Abstract
The present study was designed to evaluate the influence of long-term environmental human exposure to three heavy metals, lead (Pb), cadmium (Cd), and mercury (Hg), on the expression of detoxifying, xenobiotic metabolizing, and DNA repair genes in Mahd Ad-Dahab city. The study groups consisted of 40 healthy male residents (heavy metal-exposed) and 20 healthy male from Riyadh city, 700 km away, and served as control group. The heavy metal-exposed group with high exposure to Pb, Cd, or Hg was divided into three subgroups Pb-, Cd-, and Hg-exposed groups, respectively. The mRNA expression levels of detoxifying, NQO1, HO-1, GSTA1, MT-1, and HSP70, were significantly decreased in all heavy metal-exposed group as compared to control group. This was accompanied with a proportional decrease in the expression of xenobiotic metabolizing gene, cytochrome P4501A1. On the other hand, the DNA repair gene OGG1 and the 8-OHdG level were dramatically inhibited in Cd-exposed group only.
•Cd, Pb, & Hg blood concentrations in metal-exposed group were higher than control.•The levels of Pb were highly correlated with residency time & source of drinking.•Significant decreases in detoxifying and oxidative stress genes was reported.•Significant increase in OGG1 mRNA & 8-OHdG levels was observed in Cd-exposed group.
Long-term human exposure to environmental metals increased the risk of metals contamination and altered expression of detoxifying, metabolizing, and DNA repair genes.