Cytochrome P450 isozymes: substrates and inducing agents determined from human and rodent studies
| Cytochrome P450 | C/I2-a | Inducing Agent (If Any) | Substrates Used in This Study2-b |
|---|---|---|---|
| 1A1 | I | 3MC | Benzo(a)pyrene Phenacetin |
| 1A2 | C, I | 3MC, β-naphthoflavone | 7-Ethoxyresorufin 7-Ethoxycoumarin2-c Phenacetin |
| 2A6 | C | ?? | Coumarin |
| 2B1 | C, I | Phenobarbital | 7-Methoxycoumarin 7-Pentoxyresorufin Aminopyrine 7-Benzyloxyresorufin |
| 2B2 | I | Phenobarbital | 7-Methoxycoumarin 7-Pentoxyresorufin Aminopyrine 7-Benzyloxyresorufin |
| 2B6 | C | ?? | 7-Ethoxy-4-methylcoumarin 7-Benzyloxyresorufin |
| 2C6, 2C11, 2C13 | C, I | Phenobarbital | Diclofenac Tolbutamide Mephenytoin |
| 2D6 | C | ?? | Propranolol Bufuralol Dextromethorphan |
| 2E1 | C,I | Acetone, ethanol | Aniline2-d p-Nitrophenol2-d Chlorzoxazone |
| 3A1/3A2 | C, I | Dexamethasone Phenobarbital | Cortisol Erythromycin Dextromethorphan Androstenedione Testosterone |
| 4A1/3 | C, I | Clofibrate | Lauric acid |
3MC, 3-methylcholanthrene.
↵2-a Constitutively (C) expressed or induced (I) expression. The concentration of a constitutively expressed P450 can be augmented by inducing agents. The expression/presence of the “induced” P450 enzymes is observed only following in vivo exposure to inducing agents.
↵2-b The substrate specificity/selectivity for a given P450 is based on rodent and human studies (Omiecinski et al., 1999 and Wrighton and Stevens, 1992).
↵2-c May also be metabolized by 2B1/2 and 2E1.
↵2-d May also be metabolized by 2A1.