Effects of 7, 12-dimethylbenz (a)Anthracene (DMBA) Treatment on Serum Oxidative and Nitrositive Stress in Obese Zucker Rats

Epidemiological studies showed that obese women have higher mortality rates from all cancers including breast cancer. Previously we reported that obesity effects methylation and create higher oxidative stress in obese Zucker rats. The objective of this study was to investigate the effects of DMBA on serum oxidative and nitrosative stress biomarkers. Forty day-old, obese (n=20) female Zucker rats were placed on AIN-93G diet for 10 days. Rats were treated with either sesame oil (control) or 65 mg/kg DMBA and were sacrificed 24 hours later. Serum concentrations of free Cysteine, Cystine and 3-nitroTyrosine were measured by HPLC with electrochemical detection or LC-MS method. Obese DMBA treated rats had higher concentrations of free Cysteine (P<0.005), and its oxidized form (Cystine) (P<0.001), and lower of fCysteine/Cystine ratio (P<0.05) compared to obese control rats. Serum concentration of 3-nitroTyrosine, DMBA-treated obese rats was two time higher and was negatively (R² = 0.2605) correlated with the fCy...