Table 4.
Cytotoxicity of Extract Stock Solutions from Dried Frontier Herb Hp in Three Cancer Cell Linesa
| mean ± SE
|
||||||
|---|---|---|---|---|---|---|
| NIH3T3 mouse fibroblasts
|
SW480 human colon cancer cells
|
HaCaT human skin keratinocytes
|
||||
| extraction method and solvents (treatment concn of extracts in media) | light | dark | light | dark | light | dark |
| Soxhlet | ||||||
| 100% EtOH (1161 μg/mL) | 7.7** (±4.2) | 10.3** (±4.9) | 8.3** (±3.5) | 11.7** (±2.8) | 35.4** (±7.5) | 40.3** (±8.9) |
| chloroform (284 μg/mL) | 5.5** (±3.7) | 9.0** (±5.1) | 2.5** (±1.7) | 8.2** (±4.1) | 1.6** (±1.1) | 0.4** (±0.2) |
| hexane (166 μg/mL) | 3.1** (±2.0) | 4.1** (±2.6) | 1.5** (±1.3) | 2.9** (±2.5) | 0.3** (±0.3) | 0.3** (±0.3) |
| 100% ethanol (–chloroform) (589 μg/mL) | 38.1* (±3.4) | 49.0* (±3.3) | 55.1** ## (±2.7) | 77.2 (±1.2) | 35.6** ## (±6.8) | 77.4* (±9.9) |
| 100% ethanol (–hexane) (568 μg/mL) | 12.0** ## (± 4.6) | 32.5** (± 3.1) | 8.7** ## (± 2.7) | 32.4** (± 4.9) | 40.8** (± 11.8) | 50.4** (± 9.6) |
| room temperature shaking | ||||||
| 70% EtOH (740 μg/mL) | 11.1** (±9.1) | 12.5** (±7.4) | 2.5** (±0.9) | 14.2** (±5.5) | 42.8** (±8.9) | 34.3** (±10.6) |
| chloroform (174 μg/mL) | 34.8** (±6.5) | 33.1** (±6.7) | 26.8** (±11.8) | 47.6* (±5.2) | 8.5** (±5.1) | 12.1** (±2.9) |
| hexane (58 μg/mL) | 82.6 (±1.9) | 81.4 (±2.9) | 83.3 (±9.0) | 88.5 (±2.4) | 89.5 (±4.9) | 94.1 (±3.6) |
| 70% ethanol (–chloroform) (692 μg/mL) | 33.6** (±7.4) | 27.6** (±6.7) | 57.7** (±7.5) | 44.6** (±6.7) | 41.6** (±3.6) | 66.2* (±13.7) |
| 70% ethanol (–hexane) (556 μg/mL) | 29.7** (±8.5) | 35.1** (±6.1) | 25.0** (±4.9) | 39.2** (±8.2) | 32.9** (±7.8) | 45.4** (±9.4) |
| water (213 μg/mL) | 84.4* (±3.0) | 85.5* (±1.7) | 95.6 (±5.0) | 85.1 (±5.7) | 73.6 (±16.2) | 87.7 (±8.1) |
| 20 μM hypericin | 10.1** ## (±6.2) | 60.9** (±5.7) | 20.8** ## (±2.4) | 80.5 (±1.3) | 0.87** # (±0.4) | 53.2** (±10.9) |
Cytotoxicity (% survival as compared to vehicle control-treated cells) of Hp extracts screened via the Celltiter96 Aqueous One Solution Cytotoxicity assay (n = 3–5). All extract stock solutions were prepared from 6 g (water extract from 5 g) of dried plant material by either Soxhlet or room temperature extraction and included as 1% of the cell culture media. One set of chloroform and hexane extracts was sequentially extracted in ethanol:ethanol(–chloroform) or ethanol(–hexane). The treatment concentration listed for each extract or fraction (μg/mL) is the amount of extract residue obtained after extraction, diluted in DMSO, and used in the assay. A 20 μM concentration of hypericin was the positive control.
= p < 0.0001 and
= p < 0.01 significantly different cell growth survival as compared to DMSO solvent control.
= p < 0.0001 and
= p < 0.01 significantly different cell growth survival after exposure to 30 min of ambient light as compared to the dark incubation.