Synergistic antioxidant and anti-inflammatory action of N-acetylcysteine in portal hypertensive gastropathy in rats.

Background and Aim: Portal hypertension (PH) is a syndrome associated with cirrhosis and characterized by a progressive increase in portal pressure, with consequent compensatory vascular dilation. Gastric vascular changes associated with oxidative and nitrosative stress characterize the clinical presentation of portal hypertensive gastropathy (PHG). In addition, the inflammatory process is considered an aggravating factor for severity by contributing to gastric tissue injury. The aim of this study was to investigate the synergistic anti-inflammatory and antioxidant action of N-acetylcysteine (NAC) in the stomach of rats with PH. Materials and Methods: Eighteen Wistar male rats were used in this experimental protocol and were divided into three groups with six in each group: sham-operated (SO), partial portal vein ligation (PPVL), and PPVL + NAC. Treatment with NAC at a dose of 10 mg/kg (i.p.) was initiated on day 8 after surgery and continued for 7 days. We evaluated the expression of iNOS, NQO-1, HSP-90, and SOD by Western blot, as well as nuclear factor-kappa B (NF-κB) and tumor necrosis factor (TNF)-α staining by immunohistochemistry, in the rat stomach. Results: The PPVL group exhibited increased expression of HSP-90, iNOS, SOD, and NQO-1 when compared with controls. NAC reduced the expression of all studied proteins. Similarly, NF-κB and TNF-α staining was increased in PPVL animals versus controls and reduced in PPVL + NAC versus PPVL animals, respectively. Conclusion: These results suggest the effectiveness of NAC as a dual anti-inflammatory and antioxidant in animals with experimental PHG induced by partial ligation of the portal vein.

Campsiandra laurifolia reduces oxidative stress and Iiflammation in rats with ulcerative colitis

Ulcerative colitis (UC) affects the mucosa and submucosa of the large intestine. One of the mechanisms involved in its etiology is oxidative stress (OS), directly involved in the inflammatory process characteristic of UC. The Campsiandra laurifolia, known as acapurana, was described as possessing antioxidant properties. We used 24 male Wistar rats, divided into control (CO), control + acapurana (CO + A), colitis (CL), and colitis + acapurana (CL + A) groups. This study performed histological analysis, measuring anal sphincter pressure (ASP) and lipoperoxidation (LPO). The activity of the antioxidant enzyme superoxide dismutase (SOD) and glutathione (GSH) levels were evaluated. The expression of the nuclear factor kappa B (NFkB) and inducible nitric oxide synthase (iNOS) was analyzed by immunohistochemistry. The statistical analysis used was the one-way analysis of variance (ANOVA), followed by the Student-Newman-Keuls test; values were expressed as mean ± standard error, and the significance level was p < 0.05. In the animals of the CL group, we observed the destruction of the crypts and the presence of mucosal ulcers, edema, and submucosal inflammatory infiltrate, as well as increased damage to the intestinal mucosa, reduced ASP, increased LPO and SOD activity, reduced GSH levels, and increased expression of NFkB and iNOS. The administration of C. laurifolia in the CL + A group was shown to cause regeneration of crypts, reduction of inflammatory infiltrate, reduction of damage to the intestinal mucosa, increase in ASP, and reduction in LPO with the restoration of SOD activity and GSH levels. The immunohistochemistry of NFkB and iNOS was significantly reduced. Therefore, the C. laurifolia aqueous extract appears to exert an antioxidant and anti-inflammatory effect in rats with AA-induced colitis. (AU)

Exposure in the tobacco fields: Genetic damage and oxidative stress in tobacco farmers occupationally exposed during harvest and grading seasons.

Agricultural workers engaged in tobacco cultivation are constantly exposed to large amounts of harmful agents, such as pesticides and nicotine. Furthermore, most of the flue-cured tobacco leaves are manually graded exposing workers to agents such as tobacco-specific nitrosamines. This study aimed to evaluate genetic damage and oxidative stress in tobacco farmers occupationally exposed during the harvest and grading seasons. We obtained data on DNA damage detected in Comet assay in blood cells and micronucleus experiment with buccal cells from 241 individuals. The serum cotinine levels and nitrates were also evaluated. The Comet Assay results showed a showed an increased visual score for males and females during harvest time and tobacco grading. An increase of micronucleated and binucleated cells was observed in the grading group compared to the control and harvest groups. The oxidative stress measurements showed a clear increase of thiobarbituric acid reactive substances (TBARS) in tobacco farmers during harvest time, and trolox equivalent antioxidant capacity (TEAC) in individuals during harvest and grading time compared to the controls. Significant increases of the cotinine levels were observed during the harvest and grading period (harvest>grading), and nitrates for the grading period compared to the control. In this study, tobacco farmers presented compromised DNA integrity associated with enhanced oxidative stress levels.

Lupin Protein Concentrate as a Novel Functional Food Additive That Can Reduce Colitis-Induced Inflammation and Oxidative Stress.

Food fortification with bioactive compounds may constitute a way to ameliorate inflammatory bowel diseases (IBDs). Lupin seeds contain an oligomer named deflamin that can reduce IBD's symptoms via MMP-9 inhibition. Here, our goal was to develop a lupin protein concentrate (LPC) enriched in deflamin and to test its application as a food additive to be used as a functional food against colitis. The nutritional profile of the LPC was evaluated, and its efficacy in vivo was tested, either alone or as added to wheat cookies. The LPC presented high protein and carbohydrate contents (20.09 g/100 g and 62.05/100 g, respectively), as well as antioxidant activity (FRAP: 351.19 mg AAE/10 mg and DPPH: 273.9 mg AAE/10 mg). It was also effective against TNBS-induced colitis in a dose dependent-manner, reducing DAI scores by more than 50% and concomitantly inhibiting MMP-9 activity. When added to cookies, the LPC activities were maintained after baking, and a 4-day diet with LPC cookies induced a significant protective effect against acetic acid-induced colitis, overall bringing lesions, oxidative stress and DNA damage levels to values significantly similar to controls (p < 0.001). The results show that the LPC is an efficient way to deliver deflamin in IBD-targeted diets.

Melatonin restores zinc levels, activates the Keap1/Nrf2 pathway, and modulates endoplasmic reticular stress and HSP in rats with chronic hepatotoxicity.

BACKGROUND: Melatonin (MLT) is a potent antioxidant molecule that is shown to have a beneficial effect in various pathological situations, due to its action against free radicals. AIM: To evaluate the effect of MLT on carbon tetrachloride (CCl4) induced liver injury in rats in terms of oxidative stress, reticular stress, and cell damage. METHODS: Twenty male Wistar rats (230-250 g) were divided into four groups: Control rats, rats treated with MLT alone, rats treated with CCl4 alone, and rats treated with CCl4 plus MLT. CCl4 was administered as follows: Ten doses every 5 d, ten every 4 d, and seven every 3 d. MLT was administered intraperitoneally at a dose of 20 mg/kg from the 10th wk to the end of the experiment (16th wk). RESULTS: MLT was able to reduce the release of liver enzymes in the bloodstream and to decrease oxidative stress in CCl4 treated rats by decreasing the level of thiobarbituric acid reactive substances and increasing superoxide dismutase activity, with a lower reduction in serum zinc levels, guaranteeing a reduction in liver damage; additionally, it increased the expression of nuclear factor (erythroid-derived 2)-like 2 and decreased the expression of Kelch-like ECH-associated protein 1. MLT also decreased the expression of the proteins associated with endoplasmic reticulum stress, i.e., glucose-regulated protein 78 and activating transcription factor 6, as well as of heat shock factor 1 and heat shock protein 70. CONCLUSION: MLT has a hepatoprotective effect in an experimental model of CCl4-induced liver injury, since it reduces oxidative stress, restores zinc levels, and modulates endoplasmic reticulum stress.

Melatonin Attenuates Inflammation, Oxidative Stress, and DNA Damage in Mice with Nonalcoholic Steatohepatitis Induced by a Methionine- and Choline-Deficient Diet.

Nonalcoholic steatohepatitis (NASH) is a disease with a high incidence worldwide, but its diagnosis and treatment are poorly managed. In this study, NASH pathophysiology and DNA damage biomarkers were investigated in mice with NASH treated and untreated with melatonin (MLT). C57BL/6 mice were fed a methionine- and choline-deficient (MCD) diet for 4 weeks to develop NASH. Melatonin was administered at 20 mg/kg during the last 2 weeks. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured, and hepatic tissue was dissected for histological analysis, evaluation of lipoperoxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as nuclear factor-erythroid 2 (Nrf2), tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS), and transforming growth factor beta (TGF-ß) expression by immunohistochemistry. DNA damage was evaluated using Comet assay, while a micronucleus test in bone marrow was performed to assess the genomic instability associated with the disease. Melatonin decreased AST and ALT, liver inflammatory processes, balloonization, and fibrosis in mice with NASH, decreasing TNF-α, iNOS, and TGF-ß, as well as oxidative stress, shown by reducing lipoperoxidation and intensifying Nrf2 expression. The SOD and GPx activities were increased, while CAT was decreased by treatment with MLT. Although the micronucleus frequency was not increased in mice with NASH, a protective effect on DNA was observed with MLT treatment in blood and liver tissues using Comet assay. As conclusions, MLT slows down the progression of NASH, reducing hepatic oxidative stress and inflammatory processes, inhibiting DNA damage via anti-inflammatory and antioxidant actions.

Melatonin prevents oxidative stress, inflammatory activity, and DNA damage in cirrhotic rats.

BACKGROUND: Cirrhosis is an important health problem characterized by a significant change in liver parenchyma. In animals, this can be reproduced by an experimental model of bile duct ligation (BDL). Melatonin (MLT) is a physiological hormone synthesized from serotonin that has been studied for its beneficial properties, including its antioxidant potential. AIM: To evaluate MLT's effects on oxidative stress, the inflammatory process, and DNA damage in an experimental model of secondary biliary cirrhosis. METHODS: Male Wistar rats were divided into 4 groups: Control (CO), CO + MLT, BDL, and BDL + MLT. MLT was administered (20 mg/kg) daily beginning on day 15 after biliary obstruction. On day 29 the animals were killed. Blood samples, liver tissue, and bone marrow were collected for further analysis. RESULTS: BDL caused changes in biochemical and histological parameters and markers of inflammatory process. Thiobarbituric acid (0.46 ± 0.01) reactive substance levels, superoxide dismutase activity (2.30 ± 0.07) and nitric oxide levels (2.48 ± 0.36) were significantly lower (P < 0.001) n the groups that received MLT. DNA damage was also lower (P < 0.001) in MLT-treated groups (171.6 ± 32.9) than the BDL-only group (295.5 ± 34.8). Tissue damage and the expression of nuclear factor kappa B, interleukin-1ß, Nrf2, NQO1 and Hsp70 were significantly lower in animals treated with MLT (P < 0.001). CONCLUSION: When administered to rats with BDL-induced secondary biliary cirrhosis, MLT effectively restored the evaluated parameters.

Combination of Trans-Resveratrol and ε-Viniferin Induces a Hepatoprotective Effect in Rats with Severe Acute Liver Failure via Reduction of Oxidative Stress and MMP-9 Expression.

Stilbenes are a major grapevine class of phenolic compounds, known for their biological activities, including anti-inflammatory and antioxidant, but never studied in combination. We aimed to evaluate the effect of trans-resveratrol + ε-viniferin as an antioxidant mixture and its role in inflammatory development an in vivo model of severe acute liver failure induced with TAA. Trans-resveratrol + trans-ε-viniferin (5 mg/kg each) was administered to Wistar rats. Resveratrol + ε-viniferin significantly decreased TBARS and SOD activity and restored CAT and GST activities in the treated group. This stilbene combination reduced the expression of TNFα, iNOS, and COX-2, and inhibited MMP-9. The combination of resveratrol + ε-viniferin had a hepatoprotective effect, reducing DNA damage, exhibiting a protective role on the antioxidant pathway by altering SOD, CAT, and GST activities; by downregulating TNFα, COX-2, and iNOS; and upregulating IL-10. Our results suggested that adding viniferin to resveratrol may be more effective in hepatoprotection than resveratrol alone, opening a new perspective on using this stilbene combination in functional diets.

Exposure to organic solvents and hepatotoxicity.

The purpose of this study was to identify the long-term effect of chemical exposure on the liver. Laboratory tests included alanine aminotransferase (ALT) dosage and oxidative stress tests, such as thiobarbituric acid reactive substances in plasma and superoxide dismutase (SOD) and glutathione S-transferase analysis in erythrocytes. The cross-sectional study comprised 70 workers, 30 of them exposed to organic solvents and 40 not exposed. All those exposed presented at least 5 years of exposure to solvents. Hepatitis B and C, known hepatic disease, comorbidities, use of alcohol, illicit drugs or hepatotoxic medications, smoking, body mass index >30, female sex and age (<18 or >65) were excluded from the sample. Results indicated that elevated ALT was more frequent in the exposed group compared to controls: 33% vs. 10.5%, with a statistical significance (p < 0.05). Thiobarbituric acid reactive substances were significantly elevated (p < 0.01) in the exposed group in comparison to controls. Antioxidant enzymes were more elevated in the exposed group compared to controls: SOD 7.29 (4.30-8.91) USOD/mg of protein vs. 3.48 (2.98-5.28) USOD/mg of protein and GST 2.57 µmol/min/mg of protein (1.80-4.78) vs. 1.81 µmol/min/mg of protein (1.45- 2.30) µM/min/mg of protein. The results suggest an association between exposure to organic solvents and hepatotoxicity.

Effects of Pulsed Radiofrequency on a Standard Model of Muscle Injury in Rats.

BACKGROUND: Pulsed radiofrequency (PRF) affects animal and plant tissues; however, the mechanism has not been defined. We hypothesized that the magnetic field produced by PRF exerts its effects by the magnetic sensitivity of transitions between spin states -a spin-correlated radical-pair mechanism (SCRPM)- which, in turn, affects the rates of chemical reactions with participation of paramagnetic species. OBJECTIVES: This study aimed to evaluate the effects of PRF on redox equilibrium and inflammatory status in a standard model of muscle injury in rats. METHODS: Twenty-four animals were subjected to a single impact trauma to the left quadriceps and the groups exposed and not exposed to PRF were compared. On day 7 of the experiment, the animals were killed and the quadriceps muscles were removed for analysis. RESULTS: There was a significant increase in the concentration of thiobarbituric acid reactive substances (TBARS) in the muscle of animals from the trauma group (+233%), and this increase was eliminated by PRF administration. Superoxide dismutase (SOD) activity was increased (+411%) by trauma, resulting in significantly higher consumption of catalase (-72%), while PRF administration brought both of these markers back to levels close to those of the control group. Trauma induced considerable production of interleukins TNF-α, IL-1ß, and IL-6 (+215%, +262%, and +326% vs. controls, respectively) and these effects were also significantly reduced by PRF administration. CONCLUSIONS: In total, PRF inhibits oxidative stress and restores antioxidant enzymes to control levels and may block production of inflammatory markers in muscles of animals subjected to trauma. By modulating redox equilibrium, PRF treatment might block production of noxious mediators involved in development of trauma-induced injury.

Recombinant peptide derived from the venom the Phoneutria nigriventer spider relieves nociception by nerve deafferentation.

The avulsion of nerve roots of the brachial plexus that is commonly seen in motorcycle accidents is a type of neuropathy due to deafferentation. This type of pain is clinically challenging since therapeutical protocols fail or have severe side effects. Thus, it is proposed to evaluate the antinociceptive activity of the recombinant CTK 01512-2 peptide that is derived from the venom of the Phoneutria nigriventer spider, as a future new therapeutical option. The neuropathic pain was surgically induced by avulsion of the upper brachial plexus trunk in groups of male Wistar rats and after 17 days, they were treated intrathecally with morphine, ziconotide, and CTK 01512-2. Behavioral tests were performed to evaluate mechanical and thermal hyperalgesia, cold allodynia, the functional activity of the front paw, and exploratory locomotion after the treatments. The peripheral blood samples were collected 6 h after the treatments and a comet assay was performed. The spinal cord was removed for the lipoperoxidation dosing of the membranes. The cerebrospinal fluid was analyzed for the dosage of glutamate. The recombinant peptide showed an antinociceptive effect when compared to the other drugs, without affecting the locomotor activity of the animals. Mechanical and thermal hyperalgesia, as well as cold allodynia, were reduced in the first hours of treatment. The levels of glutamate and the damage by membrane lipoperoxidation were shown to be improved, and genotoxicity was not demonstrated. In a scenario of therapeutical failures in the treatment of this type of pain, CTK 01512-2 was shown as a new effective alternative protocol. However, further testing is required to determine pharmacokinetics.

Effect of therapeutic ultrasound on the quadriceps muscle injury in rats - evaluation of oxidative stress and inflammatory process.

Muscle injuries are frequent, both in sports and work, and may be caused by stretching, distension, repetitive effort or bruising. Such lesions can lead to the generation of free radicals, triggering oxidative stress and the release of some inflammatory mediators. Therapeutic ultrasound (UST) is one of the most used electrotherapy resources in the physiotherapist's clinical practice. Our aim was to evaluate the use of therapeutic ultrasound on oxidative stress and inflammatory process in an experimental model of single quadriceps muscle injury in Wistar rats. We used a total of 28 male rats, weighing between 250-300 grams, randomly divided into four groups. In the right quadriceps, a simple impact of contusion was induced by means of a press. The animals were submitted to a daily UST treatment for a total of seven consecutive applications for three minutes each, that started 24 hours after the trauma induction. The results in the Trauma + Therapeutic ultrasound group at TBARS levels and in the enzymatic activity of SOD and GPx presented a significant difference. In the histological analysis of the Trauma + Therapeutic ultrasound group presented a reorganization of the fiber's structure and a reduction of the presence of inflammatory infiltrate. In the results of the immunohistochemistry of iNOS, TNF-α and NF-κB in muscle tissue, we observed that the group treated with ultrasound showed a reduction in the expression of the proteins. The use of UST was effective in protecting muscle tissue from oxidative stress, inflammatory process and in the rearrangement of muscle fibers.

Oral glutamine supplementation attenuates inflammation and oxidative stress-mediated skeletal muscle protein content degradation in immobilized rats: Role of 70 kDa heat shock protein.

Skeletal muscle disuse results in myofibrillar atrophy and protein degradation, via inflammatory and oxidative stress-mediated NF-kB signaling pathway activation. Nutritional interventions, such as l-glutamine (GLN) supplementation have shown antioxidant properties and cytoprotective effects through the modulation on the 70-kDa heat shock protein (HSP70) expression. However, these GLN-mediated effects on cell signaling pathways and biochemical mechanisms that control the myofibrillar protein content degradation in muscle disuse situations are poorly known yet. This study investigated the effects of oral GLN plus l-alanine (ALA; GLN â€‹+ â€‹ALA-solution) supplementation, either in their free or dipeptide (L-alanyl-l-glutamine-DIP) form, on GLN-glutathione (GSH) axis and cytoprotection mediated by HSP70 protein expression in the slow-twitch soleus and fast-twitch gastrocnemius skeletal muscle of rats submitted to 14-days of hindlimb immobilization-induced disuse muscle atrophy. Forty-eight Wistar rats were distributed into 6 groups: hindlimb immobilized (IMOB group) and hindlimb immobilized orally supplemented with either GLN (1 g kg-1) plus ALA (0.61 g kg-1) â€‹(GLN â€‹+ â€‹ALA-IMOB group) or 1.49 â€‹g â€‹kg-1 of DIP (DIP-IMOB group) and; no-immobilized (CTRL) and no-immobilized supplemented GLN â€‹+ â€‹ALA and DIP baselines groups. All animals, including CTRL and IMOB rats (water), were supplemented via intragastric gavage for 14 days, concomitantly to immobilization period. Plasma and muscle GLN levels, lipid (thiobarbituric acid reactive substances-TBARS) and protein (carbonyl) peroxidation, erythrocyte concentration of reduced GSH and GSH disulfide (GSSG), plasma and muscle pro-inflammatory TNF-α levels, muscle IKKα/ß-NF-kB signaling pathway and, the myofibrillar protein content (MPC) were measured. The MPC was significantly lower in IMOB rats, compared to CTRL, GLN â€‹+ â€‹ALA, and DIP animals (p â€‹< â€‹0.05). This finding was associated with reduced plasma and muscle GLN concentration, equally in IMOB animals. Conversely, both GLN â€‹+ â€‹ALA and DIP supplementation restored plasma and muscle GLN levels, which equilibrated GSH and intracellular redox status (GSSG/GSH ratio) in erythrocytes and skeletal muscle even as, increased muscle HSP70 protein expression; attenuating oxidative stress and TNF-α-mediated NF-kB pathway activation, fact that reverberated on reduction of MPC degradation in GLN â€‹+ â€‹ALA-IMOB and DIP-IMOB animals (p â€‹< â€‹0.05). In conclusion, the findings shown herein support the oral GLN â€‹+ â€‹ALA and DIP supplementations as a therapeutic and effective nutritional alternative to attenuate the deleterious effects of the skeletal muscle protein degradation induced by muscle disuse.

Simvastatin Reduces Hepatic Oxidative Stress and Endoplasmic Reticulum Stress in Nonalcoholic Steatohepatitis Experimental Model.

OBJECTIVE: In this study, we evaluated the efficacy of simvastatin in the treatment of nonalcoholic steatohepatitis induced by methionine and choline-deficient diet in mice and its possible effect on factors involved in the pathogenesis of the disease including oxidative stress and endoplasmic reticulum stress. METHOD: Male C57BL6 mice were fed either a normal diet (control) or a methionine and choline-deficient diet for four weeks and then treated orally with simvastatin (4 mg/kg once a day) for two final weeks. At the end of the experimental period, liver integrity, biochemical analysis, hepatic lipids, histology, DNA damage, biomarkers of oxidative stress, and endoplasmic reticulum stress were assessed. RESULTS: Simvastatin treatment was able to significantly reduce hepatic damage enzymes and hepatic lipids and lower the degree of hepatocellular ballooning, without showing genotoxic effects. Simvastatin caused significant decreases in lipid peroxidation, with some changes in antioxidant enzymes superoxide dismutase and glutathione peroxidase. Simvastatin activates antioxidant enzymes via Nrf2 and inhibits endoplasmic reticulum stress in the liver. CONCLUSIONS: In summary, the results provide evidence that in mice with experimental nonalcoholic steatohepatitis induced by a methionine and choline-deficient diet, the reduction of liver damage by simvastatin is associated with attenuated oxidative and endoplasmic reticulum stress.

Protective action of glutamine in rats with severe acute liver failure.

BACKGROUND: Severe acute liver failure (SALF) is a rare, but high-mortality, rapidly evolving syndrome that leads to hepatocyte degeneration with impaired liver function. Thioacetamide (TAA) is a known xenobiotic, which promotes the increase of the formation of reactive oxygen species. Erythroid 2-related factor 2 (Nrf2) activates the antioxidant protection of cells. Studies have evidenced the involvement of inflammatory mediators in conditions of oxidative stress. AIM: To evaluate the antioxidant effects of glutamine on Nrf2 activation and NFκB-mediated inflammation in rats with TAA-induced IHAG. METHODS: Male Wistar rats (n = 28) were divided into four groups: control, control+glutamine, TAA, and TAA + glutamine. Two TAA doses (400 mg/kg) were administered intraperitoneally, 8 h apart. Glutamine (25 mg/kg) was administered at 30 min, 24 h, and 36 h. At 48 h, blood was collected for liver integrity analysis [aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP)]. The liver was harvested for histology and assessment of oxidative stress [thiobarbituric acid-reactive substances (TBARS), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione (GSH), Nrf2, Kelch-like ECH-associated protein 1 (Keap1), NADPH quinone oxidoreductase1 (NQO1), superoxide dismutase (SOD)] and inflammatory process. RESULTS: TAA caused disruption of the hepatic parenchyma, with inflammatory infiltration, massive necrosis, and ballooning degeneration. Glutamine mitigated this tissue damage, with visible regeneration of hepatic parenchyma; decreased TBARS (P < 0.001), GSH (P < 0.01), IL-1ß, IL6, and TNFα levels (P <0.01) in hepatic tissue; and decreased blood levels of AST, ALT, and ALP (P <0.05). In addition, CAT, GPx, and GST activities were restored in the glutamine group (P <0.01, P <0.01, and P <0.001, respectively vs TAA alone). Glutamine increased expression of Nrf2 (P < 0.05), NQO1, and SOD (P < 0.01), as well as levels of IL-10 (P <0.001), while decreasing expression of Keap1, TLR4, NFκB (P < 0.001), COX-2 and iNOS, (P < 0.01), and reducing NO2 and NO3 levels (P < 0.05). CONCLUSION: In the TAA experimental model of IHAG, glutamine activated the Nrf2 pathway, thus promoting antioxidant protection, and blunted the NFκB-mediated pathway, reducing inflammation.

Zinc supplementation reduces diet-induced obesity and improves insulin sensitivity in rats.

Rates of obesity have been growing at alarming rates, compromising the health of the world population. Thus, the search for interventions that address the metabolic repercussions of obesity are necessary. Here we evaluated the metabolic and antioxidant effects of zinc and branched-chain amino acids (BCAA) supplementation on obese rats. Male Wistar rats were fed either a high-fat/high-fructose diet (HFD) or a standard diet (SD) for 19 weeks. From the fifteenth week until the end of the experiment, HFD- and SD-fed rats received zinc (6 mg/kg) or BCAA (750 mg/kg) supplementation. Body weight, abdominal fat, lipid profile, blood glucose, insulin, leptin, and hepatic transaminases were evaluated. In the liver, superoxide dismutase and catalase activities and lipid peroxidation were also analyzed. HFD-fed animals showed increased weight gain, abdominal fat pad, plasma insulin, leptin, and triglycerides levels in comparison with SD-fed rats. Zinc supplementation reduced all these parameters, suggesting a beneficial role for the treatment of obesity. BCAA, on the other hand, did not show any beneficial effect. Liver antioxidant enzymes and hepatic transaminases plasma levels did not change among groups. Lipid peroxidation was higher in HFD-fed rats and was not reverted by zinc or BCAA supplementation. In conclusion, zinc supplementation may be a useful strategy for the treatment of the metabolic dysfunction associated with obesity.

Anti-inflammatory and antioxidant effect of melatonin on recovery from muscular trauma induced in rats.

In recent decades, the number of people who practice sports has grown exponentially, increasing the number of muscular injuries. Trauma injury occurs when the muscle is exposed to a sudden compression force. Melatonin (MLT) has often been cited in the literature as a potent antioxidant and anti-inflammatory agent. This study was designed to evaluate MLT action on muscle tissue in Wistar rats in an experimental model of muscle trauma. Twenty-eight Wistar rats were used, divided into four groups: CO (Control), CO + MLT (Control + Melatonin), T (Trauma) and T + MLT (Trauma + Melatonin). MLT (20 mg/kg) was administered (ip) daily at dusk until day 7. The trauma occurred on day 1, 2 h before the first MLT application. On day 8, muscle tissue was collected for histological analysis (HE), immunohistochemistry (TNF-α and NFκB), evaluation of oxidative stress through analysis of lipoperoxidation by TBARS and activity of SOD and GPx enzymes, and analysis of nitrites and nitrates. In the evaluation of TBARS and SOD, we observed a significant increase in the T group and a significant decrease in the T + MLT group. In the evaluation of GPx, there was a significant increase in the T group and a significant decrease in the T + MLT group. The histological analysis of muscle tissue revealed structural changes of muscle fibers and inflammatory infiltrate in the T group but a decrease in this damage in the T + MLT group. In the immunohistochemical evaluation, increased expression of TNFα and NFκB proteins in the T group was observed and a significant decrease of this expression in the T + MLT group. MLT was shown to attenuate oxidative damage and to diminish the expression of inflammatory proteins and tissue damage in this experimental model.

Effect of glutamine on liver injuries induced by intestinal ischemia-reperfusion in rats

INTRODUCTION: Intestinal ischemia-reperfusion (I/R) injury may cause cell and tissue damage, reaching also other organs such as the liver. Because of the involvement of free radicals in I/R injury, treatment options with antioxidants have been studied and tested. OBJECTIVE: To evaluate the effect of glutamine (Gln) in the liver of animals with intestinal I/R injury. METHODS: We used 20 male Wistar rats divided into four groups: sham-operated (SO); glutamine + sham-operated (G+SO); intestinal ischemia-reperfusion (I/R); glutamine + intestinal ischemia-reperfusion (G+I/R). The superior mesenteric artery was clamped for 30 minutes and reperfused for 15 minutes. Gln (25 mg/kg/day) diluted in 1 ml of saline was administered intraperitoneally on the two days before I/R induction. RESULTS: Levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP), lipid peroxidation (LPO) and expressions of interleukin-6 (IL-6) and nuclear factor kappa B (NF-kB) showed a significant reduction in the G+I/R group as compared with the I/R group. The activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and the levels of glutathione (GSH) showed an increase in the G+I/R group as compared with the I/R group. CONCLUSION: Pretreatment with Gln reduced oxidative, tissue damage and showed a decrease expression of inflammatory mediators.

Action of vitamin e on experimental severe acute liver failure / Composição corporal de pacientes com doença de Crohn e colite ulcerativa

ABSTRACT BACKGROUND Severe Acute Liver Failure (ALF) is a life-threatening clinical syndrome characterized by hepatocyte necrosis, loss of hepatic architecture, and impairment of liver functions. One of the main causes of ALF is hepatotoxicity from chemical agents, which damage hepatocytes and result in increase of reactive oxygen species. The vitamin E isoform is the one with the strongest biological antioxidant activity. OBJECTIVE To evaluate the antioxidant effect of vitamin E in this ALF model. METHODS We used 56 rats (mean weight of 300 g) divided into eight groups, four groups assessed at 24 hours and 4 assessed at 48 hours after induction: control group (CO); Vitamin E (Vit. E); Thioacetamide (TAA) and Thioacetamide + Vitamina E (TAA+Vit.E). Rats were submitted to injections of thioacetamide (400 mg/kg i.p.) at baseline and 8 hours later. Vitamin E (100 mg/kg ip) was administered 30 minutes after the second dose of thioacetamide. The 48-hour group rats received two additional doses of vitamin E (24h and 36h). At 24h or 48 hours after the administration of the first dose of TAA, rats were weighed and anesthetized and their blood sampled for evaluation of liver integrity through enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Liver tissue was sampled for assessment of lipid peroxidation (LPO) by the technique TBARS, antioxidant enzymes SOD, CAT, GPx and GST activity, levels of the NO 2 /NO 3 and histology by H&E in two times. The results were expressed as mean ± standard deviation and statistically analyzed by ANOVA followed by Student-Newman-Keuls, with P <0.05 considered as significant. RESULTS After treatment with vitamin E, we observed a reduction in liver enzymes AST (U/L) (101.32±19.45 in 24 hours and 97.85±29.65 in 48 hours) related to the TAA group (469.56± 0.69 in 24 hours and 598.23±55.45 in 48 hours) and ALT (U/L) (76.59±8.56 in 24 hours and 68.47±6.49 in 48 hours) compared to the TAA group (312.21±10.23 in 24 hours and 359.15±17.58 in 48 hours). There was a reduction of LPO (nmol/mg Prot) in the TAA+Vit.E group (0.77±0.07 in 24 hours and 0.95±0.08 in 48 hours) compared to the TAA group (1.50±0.07 in 24 hours e 1.65±0.16 in 48 hours). SOD decreased in the TAA+Vit.E group (49.48±9.47 in 24 hours and 62.45±18, 47 in 48 hours), related to the TAA group (98.46±15.48 in 24 hours and 154.13±21.46 in 48 hours), as well as GST (nmol/min/mg Prot) in the TAA+Vit.E group (350.57±36.93 in 24 hours and 453.29±13.84 in 48 hours) compared to the TAA group (561.57±64.56 in 24 hours and 673.43±38.13 in 48 hours). There was an increase in CAT (pmol/min/mg Prot) in the TAA+Vit.E group (3.40±0.44 in 24 hours and 3.0±0.35 in 48 hours) compared to the TAA group (1.65±0.21 in 24 hours and 1.86±0.42 in 48 hours). The GPx (nmol/min/mg Prot) increased in 24 hours in the TAA+Vit.E group (1.01±0.16) compared to the TAA group (0.41±0.04) and decreased in 48 hours (1.19±0.17) compared to the TAA group (1.76±0.21). There was a reduction in NO2/NO3 (mmol/L) levels in the TAA+Vit.E group (31.47±4.26 in 24 hours and 38.93±5.20 in 48 hours) compared to the TAA group (49.37±5.12 in 24 hours and 53.53±5.97 in 48 hours). The histopathological evaluation showed a decrease in liver injury (necrosis and inflammation) in both studied times. CONCLUSION These results suggest that vitamin E was able to protect the liver from lesions caused by thioacetamide.

RESUMO CONTEXTO A Insuficiência Hepática Aguda Grave (IHAG) é uma síndrome clínica potencialmente fatal, na qual ocorre necrose dos hepatócitos, perda da arquitetura hepática e deterioração de suas funções. Dentre as principais causas da IHAG está a hepatotoxicidade decorrente de agentes químicos, que lesam os hepatócitos e acarretam aumento das espécies reativas de oxigênio. A vitamina E tem alta atividade antioxidante biológica e é amplamente distribuída nos tecidos. OBJETIVO Avaliar o efeito antioxidante da Vitamina E no modelo de IHAG. MÉTODOS Foram utilizados 56 ratos, com peso médio de 300 g, divididos em oito grupos, quatro grupos avaliados em 24 horas e quatro em 48 horas após a indução: grupo controle (CO); Vitamina E (Vit.E); Tioacetamida (TAA) e Tioacetamida + Vitamina E (TAA+Vit.E). Os ratos foram submetidos a injeções de tioacetamida, na dose de 400 mg/Kg de peso i.p., no início do experimento e, posteriormente, após 8 horas. A vit E (100 mg//Kg i.p.) foi administrada 30 minutos após a segunda dose de tioacetamida. Os animais do tempo 48 horas receberam mais duas doses de vit. E (24h e 36h). Transcorridas 24 ou 48 horas após a administração da primeira dose de TAA, os animais foram pesados, anestesiados e o sangue retirado para a avaliação da integridade hepática através das enzimas Aspartatoaminotransferase (AST) e Alanina aminotransferase (ALT). O tecido hepático foi retirado para avaliação da lipoperoxidação através da técnica de TBARS, atividade das enzimas antioxidantes SOD, CAT, GPx, e GST, avaliação de NO 2 /NO 3 e avaliação histológica pela coloração de hematoxilina e eosina nos dois tempos. Os resultados foram expressos como média ± erro padrão e a análise estatística utilizada foi ANOVA, seguido de teste de Student-Newman-Keuls, considerado significativo P <0,05. RESULTADOS Após o tratamento com a vit. E, observamos uma redução nas enzimas de integridade hepática AST (U/L) (101,32±19,45 em 24h e 97,85±29,65 em 48h) relacionado ao grupo TAA (469,56±20,69 em 24h e 598,23±55,45 em 48h) e ALT (U/L) (76,59±8,56 em 24h e 68,47±6,49 em 48h) comparado ao grupo TAA (312,21±10,23 em 24h e 359,15±17,58 em 48h). Houve uma redução da LPO (nmol/mg Prot), no grupo TAA+Vit.E (0,77±0,07 em 24h e 0,95±0,08 em 48h) comparado ao grupo TAA (1,50±0,07 em 24h e 1,65±0,16 em 48h). A SOD (USOD/min/mg Prot) diminuiu no grupo TAA+Vit.E (49,48±9,47 em 24h e 62,45±18,47 em 48h) relacionado ao grupo TAA (98,46±15,48 em 24h e 154,13±21,46 em 48h), assim como a GST (nmol/min/mg Prot) no grupo TAA+Vit.E (350,57±36,93 em 24h e 453,29±13,84 em 48h) comparado ao grupo TAA (561,57±64,56 em 24h e 673,43±38,13 em 48h). Houve aumento da CAT (pmol/min/mg Prot) no grupo TAA+Vit.E (3,40±0,44 em 24h e 3,01±0,35 em 48h) em relação ao grupo TAA (1,65±0,21 em 24h e 1,86±0,42 em 48h). A GPx (nmol/min/mg Prot) aumentou em 24h no grupo TAA+Vit.E (1,01±0,16) comparado ao grupo TAA (0,41±0,04) e diminuiu em 48h (1,19±0,17) em relação ao grupo TAA (1,76±0,21). Verificou-se redução nos níveis de NO 2 /NO 3 (mmol/L) no grupo TAA+Vit.E (31,47±4,26 em 24h e 38,93±5,20 em 48h) em relação ao grupo TAA (49,37±5,12 em 24h e 53,53±5,97 em 48h). A avaliação histopatológica mostrou diminuição da lesão hepática (necrose e inflamação) em ambas os tempos estudados. CONCLUSÃO Estes resultados sugerem que a vitamina E foi capaz de proteger o fígado de lesões causadas por tioacetamida.

Protective effect of glutamine on the main and adjacent organs damaged by ischemia-reperfusion in rats.

Intestinal ischemia and reperfusion (I/R) causes cellular and tissue damage to the intestine and remote organs such as the liver. Increased production of ROS and nitric oxide and dysregulation of cytoprotective enzymes may be involved in intestinal I/R. The aim was to evaluate the protective effects of glutamine on the intestine and liver of rats with intestinal I/R injury. Twenty male Wistar rats (300 g) were divided into four groups: sham-operated (SO), glutamine + SO (G + SO), I/R, and glutamine + I/R (G + I/R). Occlusion of the SMA for 30 min was followed by 15-min reperfusion. Glutamine (25 mg/kg/day) was administered once daily 24 and 48 h before I/R induction. Blood and tissue of were collected for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, histopathological analysis, immunohistochemistry of IL-1ß and TNF-α, thiobarbituric acid reactive substance (TBARS) and nitric oxide, Nrf2/keap1, superoxide dismutase (SOD), NADPH quinone oxidoreductase1 (NQO1), inducible nitric oxide synthase (iNOS), heat shock protein (HSP70), glucose-regulated protein 78 (GRP78), and activating transcription factor 6 (ATF-6) by western blot. Statistic analysis by ANOVA-Student-Newman-Keuls test (mean ± SE) significantly was p < 0.05. Tissue damage, AST, ALT, IL-1ß, TNF-α, TBARS, NO, Keap1, iNOS, GRP78, and ATF-6 expression were significantly lower in the G + I/R group as compared to the I/R group. Expression of Nrf2, SOD, NQO1, and HSP70, was significantly higher in the G + I/R group as compared to I/R group. Pre-treatment with glutamine provided protection against oxidative damage in the intestine and liver in an experimental model of intestinal I/R.