Cancer preventive effect of Thai rat-tailed radish (Raphanus sativus L. var. caudatus Alef)

• First report of anticancer effect of R. sativus L. var. caudatus Alef.
• R. sativus extract induced HCT116 colon cancer apoptosis.
• Cytotoxic IC50 of R. sativus extract against HCT116 9.42 ± 0.46 μg/ml.
• GC–MS profile revealed sulforaphane and sulforaphene in extract.
• Cancer preventive effect of R. sativus extract may be attributed to these compounds.

The cancer preventive effect of Raphanus sativus L. var. caudatus Alef (Thai rat-tailed radish) extract was evaluated against the HCT116 colon cancer cell line. HPLC and GC–MS were used to identify the phytoconstituents in Thai rat-tailed radish extract. Thai rat-tailed radish extract showed high cytotoxicity against HCT116 with an IC50 at 9.42 ± 0.46 μg/ml. Apoptosis induced by Thai rat-tailed radish extract was confirmed (a) by DAPI staining which demonstrated nuclei morphological changes, chromatin condensation and nuclear fragmentation and (b) by Annexin V/PI flow cytometry. GC–MS analysis of Thai rat-tailed radish extract revealed two isothiocyanates; sulforaphane and sulforaphene, whose cytotoxicity and apoptosis induction effect were evident, giving Thai rat-tailed radish extract its anticancer attributes. This is the first report on the cancer preventive effect of Thai rat-tailed radish extract against HCT116 colon cancer cell line, through apoptosis induction.