Coordenação dos sistemas antioxidantes da catalase e da ascorbato peroxidase durante o envelhecimento acelerado de sementes de cártamo e girassol

World consumption of vegetable oils has increased in recent years because of its application in food, chemical, pharmaceutical and, more recently, energy industry. However, oilseeds, which these oils are extracted, have low viability, affecting the cultivation and productivity of these species. The aim of this study was to analyze the effect of aging on the coordination of catalase (CAT) and ascorbate peroxidase (APX) antioxidant systems in safflower and sunflower. . Therefore, seeds were subjected to accelerated aging for 3, 6 and 9 days and grown in moistened paper towel for 72 hours. Additionally, before accelerated aging, sunflower seeds were pretreated by osmopriming with 10 mM ascorbate (ASC) or 3 amino 1,2,4 triazol (3-AT), a specific inhibitor of CAT activitie. The method of artificial aging used was efficient in both species, because it caused a decrease in germination, seedling development and growth, especially in safflower. The aging caused inhibition of CAT activity for both species and to compensate for such inhibition , sunflower increased mRNA expression of this enzyme , while safflower mobilized over the activity of APX. Analysis of the expression of malate synthase and sugar content demonstrated that sunflower seeds consumes lipid reserves in quiescent state, while the safflower is more dependent on carbohydrate. Pretreatment with 3-AT inhibited CAT activity and stimulated the APX, though with ASC acted reverse on these systems. None of the treatments recovered the physiological decline aging. It is concluded that aging change the oilseeds antioxidant metabolism, despite interspecies variations in response to this process, the depletion of the CAT antioxidant system was common. Because of this we propose that the measurement of CAT activity can be used to identify aging seed lots.

Efeitos da microgravidade em plantas de cana-de-açúcar

Sugarcane (Saccharum spp.) is a plant from Poaceae family that has an impressive ability to accumulate sucrose in the stalk, making it a significant component of the economy of many countries. About 100 countries produce sugarcane in an area of 22 million hectares worldwide. For this reason, many studies have been done using sugarcane as a plant model in order to improve production. A change in gravity may be one kind of abiotic stress, since it generates rapid responses after stimulation. In this work we decided to investigate the possible morphophysiological, biochemical and molecular changes resulting from microgravity. Here, we present the contributions of an experiment where sugarcane plants were submitted to microgravity flight using a vehicle VSB-30, a sounding rocket developed by Aeronautics and Space Institute teams, in cooperation with the German Space Agency. Sugarcane plants with 10 days older were submitted to a period of six minutes of microgravity using the VSB-30 rocket. The morphophysiological analyses of roots and leaves showed that plants submitted to the flight showed changes in the conduction tissues, irregular pattern of arrangement of vascular bundles and thickening of the cell walls, among other anatomical changes that indicate that the morphology of the plants was substantially influenced by gravitational stimulation, besides the accumulation of hydrogen peroxide, an important signaling molecule in stress conditions. We carried out RNA extraction and sequencing using Illumina platform. Plants subjected to microgravity also showed changes in enzyme activity. It was observed an increased in superoxide dismutase activity in leaves and a decreased in its activity in roots as well as for ascorbate peroxidase activity. Thus, it was concluded that the changes in gravity were perceived by plants, and that microgravity environment triggered changes associated with a reactive oxygen specie signaling process. This work has helped the understanding of how the gravity affects the structural organization of the plants, by comparing the anatomy of plants subjected to microgravity and plants grown in 1g gravity

Influência do tratamento com ácido lipoico sobre o metabolismo ósseo e perfil antioxidante de mulheres na perimenopausa

Bone is a dynamic tissue that is in constant process of remodeling in response to mechanical stress and hormonal changes. This study aimed to understand the relationship between the biochemical changes, which women in the menopausal transition are subject to, and how the use of an alternative therapy with lipoic acid (LA) could influence these changes. The study of double-blind, was carried out in perimenopausal women that underwent a three month treatment with 600 mg of AL compared with another group that received placebo during the same period. This study showed that women had a waist circunference and body mass index above the values recommended by WHO (WC ≥ 80 cm; BMI > 25kg/m2). Associated with this, these women had increased concentrations of total cholesterol and triglycerides, and borderline LDL (Total Cholesterol > 200mg/dL; Triglycerides > 150mg/dL; LDL >130mg/dL). These changes were not affected by treatment with AL. There were no shifts in liver profile (ALT, AST and GGT), kidney profile (urea, creatinine, total protein and albumin), mineral profile (Total Calcium, Ionized Calcium, Phosphorus and Magnesium) as well in bone markers (osteocalcin, Total Alkaline Phosphatase and Tartrate Resistant Acid Phosphatase) after treatment with LA. The results of the oxidative profile showed that treatment with LA decreased GPx activity (p < 0,01), while for the TBARS, GSH and SOD activity there were no differences. With regard to SOD, this enzyme will submit to be high in the placebo group after 3 months of study (p<0,05). The expression of RANKL mRNA was reduced (p < 0,05) and of RANK increased (p <0.001), after treatment with LA, while the expression of IL-6 and TNF-ɑ genes were no changed. We conclude that women already in the perimenopause stage have changes in lipid profile and body composition that could induce shifts in oxidative and bone metabolism. However, LA treatment has provided an effective effect in the oxidative and bone profile since the earliest markers such as GPx activity and mRNA expression of RANKL, respectively, were reduced associated with no change in SOD activity. These results suggest a beneficial and protective effect of LA, indicating it potential as an alternative treatment to help the to prevent the complications associated with estrogen deficiency

Avaliação do estado nutricional relativo ao selênio e da expressão gênica de selenoproteínas em pacientes com aterosclerose tratados com estatinas

The aim of this study was to determine the effects of the use of rosuvastatin in patients with atherosclerosis, in relation to blood parameters of selenium and selenoproteins, and also observe possible changes in gene expression of selenoproteins in these patients. The sample consisted of 27 adult and elderly patients with a clinical diagnosis of coronary artery disease undergoing angioplasty, treated at Natal Hospital Center hospital, Natal, RN. Patients were treated with rosuvastatin 10 mg/day during four months. Anthropometric variables such as body mass index (BMI) and Waist circumference (WC) were measured before and after treatment, as well as lipid profile, blood glucose and liver enzymes (AST and ALT). The diet of the patients was also analyzed using 24-hour diet recall. We analyzed the concentrations of selenium in plasma and erythrocytes, and also the activity of Glutathione Peroxidase and gene expression by Real Time PCR of selenoproteins GPx1, SelP1 and SelN1. Patients had mean age of 61.0 ± 9.4 years, 59.3% were men and 40.7% were women. After four months of treatment there was significant reduction of CA and, according to BMI, most were overweight. The intake of macronutrients, cholesterol, polyunsaturated fatty acids, monounsaturated and saturated was adequate, but the energy and fiber intake was below the recommendations. Regarding the selenium intake was observed a high prevalence of inadequacy. As expected, after treatment with rosuvastatin, a significant reduction in total cholesterol, LDL and glucose, which was not observed for HDL. Selenium concentrations in plasma and erythrocytes showed no changes, keeping within the established cutoffs. We observed a significant increase in GPx enzyme activity and mRNA expression of GPX1 and SEPN1, but not for gene SEPP1. Thus, it was found that treatment with rosuvastatin did not reduce the expression of selenoproteins. More studies are needed to clarify the effects of rosuvastatin on gene expression of selenoproteins in patients with atherosclerosis

Avaliação do status antioxidante, expressão gênica e polimorfismos dos genes SOD1, SOD2 e GPx1 em crianças, adolescentes e adultos jovens com diabetes tipo 1

Studies report that the pathophysiological mechanism of diabetes complications is associated with increased production of Reactive Oxygen Species (ROS)-induced by hyperglycemia and changes in the capacity the antioxidant defense system. In this sense, the aim of this study was to evaluate changes in the capacity of antioxidant defense system, by evaluating antioxidant status, gene expression and polymorphisms in the genes of GPx1, SOD1 and SOD2 in children, adolescents and young adults with type 1 diabetes. We studied 101 individuals with type 1 diabetes (T1D) and 106 normoglycemic individuals (NG) aged between 6 and 20 years. Individuals with type 1 diabetes were evaluated as a whole group and subdivided according to glycemic control in DM1G good glycemic control and DM1P poor glycemic control. Glycemic and metabolic control was evaluate by serum glucose, glycated hemoglobin, triglycerides, total cholesterol and fractions (HDL and LDL). Renal function was assessed by measurement of serum urea and creatinine and albumin-to-creatinine ratio (ACR) in spot urine. Antioxidant status was evaluate by content of reduced glutathione (GSH) in whole blood and the activity of erythrocyte enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD). We also analyzed gene expression and gene polymorphisms of GPx1 (rs1050450), SOD1 (rs17881135) and SOD2 (rs4880) by the technique of real-time PCR (Taqman®). Most individuals with DM1 (70.3%) had poor glycemic control (glycated hemoglobin> 8%). Regarding the lipid profile, individuals with type 1 diabetes had significantly elevated total cholesterol (p <0.001) and LDL (p <0.000) compared to NG; for triglycerides only DM1NC group showed significant increase compared to NG. There was an increase in serum urea and RAC of individuals with DM1 compared to NG. Nine individuals with type 1 diabetes showed microalbuminuria (ACR> 30 mg / mg). There was a decrease in GSH content (p = 0.006) and increased erythrocyte GPx activity (p <0.001) and SOD (p <0.001) in DM1 group compared to NG. There was no significant difference in the expression of GPx1 (p = 0.305), SOD1 (.365) and SOD2 (0.385) between NG and DM1. The allele and genotype frequencies of the polymorphisms studied showed no statistically significant difference between the groups DM1 and NG. However, the GPx1 polymorphism showed the influence of erythrocyte enzyme activity. There was a decrease in GPx activity in individuals with type 1 diabetes who had a polymorphic variant T (p = 0.012). DM1 patients with the polymorphic variant G (AG + GG) for polymorphism of SOD2 (rs4880) showed an increase in the RAC (p <0.05). The combined data suggest that glucose control seems to be the predominant factor for the emergence of changes in lipid profile, renal function and antioxidant system, but the presence of the polymorphisms studied may partly contribute to the onset of complications