Table 1. Effect of asclepiasterol on reversing ABCB-1/P-gp mediated drug resistance.
| Compounds | IC50±SDa (μM) (fold-reversal)b | ||||
|---|---|---|---|---|---|
| MCF-7 | MCF-7/ADR | HepG-2 | HepG-2/ADM | ||
| Doxorubicin | 0.995±0.012 (1.00) | 14.401±2.811 (1.00) | 0.430±0.019 (1.00) | 46.856±8.244 (1.00) | |
| + | 2.5μM asclepiasterol | 1.012±0.011 (1.02) | 1.240±0.008 (11.61)** | 0.429±0.020 (1.00) | 4.584±0.027 (10.22)** |
| + | 5.0μM asclepiasterol | 1.022±0.012 (1.03) | 0.411±0.010 (35.06)*** | 0.404±0.021 (0.94) | 0.751±0.019 (62.41)*** |
| + | 10.0μM VRP | 0.709±0.013 (0.71) | 0.415±0.007 (34.71)*** | 0.137±0.189 (0.32) | 1.219±0.024 (38.44)** |
| Epirubicin | 4.282±1.202 (1.00) | 75.466±9.523 (1.00) | 3.556±0.852 (1.00) | 283.973±12.254 (1.00) | |
| + | 2.5μM asclepiasterol | 3.578±0.984 (0.84) | 10.988±1.254 (6.87)** | 3.088±1.258 (0.87) | 21.268±4.579 (13.35)** |
| + | 5.0μM asclepiasterol | 3.540±0.842 (0.83) | 4.528±1.362 (16.67)*** | 2.649±0.522 (0.75) | 8.483±2.478 (33.48)*** |
| + | 10.0μM VRP | 3.780±0.942 (0.88) | 15.003±3.547 (5.03)* | 1.210±0.014 (0.34) | 38.234±9.547 (7.43)* |
| Daunorubicin | 0.203±0.012 (1.00) | 40.522±5.214 (1.00) | 0.185±0.001 (1.00) | 21.586±5.247 (1.00) | |
| + | 2.5μM asclepiasterol | 0.260±0.022 (1.28) | 1.051±0.987 (38.55)** | 0.151±0.014 (0.82) | 1.503±0.125 (14.36)** |
| + | 5.0μM asclepiasterol | 0.215±0.012 (1.06) | 0.242±0.012 (167.31)*** | 0.192±0.051 (1.04) | 0.889±0.128 (24.29)*** |
| + | 10.0μM VRP | 0.234±0.531 (1.16) | 0.694±0.052 (3.42)** | 0.145±0.045 (0.78) | 0.381±0.095 (56.69)** |
| Paclitaxel | 0.239±0.091 (1.00) | 105.738±12.345 (1.00) | 0.101±0.012 (1.00) | 7.531±1.242 (1.00) | |
| + | 2.5μM asclepiasterol | 0.318±0.114 (1.33) | 5.082±1.475 (20.81)** | 0.105±0.009 (1.04) | 0.117±0.009 (64.42)** |
| + | 5.0μM asclepiasterol | 0.262±0.051 (1.10) | 0.370±0.095 (285.70)*** | 0.102±0.022 (1.01) | 0.089±0.009 (85.09)*** |
| + | 10.0μM VRP | 0.253±0.042 (1.06) | 8.969±2.547 (11.79)** | 0.099±0.003 (0.98) | 0.096±0.003 (78.12)*** |
| Cisplatin | 39.881±2.515 (1.00) | 37.685±0.395 (1.00) | 40.019±1.267 (1.00) | 30.937±1.439 (0.77) | |
| + | 2.5μM asclepiasterol | 38.687±0.650 (0.97) | 40.039±2.239 (0.94) | 43.053±1.413 (1.07) | 30.331±0.637 (0.76) |
| + | 5.0μM asclepiasterol | 38.792±1.080 (0.97) | 38.726±0.706 (0.97) | 42.477±3.498 (1.06) | 31.213±1.573 (0.78) |
| + | 10.0μM VRP | 39.127±1.356 (0.98) | 39.755±1.357 (0.95) | 41.087±1.752 (1.02) | 32.083±1.679 (0.80) |
a
Data in the table are shown as the means ± SD (n=6) of at least three independent experiments.
b
The fold-reversals are calculated as RR value indicating the fold MDR reversal of inhibitors.
*
P < 0.05
**
P < 0.01
***
P < 0.001 for the IC50 versus that in the absence of inhibitors.