The Consumption of Beef Burgers Prepared with Wine Grape Pomace Flour Improves Fasting Glucose, Plasma Antioxidant Levels, and Oxidative Damage Markers in Humans: A Controlled Trial.

Wine grape pomace flour (WGPF) is a fruit byproduct that is high in fiber and antioxidants. We tested whether WGPF consumption could affect blood biochemical parameters, including oxidative stress biomarkers. In a three-month intervention study, 27 male volunteers, each with some components of metabolic syndrome, consumed a beef burger supplemented with 7% WGPF containing 3.5% of fiber and 1.2 mg gallic equivalents (GE)/g of polyphenols (WGPF-burger), daily, during the first month. The volunteers consumed no burgers in the second month, and one control-burger daily in the third month. At baseline and after these periods, we evaluated the metabolic syndrome components, plasma antioxidant status (i.e., 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH), vitamin E, vitamin C), and oxidative damage markers (i.e., advanced oxidation protein products (AOPPs), oxidized low-density lipoproteins (oxLDLs), malondialdehyde (MDA)). The WGPF-burger intake significantly reduced glycemia and homeostatic model assessment-based measurement of insulin resistance. Vitamin C increased and decreased during the consumption of the WGPF-burger and control-burger, respectively. The WGPF-burger intake significantly decreased AOPP and oxLDL levels. Vitamin E and MDA levels showed no significant changes. In conclusion, the consumption of beef burgers prepared with WGPF improved fasting glucose and insulin resistance, plasma antioxidant levels, and oxidative damage markers. Therefore, this functional ingredient has potential as a dietary supplement to manage chronic disease risk in humans.

Effects of Environmental Heat and Antioxidant Ingestion on Blood Markers of Oxidative Stress in Professional Firefighters Performing Structural Fire Exercises.

OBJECTIVE: Firefighters (FFs) involved in fire suppression have the greatest on-duty risk of cardiovascular disease (CVD), which may be caused by oxidative stress (OS). METHODS: Healthy, active FFs performed a victim "search and clear" exercise involving three conditions: (1) no heat, (2) heat + antioxidant, and (3) heat + placebo. Blood samples were analyzed for OS markers glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), catalase (CAT), and advanced oxidation protein products (AOPP). RESULTS: Increased GSH was found during both heat conditions compared with no heat. CAT activity was higher immediately post exercise. AOPP was reduced post exercise. CONCLUSIONS: Antioxidant supplementation did not impact the OS response to exercise. Added heat did not cause OS and exercise resulted in reductions in OS markers. These findings can be attributed to the training status of the FFs involved.

Amyotrophic Lateral Sclerosis and Oxidative Stress: A Double-Blind Therapeutic Trial After Curcumin Supplementation.

OBJECTIVE: To investigate the efficacy of curcumin oral supplementation (600 mg/day, Brainoil), a natural antioxidant compound, in Amyotrophic Lateral Sclerosis (ALS). METHODS: Patients were randomized into two groups: Group A received placebo for 3 months, then Brainoil for the following 3 months, Group B took Brainoil for 6 months. The evaluations were conducted at basal (T0), after 3 months of double blinded Brainoil or placebo treatment (T1), and after the 3 month open-label phase (T2). Clinical evaluations and oxidative stress biomarkers, including oxidative protein products (AOPPs), ferric reducing ability (FRAP), total thiols (T-SH) and lactate, were evaluated, compared to a control group, during an incremental forearm exercise test. RESULTS: Over the entire study Group B showed a stable score of the ALS-FRS-r which decreased in Group A (p<0.01), in parallel with a reduction of AOPPs (p<0.01) which was not detected into Group A. Also FRAP exercise values remained stable in Group B, while in Group A they were reduced without treatment at T1 (0.05T0 exercise lactate was lower compared to Group A (p<0.01). Compared to controls, the whole ALS population showed a greater oxidative stress (p<0.001), those treated with curcumin (Group B) exhibiting decreased exercise AOPPs at T2 with values approaching those of controls. CONCLUSION: Although further studies are needed to confirm these data, treatment with curcumin shows encouraging results indicating a slight slowdown in disease progression, improving aerobic metabolism and oxidative damage, this also contributing to deepen knowledge into the pathogenic mechanisms of ALS.

The effects of supplemental melatonin administration on the healing of bone defects in streptozotocin-induced diabetic rats.

OBJECTIVE: The aim of this study was to investigate histologic and biochemical effects of supplemental melatonin administration on bone healing and antioxidant defense mechanism in diabetic rats. MATERIAL AND METHODS: Eighty-six Sprague-Dawley male rats were used in this study. Diabetes mellitus was induced by intraperitoneal (i.p.) administration of 65 mg/kg streptozotocin (STZ). Surgical bone defects were prepared in the tibia of each animal. Diabetic animals and those in control groups were treated either with daily melatonin (250 µg/animal/day/i.p.) diluted in ethanol, only ethanol, or sterile saline solution. Rats were humanely killed at the 10th and 30th postoperative days. Plasma levels of Advanced Oxidation Protein Products (AOPP), Malondialdehyde (MDA), and Superoxide Dismutase (SOD) were measured. The number of osteoblasts, blood vessels and the area of new mineralized tissue formation were calculated in histologic sections. RESULTS: At the 10th day, DM+MEL (rats receiving both STZ and melatonin) group had significantly higher number of osteoblasts and blood vessels as well as larger new mineralized tissue surfaces (p<0.05 for each) when compared with DM group. At the 30th day, DM group treated with melatonin had significantly lower levels of AOPP and MDA than those of DM group (p<0.05). CONCLUSION: Melatonin administration in STZ induced diabetic rats reduced oxidative stress related biomarkers and showed beneficial effects on bone healing at short term.

The effects of supplemental melatonin administration on the healing of bone defects in streptozotocin-induced diabetic rats

ABSTRACT Diabetes mellitus (DM) causes an increased production of free radicals that can impair bone healing. Melatonin is a hormone secreted mainly by the pineal gland, which participates in the neutralization process of free radicals. Objective The aim of this study was to investigate histologic and biochemical effects of supplemental melatonin administration on bone healing and antioxidant defense mechanism in diabetic rats. Material and Methods Eighty-six Sprague-Dawley male rats were used in this study. Diabetes mellitus was induced by intraperitoneal (i.p.) administration of 65 mg/kg streptozotocin (STZ). Surgical bone defects were prepared in the tibia of each animal. Diabetic animals and those in control groups were treated either with daily melatonin (250 μg/animal/day/i.p.) diluted in ethanol, only ethanol, or sterile saline solution. Rats were humanely killed at the 10th and 30th postoperative days. Plasma levels of Advanced Oxidation Protein Products (AOPP), Malondialdehyde (MDA), and Superoxide Dismutase (SOD) were measured. The number of osteoblasts, blood vessels and the area of new mineralized tissue formation were calculated in histologic sections. Results At the 10th day, DM+MEL (rats receiving both STZ and melatonin) group had significantly higher number of osteoblasts and blood vessels as well as larger new mineralized tissue surfaces (p<0.05 for each) when compared with DM group. At the 30th day, DM group treated with melatonin had significantly lower levels of AOPP and MDA than those of DM group (p<0.05). Conclusion Melatonin administration in STZ induced diabetic rats reduced oxidative stress related biomarkers and showed beneficial effects on bone healing at short term.

Protective Effect of Abelmoschus esculentus Against Alloxan-induced Diabetes in Wistar Strain Rats.

Increased oxidative stress has been shown to play an important role in the etiology and pathogenesis of diabetes and its complications. Abelmoschus esculentus (Okra) has been reported to possess many important biological properties. We undertook in vivo studies on male Wistar rats to examine the antioxidative potential of okra in normal and alloxan-treated diabetic rats. Okra extract was administered to control and diabetic rats for 35 consecutive days. Erythrocyte plasma membrane redox system (PMRS) activity (p < 0.05), erythrocytes lipid peroxidation (MDA) (p < 0.01), and advanced oxidation protein products (AOPP) (p < 0.001), increased by 153%, 31%, and 290%, respectively, in response to alloxan treatment, while intracellular reduced glutathione (p < 0.001) and total antioxidant potential of plasma in terms of Ferric reducing ability (FRAP) (p < 0.01) decreased by 75% and 22%, respectively, on alloxan treatment. Okra supplementation provided protection to the rats against alloxan-induced changes. Based on the present results, we hypothesize that okra has strong antioxidative potential and may be used as a dietary supplementation in diabetes for prevention of oxidative stress-mediated complications.

Oxidative stress and menopause-related hot flashes may be independent events.

OBJECTIVE: At present, there is growing demand for alternative, or additional, treatments to hormone replacement therapy for menopause-related hot flashes (HF). Antioxidant supplements have been recently proposed as possible candidates for this purpose, regardless of the absence of clear evidence in support of a link between these vasomotor symptoms and oxidative stress (OxS). The aim of our study was to evaluate the association between HF and OxS serum markers in a large sample of middle-aged women. MATERIALS AND METHODS: We conducted a cross-sectional study on 245 perimenopausal and early postmenopausal women (age 45-60 years). The variables examined were presence of self-reported HF and levels of 8-iso-prostaglandin F2α, 8-OH-deoxy-2'-guanosine, advanced oxidation protein products, total antioxidant power, uric acid, thiols, and paroxonase-1. RESULTS: Seventy-six women (31%) reported to suffer from HF (either medium or high intensity). None of the peripheral markers of OxS examined was found to be significantly associated with the presence of HF. CONCLUSION: Taken together, our data suggest that systemic OxS might not be implicated with the onset of the climacteric vasomotor symptoms that most commonly affect women experiencing perimenopause and early postmenopause.

Black tea extract improves anti-oxidant profile in experimental diabetic rats.

OBJECTIVE: The purpose of this study was to investigate the in vivo anti-oxidant effect of black tea extract (BTE) supplemented to normal and alloxan-induced diabetic rats. METHODS: Black tea extract (BTE) was fed to control and experimental diabetic rats by gavage technique at a dose of 1 ml/100 g body weight/day. Markers of oxidative stress in blood were determined. RESULT: Results show a significant (P < 0.01) decrease (73%) in plasma anti-oxidant potential, increase in activity of plasma membrane redox system (122%), protein oxidation and lipid peroxidation in diabetic rats, BTE supplemented diabetic rats had improved anti-oxidant profile and lower protein and lipid peroxidation levels. Diabetic rats displayed lower intracellular glutathione (GSH), BTE supplementation improved GSH levels. CONCLUSION: Results of this study suggest that the 2.5% aqueous extract of black tea is effective to ameliorate diabetes associated oxidative stress parameters in experimental model of diabetes.

Investigation on malondialdehyde, S100B, and advanced oxidation protein product levels in significant hyperbilirubinemia and the effect of intensive phototherapy on these parameters.

BACKGROUND: The parameters of oxidative stress [advanced oxidation protein products (AOPPs), malondialdehyde (MDA), and S100B] and the effect of intensive phototherapy (PT) on these parameters have not been studied extensively in newborns with significant hyperbilirubinemia (SH). We aimed to measure the levels of MDA, S100B, and AOPPs in newborns with SH, and to compare newborns with healthy control newborns without hyperbilirubinemia on the basis of these parameters of oxidative stress. In addition, we investigated the effect of intensive PT on these parameters during the treatment of SH and report our findings for the first time in the literature. METHODS: The study was performed in newborns (n = 62) who underwent intensive PT because of SH. Newborns without jaundice constituted the control group (n = 30). Both groups were compared with respect to demographic characteristics and biochemical (laboratory) parameters including MDA, AOPPs, and S100B. MDA, AOPPs, and S100B were also compared before and after intensive PT in the PT group. In the study group, a correlation analysis of demographic characteristics; MDA, AOPP, and S100B values; and changes occurring in MDA, AOPPs, and S100B values due to the effect of intensive PT was performed. RESULTS: Serum total bilirubin, S100B, and MDA levels in the PT group before performing PT were significantly higher than those in the control group. In newborns receiving PT serum total bilirubin, MDA and AOPP levels decreased significantly after intensive PT. In correlation analysis, a statistically significant negative correlation was found only between the amount of bilirubin decrease with PT and AOPP levels after PT in the study group. CONCLUSION: Whether the significant decrease in MDA levels, which was higher prior to PT, is due to the decrease in serum bilirubin levels or due to the effect of intensive PT itself remains to be determined in further studies. The decrease in AOPP levels after PT implies that intensive PT has protective effects on oxidative stress.

Effect of alpha-lipoic acid supplementation on oxidative stress markers and antioxidative defense in patients with schizophrenia.

BACKGROUND: The purpose of this study was to examine the effects of alpha-lipoic acid (LA) supplementation on oxidative stress markers in patients with schizophrenia. SUBJECTS AND METHODS: Eighteen (18) medicated patients with schizophrenia and 38 healthy controls received daily supplements of LA (500 mg/day) for three months. At baseline, 45th and 90th days of supplementation, venous blood collected for analysis of oxidative stress markers [superoxide anion (O2(•-)), thiobarbituric acid-reactive substances (TBARS) and advanced oxidation protein products (AOPP)] and antioxidative defense markers [superoxide dismutase (SOD), total sulfhydryl groups (-SH) and total antioxidant status (TAS)]. RESULTS: Increased plasma TBARS, TAS, SH groups levels and SOD activity were found in schizophrenic patients compared to control group. LA supplementation significantly reduced TBARS, AOPP and improved TAS levels in healthy subjects, while there were no significant differences in patients group. SH groups increased after 45 days and decreased to baseline levels after 90 days of supplementation in the control group. SOD activity decreased significantly in patients group after 45 days and 90 days of supplementation. After initial rose SOD activity in control group, decreased to baseline levels found after 90 days. CONCLUSION: LA supplementation decreased lipid peroxidation and oxidative damage of proteins and improved non-enzymatic antioxidant capacity in healthy controls. No significant changes were observed on oxidative damage in patients with schizophrenia.

Lipid and protein oxidation in newborn infants after lutein administration.

OBJECTIVES: To test the hypothesis that neonatal supplementation with lutein in the first hours of life reduces neonatal oxidative stress (OS) in the immediate postpartum period. METHODS: A randomized controlled, double-blinded clinical trial was conducted among 150 newborns divided into control group, not supplemented (n = 47), and test group, supplemented with lutein on the first day postpartum (n = 103). Blood Samples were collected at birth from cord and at 48 hrs postpartum while routine neonatal metabolic screenings were taking place. Total hydroperoxide (TH), advanced oxidation protein products (AOPP), and biological antioxidant potential (BAP) were measured by spectrophotometry and data were analyzed by Wilcoxon rank sum test and by multivariate logistic regression analysis. RESULTS: Before lutein supplementation, the mean blood concentrations of AOPP, TH, and BAP were 36.10 umol/L, 156.75 mmol/H2O2, and 2361.04 umol/L in the test group. After lutein supplementation, significantly higher BAP increment (0.17 ± 0.22 versus 0.06 versus ± 0.46) and lower TH increment (0.46 ± 0.54 versus 0.34 ± 0.52) were observed in the test group compared to controls. CONCLUSION: Neonatal supplementation with lutein in the first hours of life increases BAP and reduces TH in supplemented babies compared to those untreated. The generation of free radical-induced damage at birth is reduced by lutein. This trial is registered with ClinicalTrials.gov NCT02068807.

Nitrosylation: an adverse factor in Uremic Hemolytic Syndrome. Antitoxin effect of Ziziphus mistol Griseb.

Toxins of Escherichia coli (STEC) causing Uremic Hemolytic Syndrome (UHS) generate oxidative stress in human blood with more production of nitric oxide (NO) than reactive oxygen species (ROS). Shiga toxin (Stx) together with the hemolysin (Hly) increased lipid oxidation, as evaluated by malondialdehyde MDA and oxidation of proteins. The addition of Ziziphus mistol Griseb extracts decreased NO, ROS, MDA and simultaneously caused an increase in the degradation of oxidized proteins to advanced oxidation protein products (AOPPs) in controls and samples with toxins. Furthermore, the nitrosylated proteins/AOPP ratio was reduced, due to the increase of AOPP. Z. mistol Griseb extracts exhibited a high proportion of polyphenols and flavonoids, with evident correlation with ferrous reduction antioxidant potential (FRAP). The plasma of eight children with UHS showed oxidative stress and NO stimulus, comparable to the effect of toxins during the assays in vitro. UHS children presented high levels of nitrosylated proteins respect to control children of similar age. Although the degradation of oxidized proteins to AOPP rose in UHS children, the nitrosylated proteins/AOPP rate increased as a consequence of the elevated nitrosative stress observed in these patients.

Effect of 900 MHz radiofrequency radiation on oxidative stress in rat brain and serum.

The increasing use of mobile telephones raises the question of possible adverse effects of the electromagnetic fields (EMF) that these phones produce. In this study, we examined the oxidative stress in the brain tissue and serum of rats that resulted from exposure to a 900-MHz EMF at a whole body average specific absorption rate (SAR) of 1.08 W/kg for 1 h/day for 3 weeks. We also examined the antioxidant effect of garlic powder (500 mg/kg/day) given orally to EMF-exposed rats. We found that malondialdehyde (MDA) (p < 0.001) and advanced oxidation protein product (AOPP) (p < 0.05) increased in rat brain tissue exposed to the EMF and that garlic reduced these effects (p < 0.05). There was no significant difference in the nitric oxide (NO) levels in the brain. Paraoxonase (PON) was not detected in the brain. There was a significant increase in the levels of NO (p < 0.001) detected in the serum after EMF exposure, and garlic intake did not affect this increase in NO. Our results suggest that there is a significant increase in brain lipid and protein oxidation after electromagnetic radiation (EMR) exposure and that garlic has a protective effect against this oxidative stress.

Effects of metformin on markers of oxidative stress and antioxidant reserve in patients with newly diagnosed type 2 diabetes: a randomized clinical trial.

BACKGROUND & AIMS: Given the long term benefits observed with metformin use in diabetes patients, a role in modulating oxidative stress is imputable. Effects of metformin on markers of oxidative stress, antioxidant reserve, and HDL-c associated antioxidant enzymes were investigated. METHODS: In a clinical trial setting (Registered under Clinical Trials.gov Identifier no. NCT01521624) 99 medication-naïve, newly diagnosed type 2 diabetes patients were randomly assigned to either metformin or lifestyle modification. AOPP, AGE, FRAP, activities of LCAT, and PON were measured at baseline and after 12-weeks. RESULTS: Baseline values of the oxidative stress markers did not differ significantly between the two groups. In cases, after three months treatment, there was a significant reduction in AOPP (137.52 ± 25.59, 118.45 ± 38.42, p < 0.001), and AGE (69.28 ± 4.58, 64.31 ± 8.64, p = 0.002). FRAP and PON increased significantly (1060.67 ± 226.69, 1347.80 ± 251.40, p < 0.001 and 29.85 ± 23.18, 37.86 ± 27.60, p = 0.012 respectively). LCAT levels remained unchanged (45.23 ± 4.95, 46.15 ± 6.28, p = 0.439). Comparing the two groups in a final multivariate model, AOPP, FRAP, and AGE levels changed more significantly in metformin compared with lifestyle modification alone (p = 0.007, p < 0.001 and p < 0.001 respectively). Escalation in LCAT or PON activities did not differ between the two groups (p = 0.199 and 0.843 respectively). CONCLUSIONS: Use of metformin is more effective in reducing oxidative stress compared with lifestyle modification alone.

Sorafenib-induced hepatocellular carcinoma cell death depends on reactive oxygen species production in vitro and in vivo.

Sorafenib is presently the only effective therapy in advanced hepatocellular carcinoma (HCC). Because most anticancer drugs act, at least in part, through the generation of reactive oxygen species, we investigated whether sorafenib can induce an oxidative stress. The effects of sorafenib on intracellular ROS production and cell death were assessed in vitro in human (HepG2) and murine (Hepa 1.6) HCC cell lines and human endothelial cells (HUVEC) as controls. In addition, 26 sera from HCC patients treated by sorafenib were analyzed for serum levels of advanced oxidation protein products (AOPP). Sorafenib significantly and dose-dependently enhanced in vitro ROS production by HCC cells. The SOD mimic MnTBAP decreased sorafenib-induced lysis of HepG2 cells by 20% and of Hepa 1.6 cells by 75% compared with HCC cells treated with 5 mg/L sorafenib alone. MnTBAP significantly enhanced by 25% tumor growth in mice treated by sorafenib. On the other hand, serum levels of AOPP were higher in HCC patients treated by sorafenib than in sera collected before treatment (P < 0.001). An increase in serum AOPP concentration ≥0.2 µmol/L chloramine T equivalent after 15 days of treatment is a predictive factor for sorafenib response with higher progression free survival (P < 0.05) and overall survival rates (P < 0.05). As a conclusion, sorafenib dose-dependently induces the generation of ROS in tumor cells in vitro and in vivo. The sera of Sorafenib-treated HCC patients contain increased AOPP levels that are correlated with the clinical effectiveness of sorafenib and can be used as a marker of effectiveness of the drug. .

Oxidative stress induced by 1.8 GHz radio frequency electromagnetic radiation and effects of garlic extract in rats.

PURPOSE: We aimed to study the oxidative damage induced by radiofrequency electromagnetic radiation (RF-EMR) emitted by mobile telephones and the protective effect of garlic extract used as an anti-oxidant against this damage. MATERIALS AND METHODS: A total of 66 albino Wistar rats were divided into three groups. The first group of rats was given 1.8 GHz, 0.4 W/kg specific absorption rate (SAR) for 1 h a day for three weeks. The second group was given 500 mg/kg garlic extract in addition to RF-EMR. The third group of rats was used as the control group. At the end of the study, blood and brain tissue samples were collected from the rats. RESULTS: After the RF-EMR exposed, the advanced oxidation protein product (AOPP) levels of brain tissue increased compared with the control group (p < 0.001). Garlic administration accompanying the RF-EMR, on the other hand, significantly reduced AOPP levels in brain tissue (p < 0.001). The serum nitric oxide (NO) levels significantly increased both in the first and second group (p < 0.001). However, in the group for which garlic administration accompanied that of RF-EMR, there was no difference in serum NO levels compared with the RF-EMR exposed group (p > 0.05). There was no significant difference among the groups with respect to malondialdehyde (MDA) levels in brain tissue and blood samples (p > 0.05). Similarly, no difference was detected among the groups regarding serum paroxonase (PON) levels (p > 0.05). We did not detect any PON levels in the brain tissue. CONCLUSIONS: The exposure of RF-EMR similar to 1.8 GHz Global system for mobile communication (GSM) leads to protein oxidation in brain tissue and an increase in serum NO. We observed that garlic administration reduced protein oxidation in brain tissue and that it did not have any effects on serum NO levels.