Antioxidant and genotoxic properties of Maytenus dasyclada: a comparative study in relation to Maytenus reference species.

In these work the in vitro antioxidant activity and the in vivo genotoxicity of M. dasyclada was compared to the reference species M. aquifolium and M. ilicifolia. M. dasyclada showed in vitro antioxidant activity comparable to M. aquifolium but lower than M. ilicifolia, being that a inverse Pearson correlation between DPPH IC50 values and total phenolic content was detected (-0.932). The carbonyl content of M. dasyclada and M. aquifolium extracts promoted a similar increase in protein oxidation in vivo, while M. ilicifolia no altered the carbonyl levels. The comet assay demonstrated that the three analyzed species promoted a low and similar level of genotoxicity; which is compatible with DNA damage induced by other medicinal plants and is partially recovered by a co-treatment with vitamin C. The data showed M. dasyclada as antioxidant activity in vitro, and that its genotoxic and pro-oxidant effects in vivo are comparable to the Maytenus reference species.

Antioxidant and genotoxic properties of Maytenus dasyclada: a comparative study in relation to Maytenus reference species / Propriedades antioxidantes e genotóxicas de Maytenus dasyclada: um estudo comparativo em relação às espécies de referência de Maytenus

In these work the in vitro antioxidant activity and the in vivo genotoxicity of M. dasyclada was compared to the reference species M. aquifolium and M. ilicifolia. M. dasyclada showed in vitro antioxidant activity comparable to M. aquifolium but lower than M. ilicifolia, being that a inverse Pearson correlation between DPPH IC50 values and total phenolic content was detected (–0.932). The carbonyl content of M. dasyclada and M. aquifolium extracts promoted a similar increase in protein oxidation in vivo, while M. ilicifolia no altered the carbonyl levels. The comet assay demonstrated that the three analyzed species promoted a low and similar level of genotoxicity; which is compatible with DNA damage induced by other medicinal plants and is partially recovered by a co-treatment with vitamin C. The data showed M. dasyclada as antioxidant activity in vitro, and that its genotoxic and pro-oxidant effects in vivo are comparable to the Maytenus reference species.

No presente trabalho a atividade antioxidante in vitro e a genotoxicidade in vivo de M. dasyclada foi comparada com as espécies de referência M.aquifolium e M. ilicifolia. M. dasyclada mostrou atividade antioxidante in vitro comparável a de M. aquifolium mas inferior a M. ilicifolia, sendo que foi detectada uma correlação de Pearson inversa entre os valores de IC50 por DPPH e o conteúdo fenólico total (–0,932). Em relação ao teor de carbonila, os extratos de M. dasyclada e M. aquifolium promoveram um aumento semelhante na oxidação das proteínas in vivo, ao passo que Maytenus ilicifolia não alterou os níveis de carbonila. O ensaio do cometa demonstrou que as três espécies analisadas promoveram um nível baixo e semelhante de genotoxicidade, o que é compatível com os danos no DNA induzidos por outras plantas medicinais e é parcialmente recuperada por um co-tratamento com a vitamina C. Os dados mostraram M. dasyclada com atividade antioxidante in vitro, e que os seus efeitos genotóxicos e pró-oxidantes in vivo são comparáveis às espécies de referência de Maytenus.

Association between endothelial nitric oxide synthase gene polymorphism (-786T>C) and interleukin-6 in acute coronary syndrome.

Atherosclerosis is morphologically an inflammatory disease, where endothelial dysfunction plays a key role in all the stages. The nitric oxide (NO) synthase 3 (NOS3) gene is responsible for the synthesis of endothelial NO synthase (eNOS) in humans and some genetic polymorphisms are considered "polymorphisms associated with risk" for the development of coronary artery diseases, such as acute coronary syndrome. Thus, the present study aimed to evaluate the influence of the -786T>C polymorphism of the eNOS gene on inflammatory and oxidative process. A prospective cohort study of 125 consecutive patients with clinical diagnosis of non-ST-elevation acute coronary syndromes was conducted. Patients were assessed using a standardized questionnaire. Blood samples were drawn to measure serum levels of high-sensitivity C-reactive protein, soluble CD40 ligand, interleukin-6 (IL-6), N-terminal prohormone of brain natriuretic peptide, immunoglobulin G antibodies against oxidized low-density lipoprotein. The genotypes for the -786T>C polymorphism in the 5'-flanking region of eNOS gene were determined. The -786C allele was found in 92 of 250 alleles (38.8%). No statistical association was observed between demographic and clinical characteristics and distribution of eNOS-786T>C polymorphism. We found that -786CC was associated with lower levels of IL-6. No significant differences were observed between the distribution of -786T>C polymorphism and other investigated markers.

Evidence that L-carnitine and selenium supplementation reduces oxidative stress in phenylketonuric patients.

It is well established that the involvement of reactive species in the pathophysiology of several neurological diseases, including phenylketonuria (PKU), a metabolic genetic disorder biochemically characterized by elevated levels of phenylalanine (Phe). In previous studies, we verified that PKU patients (treated with a protein-restricted diet supplemented with a special formula not containing L-carnitine and selenium) presented high lipid and protein oxidative damage as well as a reduction of antioxidants when compared to the healthy individuals. Our goal in the present study was to evaluate the effect of Phe-restricted diet supplemented with L-carnitine and selenium, two well-known antioxidant compounds, on oxidative damage in PKU patients. We investigated various oxidative stress parameters in blood of 18 treated PKU patients before and after 6 months of supplementation with a special formula containing L-carnitine and selenium. It was verified that treatment with L-carnitine and selenium was capable of reverting the lipid peroxidation, measured by thiobarbituric acid-reactive species, and the protein oxidative damage, measured by sulfhydryl oxidation, to the levels of controls. Additionally, the reduced activity of glutathione peroxidase was normalized by the antioxidant supplementation. It was also verified a significant inverse correlation between lipid peroxidation and L-carnitine blood levels as well as a significant positive correlation between glutathione peroxidase activity and blood selenium concentration. In conclusion, our results suggest that supplementation of L-carnitine and selenium is important for PKU patients since it could help to correct the oxidative stress process which possibly contributes, at least in part, to the neurological symptoms found in phenylketonuric patients.

A dangerous freshwater contact.

An 8-year-old girl was presented to our department for persistent diarrhoea. A first diagnosis of tuberculosis, along with the result of the chest x-ray scan, had been posed some months before, after a holiday in Brazil, when she started presenting aspecific systemic and gastrointestinal symptoms. The girl was under specific antitubercular treatment when we first saw her. New diagnosis of schistosomiasis was posed by our laboratory tests. Treatment with praziquantel was started and complete resolution of clinical and radiological picture was observed.

Oxidative stress in older patients with iron deficiency anaemia.

We propose that oxidative damage may play a role in the pathogenesis of iron deficiency anaemia (IDA). Participants were selected from Basic Attention Ambulatory from North of Rio Grande do Sul, Brazil. All subjects were older than 65 years - 17 patients with IDA and primary hypertension and 18 patients with primary hypertension (control group) were included in the present study. We measured antioxidant defenses including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and total glutathione (GSH) by spectrophotometric assays. We also determined protein oxidative damage in haemolysate and plasma by carbonyl assay. We characterized the lipid peroxidation by malondialdehyde (MDA) accumulation. The results show that IDA patients had significantly higher CAT and SOD levels than controls. GPx activity was not different between the groups. Oxidative protein damage was noted in the plasma but not in the haemolysate. A significantly enhanced production of MDA was observed in the serum of IDA patients, as an indication of increased level of auto-oxidizable lipids under oxidative stress. These results support the idea that patients with IDA are subjected to chronic oxidative stress. Therefore it is important that IDA in older persons receives adequate attention in clinical practice and is not considered simply a part of normal aging.

Height of the cerebellar vermis and gestational age at birth.

OBJECTIVES: The objective of this study was to construct reference ranges of the neonatal cerebellar vermis height with respect to the gestational age at birth. METHODS: This observational study assessed 434 neonates born at 25-42 weeks' gestation. The neonates were singleton and appropriate in size for gestational age, and did not exhibit any abnormalities or neonatal disease. Gestational age was based on the date of the last menstrual period and confirmed by ultrasound examination performed within the 12(th) week of pregnancy. Sonographic measurements of the height of the cerebellar vermis in the mid-sagittal plane were performed within 24 h of birth by the same neonatal sonographer. Reference ranges (5(th), 50(th) and 95(th) centiles) were estimated by a mean and SD model based on least-squares polynomial regression. RESULTS: Neonatal sonographic measurements were obtained in all cases. Mean (SD) maternal age was 30.2 (4.3) years. Mean cerebellar vermis height adjusted for gestational age did not differ between males and females, the mean adjusted difference being 0.012 (95% CI, - 0.009 to 0.033) cm. Mean cerebellar vermis height (cm) against gestational age (weeks) was suitably modeled by a linear-cubic polynomial as - 1.784 + 0.137 x GA - 0.000019 x GA(3) (SD = - 0.147 + 0.008 x GA), where GA = gestational age. CONCLUSIONS: Reference ranges for the height of the cerebellar vermis at birth with respect to gestational age at birth have been constructed in appropriate-for-gestational-age neonates.

Glutathione peroxidase induction protects Saccharomyces cerevisiae sod1deltasod2delta double mutants against oxidative damage.

Saccharomyces cerevisiae mutants deficient in superoxide dismutase genes (sod1delta, sod2delta and the double mutant) were subjected to H2O2 stress in the stationary phase. The highest sensitivity was observed in the sod2delta mutant, while the sod1deltasod2delta double mutant was not sensitive. Sod mutants had lower catalase activity (44%) than wild-type cells, independent of H2O2 stress. Untreated cells of sod1deltasod2delta double mutants showed increased glutathione peroxidase activity (126%), while sod1delta had lower activity (77%) than the wild type. Glutathione levels in sod1delta were increased (200-260%) after exposure to various H2O2 concentrations. In addition, the highest malondialdehyde levels could be observed without H2O2 treatment in sod1delta (167%) and sod2delta (225%) mutants. In contrast, the level of malondialdehyde in the sod1deltasod2delta double mutant was indistinguishable from that of the wild type. These results suggest that resistance to H2O2 by sod1deltasod2delta cells depends on the induction of glutathione peroxidase and is independent of catalase, and that glutathione is a primary antioxidant in the defense against H2O2 in stationary phase sod1delta mutants.

Glutathione peroxidase induction protects Saccharomyces cerevisiae sod1deltasod2delta double mutants against oxidative damage

Saccharomyces cerevisiae mutants deficient in superoxide dismutase genes (sod1delta, sod2delta and the double mutant) were subjected to H2O2 stress in the stationary phase. The highest sensitivity was observed in the sod2delta mutant, while the sod1deltasod2delta double mutant was not sensitive. Sod mutants had lower catalase activity (44 percent) than wild-type cells, independent of H2O2 stress. Untreated cells of sod1deltasod2delta double mutants showed increased glutathione peroxidase activity (126 percent), while sod1delta had lower activity (77 percent) than the wild type. Glutathione levels in sod1delta were increased (200-260 percent) after exposure to various H2O2 concentrations. In addition, the highest malondialdehyde levels could be observed without H2O2 treatment in sod1delta (167 percent) and sod2delta (225 percent) mutants. In contrast, the level of malondialdehyde in the sod1deltasod2delta double mutant was indistinguishable from that of the wild type. These results suggest that resistance to H2O2 by sod1deltasod2delta cells depends on the induction of glutathione peroxidase and is independent of catalase, and that glutathione is a primary antioxidant in the defense against H2O2 in stationary phase sod1delta mutants.