Cytotoxic Activity of Four Medicinal Plants and Four Food Plants Occurring in Thai Gynaecological Scriptures on Two Cancers Cell Lines

Medicinal plants found in Thai gynaecological scriptures are still used in the treatment of ovarian and breast cancer and some medicinal plants are used daily in Thai food. They are Boesenbergia rotunda (L.) Mansf, Piper nigrum Linn, Zingiber officinale Roscoe,Piper sarmentosum Roxb, Zingiber cassumunar Roxb, Zingiber zerumbet (L.) Smith, Oroxylum indicum(L.) Kurz. and Dioscorea birmanica Prain & Burkill. The objective was to investigate cytotoxicity of these plants. Sample plants were extracted similarly to that practiced by Thai traditional practitioners (ethanol extraction). Bioassay-guided fractionation was used for isolating the pure compound from D.birmanica extract and elucidated by spectrophotometry. All extracts were tested for their cytotoxic activity against ovarian(SKOV-3) and breast(MCF-7) cancer cell lines and keratocyte cells (Hacat) by sulforhodamine B assay, involving eight herbal extracts plus the purified compound named Prosapogenin A of dioscin, which was purified from the 95% ethanolic extract of D.birmanica. Prosapogenin A of dioscin was cytotoxic against both ovarian and breast cancer cells with IC₅₀ values of 7.30 ± 0.05 and 5.36 ± 0.26 µg/ml. but not toxic to keratocyte cells with IC₅₀ value of 94.76 ± 1.25 µg/ml. Z.zerumbet had the highest cytotoxicity against both ovarian and breast cancer cells with IC₅₀ values of 5.57 ± 0.47 and 0.25 ± 0.32 µg/ml. but toxic to keratocyte cells with IC₅₀ value of 1.86 ± 0.23 µg/ml. Z.cassumunar, P.nigrum, B.rotunda, O.indicum, Z.officinale and P.sarmentosum showed toxicity against only breast cancer cells with IC₅₀ values of 11.14 ± 1.48, 18.24 ± 2.77, 19.20 ± 0.32, 23.22 ± 1.97, 24.19 ± 1.34 and 24.84 ± 2.03 µg/ml, respectively. They were not toxic to keratocyte cells with IC₅₀ values of 48.53 ± 4.35, 36.13 ± 1.41, 34.25 ± 0.62, > 100, 35.63 ± 0.12 and 40.39 ± 0.98 µg/ml, respectively.In conclusion, medicinal and food plants showed high toxicity against both ovarian and breast cancer cells, while not damaging normal cells. In particular, B.rotunda, Z.cassumunar and D.birmanica were highly toxic against breast cancer cells.