探討添加三種不同的含硫鹽類以加強十字花科植物芽菜的抗癌活性

Abstract

芽菜已知富含多種對人體健康有益的植物化合物，為一種具潛力的新興機能性食品。已有文獻指出芽菜比其成熟的蔬菜具更多量的植物成分，例如十字花科植物中的硫配醣體 (Glucosinolates)，其已被證實可提高人體中解毒酵素系統 phase II 酵素的解毒作用、抑制腫瘤的形成及抗氧化等功能，具有許多保健功效。亦有許多文獻證實在栽培芽菜時，於培養基中添加額外的營養物質，更能有效提升其生物活性。本實驗嘗試添加三種不同的含硫鹽類 – 硫酸銨鹽 (Ammonium sulfate)、硫酸鎂鹽 (Magnesium sulfate) 以及硫代硫酸鈉鹽 (Sodium thiosulfate) 於三種十字花科植物：甘藍菜芽 (Cabbage sprout)、綠色花椰菜芽 (Broccoli sprout) 與蘿蔔嬰 (Radish sprout) 的培養土中，以期增加活性成分並提升抗癌功能。結果顯示，在培養到達第十二天時，三種芽菜含有的總硫配醣體含量達最大量。而選擇三種不會影響植物生長的含硫鹽類濃度：20、40 及 60 kg/ha 添加於甘藍菜芽、綠色花椰菜芽與蘿蔔嬰的培養土中培養十二天後，皆能有效提升總硫配醣體的含量。在蘿蔔嬰方面，添加硫代硫酸鈉鹽 (60 kg/ha) 其水萃液中硫配醣體的含量 (1.996 mM) 比未添加組 (0.699 mM) 高，約提升了 5.58 倍，且其也具有良好清除 DPPH 及 ABTS+． 自由基的能力 (清除率分別為 89% 及 96%) 與抑制肝癌細胞 Hep G2 與結腸癌細胞 CT-26 的活性 (抑制率分別為 53% 與 78%)。相同地添加硫代硫酸鈉鹽 (60 kg/ha) 於甘藍菜與綠花椰菜方面，也能有效提升其總硫配醣體的含量、清除自由基與抑制癌細胞生長的能力。在甘藍菜芽方面抑制Hep G2 與 CT-26 的抑制率分別為 72% 與 84%，而在綠花椰菜芽方面的抑制率則分別為 67% 與 77%。因此在添加不同的含硫鹽類於十字花科植物芽菜上皆能有效地提升其抗癌活性的能力。

Edible sprouts are one of the potentially new functional foods. Especially, cruciferous sprouts contain high concentration of glucosinolates, which are potent source of protective chemicals against cancer. Glucosinolates can induce the phase II enzyme system thus inhibiting the growth of tumor. Besides, it has been observed that supplementing the nutrient medium (water/soil) of sprouting seeds can be of great benefit for improving the nutritional quality of the sprouts. The purpose of our efforts was to enhance the antioxidant and anticancer properties of cruciferous sprouts by supplementing the growth medium with different sulphur salts (ammonium sulfate, magnesium sulfate and sodium thiosulfate), which could increase the main concentration of the bioactive compounds – glucosinolates. Three cruciferous sprouts used in our studies namely, cabbage, broccoli and radish, showed an increase in glucosinolates content during sprouting with a maximum at day 12. Sulfur salt concentrations were optimized and finally used at 20, 40 and 60 kg/ha, where the sprout yield was not adversely affected by salt concentrations. In case of radish sprouts supplemented with sodium thiosulfate (60 kg/ha), the aqueous extracts showed higher glucosinolate content (1.996 mM) than ethanolic extract (0.699 mM). Also there was a 5.58 fold increase as compared to control. Further it showed very good DPPH and ABTS+． scavenging activity, i.e., 89% and 96% respectively. The anticancer activity of radish aqueous extract was also check and was found to suppress the growth of Hep G2 hepatoma cells by 53% and CT-26 colon cancer cells by 78%. Similar increase of glucosinolate content and free radical scavenging activity were obtained in case of cabbage and broccoli sprouts. Accordingly, the cancer cell inhibition for cabbage sprouts was found to be 72% and 84% for Hep G2 and CT-26 cells, respectively. While for broccoli sprouts the cancer cell inhibition was found to be 67% and 77% for Hep G2 and CT-26 cells, respectively. Thus the supplementation of different cruciferous sprouts with sulfur salts was found to be very effective in increasing their anticancer properties against different cancer cell lines.