Dietary management has been considered an alternative means of modulating adiponectin levels. The purpose of this review is to examine the scientific evidence regarding the effect of diet on adiponectin levels in blood. Clinical trials were selected from Medline until April 2010 using the following MeSH terms: adipokines OR adiponectin AND diet OR lifestyle. A total of 220 articles were identified in the initial search, and 52 studies utilizing three different methods of dietary management were included in the present review: low-calorie diets (n = 9 studies), modification of diet composition (n = 33), and diet plus exercise (n = 10). Daily intake of fish or omega-3 supplementation increased adiponectin levels by 14-60%. Weight loss achieved with a low-calorie diet plus exercise increased adiponectin levels in the range of 18-48%. A 60-115% increase in adiponectin levels was obtained with fiber supplementation. In conclusion, dietary management can be an effective therapeutic means of increasing adiponectin levels. Studies investigating different forms of adiponectin and changes in the types of adipose tissue are necessary in order to elucidate the mechanisms involved in the modulation of adiponectin levels.
Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a polyphenol present in grapes and red wine, which has antioxidant properties and a wide range of other biological effects. In this study, we investigated the effect of resveratrol, in a concentration range of 10-250 microM, on primary cortical astrocytes; evaluating cell morphology, parameters of glutamate metabolism such as glutamate uptake, glutamine synthetase activity and glutathione total content, and S100B secretion. Astrocyte cultures were prepared of cerebral cortex from neonate Wistar rats. Morphology was evaluated by phase-contrast microscopy and immunocytochemistry for glial fibrillary acidic protein (GFAP). Glutamate uptake was measured using L-[2,3-3H]glutamate. Glutamine synthetase and content of glutathione were measured by enzymatic colorimetric assays. S100B content was determined by ELISA. Typical polygonal morphology becomes stellated when astrocyte cultures were exposed to 250 microM resveratrol for 24 h. At concentration of 25 microM, resveratrol was able to increase glutamate uptake and glutathione content. Conversely, at 250 microM, resveratrol decreased glutamate uptake. Unexpectedly, resveratrol at this high concentration increased glutamine synthetase activity. Extracellular S100B increased from 50 microM upwards. Our findings reinforce the protective role of this compound in some brain disorders, particularly those involving glutamate toxicity. However, the underlying mechanisms of these changes are not clear at the moment and it is necessary caution with its administration because elevated levels of this compound could contribute to aggravate these conditions.
The randomized controlled trial evaluated the effectiveness of an intervention based on the Transtheoretical Model of Change on anthropometric, metabolic and motivational outcomes in obese adolescents. A total of 135 male and female adolescents were randomized to two groups: intervention group ( n = 65) and control group ( n = 70). The adolescents were evaluated 1 week before the interventions began and at the end of 12 weeks. There was no statistically significant difference between groups in the outcome variables. Intervention group reported magnitude of effect more expressive on body mass index percentile, waist circumference, waist-to-hip ratio, readiness to change diet and readiness to start exercise.
Objective. The main goal of the present study was to investigate the xanthine oxidase (XO) activity in metabolic syndrome in subjects submitted to a single exercise session. We also investigated parameters of oxidative and inflammatory status. Materials/Methods. A case-control study (9 healthy and 8 MS volunteers) was performed to measure XO, superoxide dismutase (SOD), glutathione peroxidase activities, lipid peroxidation, high-sensitivity C-reactive protein (hsCRP) content, glucose levels, and lipid profile. Body mass indices, abdominal circumference, systolic and diastolic blood pressure, and TG levels were also determined. The exercise session consisted of 3 minutes of stretching, 3 minutes of warm-up, 30 minutes at a constant dynamic workload at a moderate intensity, and 3 minutes at a low speed. The blood samples were collected before and 15 minutes after the exercise session. Results. Serum XO activity was higher in MS group compared to control group. SOD activity was lower in MS subjects. XO activity was correlated with SOD, abdominal circumference, body mass indices, and hsCRP. The single exercise session reduced the SOD activity in the control group. Conclusions. Our data support the association between oxidative stress and risk factors for cardiovascular diseases and suggest XO is present in the pathogenesis of metabolic syndrome.
The study objectives were (1) comparison of baseline characteristics between individuals with metabolic syndrome, adhering/not adhering to a primary prevention program modificação do estilo de vida e risco cardiovascular; and (2) determination of risk factors for program adherence. The sample included 127 participants with mean age (±standard deviation) of 49.58 (±7.77) years, participating in the modificação do estilo de vida e risco cardiovascular between 2010 and 2012. Results show that program adherence predictors were age (odds ratio: 1.134, 95% confidence interval: 1.106-1.833); practicing physical exercise (odds ratio: 1.322, 95% confidence interval: 1.115-7.589); self-efficacy for regular eating habits (odds ratio: 2.044, 95% confidence interval: 1.184-3.377); low binge eating scores (odds ratio: 1.922, 95% confidence interval: 1.118-3.974); and low isolation and depression scores (odds ratio: 0.721, 95% confidence interval: 0.322-0.917).
The brain is particularly susceptible to oxidative insults and its antioxidant defense is dependent on its glutathione content. Protein malnutrition (PMN) is an important and very common insult during development and compromises antioxidant defenses in the body, particularly glutathione levels. We investigated whether brain glutathione content and related metabolic pathways, predominantly regulated by astrocytes (particularly glutamate uptake and glutamine synthesis), are altered by pre- and postnatal PMN in rats. Thus, we measured the glutathione content, glutamine synthetase (GS) activity, and glutamate uptake activity in the cerebral cortex (Cx) and hippocampus of rats subjected to pre- and postnatal PMN and in nourished controls. Although malnourished rats exhibited an ontogenetic profile of glutathione levels in both brain regions similar to that of controls, they had lower levels on postnatal d 2 (P2); in Cx this decrease persisted until postnatal d 15. In addition, we found other changes, such as reduced total antioxidant reactivity and glutathione peroxidase activity on P2, and these were not accompanied by alterations in free radical levels or lipoperoxidation in either brain region. Moreover, malnourished rats had elevated GS and reduced glutamate uptake. Taken together, these alterations indicate specific changes in astrocyte metabolism, possibly responsible for the higher vulnerability to excitotoxic/oxidative damage in malnourished rats. The lower antioxidant defense appears to be the main alteration that causes oxidative imbalance, rather than an increase in reactive oxygen species. Moreover, a recovery of altered metabolic variables may occur during adulthood, despite persistent PMN.
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