Hepatic Glutathione Reductase Activities Research Articles

Ameliorating the impairment of glucose utilization in a high-fat diet-induced obesity model through the consumption of Tucum-do-Cerrado (Bactris Setosa Mart.).

We evaluated the effect of Tucum-do-Cerrado on glucose metabolism homeostasis and its relationship with redox-inflammatory responses in a high-fat (HF) diet-induced obesity model. The HF diet increased energy intake, feed efficiency, body weight, muscle and hepatic glycogen, insulin, homeostatic model assessment of insulin resistance (HOMA IR) and beta (β)-cell function, and gut catalase (CAT) activity, and decreased food intake, hepatic glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST), and superoxide dismutase (SOD) activities, hepatic phosphoenolpyruvate carboxykinase 1 (Pck1), and intestinal solute carrier family 5 member 1 (Slc5a1) mRNA levels compared with the control diet. However, the HF diet with Tucum-do-Cerrado decreased hepatic glycogen, and increased hepatic GR activity, hepatic Slc2a2 mRNA levels and serum Tnfa compared with the HF diet. Tucum-do-Cerrado decreased muscle glycogen, intestinal CAT and GPX activities, muscle PFK-1 and HK activities, and increased hepatic protein (CARB) and intestinal lipid (MDA) oxidation, hepatic GST activity, serum antioxidant potential, hepatic phosphofructokinase-1 (PFK-1) activity, intestinal solute carrier family 2 member 2 (Slc2a2), tumor necrosis factor (Tnf), interleukin-1 beta (Il1b), muscle protein kinase AMP-activated alpha 1 (Prkaa1), solute carrier family 2 member 2 (Slc2a2) mRNA levels, and serum interleukin-6 (IL-6) levels, regardless of diet type. Tucum-do-Cerrado consumption may ameliorate impaired glucose utilization in a HF diet-induced obesity model by increasing liver and muscle glucose uptake and oxidation. These data suggest that Tucum-do-Cerrado consumption improves muscle glucose oxidation in non-obese and obese rats. This response may be related to the improvement in the total antioxidant capacity of rats.

Evaluation of Cottonseed Meal as an Alternative to Fish Meal in Diet for Juvenile Asian Red-Tailed Catfish Hemibagrus wyckioides.

A 10-week trial was performed to investigate the effects of replacing fishmeal with cottonseed meal (CSM) on the growth rate, protein metabolism, and antioxidant response of Asian red-tailed catfish Hemibagrus wyckioides. Five isonitrogenous and isocaloric diets (C0, C8.5, C17.2, C25.7, and C34.4) were prepared to contain 0%, 8.5%, 17.2%, 25.7%, and 34.4% CSM replacing fishmeal, respectively. The weight gain, daily growth coefficient, pepsin, and intestinal amylase activities initially increased and then decreased with the raising dietary CSM levels; the highest values were observed in the C17.2 group (P < 0.05). However, feed cost exhibited the opposite trend. With the increasing dietary CSM levels, the protein efficiency ratio and intestinal trypsin activity decreased but feed conversion rate increased gradually; while no differences were observed among the C0, C8.5, and C17.2 groups (P > 0.05). Dietary CSM inclusion regardless of levels increased the plasma growth hormone level as well as hepatic aspartate aminotransferase (AST) and γ-glutamyl transpeptidase activities but decreased the plasma glutamate dehydrogenase and AST activities (P < 0.05). With the increasing dietary CSM levels, the plasma alkaline phosphatase (AKP) and hepatic superoxide dismutase activities decreased but malondialdehyde content increased gradually, while no differences were observed among the C0, C8.5, and C17.2 groups (P > 0.05). The plasma immunoglobulin M content and hepatic glutathione reductase activity initially increased but then decreased with the raising dietary CSM levels; the highest values were found in the C17.2 group. These results indicated that dietary CSM inclusion level up to 17.2% improved the growth rate, feed cost, digestive enzyme activity, and protein metabolism without compromising antioxidant capacity of H. wyckioide, whereas these parameters were depressed by further inclusion of CSM. CSM is a potentially cost-effective alternative plant protein source in diet of H. wyckioide.

Microencapsulated feruloyl esterase-producing lactobacilli ameliorate lipid profile and glycaemia in high fat diet-induced obese mice.

The effect of oral administration of spray-dried microcapsules of feruloyl esterase (FE) producing Lactobacillus fermentum CRL1446 (Lf) and Lactobacillus johnsonii CRL1231 (Lj) on high fat diet-induced obese mice was investigated to evaluate whether these strains could be used as a biotherapeutic for obesity. Swiss albino mice were divided into a normal diet fed group receiving empty microcapsules (control), a high fat diet plus empty microcapsules (HFD group), HFD plus microcapsules with Lf (HFD-Lf group) and HDF plus microcapsules with Lj (HFD-Lj group). Microcapsules containing Lf or Lj at a dose of ~107 cells/day/mouse were given orally for 7 weeks. Body weight gain, adiposity index, plasma leptin, lipid profiles, glycaemia, insulinemia, oral glucose tolerance, intestinal FE, glutathione peroxidase and glutathione reductase (GR) activities were determined. Administration of lactobacilli (HFD-Lf and HFD-Lj groups) improved metabolic parameters (triglyceride, total cholesterol, low-density lipoprotein cholesterol levels) and cardiovascular risk indicators (37-46% decrease of atherogenic index), and reduced body weight gain (29-38%), adiposity index (42-62%), plasma leptin levels, liver weight and fat deposition in liver. Intestinal FE activities significantly increased in HFD-Lf (62%) and HFD-Lj group (48%), thus improving hepatic GR activity (42% increment) compared to HFD group. Moreover, L. johnsonii increased HDL-cholesterol and L. fermentum reduced blood glucose to levels similar to the control. These FE-producing lactobacilli have the potential to improve biomarkers involved in obesity by increasing intestinal FE activity.

The impact of nutritional and environmental stressors on the immune response, oxidative stress and energy use of rainbow trout (Oncorhynchus mykiss).

The impact of nutritional and environmental stressors on the immune response, oxidative stress and energy use of rainbow trout (Oncorhynchus mykiss).

Confinement during field studies may jeopardize antioxidant and physiological responses of Nile tilapia to contaminants

This work evaluates the effects of caging, a known confinement stress, in Nile tilapia (Oreochromis niloticus) during an environmental study in Cubatão river, southern Brazil. Caging animals for 7 days, regardless of being at the reference or at a contaminated site, resulted in lower levels of antioxidant-related defenses (glutathione, glutathione S-transferase, glucose-6-phosphate dehydrogenase) in liver and physiological parameters (blood glucose and lactate) as compared with free-swimming animals. Higher hepatic glutathione reductase activity and elevated Hb content could be associated to contaminant exposure. In conclusion, the confinement stress in caged Nile tilapia biochemical and physiological disturbances, acting as a confounding factor in field studies.

Protective effect of apigenin on mouse acute liver injury induced by acetaminophen is associated with increment of hepatic glutathione reductase activity

Apigenin, a natural plant flavone, has many beneficial effects, but there is no report about treatment of acetaminophen-induced liver injury. Our aim was to examine the protective effect of apigenin on acetaminophen-induced mouse acute liver injury and to investigate the potential mechanisms. A mouse model with acute liver injury was induced by intraperitoneally given acetaminophen 350 mg kg(-1) after oral administration of apigenin 100 and 200 mg kg(-1) for 7 days. The results showed that after treatment with apigenin, the levels of serum alanine aminotransferase and aspartate aminotransferase were gradually decreased, and the severity of liver injury was decreased. In particular, significant changes in liver necrosis were observed in the apigenin 200 mg kg(-1) group. Apigenin could gradually increase the hepatic glutathione reductase (GR) activity and reduced glutathione (GSH) content, and decrease the hepatic malondialdehyde content, but the activities of glutathione peroxidase and glutathione S-transferase in hepatic tissues between the model group and the apigenin-treated groups were not significantly different. It was concluded that apigenin could protect against acetaminophen-induced acute liver injury in mice, and the mechanisms might be associated with enhancing hepatic GSH content via increment of GR activity.

Effects of feeding corn naturally contaminated with aflatoxin B1 and B2 on hepatic functions of broilers

The purpose of this study was to evaluate the effects of feeding corn naturally contaminated with aflatoxin B(1) (AFB(1)) and aflatoxin B(2) (AFB(2)) on serum biochemical parameters, hepatic antioxidant enzyme activities, and pathological lesions of broilers. In total, 1,200 Cobb male broilers were randomly allocated into 5 treatments, with 8 replicates per treatment and 30 birds per replicate, in a 42-d experiment. The dietary treatments were as follows: control, 25, 50, 75, and 100% contaminated corn groups. Results showed that serum aspartate aminotransferase activity in the 75 and 100% contaminated groups were higher than that in the control group on d 21 (P < 0.05). Decreased content of hepatic total protein and increased activities of hepatic glutathione reductase and glutathione-S-transferase were observed as the percentage of contaminated corn increased (P < 0.05). The activity of superoxide dismutase and the content of hepatic malondialdehyde increased when the broilers were fed with more than 50% contaminated corn (P < 0.05). A reduction in glutathione peroxidase level was observed in the AFB(1)- and AFB(2)-contaminated groups on d 21 (P < 0.05). The average pathological lesion scores and apoptosis rate of liver cells increased as the concentration of dietary AFB(1) and AFB(2) increased. Ultrastructural changes were found in the livers of broilers fed 100% contaminated corn. In conclusion, diets containing AFB(1) and AFB(2) could induce pathological lesions in the livers, slightly change the serum biochemical parameters, and damage the hepatic antioxidant functions when the inclusion of AFB(1)- and AFB(2)-contaminated corn reached or exceeded 50%.

Effect of exposure to perfluorooctanoic acid on hepatic antioxidants in mice

The present study was undertaken to evaluate hepatic antioxidants status in female mice after exposure to perfluorooctanoic acid (PFOA). A total number of 20 female mice were subjected to the study; out of them, 15 mice were treated with PFOA. PFOA solutions were prepared at 0.1, 0.5, and 1 mg/ml of deionized water and administered to the mice by gavage once daily for 3 weeks at a volume of 10 ml/kg. Controls (five mice) received an equivalent volume of deionized water. The results revealed significant increase in liver weight at dose of 5 (p < 0.01) and 10 mg/kg body weight (b.w., p < 0.01). Both hepatic total glutathione level and hepatic catalase activity were significantly increased (p < 0.01) at dose of 5 mg/kg b.w. On the other hand, hepatic glutathione reductase activity was significantly increased at dose of 10 mg/kg b.w. In this model system, PFOA administration was effective in inducing oxidative stress particularly reflected in the liver.

Antilithogenic influence of dietary capsaicin and curcumin during experimental induction of cholesterol gallstone in mice

Spice bioactive compounds, capsaicin and curcumin, were both individually and in combination examined for antilithogenic potential during experimental induction of cholesterol gallstones in mice. Cholesterol gallstones were induced by feeding mice a high-cholesterol (0.5%) diet for 10weeks. Groups of mice were maintained on a lithogenic diet that was supplemented with 0.015% capsaicin/0.2% curcumin/0.015% capsaicin+ 0.2% curcumin. The lithogenic diet that contained capsaicin, curcumin, or their combination reduced the incidence of cholesterol gallstones by 50%, 66%, and 56%, respectively, compared with lithogenic control. This was accompanied by reduced biliary cholesterol and a marginal increase in phospholipid in these spice-fed groups. Increased cholesterol saturation index and cholesterol: phospholipid ratio in the bile caused by the lithogenic diet was countered by the dietary spice compounds. The antilithogenic influence of spice compounds was attributable to the cholesterol-lowering effect of these dietary spices in blood and liver, as well as a moderate increase in phospholipids. Decreased activities of hepatic glutathione reductase and glutathione-S-transferase caused by the lithogenic diet were countered by the combination of capsaicin and curcumin. The increased lipid peroxidation and the decreased concentration of ascorbic acid in the liver that was caused by the lithogenic diet was countered by the dietary spice compounds, individually or in combination. Thus, while the capsaicin and curcumin combination did not have an additive influence in reducing the incidence of cholesterol gallstones in mice, their combination nevertheless was more beneficial in enhancing the activity of hepatic antioxidant enzyme ─ glutathione reductase in the lithogenic situation. The antioxidant effects of dietary spice compounds are consistent with the observed reduction in cholesterol gallstones formed under lithogenic condition.

The effects of dietary oxidized fat and selenium source on performance, glutathione peroxidase, and glutathione reductase activity in broiler chickens

Normal or elevated selenium status of broilers, which is influenced by dietary selenium sources, improves the bird’s ability to overcome the adverse effects of reactive oxygen metabolites. The objective of this study was to evaluate the effects of feeding graded levels of peroxidized poultry fat on blood and hepatic glutathione peroxidase (GSH-Px), and hepatic glutathione reductase activity in broiler chickens fed either inorganic sodium selenite (SEL) or organic selenium enriched in the organic selenium yeast product Sel-Plex (SP). Nine starter diets, varying in levels of oxidized fat (0, 3, and 6 mEq/kg) and dietary selenium sources, were fed to 360 male chicks from hatch to 21 d of age. Sel-Plex or SEL was added to the basal diet to provide either 0 or 0.2 ppm of supplemental selenium in the diets. Blood and hepatic samples were obtained for each treatment group at 21 d of age. Neither peroxidized fat nor selenium source significantly altered the activity of hepatic glutathione reductase (P ≤ 0.05). Blood GSH-Px was influenced significantly by both fat and selenium source (P ≤ 0.05), but the fat × selenium source interaction was not significant (P ≥ 0.3). A selenium source effect on the hepatic GSH-Px activity (P ≤ 0.05) was evidenced by higher GSH-Px activity, even in the basal diet with no added peroxidized fat. An increase in GSH-Px activity was seen in the erythrocyte and hepatic samples in both the SEL and SP treatments when peroxidized fat was given at 3 mEq/kg, but in the erythrocytes and in the hepatic tissues from SEL-supplemented birds, there was an apparent inhibition of GSH-Px activity. This inhibition was not seen in the hepatic tissue samples from SP-fed birds. Because elevated GSH-Px activity is indicative of oxidative stress, it was concluded that dietary SP supplementation resulted in better selenium and redox status in broilers than did SEL. These results indicate that the dietary selenium supplied in an organic form (selenium yeast as SP) improved the selenium and redox status in broilers, leading to greater resistance to oxidative stress than when the inorganic form of selenium (SEL) was fed.

Total Glutathione and Glutathione Reductase in Bovine Erythrocytes and Liver Biopsy

The goal of the present study was to measure the total glutathione level and glutathione reductase activity in bovine erythrocytes and liver biopsy. Five cows were injected intraperitoneally with DL-ethionine (12.5 mg/kg B.W.), and two control cows were injected with normal saline (0.9% NaCl). Ultrasonography guided liver biopsy, and blood samples were collected at 0, 4, 7 and 10 days after injection. The hepatic total glutathione level was significantly increased on Days 7 (p<0.05) and 10 (p<0.01), and hepatic glutathione reductase activity was significantly increased on Days 4 (p<0.05), 7 (p<0.01) and 10 (p<0.01). There were insignificant changes in the erythrocytic total glutathione level. The present study demonstrated that liver biopsy is a valuable tool for detecting oxidative stress and for diagnosing hepatic dysfunction in cattle from the viewpoint of the status of glutathione and glutathione reductase.

Effects of anthocyanin-rich purple potato flakes on antioxidant status in F344 rats fed a cholesterol-rich diet

We examined the antioxidant effects of polyphenol/anthocyanin-rich potato (Solanum tuberosum cv. Shadow-Queen) flakes in male rats fed a high-cholesterol diet. The rats were served either a high-cholesterol (0.5% cholesterol plus 0.125% sodium cholate) diet, or a high-cholesterol diet containing a mixture of 243 g alpha-maize starch/kg supplemented with one of the following (per kg diet): 300 g medium purple potato (Shadow-Queen), 300 g white potato (Solanum tuberosum cv. Toyoshiro) or 300 g dark purple sweet potato (Ipomoea batatas cv. Ayamurasaki) flakes for 28 d. We analysed thiobarbituric acid reactive substance (TBARS) levels in the serum and liver, and antioxidant enzyme activities in the liver. At this dosage, TBARS levels in the serum and liver of the Shadow-Queen and Ayamurasaki groups were significantly lower than those in the control and Toyoshiro groups. The serum urate levels in all the flake groups were significantly lower than that in the control group. The hepatic glutathione levels in the Shadow-Queen and Ayamurasaki groups were significantly higher than in the control and Toyoshiro groups. The activities of hepatic glutathione reductase and glutathione S-transferase in the Shadow-Queen and Ayamurasaki groups were significantly greater than those in the control group. These results show that modulation of antioxidant enzymes and oxidative status in the serum and liver by the purple potato flake diet (Shadow-Queen) containing polyphenols/anthocyanins may play an important role in the protection against adverse effects related to oxidative damage in rats fed a high-cholesterol diet.

The glutathione antioxidant system is enhanced in growth hormone transgenic coho salmon (Oncorhynchus kisutch)

Insertion of a growth hormone (GH) transgene in coho salmon results in accelerated growth, and increased feeding and metabolic rates. Whether other physiological systems within the fish are adjusted to this accelerated growth has not been well explored. We examined the effects of a GH transgene and feeding level on the antioxidant glutathione and its associated enzymes in various tissues of coho salmon. When transgenic and control salmon were fed to satiation, transgenic fish had increased tissue glutathione, increased hepatic glutathione reductase activity, decreased hepatic activity of the glutathione synthesis enzyme gamma-glutamylcysteine synthetase, and increased intestinal activity of the glutathione catabolic enzyme gamma-glutamyltranspeptidase. However, these differences were mostly abolished by ration restriction and fasting, indicating that upregulation of the glutathione antioxidant system was due to accelerated growth, and not to intrinsic effects of the transgene. Increased food intake and ability to digest potential dietary glutathione, and not increased activity of glutathione synthesis enzymes, likely contributed to the higher levels of glutathione in transgenic fish. Components of the glutathione antioxidant system are likely upregulated to combat potentially higher reactive oxygen species production from increased metabolic rates in GH transgenic salmon.

N. 6 Fuel Oil Effects on Antioxidant Enzymes and Immunological Responses in the Fish Thalassophryne maculosa (Pisces: Batrochoididae)

With the aim of investigate the acute effects of two concentrations (25 and 100%) of N. 6 fuel oil-water-accommodated fraction (OWAF) on antioxidant enzyme activities and immunological responses, fishes Thalassophryne maculosa were sampled from the La Restiga Lagoon, Margarita island, in eastern Venezuela. The antioxidant enzymes, catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) were measured in liver and gills. The macrophagic phagocytosis and antibacterial lysozyme activity of anterior kidney were the immune parameters examined. Increases in gill GST activity and hepatic GR activity were observed after the exposure to 25 and 100% OWAF, respectively. GPX, CAT and immune responses were not affected by the experimental treatments. Our results demonstrated that among the antioxidant enzymes tested, GR and GST activities were the most sensible to the acute treatment with fuel oil, indicating changes in the redox cellular state that may result in oxidative stress in T. maculosa.

N. 6 Fuel Oil Effects on Antioxidant Enzymes and Immunological Responses in the Fish Thalassophryne maculosa (Pisces: Batrochoididae)

With the aim of investigate the acute effects of two concentrations (25 and 100%) of N. 6 fuel oil-water-accommodated fraction (OWAF) on antioxidant enzyme activities and immunological responses, fishes Thalassophryne maculosa were sampled from the La Restiga Lagoon, Margarita island, in eastern Venezuela. The antioxidant enzymes, catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) were measured in liver and gills. The macrophagic phagocytosis and antibacterial lysozyme activity of anterior kidney were the immune parameters examined. Increases in gill GST activity and hepatic GR activity were observed after the exposure to 25 and 100% OWAF, respectively. GPX, CAT and immune responses were not affected by the experimental treatments. Our results demonstrated that among the antioxidant enzymes tested, GR and GST activities were the most sensible to the acute treatment with fuel oil, indicating changes in the redox cellular state that may result in oxidative stress in T. maculosa.

N. 6 Fuel Oil Effects on Antioxidant Enzymes and Immunological Responses in the Fish Thalassophryne maculosa (Pisces: Batrochoididae)

With the aim of investigate the acute effects of two concentrations (25 and 100%) of N. 6 fuel oil-water-accommodated fraction (OWAF) on antioxidant enzyme activities and immunological responses, fishes Thalassophryne maculosa were sampled from the La Restiga Lagoon, Margarita island, in eastern Venezuela. The antioxidant enzymes, catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) were measured in liver and gills. The macrophagic phagocytosis and antibacterial lysozyme activity of anterior kidney were the immune parameters examined. Increases in gill GST activity and hepatic GR activity were observed after the exposure to 25 and 100% OWAF, respectively. GPX, CAT and immune responses were not affected by the experimental treatments. Our results demonstrated that among the antioxidant enzymes tested, GR and GST activities were the most sensible to the acute treatment with fuel oil, indicating changes in the redox cellular state that may result in oxidative stress in T. maculosa.

Zinc Supplementation Prevents Alcoholic Liver Injury in Mice through Attenuation of Oxidative Stress

Alcoholic liver disease is associated with zinc decrease in the liver. Therefore, we examined whether dietary zinc supplementation could provide protection from alcoholic liver injury. Metallothionein-knockout and wild-type 129/Sv mice were pair-fed an ethanol-containing liquid diet for 12 weeks, and the effects of zinc supplementation on ethanol-induced liver injury were analyzed. Zinc supplementation attenuated ethanol-induced hepatic zinc depletion and liver injury as measured by histopathological and ultrastructural changes, serum alanine transferase activity, and hepatic tumor necrosis factor-alpha in both metallothionein-knockout and wild-type mice, indicating a metallothionein-independent zinc protection. Zinc supplementation inhibited accumulation of reactive oxygen species, as indicated by dihydroethidium fluorescence, and the consequent oxidative damage, as assessed by immunohistochemical detection of 4-hydroxynonenal and nitrotyrosine and quantitative analysis of malondialdehyde and protein carbonyl in the liver. Zinc supplementation suppressed ethanol-elevated cytochrome P450 2E1 activity but increased the activity of alcohol dehydrogenase in the liver, without affecting the rate of blood ethanol elimination. Zinc supplementation also prevented ethanol-induced decreases in glutathione concentration and glutathione peroxidase activity and increased glutathione reductase activity in the liver. In conclusion, zinc supplementation prevents alcoholic liver injury in an metallothionein-independent manner by inhibiting the generation of reactive oxygen species (P450 2E1) and enhancing the activity of antioxidant pathways.

Dietary selenium requirements of juvenile grouper, Epinephelus malabaricus

Two 8-week feeding experiments were conducted to estimate the dietary selenium (Se) requirement of grouper. Selenomethionine was added to the basal diet at 0, 0.5, 1, 2, 3 and 5 mg Se/kg in Exp. 1 and 0, 0.1, 0.2, 0.4, 0.6, 1 and 2 mg Se/kg in Exp. 2 providing 0.21, 0.77, 1.38, 2.02, 2.70 and 4.00 mg Se/kg (Exp. 1) and 0.17, 0.25, 0.39, 0.55, 0.79, 1.23 and 2.10 mg Se/kg (Exp. 2), respectively. Each diet was fed to triplicate groups of fish (mean initial weight: 12.20 ± 0.14 g in Exp. 1 and 11.94 ± 0.15 g in Exp. 2) in a closed, recirculating rearing system. The Se concentration in rearing water was monitored during the feeding period, and was not detectable in both experiments. In Exp. 1, weight gain and feed efficiency (FE) were highest ( P < 0.05) in fish fed diet with 0.77 mg Se/kg, followed by fish fed diets with 2.02 and 2.70 mg Se/kg and the unsupplemented basal diet, and lowest in fish fed diet with 4.00 mg Se/kg. Hepatic glutathione peroxidase (GPx) activity was highest in fish fed diets with ≥ 2.02 mg Se/kg, followed by 0.77 and 1.38 mg Se/kg, and lowest in fish fed the basal diet. Fish fed the basal diet had higher hepatic glutathione reductase (GR) activity than fish in all the other dietary groups. In Exp. 2, weight gain and FE were higher in fish fed diets with 0.79 and 1.23 mg Se/kg than fish fed diets with 0.25, 0.55 mg Se/kg and the basal diet. Hepatic GPx activity was highest in fish fed diets with ≥ 1.23 mg Se/kg, followed by 0.79 mg Se/kg, then 0.39 and 0.55 mg Se/kg, and lowest in fish fed the basal diet. Hepatic GR activity was highest in fish fed the basal diet, followed by 0.55 mg Se/kg, and lowest in fish fed diets with ≥ 0.39 mg Se/kg. The adequate dietary Se concentration for growing grouper estimated by weight gain and by linear regression of whole-body Se retention of the fish is about 0.7 mg Se/kg.

Endothelial Cell Injury of Carmustine (BCNU) in Hepatic Sinusoids: Contribution of Oxidation and Immune Reaction.

Background: Carmustine (BCNU) is used for the treatment of brain tumors and is included in conditioning regimens of stem cell transplantation. It has been long believed that BCNU causes hepatotoxicity by inducing pericholangitis and intrahepatic cholestasis leading to biliary cirrhosis. Either hepatocytes or biliary ductal cells have been thought to be the target in BCNU-induced liver toxicity. However, the mechanisms operational at cell level have not been well elucidated. Possible explanations include glutathione depletion in cells, DNA damage accompanied by cellular oxidative stress and/or acceleration of apoptosis. It has been shown that BCNU treatment inhibits hepatic glutathione reductase activity in rats. Recently, a two-step process involving free radical formation and immune reaction has been proposed as a mechanism of BCNU-induced alveolar epithelial cell damage by our group (Savasan S, Ozdemir O, Buck S, et al., 95th annual meeting of the AACR, Orlando, March 27–31, 2004. Abstract#: 1133, 2004). In this study, we have investigated BCNU effect on human liver sinusoid endothelial cells (HLS-EC) in vitro.Material and Methods: Cytotoxicity in HLS-EC was measured by flow cytometric detection of annexin V/PI-positive cells, DiOC6(3) /PI staining, further quantification of fluorosphere-adjusted events and trypan blue exclusion test in repeated experiments. The generation of reactive oxygen species (ROS) was measured by flow cytometric DCF staining. Lymphokine activated killer (LAK) cell-mediated cytotoxicity against BCNU-treated and untreated HLS-EC was measured by flow cytometric cell mediated cytotoxicity assay. The influence ROS-scavenging compound butylated hydroxyanisole (BHA) and anti-inflammatory dexamethasone (DXM) on BCNU treatment was also studied.Results: Severe HLS-EC damage occurred following BCNU treatment shown by four different cytotoxicity methods. This effect was associated with oxidative stress demonstrated by significant increase in DCF staining. Although pre-treatment of cells with DXM did not affect BCNU cytotoxicity, BHA suppressed BCNU cytotoxicity by 25% (p < 0.05). BCNU treatment also resulted in increased LAK cell-mediated elimination of HLS-EC (65%) compared to untreated cells (16%). Similar to its effect on direct BCNU cytotoxicity, BHA prevented BCNU treated HLS-EC killing by LAK cells by 25%. However, DXM did not influence LAK cell-mediated killing of BCNU-treated HLS-EC cells. These results suggest that both ROS generation and immune reaction against perturbed endothelial cells play a central role in BCNU-associated HLS-EC injury. In contrary to our findings on human alveolar epithelial cells, BHA ameliorated BCNU-induced direct and immune-mediated cytotoxicity on HLS-EC, but not DXM.Conclusion: Reactive oxygen species scavenging may be useful in prevention of liver toxicity of BCNU.

지부자 활성성분이 D-Galactosamine 투여에 의한 흰쥐의 간손상에 미치는 영향

지부자(Kochiae Fructus)의 생리활성물질 검색 및 간손상에 미치는 영향을 연구할 목적으로 실험동물에 지부자 추출물을 경구투여한 후 GaIN으로 간손상을 유발하여 혈액 및 간조직의 생화학적 변화를 관찰하고 free radical의 생성계와 해독계의 활성에 미치는 영향을 검토한 결과는 다음과 같다. GaIN 단독투여군은 대조군에 비하여 AST와 ALT가 증가하였으나, KFB, oleanolic acid, momordin Ic 투여군에서는 GaIN 단독투여군에 비해 유의적 감소를 보였다. 간조직의 지질과산화 함량은 GaIN 단독투여군이 대조군과 비교하여 증가하였고, KFM 200-GaIN군, KFB 200-GaIN군, momordin Ic 30-GaIN군과 oleanolic acid 30-GaIN군은 대조군에는 미치지 못하였으나 GaIN 단독투여군에 비해 현저히 감소하였다. XO, AO의 활성은 대조군보다 GaIN 단독투여군에서 유의적으로 증가하였으며, KFB 200-GaIN군, momordin Ic 30-GaIN군과 oleanolic acid 30-GaIN군의 XO와 AO의 활성은 GaIN 단독투여군보다 낮게 나타났다. 간조직 중의 GSH 농도는 GaIN 단독투여군이 대조군에 비해 현저히 감소하였고, KFB 200-GaIN군과 oleanolic acid 30-GaIN 군은 GaIN 단독투여군과 비교시 증가를 보였고, momordin Ic 30-GaIN군은 대조군에 가깝게 회복되었다. GaIN 단독투여군의 γ-GCS와 GR의 활성은 대조군에 비하여 유의한 감소를 보였고, momordin Ic 30-GaIN군의 γ-GCS의 활성은 대조군에는 미치지 못하였지만 GaIN 단독투여군에 비해 유의하게 개선되었다. KFM 200-GaIN군, KFB 200-GaIN군, momordin Ic 30-GaIN군과 oleanolic acid 30-GaIN군의 GR활성은 GaIN 단독투여군보다 유의한 증가를 보였다. GST 활성은 GaIN 단독투여군이 대조군에 비하여 현저한 감소를 나타내었고, KFM 200-GaIN군, KFB 200-GaIN군, momordin Ic 30-GaIN군과 oleanolic acid 30-GaIN군은 대조군 수준에는 못미쳤으나 GaIN 단독투여군보다 통계적으로 유의한 증가를 관찰할 수 있었다. SOD, catalase 및 GSH-Px의 활성은 대조군에 비하여 GaIN 단독투여군에서 감소를 보였고, SOD와 catalase 활성은 KFM, KFB와 oleanolic acid의 투여로 GaIN 단독투여군보다 높게 나타났다. 특히 momordin Ic 30-GaIN군의 SOD 활성은 대조군에 가깝게 개선되었다. GSH-Px의 활성은 KFM 200-GaIN군, KFB 200-GaIN군과 oleanolic acid 30-GaIN군은 대조군 수준에는 미치지 못하였으나 GaIN 단독투여군에 비해 현저히 증가하였고, 특히 momordin Ic 30-GaIN군은 대조군에 가깝게 증가되었다. 이상의 결과를 종합하여 볼 때 지부자로부터 분리한 momordin Ic가 GSH 농도를 증가시키고 활성산소 해독계에 관여하는 효소의 활성을 증가시킴으로서 GaIN으로 인한 간손상을 완화시키는 것으로 사료되어진다.