TABLE 3.3 Selective substrates for individual UGT1A isozymes.Isoenzyme Endogenous substrates
Reported
K
m
Drug or xenobiotic
substrates
Inducers
Inhibitors
UGT1A1
Bilirubin
,estradiol
(3-hydroxy),
2-hydroxyestrone,2-hydroxyestradioltrans-retinoic acid,catechol estrogens(2- and 4-hydroxy)
Ethinyl estradiol
, morphine
(3-hydroxy), buprenorphineferulic acid, genisteinnaltrexone (low),naloxone (low),SN-38 (active metaboliteof irinotecan) alizarin,quinalizarin
Bilirubin,
chlorophen-oxypropionicacid, chrysin,clofibrate3-methylcholanthrene,phenylpropionic acid,phenobarbital, etc.pregnenolone-16
a-
nitrile anddexamethasone,clotrimazole,rifampin,and St. John’s wort
Atazanavir
UGT1A2
UGT1A3 Bile acids (carboxyl
functional group),catechol estrogens(2-OH
>
4-OH),
2-OH-estrone,2-hydroxyestradiol,decanoic acid,dodecanoic acid,bilirubin (low)
Cyproheptadine
, alizarin,
buprenorphine
,
norbuprenorphine,bropirimine,diphenylamine,diprenorphine, emodin,esculetin, eugenol,ezetimibe, fisetin,genestein, 3-hydroxydesloratadine,7-hydroxyflavone, hydromorphone,4-methylumbelliferone, morphine,nalorphine, naloxone, naltrexone,naringenin
, quercehtin, scopoletin,
thymol, umbelliferone.
b-Naphthoflavone,
rifampin(?)
46