Characterization of Blood Oxidative Stress in Type 2 Diabetes Mellitus Patients: Increase in Lipid Peroxidation and SOD Activity

This study evaluated the oxidative stress through enzymatic and nonenzymatic biomarkers in diabetic patients with and without hypertension and prediabetics. The SOD and CAT (in erythrocytes) and GPx (in plasma) enzymatic activities, plasma levels of lipid peroxidation, and total thiols were measured in the blood of 55 subjects with type 2 diabetes and 38 subjects without diabetes (9 pre-diabetics and 29 controls) aged 40–86 years. The total SOD activity and the lipid peroxidation were higher in diabetics compared to nondiabetics. In stratified groups, the total SOD activity was different for the hypertensive diabetics compared to the prediabetics and normotensive controls. Lipid peroxidation was significantly higher in both groups of diabetics (hypertensive and normotensive) compared to prediabetic groups and hypertensive and normotensive controls. There was no significant difference in the CAT and GPx activities, as well as in the concentration of total thiols in the groups studied. Present data strongly suggest the involvement of oxidative stress in the pathophysiology of diabetes, revealing that the increased lipid peroxidation has a close relationship with high glucose levels, as observed by the fasting glucose and HbA1c levels. The results evidence the correlation between lipid peroxidation and DM, irrespective of the presence of hypertension

Electrocatalytic Activity Of 4-nitrophthalonitrile-modified Electrode For The L-glutathione Detection.

The present work describes the substantial electrocatalytic activity of (NC)2C6H3-NHOH/(NC)2C6H3-NO redox couple-modified electrode toward the low voltage detection of l-glutathione (GSH), in neutral medium, at an applied potential of 0.4V versus Ag/AgCl. After optimizing the operational conditions, the sensor provided a linear response range for GSH from 8.0 up to 83.0 micromol L(-1) with sensitivity, detection and quantification limits of 54nA L micromol(-1), 2.7 micromol L(-1) and 8.0 micromol L(-1), respectively. The proposed sensor presented higher sensitivity when compared to other modified electrodes described in the literature and showed a stable response for at least 100 successive determinations. The repeatability of the measurements with the same sensor and different sensors, evaluated in terms of relative standard deviation, were 4.1 and 5.0%, respectively, for n=10. The developed sensor was applied for GSH determination in yeast extract and the results were statistically the same with those obtained by the comparative method described in the literature at a confidence level of 95%.47758-6

Activities of naphthoquinones against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae), vector of dengue and Biomphalaria glabrata (Say, 1818), intermediate host of Schistosoma mansoni

Larvicidal (against Aedes aegypti Linnaeus, 1762) and molluscicidal (against Biomphalaria glabrata Say,1818) activities of several natural and synthetic naphthoquinoneswere measured, with significant results. The best larvicidal compound is 3-bromojuglone, while the better molluscicides are 2-bromo- and 3- bromo-5-acetoxy-1,4-naphthoquinones together with the 3-bromo-5-methoxy derivative. The present results reinforce the potential use of substituted hydroxyquinones, their salts and halogenated quinones as very promising compounds against 4th instar larves of Aedes aegypti, the vector of dengue and against adult snail of Biomphalaria glabrata.This work was supported by CNPq, RHAE/CNPq, Ministério da Saúde/Programa Dengue, CAPES and FAPEAL (Fundac¸ ão de Apoio à Pesquisa do Estado de Alagoas, Maceió, Al. Brazil), IMSEAR, BNB, RENORBIO, IM-INOFAR/CNPq, CSIC-CNPq (2005 BR0046, to M.T.M and M.O.F.G), DGICYT ((Spain, grants BQU2003- 00813 and SAF2006-04698 to M.T.M.), CSIC (for a I3P contract to E.L.-M.)Peer reviewe