Sudan I [1-(phenylazo)-2-
hydroxynaphthalene, C.I.
Solvent Yellow 14, CAS No: 842-07-9] is used as the compound employed in chemical industry and to color materials such as
hydrocarbon solvents,
oils,
fats,
waxes, plastics, printing inks, shoe and floor polishes and
gasoline. Such a wide used could result in a considerable human exposure.
Sudan I is known to cause developments of
tumors in the liver or urinary bladder in rats, mice, and rabbits, and is considered a possible weak human
carcinogen and
mutagen. This
carcinogen is also a potent contact
allergen and sensitizer. Here, we compare the data concerning the
Sudan I oxidative metabolism catalyzed by
cytochrome P450 (CYP) and
peroxidase enzymes, which has been investigated in our laboratory during the last two decades. These two types of
enzymes are responsible both for
Sudan I detoxication and activation. Among the
Sudan I metabolites, C-hydroxylated derivatives and a dimer of
Sudan I are suggested to be the detoxication metabolites formed by CYPs and
peroxidases, respectively. Metabolic activation of
Sudan I by both types of
enzymes leads to formation of reactive species (the
benzenediazonium ion by CYP and
Sudan I radicals by
peroxidase) that bind to
DNA and
RNA, generating covalent adducts in vitro and in vivo. Whereas the structure of the major adduct formed by the
benzenediazonium ion in
DNA has already been identified to be the
8-(phenylazo)guanine adduct, the structures of adducts formed by
peroxidase, have not been characterized as yet.
Biological significance of the
DNA adducts of
Sudan I activated with CYP and
peroxidase enzymes and further aims of investigations in this field are discussed in this study.