Assay | Percentage of Control |
---|---|
7-EthoxyresorufinO-deethylation (1A) | 2 ± 1 |
7-Methoxyresorufin O-demethylation (1A) | 9 ± 1 |
Phenacetin O-deethylation (1A2) | 23 ± 4 |
Benzo[a]pyrene hydroxylation (1A, 2C, 3A4) | 115 ± 7 |
Tolbutamide hydroxylation (2C9) | 87 ± 8 |
Chlorzoxazone hydroxylation (2E1) | 93 ± 10 |
Nifedipine oxidation (3A4) | 134 ± 11 |
Monooxygenase activities were determined in the absence or presence of 1 μM rutaecarpine. The main P450s involved in the oxidations are shown in parentheses. In the absence of rutaecarpine, the same volume of vehicle (DMSO) was added as the control. Results are expressed as means ± S.E. of the percentage of those in the absence of rutaecarpine. The representative control activities of 7-ethoxyresorufin O-deethylation, 7-methoxyresorufinO-demethylation, phenacetin O-deethylation, benzo[a]pyrene hydroxylation, tolbutamide hydroxylation, chlorzoxazone hydroxylation, and nifedipine oxidation were in the ranges (mean ± S.E.) of 0.02 to 0.32 (0.10 ± 0.05), 0.03 to 0.13 (0.07 ± 0.02), 0.09 to 1.8 (0.57 ± 0.31), 0.01 to 0.27 (0.12 ± 0.04), 0.04 to 0.36 (0.14 ± 0.05), 0.26 to 1.4 (0.58 ± 0.17), and 0.12 to 1.2 (0.40 ± 0.16) nmol/min/mg of protein, respectively.