Sulforaphene in Raphanus sativus L. var. caudatus Alef increased in late-bolting stage as well as anticancer activity

Objectives: To evaluate the concentration differences of sulforaphene and sulforaphane at various ages and in different parts of Raphanus sativus L. var. caudatus with respect to their potential cancer preventive effect on HCT116 colon cancer cells. Methods: FTIR-ATR and GC-MS were used to characterize the isothiocyanates in the plant extracts followed by HPLC for quantification. Antiproliferation and apoptosis induction were determined by using MTT assay and flow cytometry, respectively. Results: The respective rank of anticancer activity of Raphanus sativus were as follows: vegetative (3 week) < older rosette (4 week) < early-bolting (5 week) < senescence (7 week) < late-bolting (6 week). The low to high concentration of sulforaphene and sulforaphane occurred in the same stage order. Conclusions: The reproductive parts (flower, pod, and dry seed) of Raphanus sativus have the greatest isothiocyanate concentration, evidenced by a sulforaphene concentration higher than the sulforaphane. This result should inform the selection of the most appropriate harvesting stage and plant part for use as a potential chemopreventive agent.