DPPH test application the for evaluation of the antioxidant serum activity in field environmental study

The method of the evaluation of the antioxidant activity (AOA) with a help of stable radical 2,2-diphenyl-1-picrylhydrazyl test (DPPH test) widely applied in pharmacological and food chemistry, was used also in some clinic investigations for the assessment of the total activity of serum low-molecular-weight antioxidants, but never was applied earlier for toxicological and environmental studies. We have developed the new modification of DPPH test, by replacing methanol-based incubation medium to non-ionic water detergent solution, compatible with native blood serum. Modified DPPH test was approved in 5 toxicological experiments on laboratory animals (Gig. Sanit., 2016, 9: 884-90) and in the hygienic study of the influence of ambient air pollution on the health state in a cohort of 142 capable Moscow residents (aged of 43.5 ± 11.8 years). As a results of the cohort observation, AOA of human serum in DPPH test had close to the normal distribution without gender differences, the slowly decrease with age by nearly 0.4% per year and was positively associated with serum concentrations of catabolic antioxidant — uric acid (R=0.257; p=0.002). The influence of outdoor air pollution in the points of the persons permanent homes was studied by 2 methods: 1) dividing Moscow territory into 2 zones accordingly the long-term monitoring of Hydrometereology and Environmental Monitoring Service; 2) by cartographic adjustment of corresponding home buildings to the nearest of 46 route stations of Moscow Agency for Health and Consumer Rights. No significant differences was found between residents of 2 preferred city zones in 12 used serum biochemical markers, the results of DPPH test including. Significant correlation exposure-response was found between the variables “serum AOA in DPPH test” and “benzene annual outdoor concentration” (R=0.342; p=0.00003) by individual exposure evaluation according to the data of route stations. Two main independent predictors of serum AOA values in the observed cohort of Moscow residents (outdoor air benzene and serum uric acid concentrations) detected 14 and 8.5 % of AOA total variance (p = 0.000002 and p =0.00018 correspondingly).