Evaluation of oxidative stress biomarkers in acute mercury intoxication

Abstract

Introduction: Very few studies have evaluated the association between mercury exposure and oxidative stress in humans, particularly in children.

Aim: This is the first report where we aimed to determine the oxidative stress status of children who were accidentally exposed to elemental mercury.

Materials and methods: In the present study, the study group was composed of 86 randomly selected children poisoned by mercury; the control group was composed of 78 children who had no history of mercury exposure. At admission, blood samples were collected. Blood superoxide dismutase activity, catalase enzyme activity, and glutathione peroxidase activity were measured by Fridovich, Beutler, and Lawrence Burk methods respectively, and the results were given as U/g Hb. Malondialdehyde level was measured by Ohkawa methods, and the results were given as mmol/ml.

Results: Catalase activity was significantly lower in the patient group compared to the control group (1.28±0.62 vs. 3.90±0.86 U/g Hb, p=0.010). In exposed children, SOD activity was significantly higher than the controls (5936±810 vs. 2226±464 U/g Hb, p=0.03), while the GSH-Px activity was significantly lower (13.01±3.21 vs. 34.97±7.32 U/g Hb, p=0.013). The MDA levels of the mercury group were significantly higher than the MDA levels of the control group (2.85±0.84 vs. 2.05±0.79 mmol/ml, p=0.04).

Conclusions: The results of the present study showed that acute mercury poisoning causes an alteration of oxidative stress status in children exposed to elemental mercury.

Keywords: catalase; glutathione peroxidase; intoxication; malondialdehyde; mercury; superoxide dismutase.