Inspiratory threshold loading reduces lipoperoxidation in obese and normal-weight subjects.

Obesity is related to increased oxidative stress. Although low-intensity physical exercise reduces oxidative stress, obese subjects may show exercise intolerance. For these subjects, inspiratory threshold loading could be an alternative tool to reduce oxidative stress. We investigated the effects of inspiratory threshold loading on biomarkers of oxidative stress in obese and normal-weight subjects. Twenty obese (31.4 ± 6 years old, 10 men and 10 women, 37.5 ± 4.7 kg/m2) and 20 normal-weight (29.4 ± 8 years old, 10 men and 10 women, 23.2 ± 1.5 kg/m2) subjects matched for age and gender participated in the study. Maximal inspiratory pressure (MIP) was assessed by a pressure transducer. Blood sampling was performed before and after loading and control protocols to assess thiobarbituric acid reactive substances (TBARS), protein carbonylation, and reduced glutathione. Inspiratory threshold loading was performed at 60% MIP and maintained until task failure. The 30-min control protocol was performed at 0 cmH2O. Our results demonstrated that inspiratory threshold loading reduced TBARS across time in obese (6.21 ± 2.03 to 4.91 ± 2.14 nmol MDA/ml) and normal-weight subjects (5.60 ± 3.58 to 4.69 ± 2.80 nmol MDA/ml; p = 0.007), but no change was observed in protein carbonyls and glutathione in both groups. The control protocol showed no significant changes in TBARS and protein carbonyls. However, reduced glutathione was increased across time in both groups (obese: from 0.50 ± 0.37 to 0.56 ± 0.35 µmol GSH/ml; normal-weight: from 0.61 ± 0.11 to 0.81 ± 0.23 µmol GSH/ml; p = 0.002). These findings suggest that inspiratory threshold loading could be potentially used as an alternative tool to reduce oxidative stress in both normal-weight and obese individuals.

Avaliação "in vitro" do efeito da infusão de Cunila microcephala Benth sobre a atividade da enzima acetilcolinesterase e biomarcadores de estresse oxidativo em eritrócitos de agricultores / Effect of the Cunila microcephala Benth infusion on the activity of Acetilcolinesterase enzyme and on the biomarkers of oxidative stress in farmers erythrocytes

RESUMO Tivemos como objetivo avaliar o efeito da infusão de Cunila microcephala Benth sobre a atividade da enzima acetilcolinesterase (AChE) e marcadores de estresse oxidativo em eritrócitos de agricultores. Foram utilizadas amostras provenientes de 16 trabalhadores rurais expostos a pesticidas agrícolas pelo período mínimo de 5 anos e um grupo controle constituído de 16 indivíduos não expostos a agrotóxicos. As hemácias dos agricultores e o grupo A foram expostos “in vitro” à solução salina (NaCl 0,9%). Os demais grupos foram expostos à infusão de poejo nas concentrações de 0; 5; 10; 25 e 50 g/L (Grupos B; C; D e E, respectivamente). Em seguida, foram realizadas as determinações da atividade da AChE e dos níveis de substâncias reativas ao ácido tiobarbitúrico (TBARS), proteínas carboniladas (PCs) e glutationa reduzida (GSH). Os resultados mostram que a infusão de poejo 50g/L, aumenta a atividade da enzima AChE e os níveis de GSH. Contudo, os níveis de TBARS e PCs diminuíram após o tratamento com a infusão de poejo 25 e 50 g/L. A infusão de poejo, na concentração de 50 g/L, é capaz de reverter, “in vitro” a inibição da atividade da AChE que ocorre pela exposição a pesticidas, e ainda demonstra um importante potencial antioxidante, tendo em vista que diminuiu danos lipídicos e proteicos e ainda, estimulou a produção do principal antioxidante não enzimático endógeno.

ABSTRACT Evaluating the effect of infusion Cunila microcephala Benth on acetylcholinesterase activity (AChE) enzyme and on biomarkers of oxidative stress in farmers erythrocytes. We used samples from 16 rural workers exposed to pesticides for a minimum of five years, and a control group composed of 16 individuals not exposed to pesticides. The erythrocytes of farmers and from group A were exposed “in vitro” the saline solution (NaCl 0,9%). The other groups were exposed to the infusion of “poejo” at concentrations of 0; 5; 10; 25 and 50 g/L (Groups B, C, D and E, respectively). Then, it was realized the analitical determinations of AChE activity and TBARS, PCs and GSH levels. The results showed that “poejo” infusion 50g/L, increased the AChE activity and GSH levels. However, the TBARS e PCs levels decreased after the treatment with “poejo” infusion 25 e 50 g/L. The “poejo” infusion 50 g/L is able to revert “in vitro” the inhibition of AChE activity that occurs by exposure to pesticides and also demonstrates an important antioxidant potential, given that decreased lipid and protein damage and also it stimulated the production of the main non-enzymatic antioxidant endogenous.

Genotoxicity assessment in aquatic environments under the influence of heavy metals and organic contaminants.

The genotoxicity of river water and sediment including interstitial water was evaluated by microscreen phage-induction and Salmonella/microsome assays. Different processes used to fractionate the sediment sample were compared using solvents with different polarities. The results obtained for mutagenic activity using the Salmonella/microsome test were negative in the water and interstitial water samples analysed using the direct concentration method. The responses in the microscreen phage-induction assay showed the presence of genotoxic or indicative genotoxic activity for at least one water sample of each site analysed using the same concentration method. Similar results were obtained for interstitial water samples, i.e. absence of mutagenic activity in the Salmonella/microsome test and presence of genotoxic activity in the microscreen phage-induction assay. Metal contamination, as evidenced by the concentrations in stream sediments, may also help explain some of these genotoxic results. Stream sediment organic extracts showed frameshift mutagenic activity in the ether extract detected by Salmonella/microsome assay. The concentrates evaluated by microscreen phage-induction assay identified the action of organic compounds in the non-polar, medium polar and polar fractions. Thus, the microscreen phage-induction assay has proven to be a more appropriate methodology than the Salmonella/microsome test to analyse multiple pollutants in this ecosystem where both organic compounds and heavy metals are present.