liver of grass carp (Ctenopharyngodon idella) against A. hydrophila-induced oxidative damage. Experiment I evaluated the antimicrobial properties of caffeine dietary supplementation linked to longevity and mortality rates during aeromonosis. Fish infected with A. hydrophila that were fed diets containing 5% and 8% caffeine lived significantly longer than those fed with control diets. Experiment II evaluated hepatic oxidative stress-related parameters and microbial loads on day 7 post-infection. Levels of hepatic reactive oxygen species (ROS), lipid peroxidation (LOOH) and protein carbonylation (PC) levels were significantly higher in infected fish fed with control diet than in uninfected fish, and hepatic antioxidant capacity against peroxyl radicals (ACAP) levels, and superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) activities were significantly inhibited. Dietary supplementation with 5% and 8% caffeine prevented the increase on hepatic ROS, LOOH and PC levels (except 5% caffeine) elicited by infection. Caffeine supplementation reduced or prevented the inhibition of hepatic SOD, GPx and GST activities. Finally, both caffeine concentrations reduced the hepatic microbial load compared to fish fed with control diets that were infected with A. hydrophila. Taken together, the data suggest that dietary supplementation with 8% caffeine may be considered a compelling prophylactic approach to aeromonosis caused by A. hydrophila.