Publications (28) View all
-
Article: Gene polymorphisms against DNA damage induced by hydrogen peroxide in leukocytes of healthy humans through comet assay: a quasi-experimental study.
[show abstract] [hide abstract]
ABSTRACT: Normal cellular metabolism is well established as the source of endogenous reactive oxygen species which account for the background levels of oxidative DNA damage detected in normal tissue. Hydrogen peroxide imposes an oxidative stress condition on cells that can result in DNA damage, leading to mutagenesis and cell death. Several potentially significant genetic variants related to oxidative stress have already been identified, and angiotensin I-converting enzyme (ACE) inhibitors have been reported as possible antioxidant agents that can reduce vascular oxidative stress in cardiovascular events. We investigate the influences of haptoglobin, manganese superoxide dismutase (MnSOD Val9Ala), catalase (CAT -21A/T), glutathione peroxidase 1 (GPx-1 Pro198Leu), ACE (I/D) and gluthatione S-transferases GSTM1 and GSTT1 gene polymorphisms against DNA damage and oxidative stress. These were induced by exposing leukocytes from peripheral blood of healthy humans (N = 135) to hydrogen peroxide (H2O2), and the effects were tested by comet assay. Blood samples were submitted to genotyping and comet assay (before and after treatment with H2O2 at 250 microM and 1 mM). After treatment with H2O2 at 250 microM, the GPx-1 polymorphism significantly influenced results of comet assay and a possible association of the Pro/Leu genotype with higher DNA damage was found. The highest or lowest DNA damage also depended on interaction between GPX-1/ACE and Hp/GSTM1T1 polymorphisms when hydrogen peroxide treatment increased oxidative stress. The GPx-1 polymorphism and the interactions between GPX-1/ACE and Hp/GSTM1T1 can be determining factors for DNA oxidation provoked by hydrogen peroxide, and thus for higher susceptibility to or protection against oxidative stress suffered by healthy individuals.Environmental Health 01/2010; 9:21. · 2.65 Impact Factor -
Article: Pequi fruit (Caryocar brasiliense Camb.) pulp oil reduces exercise-induced inflammatory markers and blood pressure of male and female runners.
[show abstract] [hide abstract]
ABSTRACT: The objective of this study was to investigate the anti-inflammatory properties of pequi (Caryocar brasiliense) fruit oil and its effects on the postprandial lipidemia and arterial blood pressure of male and female athletes. These athletes were evaluated after races in the same environment and under the same type, intensity, and length of weekly training conditions, both before and after ingestion of 400 mg pequi oil capsules for 14 days. Pequi fruit contains several antioxidants, and its oil has been associated with anti-inflammatory properties in other pequi species. Because the oil of pequi is mostly composed of oleic and palmitic fatty acids, the oil may alter the ratio of triglyceride to cholesterol in postprandial lipidemia. Epidemiologic studies suggest that an increased intake of monounsaturated fatty acids (such as oleic acid) is inversely related to blood pressure. Thus, we hypothesize that pequi oil could reduce exercise-induced inflammation and blood pressure, and modulate postprandial lipidemia in runners. To test this hypothesis, arterial blood pressures were checked before races; blood samples were taken after the races and submitted for analysis of leukocytes and platelets analysis, high-sensitivity C-reactive protein values, and postprandial lipids. Pequi oil resulted in anti-inflammatory effects and reduced the total cholesterol and low-density lipoprotein in the age group older than 45 years, mainly for men. The results showed a general trend for reduced arterial pressure, suggesting that pequi oil may have a hypotensive effect. However, this finding needs additional investigation. Thus, pequi oil, besides possessing many nutritional properties, may be a good candidate supplement for athletes.Nutrition research (New York, N.Y.) 12/2009; 29(12):850-8. · 1.20 Impact Factor -
Article: High fat and highly thermolyzed fat diets promote insulin resistance and increase DNA damage in rats.
[show abstract] [hide abstract]
ABSTRACT: Many studies have demonstrated that DNA damage may be associated with type 2 diabetes mellitus (T2DM) and its complications. The goal of this study was to evaluate the effects of the potential relationship between fat (thermolyzed) intake, glucose dyshomeostasis and DNA injury in rats. Biochemical parameters related to glucose metabolism (i.e., blood glucose levels, insulin tolerance tests, glucose tolerance tests and fat cell glucose oxidation) and general health parameters (i.e., body weight, retroperitoneal and epididymal adipose tissue) were evaluated in rats after a 12-month treatment with either a high fat or a high thermolyzed fat diet. The high fat diet (HFD) and high fat thermolyzed diet (HFTD) showed increased body weight and impaired insulin sensitivity at the studied time-points in insulin tolerance test (ITT) and glucose tolerance test (GTT). Interestingly, only animals subjected to the HFTD diet showed decreased epididymal fat cell glucose oxidation. We show which high fat diets have the capacity to reduce glycogen synthesis by direct and indirect pathways. HFTD promoted an increase in lipid peroxidation in the liver, demonstrating significant damage in lipids in relation to other groups. Blood and hippocampus DNA damage was significantly higher in animals subjected to HFDs, and the highest damage was observed in animals from the HFTD group. Striatum DNA damage was significantly higher in animals subjected to HFDs, compared with the control group. These results show a positive correlation between high fat diet, glucose dyshomeostasis, oxidative stress and DNA damage.Experimental Biology and Medicine 11/2009; 234(11):1296-304. · 2.64 Impact Factor -
Article: 3-Nitrotyrosine and glutathione antioxidant system in patients in the early and late stages of bipolar disorder.
[show abstract] [hide abstract]
ABSTRACT: There has been an increasing interest in the role of oxidative stress in the pathophysiology of bipolar disorder. To explore this further, we evaluated the activity of glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), as well as 3-nitrotyrosine levels and carbonyl content in patients in the early (within 3 years of illness onset) and late (a minimum of 10 years of illness) stages of bipolar disorder. We matched 30 patients in the early stage and 30 patients in the late stage of bipolar disorder, diagnosed according to DSM-IV criteria, with 60 healthy controls (30 matched for each group of patients). We measured symptomatic status using the Hamilton Rating Scale for Depression and the Young Mania Rating Scale. We found a significant increase in 3-nitrotyrosine levels among patients in the early (p < 0.010) and late (p < 0.010) stages of bipolar disorder. The activity of GR and GST was increased only among patients in the late stage of illness. Glutathione peroxidase activity and carbonyl content did not differ among the groups. Limitations of our study include its cross-sectional design, which did not allow us to examine direct causative mechanisms or the effects of progression of illness, and the potential environmental bias introduced by comparing patient groups recruited from different regions of the world. Our data indicate a possible tyrosine nitration-induced damage in patients with bipolar disorder that is present from the early stage of illness. Our data also indicate that patients in the late stage of illness demonstrate enhanced activity of GR and GST, which could suggest the involvement of a compensatory system in bipolar disorder.Journal of psychiatry & neuroscience: JPN 08/2009; 34(4):263-71. · 5.34 Impact Factor -
Article: Morphological changes in hippocampal astrocytes induced by environmental enrichment in mice.
[show abstract] [hide abstract]
ABSTRACT: Environmental enrichment is known to induce plastic changes in the brain, including morphological changes in hippocampal neurons, with increases in synaptic and spine densities. In recent years, the evidence for a role of astrocytes in regulating synaptic transmission and plasticity has increased, and it is likely that morphological and functional changes in astrocytes play an important role in brain plasticity. Our study was designed to evaluate changes in astrocytes induced by environmental enrichment in the CA1 region of the hippocampus, focusing on astrocytic density and on morphological changes in astrocytic processes. After 8 weeks of environmental enrichment starting at weaning, male CF-1 mice presented no significant changes in astrocyte number or in the density of glial fibrillary acidic protein (GFAP) immunoreactivity in the stratum radiatum. However, they did present changes in astrocytic morphology in the same region, as expressed by a significant increase in the ramification of astrocytic processes measured by the Sholl concentric circles method, as well as by an increase in the number and length of primary processes extending in a parallel orientation to CA1 nerve fibers. This led astrocytes to acquire a more stellate morphology, a fact which could be related to the increase in hippocampal synaptic density observed in previous studies. These findings corroborate the idea that structural changes in astrocytic networks are an integral part of plasticity processes occurring in the brain.Brain research 05/2009; 1274:47-54. · 2.46 Impact Factor
