Table 2.
Specific activity and mRNA expression of phase II drug-metabolizing enzymes (DMEs) in proliferating and differentiated CaCo-2 cells.
| Enzyme | Proliferating Cells | Differentiated Cells |
|---|---|---|
| GST | ||
| Activity (nmol/min/mg) | 163.9 ± 10.4 | 400.5 ± 33.8 *** |
| mRNA GSTA1/2 | 1.00 ± 0.16 | 1.46 ± 0.08 * |
| mRNA GSTP1 | 1.00 ± 0.36 | 1.33 ± 0.25 |
| SULT | ||
| Activity (pmol/min/mg) | 86.6 ± 12.9 | 175.4 ± 52.3 * |
| mRNA SULT1A1/2 | 1.00 ± 0.23 | 2.44 ± 0.55 * |
| COMT | ||
| Activity (nmol/min/mg) | 3.1 ± 2.5 | 9.6 ± 1.2 ** |
| mRNA COMT | 1.00 ± 0.32 | 14.44 ± 4.83 ** |
| UGT | ||
| Activity | n.d. | n.d. |
| mRNA UGT1A6 | n.d. |
Data are presented as the mean ± SD (n = 3). Statistical analyses were performed using a Student’s t-test: p < 0.05 (*), p < 0.01 (**), p < 0.001 (***); * different from proliferating cells after 24 h. GST: glutathione S-transferase; SULT: sulfotransferase; COMT: catechol-O-methyltransferase; UGT: UDP-glucuronosyltransferase; n.d.: not detected.