Antioxidant effect of haptoglobin phenotypes against DNA damage induced by hydrogen peroxide in human leukocytes

Abstract

Human haptoglobin is classified into three major pheno- types: Hp1-1, Hp2-1 and Hp2-2; there are two autosomal alleles Hp*1 and Hp *2, and the Hp*1 allele has two subtypes, Hp*1F and Hp*1S. Hapto- globin acts as an antioxidant, preventing hemoglobin-driven oxidative damage. We used the comet assay to examine oxidative damage to DNA induced by hydrogen peroxide in human leukocytes; we also looked for differences in the antioxidant capacity of haptoglobin subtypes. Hapto- globin genotypes were determined through allele-specific polymerase chain reaction, visualized on a polyacrylamide gel. The Hp1-1 genotype had the least DNA damage; this indicates that Hp alleles differ in their protective effects against oxidative damage. Among Hp *1 alleles, Hp*1F was the most protective.