Oxidative stress in metabolic syndrome & its association with DNA-strand break

Background & objectives: Oxidative stress (OS) is associated with numerous components of metabolic syndrome (MetS). This study was aimed to investigate if hydrogen peroxide (H2O2) as the reactive oxygen species was capable of depicting OS in MetS, and If MetS patients showed DNA damage in the form of DNA strand breaks (DSB). Methods: A total of 160 participants (90 males, 70 females) ?20 yr of age were categorized into four groups based on the number of MetS risk parameters (n=40 in each group). Sugar and lipid profile, H2O2concentration in blood and DNA-strand breaks were measured. Results: DSB was significantly more in those with MetS (n=40) than those without (n=120) whereas H2O2levels were the same in both the study groups. The number of DSB differed significantly between the control and 3 risk factor groups. DSB was also higher in groups with 2 and 1 risk factors compared to 0 risk but the difference was not significant. H2O2 level was higher in groups with 3, 2 and 1 risk factors compared to 0 risk group but the difference was not significant. The H2O2level correlated positively with triglyceride values but not with other MetS risk parameters. There was no significant correlation between DSB and MetS risk parameters. Interpretation & conclusions: Our findings showed a cumulative and synergistic effect of the risk factors of MetS on DSB. Individuals with three risk parameters had a greater effect on DNA damage than in those with two or one risk parameter. Although plasma H2O2level increased with an increase in the fat depots, use of H2O2to depict OS in MetS should be coupled with an adjunct and estimation of DSB in peripheral blood lymphocytes may be used as indicator of OS in MetS patients.

THE ROLE OF OXYGEN RADICALS IN RAT ACUTE LUNG INJURY INDUCED BY PHORBOL MYRISTATE ACETATE / 第二军医大学学报

We tried to clarify the role of oxygen radicals [released from granulocytes stimulated by phorbol myristate acetate (PMA) in rat acute lung injury. It was found that DNA strand-break damage (DSBD) in peripheral white blood cells was significantly increased 40 min after injection of PMA. DSBD in lung tissue of rats treated with PMA was also markedly increased. The PMA-treated rats showed significantly higher lipid-peroxide (LPO) level in plasma and lung hemogenate than the controls. These results suggest that determination of DSBD, a simple and sensitive indicator for oxygen radical damaging, might be useful in the diagnosis of adult respiratory distress syndrome, when it is used together with measurement of plasma LPO.