Tsuneyoshi Tadamitsu, Yoshida Jiro, Sasaoka Takashi
Healthcare Research Institute, Wakunaga Pharmaceutical Company, Akitakata, Hiroshima 739-1195, Japan.
J Nutr. 2006 Mar;136(3 Suppl):870S-872S. doi: 10.1093/jn/136.3.870S.
Garlic enriched by selenium (Se) could be an excellent source of dietary Se for cancer chemoprevention. The production of high-Se garlic requires Se-fertilized soil, but such soil may pollute the environment. Hydroponics is a closed system that allows good control over Se fertilization without environmental consequences. We examined the effect of hydroponic cultivation on Se uptake and assimilation in garlic seedlings. Garlic bulbs were grown in the nutrient solution without Se for first 2 wk, and with potassium selenate for an additional week. Sulfate in an ordinary hydroponic solution inhibited the absorption and assimilation of selenate, but when a sulfate-free nutrient was used for Se addition, the garlic seedlings accumulated >1 mg Se, dry weight. Through HPLC inductively coupled plasma MS (HPLC-ICP-MS) analysis, Se-methlyselenocysteine (MeSeCys), gamma-glutamyl-Se-methlyselenocysteine (gamma-GluMeSeCys), selenomethionine, and nonmetabolized selenate were identified in water extracts of the garlic seedlings. The results demonstrate that hydroponic enrichment of Se in garlic seedlings could be a practical means of producing organic Se compounds for nutritional supplements.
富硒大蒜可能是用于癌症化学预防的膳食硒的优质来源。生产高硒大蒜需要用硒施肥的土壤，但这种土壤可能会污染环境。水培是一种封闭系统，能很好地控制硒施肥且不会对环境造成影响。我们研究了水培种植对大蒜幼苗硒吸收和同化的影响。大蒜鳞茎先在不含硒的营养液中培养2周，然后再添加硒酸钾培养1周。普通水培溶液中的硫酸盐会抑制硒酸盐的吸收和同化，但当使用无硫酸盐营养液添加硒时，大蒜幼苗每干重积累的硒超过1毫克。通过高效液相色谱-电感耦合等离子体质谱（HPLC-ICP-MS）分析，在大蒜幼苗的水提取物中鉴定出了甲基硒代半胱氨酸（MeSeCys）、γ-谷氨酰-甲基硒代半胱氨酸（γ-GluMeSeCys）、硒代蛋氨酸和未代谢的硒酸盐。结果表明，水培富集大蒜幼苗中的硒可能是生产用于营养补充剂的有机硒化合物的一种实用方法。
