Table 2.
Summary of disposition of apigenin (1, Fig. 6) via glucuronidation using Caco-2 and intestinal perfusion models
| Apigenin | |
|---|---|
| Caco-2 Model 71–73 | |
| Permeability (Papp) | > 1.7 ×10−5 cm/s |
| Cell lysate glucuronidation | Hyperbolic kinetics curve with Km > 25 μM and Vm ~ 250 pmol/min/mg |
| AL excreted glucuronide | 3.42 nmol a |
| BL excreted glucuronide | 5.92 nmol a |
| Rat Perfusion Model 71,72 | |
| P*eff | > 1.5 |
| P*w | > 7 |
| % absorbed | ~ 30% (476 nmol) b |
| Mgut/Mab | 33% b |
| Mbile/Mab | 7% b |
| Intestinal excreted# | 150 nmol b |
| Biliary excreted# | 30 nmol b |
| Intestinal microsomes glucuronidation | Substrate inhibition curve with Vmax > 16 nmol/min/mg |
| Liver microsomes glucuronidation | Substrate inhibition curve with Vmax > 10 nmol/min/mg |
| Regional glucuronidation | jejunum>duodenum>ileum>colon |
| Regional excretion | jejunum>duodenum>ileum>colon |
#
maximal amount per 30min;
a
at the end 2 hour of experiment;
b
perfusion experiment was performed at 35 μM of apigenin and flow rate of 0.382 ml/min. The total amount of compound perfused over a 30-min for each segment was 401 nmol.