Kaiware Daikon (Raphanus sativus L.) Extract: A Naturally Multipotent Chemopreventive Agent

详细信息    查看全文

• 作者：Jessica Barillari ; Renato Iori ; Alessio Papi ; Marina Orlandi ; Giovanna Bartolini ; Simone Gabbanini ; Gian Franco Pedulli ; Luca Valgimigli
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2008
• 出版时间：September 10, 2008
• 年：2008
• 卷：56
• 期：17
• 页码：7823-7830
• 全文大小：331K
• 年卷期：v.56,no.17(September 10, 2008)
• ISSN：1520-5118

文摘

Brassica vegetables are attracting major attention as healthy foods because of their content of glucosinolates (GLs) that release the corresponding isothiocyanates (ITCs) upon myrosinase hydrolysis. A number of studies have so far documented the chemopreventive properties of some ITCs. On the other hand, single nutrients detached from the food itself risk being somewhat “reductive”, since plants contain several classes of compounds endowed with a polyhedral mechanism of action. Our recent finding that 4-methylthio-3-butenyl isothiocyanate (GRH-ITC) and 4-methylsulfinyl-3-butenyl isothiocyanate (GRE-ITC), released by the GLs purified from Japanese (Kaiware) Daikon (Raphanus sativus L.) seeds and sprouts, had selective cytotoxic/apoptotic activity on three human colon carcinoma cell lines prompted further research on the potential chemopreventive role of a standardized Kaiware Daikon extract (KDE), containing 10.5% w/w GRH and 3.8% w/w GRE, compared to its isolated components. KDE administered in combination with myrosinase at doses corresponding to 50 μM GRH-ITC plus 15 μM GRE-ITC (50 μM KDE-ITC) to three human cancer cell lines (LoVo, HCT-116 and HT-29) significantly reduced cell growth by 94−96% of control in six days (p < 0.05), outperforming pure GRH-ITC or GRE-ITC at the same dose. On the other hand, the same treatment had no significant toxicity on normal human T-lymphocytes. A 50 μM concentration of KDE-ITC had relevant apoptosis induction in all tested cancer cell lines, as confirmed by annexin V assay (e.g., 33% induction in LoVo compared to control, p < 0.05), Bax protein induction (e.g., +20% in HT-29, p < 0.05), and Bcl2 downregulation (e.g.−20% in HT-29, p < 0.05), and induced caspase-1 and PARP-1 activation in all cancer cells as shown by Western blot analysis. Unlike pure GRH or GRH-ITC, KDE also had significant chain-breaking antioxidant activity, retarding the AAPH-initiated autoxidation of methyl linoleate in SDS micelles at concentrations as low as 4.4 ppm (−50% in oxygen consumption rate), as monitored by Clark-type microelectrode oxygen-uptake kinetics, and induced very fast quenching of DPPH· radical in methanol with t_1/2 (s) = (1.47 ± 0.25) × 10⁻²/[KDE; (g/L)], measured by stopped-flow UV−vis kinetics at 298 K. The potential chemopreventive role of KDE is discussed.