Table 2. Cytotoxicity (IC50)a of the extracts of P. watsonii and fractions and sub-fractions of PW-H.
| Test agents | Cell lines IC50 (µg/mL) (SIb) | |||
| SKOV-3 | Ca Ski | HT-29 | MRC-5 | |
| PW-Mc | 8.51 ± 0.50 (5.8) | 8.03 ± 0.87 (6.1) | 18.33 ± 1.53 (2.7) | 49.33 ± 5.80 |
| PW-H | 5.79 ± 0.29 (9.9) | 6.94 ± 0.96 (8.3) | 11.79 ± 1.61 (4.9) | 57.30 ± 2.57 |
| PW-E | 5.52 ± 0.50 (6.1) | 3.58 ± 1.01 (9.4) | 5.14 ± 0.36 (6.6) | 33.79 ± 2.57 |
| PWH-1d | 89.77 ± 1.25 | >100 | >100 | >100 |
| PWH-2 | 6.80 ± 0.29 | >100 | >100 | >100 |
| PWH-3 | 5.26 ± 0.76 | 85.52 ± 3.04 | 66.25 ± 2.02 | >100 |
| PWH-4 | 0.29 ± 0.06 (56.0) | 13.19 ± 3.25 (1.2) | 10.78 ± 0.76 (1.5) | 16.25 ± 1.76 |
| PWH-5 | 0.18 ± 0.06 (68.1) | 7.20 ± 1.15 (1.7) | 5.20 ± 0.76 (2.4) | 12.26 ± 2.52 |
| PWH-6 | 0.42 ± 0.12 (18.7) | 5.51 ± 0.50 (1.4) | 5.68 ± 0.76 (1.4) | 7.84 ± 1.04 |
| PWH-7 | 0.77 ± 0.29 (10.4) | 8.78 ± 0.58 (0.9) | 1.21 ± 1.04 (6.6) | 8.02 ± 1.80 |
| PWH-8 | 0.36 ± 0.12 (23.0) | 2.77 ± 0.76 (3.0) | 1.19 ± 0.29 (6.9) | 8.27 ± 1.04 |
| PWH-9 | 69.50±1.72 | >100 | >100 | >100 |
| PWH-10 | >100 | >100 | >100 | >100 |
| PPWH-1e | 100.00 ± 2.89 | >100 | 72.81 ± 6.66 | >100 |
| PPWH-2 | >100 | >100 | >100 | >100 |
| PPWH-3 | 74.01 ± 8.53 | 98.84 ± 2.02 | >100 | >100 |
| PPWH-4 | 37.03 ± 0.50 | 60.02 ± 2.60 | 40.82 ± 2.08 | >100 |
| PPWH-5 | 4.75 ± 2.57 | 45.18 ± 3.18 | 63.78 ± 2.08 | >100 |
| PPWH-6 | 9.52 ± 1.80 (1.5) | 12.04 ± 3.50 (12.1) | 14.76 ± 4.19 (1.0) | 14.54 ± 1.80 |
| PPWH-7 | 0.66 ± 0.06 (15.5) | 0.83 ± 0.00 (12.3) | 0.83 ± 0.10 (12.3) | 10.21 ± 1.26 |
| PPWH-8 | 0.88 ± 0.10 (19.1) | 9.16 ± 0.58 (1.8) | 18.31 ± 2.75 (0.9) | 16.83 ± 1.26 |
| Doxorubicin | 0.42 ± 0.24 (4.1) | 0.68 ± 0.08 (2.5) | 0.63 ± 0.03 (2.7) | 1.72 ± 0.08 |
a
Data are presented as mean ± SD from 3 independent experiments, triplicate for each. Values in bold characters are considered to have cytotoxic activity (IC50 ≤ 20 µg/mL).
b
Selectivity index.
c
PW-M, PW-H & PW-E: extracts of P. watsonii in 3 different solvents, MeOH, hexane and EtOAc, respectively.
d
PWH-1, PWH-2,…….,PWH-10: fractions of PW-H of P. watsonii.
e
PPWH-1, PPWH-2,….,PPWH-8: sub-fractions from pooled fractions (PWH-4,…,PWH-8).