Table 1. Plant extracts induce PRE-luciferase and bind to PR in T47D breast epithelial cells.
Progesterone responsive element (PRE)-luciferase induction, progesterone receptor (PR) binding, and cytotoxicity of plant extracts in human breast cancer epithelial cells (T47D). Botanical extracts (20 μg/mL) were tested at a single concentration in luciferase assays and at five doses in PR binding assays. N/D indicates that the plant extract interferes with measuring polarization. Data represent average ± SEM fold change of relative light units normalized to β-gal in three independent experiments. Significant differences from the control DMSO value were determined by t-test.
| Plant Extracts 75% Ethanolic (20μg/mL) | PRE-luciferase fold increase | PR Binding IC50 μg/mL | Toxicity, T47D LC50 μg/mL |
|---|---|---|---|
| Humulus lupulus (Hops) | 2.2 ± 1.2 | N/D | 2.5 |
| Cimicifuga racemosa (Black Cohosh) | 1.5 ± 0.1 | > 1 mg | > 20 |
| Cornus officinalis (Dogwood) | 1.3 ± 1.1 | 15 ± 1.4 | > 20 |
| Pueraria lobata (Kudzu) | 2.1 ± 1.4 | N/D | > 20 |
| Valeriana officinalis (Valerian) | 1.4 ± 0.7 | 97 ± 17 | > 20 |
| Vitex agnus castus (Chaste-Tree Berry) | 1.5 ± 1.0 | > 1 mg | > 20 |
| Angelica sinensis (Dong Quai) | 1.6 ± 0.7 | 106 ± 21 | > 20 |
| Trifolium pratense (Red Clover) | 4.7 ± 1.2* | 34 ± 20 | > 20 |
*
p<0.05. Progesterone has an IC50 of 25 nM in the PR binding assay and at 100 nM induces a 54 fold change in luciferase activity over basal.