Figure 1.
Molecular structures of vingerbine alkaloids: (a) vincarine, (b) vincamajine, (c) herbadine, and (d) herbamine
Figure 2.
Western blot analysis of P-gp (170 kDa) expression in cultured Caco-2 cells
Figure 3.
Effect of PAA-GSH (a), ch.GSH (b), and GSH (c) on the transepithelial transport of vingerbine alkaloids across Caco-2 cell monolayers. Values are expressed as mean ± SD of at least three independent experiments
Table 1.
Apparent permeability (Papp ± SD, n = 3) of vingerbine alkaloids across Caco-2 cell monolayers during apical-to-basolateral (A→B) transport, with and without the indicated polymers
| Apical-to-basolateral compartment | No polymer | GSH | ch.GSH | PAA-GSH |
|---|---|---|---|---|
| Papp × 10−6 (cm/s) | ||||
| Herbamine | 4.70±0.03 | 6.44 ± 0.01 | 3.68 ± 0.12 | 15.98 ± 0.46 |
| Herbadine | 6.20±0.02 | 5.64 ± 0.07 | 3.71±0.04 | 16.05 ± 0.35 |
| Vincarine | 4.20±0.02 | 3.86±0.09 | 2.78 ± 0.14 | 6.38 ± 0.03 |
Table 2.
Influence of indicated thiolated polymers on vingerbine alkaloid efflux across Caco-2 cell
| Vingerbine alkaloids | GSH | PAA-GSH |
|---|---|---|
| EMR* | ||
| Herbamine | 1.01 ± 0.28 | 0.99 ± 0.26 |
| Herbadine | 0.96 ± 0.18 | 0.94 ± 0.02 |
| Vincarine | 0.92 ± 0.09 | 0.97 ± 0.09 |
Figure 4.
Effect of ch.GSH conjugates on the apparent permeability (Papp) of vingerbine alkaloids across Caco-2 cell monolayers in the basolateral-to-apical (B→A) direction. Values represent the mean ± SD of at least three independent experiments