New insights regarding tissue Se and Hg interactions on oxidative stress from plasma IsoP and IsoF measures in the Canadian Inuit population

• Published in: Journal of Lipid Research
• Main Authors: Alkazemi, Dalal, Egeland, Grace M., Roberts, L. Jackson, Chan, Hing M., Kubow, Stan
• Format: Text
• Language: English
• Published: The American Society for Biochemistry and Molecular Biology 2013
• Subjects: Patient-Oriented and Epidemiological Research; Arctic; inuit
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3679398; http://www.ncbi.nlm.nih.gov/pubmed/23670530; https://doi.org/10.1194/jlr.M033068

Despite animal and in vitro studies demonstrating pro-oxidative effects of Hg, previous human work showed no relationship between tissue Hg and plasma levels of F2-isoprostanes (IsoPs), a whole-body oxidative stress marker. We hypothesized that another IsoP species, isofurans (IsoFs), was a more sensitive indicator of Hg-mediated oxidative stress, which can be modified by tissue Se status. A cross-sectional study was carried out involving individuals from a random subset (n = 233) of Inuit adults from a population-based survey (n = 2,595) of 36 Canadian Arctic Inuit communities to assess the relationships of plasma IsoPs to Se and Hg status indicators. F2-IsoPs were inversely correlated with blood Se (r = −0.186, P = 0.005) and toenail Se (r = −0.146, P = 0.044), but not correlated with Hg. IsoFs were inversely correlated with blood Se (r = −0.164, P = 0.014) and positively correlated with Hg (r = 0.228, P < 0.001) and Hg:Se (r = 0.340, P < 0.001). The strength of the correlations remained unchanged after multivariate adjustments. Multivariate analysis showed that F2-IsoPs were not positively associated with Hg but with Hg:Se (β = 0.148, P = 0.021). We conclude that Se and Hg status and their interactions are important factors modulating F2-IsoP and IsoF levels such that the Inuit may be protected from Hg-induced oxidative stress because of their high Se status.