Levels Of Lipid Peroxidation Markers Research Articles

Oxidative impairment in scrapie-infected mice is associated with brain metals perturbations and altered antioxidant activities.

Prion diseases are characterized by the conversion of the normal cellular prion protein (PrP(C)) into a pathogenic isoform (PrP(Sc)). PrP(C) binds copper, has superoxide dismutase (SOD)-like activity in vitro, and its expression aids in the cellular response to oxidative stress. However, the interplay between PrPs (PrP(C), PrP(Sc) and possibly other abnormal species), copper, anti-oxidation activity and pathogenesis of prion diseases remain unclear. In this study, we reported dramatic depression of SOD-like activity by the affinity-purified PrPs from scrapie-infected brains, and together with significant reduction of Cu/Zn-SOD activity, correlates with significant perturbations in the divalent metals contents. We also detected elevated levels of nitric oxide and superoxide in the infected brains, which could be escalating the oxidative modification of cellular proteins, reducing gluathione peroxidase activity and increasing the levels of lipid peroxidation markers. Taken together, our results suggest that brain metal imbalances, especially copper, in scrapie infection is likely to affect the anti-oxidation functions of PrP and SODs, which, together with other cellular dysfunctions, predispose the brains to oxidative impairment and eventual degeneration. To our knowledge, this is the first study documenting a physiological connection between brain metals imbalances, the anti-oxidation function of PrP, and aberrations in the cellular responses to oxidative stress, in scrapie infection.

Non-alcoholic fatty liver disease in an area of southern Italy: main clinical, histological, and pathophysiological aspects

Background/Aims : Studies on non-alcoholic fatty liver disease (NAFLD) have included chronic liver damage attributed to various causes. Our investigation was held to observe the main clinical, histological, and pathophysiological aspects of NAFLD in patients not exposed to any known cause of chronic liver disease. Methods : We evaluated, in 84 in-patients (male/female, 66/18; median age, 36 years), the clinical and biochemical characteristics of NAFLD, and particularly its association with diabetes, dyslipidemia, hyperinsulinemia and/or with the increase of parameters of oxidative stress (blood levels of malonyldialdehyde, 4-hydroxynonenal and total plasma antioxidant capacity). Results : Ninety percent of patients had an increased body mass index (BMI), 35% had dyslipidemia, 40% had sub-clinical diabetes (only 3% had overt diabetes), 60% had hyperinsulinemia, and more than 90% had enhanced levels of lipid peroxidation markers. In 48 patients who had consented to liver biopsy, we found: 14 with simple steatosis, 32 with steatohepatitis, and two with cirrhosis. Conclusions : Our data indicate that in our country, NAFLD may occur in young males with an increased BMI, with or without hyperinsulinemia, dyslipidemia and diabetes, generally associated with disorders of redox status, and that it may be differentiated from steatosis to steatohepatitis or cirrhosis only with a liver biopsy.

Physical activity, aerobic capacity and selected markers of oxidative stress and the anti-oxidant defence system in healthy active elderly men.

The relationship of oxidative stress and the anti-oxidant defence system to maximal oxygen consumption (VO2max) and habitual physical activity was assessed in 26 elderly men (71.0 +/- 4.2 years) and compared to that of 12 young men (22.1 +/- 5.1 years). Physical activity was assessed by a questionnaire. Malondialdehyde (MDA), plasma total anti-oxidant status (TAS), the levels of red blood cell (RBC) superoxide dismutase (SOD) and glutathione peroxidase (GPX), as well as serum GPX activities were determined under resting conditions. The older and young men had similar TAS and RBC SOD, while MDA, RBC GPX and plasma GPX were higher, and RBC SOD/GPX ratio was significantly lower in the older men. Neither MDA nor anti-oxidants were associated with any of the physical activity/aerobic capacity measures in the elderly men. We conclude that in healthy elderly men with a good nutritional status, indicators of the anti-oxidant defence system are not lower in comparison with young men. Increased RBC and plasma GPX coupled with a high level of lipid peroxidation marker may indicate an adaptation of anti-oxidant defences to sustained oxidative stress. Furthermore, the results of the present study suggest that the level of habitual physical activity and aerobic capacity have no major influence on the resting balance between radical generation and blood anti-oxidant potential in healthy older men.

Effects of gliclazide versus metformin on the clinical profile and lipid peroxidation markers in type 2 diabetes

The sulfonylurea gliclazide and the biguanide metformin have different mechanisms to reduce glycemia. We performed a randomized study to compare these two agents with respect to glycemic control and effects on lipid peroxidation markers in 36 adult patients with type 2 diabetes. Both agents significantly decreased glycosylated hemoglobin ([HbA 1c] P < .05), fructosamine ( P < .05), and the glucose-excursion curve during the oral glucose tolerance test ([OGTT] P < .01). With regard to the insulin curve during this test, no significant change was observed with metformin and a significant increase was measured with gliclazide ( P < .05). Considering the small number of events, no significant difference was detected in the number of hypoglycemic episodes between the two agents. More upper-gastrointestinal (GI) symptoms were observed with metformin compared with gliclazide ( P < .05). Even with no change in the standard lipid profile, both agents increased serum vitamin E ( P < .01) for gliclazide and P < .05 for metformin) and decreased the level of lipid peroxidation markers in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles ( P < .05). Despite different mechanisms of action, gliclazide and metformin demonstrated comparable levels of efficacy and complementary effects on lipid peroxidation markers.