Resveratrol attenuates hyperglycemia-mediated oxidative stress,proinflammatory cytokines and protects hepatocytes ultrastructure in streptozotocin–nicotinamide-induced experimental diabetic rats

The present study was hypothesized to investigate the hepatoprotective nature of resveratrol in averting hyperglycemia-mediated oxidative stress by measuring extent of oxidant stress and levels of proinflammatory cytokines and antioxidant competence in the hepatic tissues of streptozotocin–nicotinamide-induced diabetic rats. After the experimental period of 30 days, the pathophysiological markers such as serum bilirubin and hepatic aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) were studied in addition to hepatic TNF-α, IL-1β, IL-6, NF-κB p65 and nitric oxide (NO) levels in control and experimental groups of rats. The levels of vitamin C, vitamin E and reduced glutathione (GSH) and activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) were determined in the liver tissues. Extent of oxidative stress was also assessed by hepatic lipid peroxides, hydroperoxides and protein carbonyls. A portion of liver was processed for histological and ultrastructural studies. Oral administration of resveratrol (5 mg/kg b.w.) to diabetic rats showed a significant decline in hepatic proinflammatory cytokines and notable attenuation in hepatic lipid peroxides, hydroperoxides and protein carbonyls. The diminished activities of hepatic enzymic antioxidants as well as the decreased levels of hepatic non-enzymic antioxidants of diabetic rats were reverted to near normalcy by resveratrol administration. Moreover, the histological and ultrastructural observations evidenced that resveratrol effectively rescues the hepatocytes from hyperglycemia-mediated oxidative damage without affecting its cellular function and structural integrity. The findings of the present investigation demonstrated the hepatocyte protective nature of resveratrol by attenuating markers of hyperglycemia-mediated oxidative stress and antioxidant competence in hepatic tissues of diabetic rats.     

Rutin improves the antioxidant status in streptozotocin-induced diabetic rat tissues

Rutin, a polyphenolic flavonoid, was investigated for its antioxidant potential in streptozotocin (STZ)-induced diabetic rats. Rats were rendered diabetic by a single intraperitoneal injection of streptozotocin (50 mg/kg). The levels of fasting plasma glucose and insulin were estimated. Lipid peroxidative products and antioxidants were estimated in liver, kidney and brain. Histopathological studies were carried out in these tissues. A significant (p < 0.05) increase in the levels of fasting plasma glucose, lipid peroxidative products (thiobarbituric acid reactive substances [TBARS] and lipid hydroperoxides [HP]) and a significant (p < 0.05) decrease in plasma insulin, enzymic antioxidants (superoxide dismutase [SOD], catalase, glutathione peroxidase [GPx] and glutathione reductase [GRx]) and nonenzymic antioxidants (reduced glutathione [GSH], vitamin C and E) in diabetic liver, kidney and brain were observed. Oral administration of rutin (100 mg/kg) for a period of 45 days significantly (p < 0.05) decreased fasting plasma glucose, increased insulin levels and improved the antioxidant status of diabetic rats by decreasing lipid peroxidative products and increasing enzymic and nonenzymic antioxidants. Normal rats treated with rutin (100 mg/kg) showed no significant (p < 0.05) effect on any of the parameters studied. Histopathological studies of the liver, kidney and brain showed the protective role of rutin. Thus, our study clearly shows that rutin has antioxidant effect in STZ-induced experimental diabetes.     

Circadian Variation in the Response to Experimental Endotoxemia and Modulatory Effects of Exogenous Melatonin

Disturbances in circadian rhythms are commonly observed in the development of several medical conditions and may also be involved in the pathophysiology of sepsis. Melatonin, with its antioxidative and anti-inflammatory effects, is known to modulate the response to endotoxemia. In this paper, we investigated the circadian variation with or without melatonin administration in an experimental endotoxemia model based on lipopolysaccharide (LPS). Sixty male Sprague-Dawley rats were assigned to six groups receiving an intraperitoneal injection of either LPS (5?mg/kg), LPS?+?melatonin (1?mg/kg), or LPS?+?melatonin (10?mg/kg) at either daytime or nighttime. Superoxide dismutase (SOD) was analyzed in liver samples collected after decapitation. Furthermore, inflammatory plasma markers (cytokines interleukin [IL]-6, IL-10) and oxidative plasma markers (ascorbic acid [AA], dehydroascorbic acid [DHA], and malondialdehyde [MDA]) were analyzed before and 5?h after the onset of endotoxemia. There were significant higher levels of SOD (p?<?0.05), IL-6 (p?<?0.01), and IL-10 (p?<?0.05) during nighttime endotoxemia compared with daytime. At daytime, melatonin 1 and 10?mg reduced the levels of MDA and increased SOD, IL-6, IL-10, and DHA (p?<?0.05). At nighttime, melatonin reduced the levels of MDA and increased DHA (p?<?0.05). Additionally, 10?mg melatonin resulted in lower levels of AA during daytime (p?<?0.05). No dose relationship of melatonin was observed. The results showed that the response induced by experimental endotoxemia was dependent on time of day. Melatonin administration modulated the inflammatory and oxidative stress responses induced by endotoxemia and also resulted in higher levels of antioxidants during daytime. The effect of circadian time on the endotoxemia response and possible modulatory effects of melatonin need further investigations in a human endotoxemia model.     

Impact of d-pinitol on the attenuation of proinflammatory cytokines,hyperglycemia-mediated oxidative stress and protection of kidney tissue ultrastructure in streptozotocin-induced diabetic rats

Oxidative stress plays a crucial role in the progression and development of diabetes and its complications due to chronic hyperglycemia. The present study was aimed to investigate the kidney tissue protective nature of d-pinitol, a cyclitol present in soybean, by assessing the key markers of hyperglycemia-mediated oxidative stress, proinflammatory cytokines and ultrastructural alterations in streptozotocin-induced diabetic rats. Oral administration of d-pinitol (50 mg/kg body weight/day) for 30 days to diabetic group of rats showed a significant elevation in the level of total protein and significant decline in the levels of blood urea, serum uric acid, creatinine and advanced glycation endproducts (AGEs) and kidney proinflammatory cytokines such as TNF-α, IL-1β, IL-6, NF-κB p65 subunit and nitrite. Further, d-pinitol administration elicited a significant attenuation in the activities of kidney enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) and the levels of kidney non-enzymatic antioxidants such as vitamin E, vitamin C and reduced glutathione (GSH) in the diabetic group of rats, with a concomitant decline in the levels of kidney lipid peroxides, hydroperoxides and protein carbonyls. The histological and ultrastructural observations on the kidney tissues also confirmed the renoprotective nature of d-pinitol. Thus the present study demonstrated the renoprotective nature of d-pinitol by attenuating the hyperglycemia-mediated proinflammatory cytokines and antioxidant competence in kidney tissues of streptozotocin-induced diabetic rats.     

Modulatory effect of copper on nonenzymatic antioxidants in freshwater fish Channa punctatus (Bloch.)

Effect of the low level of copper exposure on nonenzymatic antioxidants was studied in a freshwater fish Channa punctatus (Bloch.). Fish were exposed to cupric chloride at the concentration of 10 ppb for 4 wk (28 d) in a static culture condition. Copper significantly (p < 0.001) increased the serum ceruloplasmin level and total iron-binding capacity. A significant (p < 0.05) increase in reduced glutathione level was recorded in all of the tissues. With regard to nonprotein thiols, copper decreased their level in the liver, but increased it in the gill. The protein-bound thiols remained unaltered except for an increase in the liver. Metallothionein (MT) induction was observed in liver only. Copper exposure had no significant effect on the ascorbic acid level and induced no lipid peroxidation over control values. It is suggested that by modulating the ceruloplasmin level, copper indirectly protects the fish, as it facilitates conversion of pro-oxidant iron to nonoxidant iron. It also induces an array of antioxidants that may be beneficial to fish in the case of oxidative stress resulting from chemical pollutants.     

Erythrocyte antioxidant defenses as a potential biomarker of liver mitochondrial status in different oxidative conditions

The need for minimally invasive biomarkers to predict the progression of non-alcoholic fatty liver disease to non-alcoholic steatohepatitis is a priority. Oxidative stress and mitochondrial dysfunction contribute in this physiopathological process. The aim of this study was to analyze the potential role of erythrocytes as surrogate biomarkers of hepatic mitochondrial oxidative status in an animal model under different dietary oxidative conditions. Interestingly, we found that erythrocyte antioxidant status correlated with triglyceride content (p?<?0.05–p?<?0.001), thiobarbituric acid reactive species levels (p?<?0.001) and with liver mitochondrial antioxidant levels (p?<?0.001). These data suggest that erythrocyte antioxidant defenses could be used as sensitive and minimally invasive biomarkers of mitochondrial status in diverse oxidative conditions.     

Protective effects of ginkgo biloba against acetaminophen-induced toxicity in mice

Background: The analgesic acetaminophen (AAP) causes a potentially fatal, hepatic centrilobular necrosis when taken in overdose. It was reported that these toxic effects of AAP are due to oxidative reactions that take place during its metabolism. Objective: In this study, we aimed to investigate the possible beneficial effect of Ginkgo biloba (EGb), an antioxidant agent, against AAP toxicity in mice. Methods: Balb/c mice were injected i.p. with: (1) vehicle, control (C) group; (2) a single dose of 50 mg/kg Ginkgo biloba extract, EGb group; (3) a single dose of 900 mg/kg i.p. acetaminophen, AAP group, and (4) EGb, in a dose of 50 mg/kg after AAP injection, AAP + EGb group. Serum ALT, AST, and tumor necrosis factor-alpha (TNF-α) levels in blood and glutathione (GSH), malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity, and collagen contents in liver tissues were measured. Formation of reactive oxygen species in hepatic tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lusigenin probe. Tissues were also examined microscopically. Results: ALT, AST levels, and TNF-α were increased significantly (p < 0.001) after AAP treatment, and reduced with EGb. Acetaminophen caused a significant (p < 0.05–0.001) decrease in GSH levels while MDA levels and MPO activity were increased (p < 0.001) in liver tissues. These changes were reversed by EGb treatment. Furthermore, luminol and lusigenin CL levels in the AAP group increased dramatically compared to control and reduced by EGb treatment (p < 0.01). Conclusion: Our results implicate that AAP causes oxidative damage in hepatic tissues and Ginkgo biloba extract, by its antioxidant effects protects the tissues. Therefore, its therapeutic role as a “tissue injury-limiting agent” must be further elucidated in drug-induced oxidative damage.     

Protective role of intraperitoneally administered vitamin E and selenium on the antioxidative defense mechanisms in rats with diabetes induced by streptozotocin

The aim of this work was to determine the protective effects of intraperitoneally administered vitamin E and selenium (as Na₂SeO₃, Se) on the lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and vitamin E levels, glutathione peroxidase (GSH-Px), reduced glutathione (GSH) activities in the plasma, red blood cell (RBC), liver, and muscle of rats with streptozotocin-induced diabetes. Fifty adult male Wistar rats were used and all rats were randomly divided into five groups. The first group was used as a control and the second group as a diabetic control. A placebo was given to first and second groups by injection. The third group was intraperitoneally administered with vitamin E (20 mg over 24 h), the fourth group with Se (0.3 mg over 24 h), and the fifth group with vitamin E and Se combination (COM) (20 mg vitamin E + 0.3 mg Se over 24 h). This administration was done for 25 days and the TBARS, vitamin E, GSH-Px, GSH levels in the plasma, RBC, liver, and muscle samples were determined. The vitamin E level in the plasma and liver was significantly (p < 0.05) higher in the control than in the diabetic control group. Also, the TBARS levels in the RBC, liver, and muscle were significantly (p < 0.05) lower in the control than in the diabetic control group. However, GSH-Px and GSH activities in RBC, liver, and muscle were not statistically different between the control and the diabetic control groups. The vitamin E levels in plasma and liver (p < 0.01 and p < 0.001) and GSH-Px activities (p < 0.01, p < 0.001) in RBC were significantly higher in vitamin E, Se, and COM groups than in both control and diabetic control groups. However, the TBARS levels of RBC, muscle, and liver in vitamin E and Se administered groups were significantly (p < 0.05-p < 0.001, respectively) decreased. These results indicate that intraperitoneally administered vitamin E and Se have significant protective effects on the blood, liver, and muscle against oxidative damage of diabetes. The abstract of this study was presented in Physiological Research 48(Suppl. 1), S99 (1999).     

Augmented nitric oxide generation in neutrophils: Oxidative and pro-inflammatory implications in hypertension

Abstract

The present study explores expression of NOS and pro-inflammatory cytokines, NOS catalysis and NO mediated modulation of oxidative response and apoptosis in neutrophils from spontaneously hypertensive rats (SHR). Neutrophils from SHR showed ～3-fold increments in iNOS expression, 1.5-fold increments in nOS expression and calcium independent NOS catalysis, whereas GTPCH expression was unaltered. Although phagocytic potential was comparable, neutrophils from SHR demonstrated augmented oxidative burst, which was reduced by NOS inhibition or in the presence of NO scavenger. SHR neutrophils also exhibited enhanced MPO catalysis and [Ca²⁺]_i levels. Levels of TNF-α and IFN-γ were comparable, but IL-1β and CRP levels in SHR plasma were (p<0.05) elevated. This study evidenced significantly enhanced expression of IL-1β in SHR neutrophils whereas those of TNF-α and IFN-γ were unaltered. Moreover neutrophils from SHR exhibited (p<0.01) delayed apoptotic response and sustained NO generation, as evident from elevated nitrite levels in neutrophil culture supernatant above the control levels. Results obtained indicate an augmented NO generation from neutrophils during hypertension which might fortify their attribute to the oxidative and inflammatory stress in SHR, emphasizing the importance of neutrophils in hypertension.     

Evaluation of the effects of cadmium on rat liver

Abstact Cadmium is one of the most toxic pollutants in environment. Cadmium accumulation in blood affects the renal cortex and causes renal failure. In this study, we aimed to evaluate the effects of cadmium on rat liver tissue. Eighteen male albino rats aged ten weeks old were used in the study. 15 ppm of cadmium was administered to rats via consumption water daily. At the end of the 30th study day, the animals were killed under ether anesthesia. After the liver tissue samples were taken, histopathological and biochemical examinations were performed. Histopathologic changes have included vacuolar and granular degenerations in hepatocytes, heterochromatic nucleuses and sinusoidal and portal widenings. Central vein diameters were normal in cadmium exposed group. Whereas, there was statistically significant difference between two groups by means of sinusoidal (p< 0.001) and portal triad diameters (p< 0.01). Malondialdehyde (MDA) is an indicator of lipid peroxidation. In this study, MDA was used as a marker of oxidative stress-induced liver impairment in cadmium exposed rats. Superoxide dismutase (SOD) and catalase (CAT) activities were also measured to evaluate the changes in antioxidative system in liver tissues. Current findings showed that MDA levels were increased and SOD and CAT activities were decreased in cadmium exposed group compared to control group. The difference between two groups was statistically significant (pvalues: MDA,p< 0.01; CAT,p< 0.01 and SOD,p< 0.05). In conclusion, these findings suggest the role of oxidative mechanisms in cadmium-induced liver tissue damage     

Protective Effect of Naringenin Against Lead-Induced Oxidative Stress in Rats

Oxidative stress is thought to be involved in lead-induced toxicity. The aim of this study was to investigate the possible protective role of naringenin on lead-induced oxidative stress in the liver and kidney of rats. In the present investigation, lead acetate (500 mg Pb/L) was administered orally for 8 weeks to induce hepatotoxicity and nephrotoxicity. The levels of hepatic and renal markers such as alanine aminotransferase, aspartate aminotransferase, urea, uric acid, and creatinine were significantly (P < 0.05) increased following lead acetate administration. Lead-induced oxidative stress in liver and kidney tissue was indicated by a significant (P < 0.05) increase in the level of maleic dialdehyde and decreased levels of reduced glutathione, superoxide dismutase, catalase, and glutathione peroxidase. Naringenin markedly attenuated lead-induced biochemical alterations in serum, liver, and kidney tissues (P < 0.05). The present study suggests that naringenin shows antioxidant activity and plays a protective role against lead-induced oxidative damage in the liver and kidney of rats.     

Buffalo (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>) Epiphyseal Proteins Counteract Arsenic-Induced Oxidative Stress in Brain,Heart, and Liver of Female Rats

Arsenic (As) toxicity through induction of oxidative stress is a well-known mechanism of organ toxicity. To address this problem, buffalo epiphyseal proteins (BEP, at 100 μg/kg BW, i.p. for 28 days) were administered intraperitoneally to female Wistar rats exposed to As (100 ppm sodium arsenite via drinking water for 28 days). Arsenic exposure resulted in marked elevation in lipid peroxidation in brain, cardiac, and hepatic tissues, whereas significant (p < 0.05) adverse change in catalase, superoxide dismutase, glutathione reductase, glutathione peroxidase, and reduced glutathione level were observed in cardiac, hepatic, and brain tissues of As-administered animals. BEP significantly (p < 0.05) counteracted all the adverse changes in antioxidant defense system brought about by As administration. Based on these results, we consider BEP as a potent antioxidant to be used for protection from arsenic-induced oxidative stress related damage of vital organs.     

Immune dysfunction in cirrhosis: Distinct cytokines phenotypes according to cirrhosis severity

Background/objectivesCirrhosis associated immune dysfunction has been proposed to switch from a pro-inflammatory phenotype in stable cirrhosis to an immunodeficient one in patients with decompensated cirrhosis and acute-on-chronic liver failure. The aim of the present study was to compare serum cytokine levels between healthy patients, stable cirrhosis, and decompensated cirrhotic patients with and without development of acute-on-chronic liver failure (ACLF); and to explore whether any of the measured cytokines is associated with cirrhosis severity and prognosis in ACLF patients.MethodsPatients were enrolled from October 2013 to May 2014 in two hospitals located in Buenos Aires. Cirrhotic patients with an acute decompensating event were enrolled accordingly to the development of ACLF defined by the CANONIC study group. There were two control groups: healthy subjects (n = 14) and stable cirrhotic patients (n = 14). Demographic, clinical and biochemical data were obtained. Seventeen cytokines were measured using Bio-Plex Pro Human Cytokine 17-plex Assay.ResultsOf the 49 decompensated cirrhotic patients enrolled, 18 (36.7%) developed ACLF. Leukocyte count, MELD score at admission, Clif-SOFA at admission and day 7 were significantly higher in the ACLF group (p = 0.046, p < 0.001, p < 0.001, p < 0.001 respectively) as well as short-term mortality (p < 0.001) compared to stable and decompensated cirrhotic patients. In comparison with healthy controls, stable cirrhotic and decompensated cirrhotic patients showed increased levels of pro-inflammatory and anti-inflammatory cytokines: IL-6, IL-7, IL-8, IL-10, IL 12, and TNF-α. Decompensated cirrhotic patients with the development of ACLF showed a significant decrease of IL-7, IL-10, IL-12, TNF-α, MCP-1 and IFN-γ, but a sustained response of IL-6 and IL-8. When evaluating cirrhosis severity, IL-6 and IL-8 correlated positively with MELD score, whereas only IL-6 correlated positively with Clif-SOFA score at day 7; IL-2 correlated negatively with Clif-SOFA at admission. In comparison with all scores, leukocyte count showed positive correlation and IFN-γ negative correlation with disease severity. When evaluating survival, only MELD and Clif-SOFA scores had a significant association with mortality.ConclusionsPro-inflammatory cytokines and chemo-attractant elements are increased in cirrhosis in comparison with healthy subjects, and display higher values concomitantly with cirrhosis progression. However, in acute-on-chronic liver failure an opposite cytokine pattern that can be resumed as a combination of immune paresis and excessive inflammatory response was observed. Several pro-inflammatory cytokines (IL-2, IL-6, IL-8 and IFN-γ) showed correlation with disease severity; their utility as prognostic biomarkers needs to be further studied.     

Alteration in some pro and anti-inflammatory cytokines associated with complete and incomplete gestation cycle of cows

The maternal immune response during pregnancy is regulated by a complex array of pro and anti-inflammatory cytokines which provide optimum conditions for the embryo implantation and survival. The possible role of pro and anti-inflammatory cytokines during the complete gestation cycle of ruminants and the difference in their circadian rhythmicity between successful and unsuccessful pregnancies is still unknown. To study this, blood samples were collected from three groups of cows, pregnant (P), non-pregnant (NP) and aborted (ABORT) cows starting from the day of Artificial Insemination (AI) till calving in P cows and till stages of non pregnancy in other cows. Various pro and anti-inflammatory cytokines were estimated by bovine-specific ELISA test and compared. Successful pregnancies had lower levels of pro-inflammatory cytokines (IL-2, IL-6 and IL-8) but higher anti-inflammatory cytokine (IL-10) mainly during implantation. Significant (p < 0.05) increase in pro-inflammatory cytokines and low IL-10 levels was noticed at abortion and at calving. This study indicates that temporal and spatial aspects of reducing the release of various pro-inflammatory cytokines and maintaining high anti-inflammatory cytokines during pregnancy are essentially required for maintenance of pregnancy. Any disturbance in the cytokine equilibrium may lead to persistent inflammation and pregnancy failure.     

Increased hepatic lipid soluble antioxidant capacity as compared to other organs of streptozotocin-induced diabetic rats: A cyclic voltammetry study

It has been suggested that oxidative stress plays an important role in the chronic complications of diabetes. The experimental findings regarding the changes in tissue antioxidant enzymes and lipid peroxidation of diabetic tissues have been inconsistent. Previous studies in our laboratory demonstrated that the reducing power of a specific tissue correlates with its low molecular weight antioxidant (LMWA) capacity. In the present study, the overall LMWA capacity (reducing equivalents) of plasma and tissues of streptozotocin (STZ)-induced diabetic rats (1–4 weeks) and insulin treated diabetic rats were measured by cyclic voltammetry. Levels of water and lipid soluble LMWA capacity progressively decreased in the diabetic plasma, kidney, heart and brain, while the diabetic liver, at 2, 3 and 4 weeks after STZ injection, showed a significant increase in the overall lipid soluble LMWA capacity (p < 0.001). Subsequently, analysis of specific components by high pressure liquid chromatography (electrochemical detection) showed decreased levels of ascorbic acid in plasma, kidney, heart and brain of diabetic animals. The α-tocopherol level dropped in all tissues, except for the liver in which there was a significant increase (p < 0.01 and p < 0.001 at 2–4 weeks). Lipid peroxidation was assessed by conjugated diene levels, which increased significantly in all diabetic tissues except the liver. Insulin treatment that was started after 3 weeks of diabetes and continued for 3 weeks showed no change in the conjugated dienes and in the overall LMWA capacity in all organs. Our results suggest a unique behavior of the liver in the STZ-induced diabetic rats to the stress and indicate its higher capacity to cope with oxidative stress as compared to other organs.     

Differential effect of early antibiotic intervention on bacterial fermentation patterns and mucosal gene expression in the colon of pigs under diets with different protein levels

The study aimed to evaluate the effects of early antibiotic intervention (EAI) on bacterial fermentation patterns and mucosal immune markers in the colon of pigs with different protein level diets. Eighteen litters of piglets at day (d) 7 were fed creep feed without or with growth promoting antibiotics until d 42. At d 42, pigs within each group were further randomly assigned to a normal- or low-crude protein (CP) diet. At d 77 and d 120, five pigs per group were slaughtered for analyzing colonic bacteria, metabolites, and mucosal gene expressions. Results showed that low-CP diet increased propionate and butyrate concentrations at d 77 but reduced ammonia and phenol concentrations (P < 0.05). EAI increased p-cresol and indole concentrations under normal-CP diet at d 77 (P < 0.05). Low-CP diet significantly affected (P < 0.05) some bacteria groups (Firmicutes, Clostridium cluster IV, Clostridium cluster XIVa, Escherichia coli, and Lactobacillus), but EAI showed limited effects. Low-CP diet down-regulated gene expressions of pro-inflammatory cytokines, toll-like receptor (TLR4), myeloid differentiating factor 88 (MyD88), and nuclear factor-κB p65 (NF-κB p65) (P < 0.05). EAI up-regulated mRNA expressions of interleukin-8 (IL-8) and interferon-γ (IFN-γ) under normal-CP diet at d 77 (P < 0.05). Furthermore, reductions of E. coli and ammonia under low-CP diet were positively correlated with down-regulated gene expressions of pro-inflammatory cytokines, which were positively correlated with the down-regulated TLR4-MyD88-NF-κB signaling pathway. In conclusion, EAI had short-term effects under normal-CP diet with increased aromatic amino acid fermentation and gene expressions of pro-inflammatory cytokines. Low-CP diet markedly reduced protein fermentation, modified microbial communities, and down-regulated gene expressions of pro-inflammatory cytokines possibly via down-regulating TLR4-MyD88-NF-κB signaling pathway.

     

Kolaviron and selenium reduce hydrogen peroxide-induced alterations of the inflammatory response

The abilities of kolaviron and selenium (either separately or in combination) to prevent hydrogen peroxide-induced alterations in cell viability and activation were investigated. The cell line U937 was incubated with the antioxidants (i.e. kolaviron or selenium) for 24?h before exposure to hydrogen peroxide and cell viability was assessed via trypan blue dye exclusion assay. The U937 cells were also transformed to the macrophage form, incubated with the antioxidants before exposure to hydrogen peroxide. Subsequently, production of nitric oxide and pro-inflammatory cytokines were assessed as indices of macrophage activation. The myoblast cell line H9c2 was also incubated with Se and kolaviron for 24?h before exposure to hydrogen peroxide. Cell viability and generation of reactive oxygen species (ROS) were assessed via MTT and DCHF assays. The results revealed that hydrogen peroxide significantly reduced (p?<?0.05) the viability of U937 cells which was ameliorated by kolaviron and selenium. Kolaviron and selenium also reduced hydrogen peroxide-induced secretion of nitric oxide, TNF-α, IL-1 and IL-6 by transformed U937 cells. Hydrogen peroxide also significantly reduced (p?<?0.05) the viability of H9c2 cells which was significantly restored by kolaviron. Though selenium had no effect on the proliferation of H9c2 cells, co-treatment with kolaviron significantly reduced hydrogen peroxide-induced alterations. Both kolaviron and selenium also reduced hydrogen peroxide-mediated ROS production by H9c2 cells. In all cases, the combined action of kolaviron and selenium offered greater amelioration of the hydrogen peroxide-induced alterations than their separate effects (p?<?0.05) but may not be synergistic or additive.     

Intranasal administration of a combination of choline chloride,vitamin C,and selenium attenuates the allergic effect in a mouse model of airway disease

Respiratory allergic disease is an inflammatory condition accompanied by oxidative stress. Supplementation of an anti-inflammatory agent with antioxidants may have a therapeutic effect. In this study, the effects of choline chloride in combination with antioxidants were evaluated via the intranasal route in a mouse model of allergic airway disease. Balb/c mice were sensitized on days 0, 7, and 14 and challenged on days 25–30 with cockroach extract (CE) and with a booster challenge on day 38. They were treated with choline chloride (ChCl; 1 mg/kg), vitamin C (Vit C; 308.33 mg/kg), and selenium (Se; 1 mg/kg) alone or in combination via the intranasal route on days 31, 33, 35, 37, and 39. The mice were sacrificed on day 40 to collect blood, bronchoalveolar lavage fluid, lungs, and spleen. Mice immunized with CE showed a significant increase in airway hyperresponsiveness (AHR), lung inflammation, Th2 cytokines, and the oxidative stress markers intracellular reactive oxygen species and 8-isoprostanes compared to the phosphate-buffered saline control group. A significant decrease was observed in these parameters with all the treatments (p<0.01). The highest decrease was noticed in the ChCl+Vit C+Se-treated group, with AHR decreased to the normal level. This group also showed the highest decrease in airway inflammation (p<0.001), IL-4 and IL-5 (p<0.001), IgE and IgG1 (p<0.001), NF-κB (p<0.001), and 8-isoprostane levels (p<0.001). Glutathione peroxidase activity, which was decreased significantly in CE-immunized mice, was restored to normal levels in this group (p<0.001). IL-10 level was decreased in CE-immunized mice and was restored to normal by combination treatment. The combination treatment induced FOXP3⁺ cells in splenocyte culture, responsible for the upregulation of IL-10. In conclusion, the combination of choline chloride, vitamin C, and selenium via the intranasal route reduces AHR, inflammation, and oxidative stress, probably by causing IL-10 production by FOXP3⁺ cells, and possesses therapeutic potential against allergic airway disease.     

Antioxidant supplementation lowers circulating IGF-1 but not F2-isoprostanes immediately following anterior cruciate ligament surgery

Abstract

Interleukin (IL)-10 is an anti-inflammatory cytokine that suppresses pro-inflammatory cytokines. We previously demonstrated that supplementation with vitamins E and C ameliorated the increase in IL-10 immediately following anterior cruciate ligament (ACL) surgery in the absence of other cytokine perturbations. Since both oxidative stress and insulin-like growth factor-1 (IGF-1) can modulate IL-10 concentrations, the mechanisms for these changes warranted further investigation. Our objective was to evaluate the mechanism for the IL-10 decrease following ACL surgery. This study consisted of randomized, double-blind, placebo-controlled experimental design. Subjects were randomly assigned to daily supplementation with either: (i) antioxidants (AO; vitamins E [α-tocopherol] and C [ascorbic acid]; n = 10); or (ii) matching placebos (PL; n = 10). Supplementation started ～2 weeks prior to surgery (baseline) and concluded 3 months after surgery. Subjects provided six fasting blood samples at: (i) baseline; (ii) immediately pre-surgery (Pre); (iii) 90 min; (iv) 72 h; (v) 7 days; and (vi) 3 months post-surgery. α-Tocopherol, ascorbic acid, F₂-isoprostane and IGF-1 concentrations were measured in each blood sample. At 90 min relative to other times, plasma F₂-isoprostane concentrations were significantly (P < 0.05) elevated in both groups, while at 90 min IGF-1 was significantly (P < 0.05) lower in the AO compared to the PL group. The changes in IGF-1 at 90 min relative to baseline were correlated (P < 0.0001) with the changes in IL-10. The decrease in IL-10 observed in the AO group is likely dependent on the decrease IGF-1 since lipid peroxidation was unchanged between the two groups.