Eight weeks of taurine supplementation associated with nutritional counseling is able to increase adiponectin levels and to decrease markers of inflammation (high-sensitivity C-reactive protein) and lipid peroxidation (TBARS) in obese women.

Cr supplementation inhibited the increase of inflammation markers TNF-α and CRP, but not oxidative stress markers, due to acute exercise.

The aim of the present study was to compare oxidative stress biomarkers determined in blood and saliva before and after acute resistance exercise. 1 week after 1 maximum repetition (1RM) test 11 healthy well-trained males completed a hypertrophy acute session of resistance training including 3 sets of 10 repetitions at 75% of the 1RM, with 90 s rest periods between sets. Venous blood and saliva samples were collected before (pre) and 10 min after (post) the resistance training session. A significant (p<0.05) rise in blood lactate accumulation (pre: 1.6+/-0.4 vs. post: 9.5+/-2.4) was found post-acute resistance training compared with baseline values. Significant increases (p<0.05) in TBARS (42%), AOPP (28%), uric acid (27%) and GSH (14%) were detected post-acute resistance training in relation to pre in blood samples. A significant increase (p<0.05) in uric acid (36%) was found in saliva post-acute resistance training as well as a significant correlation (p<0.05) between uric acid determined in blood and saliva. Statistical analysis did not reveal any other change in the salivary oxidative stress biomarkers. In conclusion, an acute session of resistance exercise induces oxidative stress in plasma of trained men after acute resistance training, which was not found in saliva samples except for uric acid.

Hyperhomocysteinaemia is an independent risk factor for CVD. Recent data show a relationship between homocysteine (Hcy) and free radical formation. Since creatine synthesis is responsible for most of the methyl group transfers that result in Hcy formation, creatine supplementation might inhibit Hcy production and reduce free radical formation. The present study investigated the effects of creatine supplementation on Hcy levels and lipid peroxidation biomarkers. Thirty rats were divided into three groups: control group; diet with creatine group (DCr; 2 % creatine in the diet for 28 d); creatine overload plus diet with creatine group (CrO þ D; 5 g creatine/kg by oral administration for 5 d þ 2 % in the diet for 23 d). Plasma Hcy was significantly lower (P,0·05) in DCr (7·5 (SD 1·2) mmol/l) and CrO þ D (7·2 (SD 1·7) mmol/l) groups compared with the control group (12·4 (SD 2·2) mmol/l). Both plasma thiobarbituric acid-reactive species (TBARS) (control, 10 (SD 3·4); DCr, 4·9 (SD 0·7); CrO þ D, 2·4 (SD 1) mmol/l) and plasma total glutathione (control, 4·3 (SD 1·9); DCr, 2·5 (SD 0·8); CrO þ D, 1·8 (SD 0·5) mmol/l) were lower in the groups that received creatine (P, 0·05). In addition, Hcy showed significant negative correlation (P, 0·05) with plasma creatine (r 2 0·61) and positive correlation with plasma TBARS (r 0·74). Plasma creatine was negatively correlated with plasma TBARS (r 20·75) and total peroxide (r 20·40). We conclude that creatine supplementation reduces plasma Hcy levels and lipid peroxidation biomarkers, suggesting a protective role against oxidative damage. Modulating Hcy formation may, however, influence glutathione synthesis and thereby affect the redox state of the cells.

The marker most frequently used to indicate the level of lipid peroxidation in the field of exercise and sports is malondialdehyde (MDA), which can be determined by many different techniques. However, there are few studies discussing differences and advantages of the methods for MDA assay in sports science field. The aim of the present study was to compare three techniques for quantification of MDA in plasma of humans subjected to acute exercise. MDA was determined by high performance liquid chromatography (MDA-HPLC), thiobarbituric acid reactive species (MDA-TBARS) and 1-methyl-2-phenylindole (MDA-MP) techniques in the plasma of 8 healthy male soccer athletes before and after acute exercise. Acute exercise significantly increased (P<0.05) plasma MDA concentration determined by MDA-HPLC (18%) and MDA-TBARS (56%) techniques. MDA-MP technique did not reveal significant differences, although it increased 25% after exercise. When correlated to the gold standard (MDA-HPLC), MDA-TBARS and MDA-MP techniques showed weak Lin concordance coefficients and non-significant correlation. Also, MDA-TBARS and MDA-MP techniques overestimated the MDA-HPLC technique by 100 and 122%, respectively. In conclusion, MDA-HPLC and MDA-TBARS are sensitive to detect change in MDA induced by acute exercise. MDA-HPLC is the most suitable technique for accurate detection of MDA in sports and exercise area due to its sensitivity and accuracy.

A prospective and double-blind study was conducted on 35 women with weight excess who consumed 25 grams of quinoa flakes (QF) or corn flakes (CF) daily during a period of four consecutive weeks. At the beginning (T1) and at the end (T2) of the intervention, total calorie intake was evaluated, anthropometric assessment was performed, blood was collected for the determination of glucose, total cholesterol and fractions, oxidative stress markers, vitamin E and enterolignans. Significant reductions were detected in serum triglyceride (CF group = 133.9 ± 89.4 to 113.7 ± 57 mg/dl and QF group = 112.3 ± 35 to 107.9 ± 33.1 mg/dl), TBARS (CF group = 3.2 ± 0.8 to 2.9 ± 0.5 µmol/l and QF group = 3.06 ± 0.6 to 2.89 ± 0.5 µmol/l) and vitamin E concentrations (CF group = 19.5 ± 5 to 17.9 ± 4 µM and QF group = 17.9 ± 4 to 16.9 ± 3 µM) and an increase in urinary excretion of enterolignans (CF group = 2.05 ± 1.3 to 2.24 ± 1.4 nm/ml and QF group = 2.9 ± 1.6 to 3.2 ± 2.7 nm/l), in both study groups. The reduction of total cholesterol (191 ± 35 to 181 ± 28 mg/dl) and LDL-cholesterol (LDL-c) (129 ± 35 to 121 ± 26 mg/dl), and the increase in GSH (1.78 ± 0.4 to 1.91 ± 0.4 µmol/l) occurred only in the QF group, showing a possible beneficial effect of QF intake.

No abstract

Previous studies have observed changes in the lacrimal gland and ocular surface related to diabetes mellitus and related it to insulin resistance or insufficiency and oxidative damage. The aim of this study was to evaluate whether insulin treatment inhibits those changes. Diabetes was induced in male Wistar rats with a single intravenous injection of streptozotocin and a subgroup was treated with insulin. After 5 and 10 weeks, the three groups (n = 5-10/group/experimental procedure) were compared for biochemical, functional, and histological parameters. After 5 weeks, changes in morphology and increased numbers of lipofucsin-like inclusions were observed in lacrimal glands of diabetic but not insulin-treated rats. After 5 weeks, malonaldehyde and total peroxidase activity were significantly higher in diabetic rats, but similar to control in insulin-treated diabetic rats (P = 0.03, P = 0.02, respectively). Our data indicate that diabetes induces histological alterations in lacrimal gland and suggests that hyperglycemia-related oxidative stress may participate in diabetic dry eye syndrome. Prevention by insulin replacement suggests direct hormone action and/or benefit by early sub optimal metabolic control.