Oxidative DNA damage and oxidative stress in lead-exposed workers
M Dobrakowski1, N Pawlas2, A Kasperczyk1
11 Department of Biochemistry, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia, Katowice, Poland.
Human & Experimental Toxicology
|September 7, 2016
Summary
Occupational lead exposure causes DNA damage and oxidative stress in human leukocytes. Increased blood lead levels correlate with higher DNA damage and elevated oxidative stress markers.
Area of Science:
- Toxicology
- Environmental Health
- Molecular Biology
Background:
- Discrepancies exist in studies on lead's genotoxicity.
- Occupational lead exposure is a significant public health concern.
- Understanding lead's impact on DNA and oxidative stress is crucial.
Purpose of the Study:
- To investigate lead-induced DNA damage, including oxidative damage, in human leukocytes.
- To correlate DNA damage with oxidative stress parameters and antioxidant defense in workers exposed to lead.
- To analyze these effects across different levels of occupational lead exposure.
Main Methods:
- Comet assay to measure DNA damage in leukocytes.
- Biochemical assays to quantify antioxidant enzyme activities (SOD, catalase, GR, G6PD, GST) and oxidative stress markers (MDA).
- Categorization of 100 male workers into low, medium, and high blood lead level (PbB) groups, with a control group (PbB < 10 μg/dL).
Main Results:
- Significantly higher DNA damage (percentage of DNA in tail) observed in all lead-exposed groups compared to controls.
- Reduced glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) activity in lower exposure groups.
- Elevated superoxide dismutase (SOD) and glutathione-S-transferase (GST) activity, alongside increased malondialdehyde (MDA) concentration, indicating heightened oxidative stress across exposure groups.
Conclusions:
- Occupational lead exposure demonstrably induces DNA damage, including oxidative damage, in human leukocytes.
- The observed increase in DNA damage is directly associated with intensified oxidative stress.
- Lead exposure significantly impacts the antioxidant defense system, highlighting its detrimental effects on cellular integrity.
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