title: The influence of beta-carotene on homocysteine level and oxidative stress in lead-exposed workers.
abstract: BACKGROUND
  Oxidative stress is involved in lead toxicity. This suggests that some antioxidants may play a role in the treatment of lead poisoning. In the light of this, the aim of the study was to determine whether beta-carotene administration reduces oxidative stress and homocysteine level in workers chronically exposed to lead.
  
  
  METHODS
  The exposed population included healthy male workers exposed to lead who were randomly divided into 2 groups (mean blood lead level ca. 44 microg/dl). Workers in the 1st group (N = 49, reference group) had no antioxidants, drugs, vitamins or dietary supplements administered, while workers in the 2nd group (N = 33) had beta-carotene administered in a dose of 10 mg per day for 12 weeks. Biochemical analysis included markers of lead-exposure and the level of malondialdehyde (MDA), an oxidative stress biomarker. We also measured the level of homocysteine (Hcy) and thiol groups as well as the activity of superoxide dismutase (SOD) and its isoenzyme EC-SOD in serum.
  
  
  RESULTS
  After supplementation, the level of MDA significantly decreased, compared to baseline, by 16%, and to the reference group. When compared to the reference group, Hcy level was also significantly decreased. However, the level of thiol groups was significantly higher after supplementation with beta-carotene compared to the reference group. Analogically, the activity of SOD and EC-SOD was significantly higher compared to the baseline and to the reference group.
  
  
  CONCLUSIONS
  Despite some controversies over antioxidant properties of beta-carotene, our results indicate that its antioxidant action could provide some beneficial effects in lead poisoning independent of chelation.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Kasperczyk
authors.forename: Michał
authors.initials: M
authors.lastname: Dobrakowski
authors.forename: Janusz
authors.initials: J
authors.lastname: Kasperczyk
authors.forename: Ewa
authors.initials: E
authors.lastname: Romuk
authors.forename: Adam
authors.initials: A
authors.lastname: Prokopowicz
authors.forename: Ewa
authors.initials: E
authors.lastname: Birkner
mesh_terms: D000975:Antioxidants / Q000627:therapeutic use; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007855:Lead Poisoning / Q000097:blood* / Q000188:drug therapy*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D009784:Occupational Diseases / Q000097:blood* / Q000188:drug therapy*; D018384:Oxidative Stress / Q000187:drug effects*; D011044:Poland; D013438:Sulfhydryl Compounds / Q000097:blood; D013482:Superoxide Dismutase / Q000097:blood; D019207:beta Carotene / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D013438:Sulfhydryl Compounds; D019207:beta Carotene; D006710:Homocysteine; D008315:Malondialdehyde; D013482:Superoxide Dismutase