Evaluation of the Antioxidant Effect of Dihydroquercetin in Adult Residents of the North under Adverse Environmental Conditions

Abstract

Introduction: Transport-related air pollution (vehicle exhaust emissions) and the consumption of poor-quality drinking water can play a key role in the activation of oxidative stress in the population of the northern region. Purpose: To study the effectiveness of taking dihydroquercetin to improve the adaptive reserves of antioxidant protection in the adult population of the Khanty-Mansi Autonomous Okrug. Materials and methods: Using test kits, we measured the content of lipid peroxidation products (lipid hydroperoxide and thiobarbituric acid reactive substances) and antioxidant defense of the body (total antioxidant activity and thiol status) in blood serum of 156 young adults residing in the Khanty-Mansi Autonomous Okrug before and after metabolic correction using Baikal dihydroquercetin, an antioxidant herbal preparation, at a dose of 60 mg/day for 30 days. The oxidative stress index was calculated by the formula: lipid hydroperoxides × 2-thiobarbituric acid reactive substances / total antioxidant activity × thiol status. Results: We established increased lipid peroxidation, i.e. higher levels of lipid hydroperoxides and 2-thiobarbituric acid reactive substances, in heavy-duty vehicle drivers occupationally exposed to car exhaust pollutants and urban residents consuming poor-quality tap water with a high content of iron and manganese ions, the excess of which in the form of inorganic compounds can demonstrate prooxidant properties before correction with dihydroquercetin. We also noted a decrease in the parameters of the antioxidant defense of the body (total antioxidant activity and thiol status) below the reference values. The oxidative stress index was 5.4 and 4.9 times higher than the upper limit of adequate values in the group of drivers and residents of the cities of Nyagan and Nefteyugansk, respectively. After taking dihydroquercetin at a dose of 60 mg/day for 30 days, all indicators of oxidative metabolism in both study groups returned to normal. A significant decrease in the level of thiabarbituric acid reactive substances was found in both groups, respectively: p¹ = 0.011 and p² = 0.002, in combination with a statistically significant increase in the total antioxidant activity (p¹ = 0.015 and p² = 0.019) against the background of the most pronounced decrease in the oxidative stress index: p¹ = 0.019 and p² = 0.001, however, not reaching the level of physiologically adequate values. Conclusion: Positive changes in redox metabolism observed following a 30-day correction with the antioxidant drug dihydroquercetin give evidence of the restoration of adaptive resources of the human organism and an increase in its resistance to adverse environmental factors.