BACKGROUND The sprouts of Brassica vegetables are known from their nutritional and chemopreventive values. Moreover, sprouts fortification with some trace elements, like selenium, may increase their importance in human diet. Thus, the aim of our study was to examine if selenium enrichment of kale and kohlrabi sprouts may influence their biochemical properties (phenolic acids and L-tryptophan content, antioxidant potential) or cytotoxic activity. Additional aim of the study was to evaluate the profile of selenium compounds and to describe the multidimensional interactions between the mentioned parameters. METHODS Selenium content in the sprouts was evaluated by double-channel atomic fluorescence spectrometer AFS-230 with the flow hydride-generation system. Separation of selenium species in water soluble fraction was performed by size-exclusion LC-ICP-MS. The identification and quantification of phenolic acids and L-tryptophan was performed by HPLC. For antioxidant activity DPPH and FRAP methods were used. Cytotoxic activity of the sprouts extracts on a panel of human metastatic carcinoma cells was evaluated by MTT test. RESULTS Selenium content in the fortified sprouts was several orders of magnitude higher than in the unfortified ones. Only small percentage of supplemented selenium (ca. 10 %) was incorporated into the sprouts as seleno-L-methionine, while the other detected selenium species remained unidentified. Selenium fortification differently stimulated the production of phenolic acids (sinapic, chlorogenic, isochlorogenic and caffeic acid) in the tested sprouts, depending on the particular species, selenium dose and the investigated compound. PCA analysis revealed strong correlation between antioxidant parameters and phenolic acids and L-tryptophan, while Se correlated only with caffeic acid. The sprouts extracts (≥1 mg/mL) showed cytotoxic potency to all the studied cancer cell lines (SW480, SW620, HepG2, SiHa), regardless the selenium supplementation. CONCLUSION Se-fortified kale and kohlrabi sprouts are good candidates for functional food ingredients. Moreover, these results indicate that the sprouts enriched with sodium selenite show higher nutritional value, without significant changes in their cytotoxic activity.

中文翻译：

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芥兰和大头菜芽中硒的强化是否会显着改变其生化和细胞毒性特性？

背景技术从芸苔属蔬菜的营养和化学预防价值入手。此外，用硒等微量元素强化的豆芽可能会增加其在人类饮食中的重要性。因此，我们的研究目的是检验富集羽衣甘蓝和大头菜豆芽中的硒是否会影响其生化特性（酚酸和L-色氨酸含量，抗氧化能力）或细胞毒性。该研究的另一个目的是评估硒化合物的分布并描述上述参数之间的多维相互作用。方法采用流动氢化物发生系统，采用双通道原子荧光光谱仪AFS-230对豆芽中的硒含量进行评估。通过尺寸排阻LC-ICP-MS分离水溶性级分中的硒。酚酸和L-色氨酸的鉴定和定量通过HPLC进行。对于抗氧化剂活性，使用了DPPH和FRAP方法。通过MTT试验评估芽苗提取物对一组人转移性癌细胞的细胞毒活性。结果强化豆芽中的硒含量比未强化豆芽中的硒含量高几个数量级。仅少量添加的硒（约10％）作为硒代L-蛋氨酸被掺入到芽中，而其他检测到的硒种类仍未鉴定。硒强化在测试的豆芽中刺激了酚酸（芥子酸，绿原酸，异绿原酸和咖啡酸）的产生，取决于特定的物种，硒剂量和所研究的化合物。PCA分析显示，抗氧化剂参数与酚酸和L-色氨酸之间具有很强的相关性，而Se仅与咖啡酸相关。无论是否补充硒，芽苗提取物（≥1mg / mL）对所有研究的癌细胞系（SW480，SW620，HepG2，SiHa）均显示出细胞毒性潜能。结论硒强化的羽衣甘蓝和大头菜豆芽是功能性食品成分的理想选择。而且，这些结果表明富含亚硒酸钠的芽苗显示出更高的营养价值，而其细胞毒性活性没有显着变化。而硒仅与咖啡酸相关。无论是否补充硒，芽苗提取物（≥1mg / mL）对所有研究的癌细胞系（SW480，SW620，HepG2，SiHa）均显示出细胞毒性潜能。结论硒强化的羽衣甘蓝和大头菜豆芽是功能性食品成分的理想选择。而且，这些结果表明富含亚硒酸钠的芽苗显示出更高的营养价值，而其细胞毒性活性没有显着变化。而硒仅与咖啡酸相关。无论是否补充硒，芽苗提取物（≥1mg / mL）对所有研究的癌细胞系（SW480，SW620，HepG2，SiHa）均显示出细胞毒性潜能。结论硒强化的羽衣甘蓝和大头菜豆芽是功能性食品成分的理想选择。而且，这些结果表明富含亚硒酸钠的芽苗显示出更高的营养价值，而其细胞毒性活性没有显着变化。