High selenium status in individuals exposed to arsenic through coal-burning in Shaanxi (PR of China) modulates antioxidant enzymes, heme oxygenase-1 and DNA damage.
BACKGROUND
Although interactions of arsenite and selenite in mammalian organisms have been suggested by literature data, the antioxidant effects and biochemical mechanisms of dietary selenium on human populations exposed to inorganic arsenic are not fully understood.


METHODS
Total blood, urine and hair concentrations of arsenic and selenium were determined in all individuals by hydride generation atomic fluorescence spectrometry. The individuals with skin lesions were subsequently classified as "High As group" and "High Se/As group" and controls were classified as "High Se group" and "Control group" according to their blood selenium concentrations.


RESULTS
High selenium status was correlated with elevated activities of serum superoxide dismutase, glutathione peroxidase, catalase, and reduced levels of malondialdehyde, and increased RNA and protein expression of heme oxygenase-1 in peripheral blood mononuclear cells (PBMC) of individuals in the high arsenic group. Urinary 8-hydroxy-2'-deoxyguanosine levels were positively associated with blood arsenic, but inversely with blood and hair selenium among individuals with skin lesions, whereas mRNA are protein levels of 8-oxoganine DNA glycosylase 1 in PBMC increased in the "High Se/As group" compared to the "High As group".


CONCLUSIONS
Inorganic arsenic exposure is associated with oxidative stress, which may be prevented by high selenium status via its antioxidative activity and detoxification effect possibly through the formation of an arsenic and selenium containing metabolite, the seleno-bis(S-glutathionyl) arsinium ion.
Xue
Wanli
W
Department of Public Health, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710061, PR China.
Wang
Zhilun
Z
Chen
Qun
Q
Chen
Jinghong
J
Yang
Haojie
H
Xue
Senhai
S
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000975:Antioxidants / Q000378:metabolism*; D001151:Arsenic; D001483:Base Sequence; D015153:Blotting, Western; D002681:China; D003031:Coal; D004249:DNA Damage; D017931:DNA Primers; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D004781:Environmental Exposure; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D006801:Humans; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012643:Selenium / Q000097:blood*
D000975:Antioxidants; D003031:Coal; D017931:DNA Primers; D000080242:8-Hydroxy-2'-Deoxyguanosine; D006419:Heme Oxygenase (Decyclizing); D003849:Deoxyguanosine; D012643:Selenium; D001151:Arsenic