A new method to evaluate oxidative stress in humans

Direct measurement of oxidative stress in biological fluids requires complex laboratory instruments and extraction procedures. Aim of the study was to analyse a new colorimetric assay and to evaluate its utility in the clinical setting. Forty-four unselected outpatients were studied. Stress oxidative levels were analysed with a colorimetric determination of oxygen free radicals, the dROMs test while serum total antioxidant capability was determined by OXY-adsorbent assay. In nine patients, ELISA 8-iso-PGF 2α plasma level determinations were obtained. The lower limit of sensitivity of dROMs test resulted 4.96 mg % H 2 O 2 . The assay was found to be linear over the range of oxidative stress levels 0–500 mg % H 2 O 2 , with correlation coefficients greater than 0.99. According to dROMs, the exposition to oxygen radical in the studied population was of moderate entity. Variation on replicate samples within or between days were lower than 5.5% and free radical levels were directly correlated with serum glucose concentration. A high significant inverse correlation between oxidative stress and total serum antioxidant levels was observed. 8-iso-PGF 2α plasma levels were positively correlated with serum free radical levels and inversely with serum concentration of antioxidant. The present data indicate that the analysis of serum free radicals with d-ROMs test is a rapid, no expensive method with good sensitivity and reproducibility.