TABLE 4

Allosteric effects of berberine on MDZ hydroxylation by recombinant CYP3A4

Values denote means ± S.D. of four separate experiments. Km and Ki are given in micromolar; Vmax is in picomoles per minute per picomole CYP3A4; Vmax/Km is in microliters per minute per picomole CYP3A4.

Berberine (μM)1′-Hydroxy MDZ4-Hydroxy MDZ
KmVmaxVmax/KmKiKmVmaxVmax/Km
01.38 ± 0.2228.0 ± 4.620.7 ± 4.1900 ± 25025.0 ± 6.926.4 ± 7.51.13 ± 0.40
51.28 ± 0.2531.3 ± 3.724.7 ± 2.6610 ± 19027.4 ± 8.927.1 ± 5.51.05 ± 0.29
251.34 ± 0.2024.7 ± 4.018.6 ± 2.9560 ± 12040.1 ± 1719.5 ± 6.30.56 ± 0.25
501.63 ± 0.3923.4 ± 2.615.2 ± 4.9420 ± 16030.0 ± 3.414.6 ± 5.40.50 ± 0.20
1002.04 ± 0.5521.4 ± 2.411.0 ± 2.7470 ± 7032.0 ± 6.211.5 ± 4.20.37 ± 0.13