Nakaya Makoto, Shojo Aiko, Hirai Hiroaki, Matsumoto Kenji, Kitamura Shinichi
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
Biosci Biotechnol Biochem. 2013;77(7):1435-40. doi: 10.1271/bbb.130087. Epub 2013 Jul 7.
waxy/amylose-extender (wx/ae) double-mutant japonica rice (Oryza sativa L.) produces resistant starch (RS) and a large amount of γ-oryzanol. Our previous study has shown the hypolipidemic effect of wx/ae brown rice on mice. To identify the functional constituents of the hypolipidemic activity in wx/ae rice, we prepared pure wx/ae starch and γ-oryzanol from wx/ae rice and investigated their effect on the lipid metabolism in BALB/c.KOR/Stm Slc-Apoe(shl) mice. The mice were fed for 3 weeks a diet containing non-mutant rice starch, non-mutant rice starch plus γ-oryzanol, wx/ae starch, or wx/ae starch plus γ-oryzanol. γ-Oryzanol by itself had no effect on the lipid metabolism, and wx/ae starch prevented an accumulation of triacylglycerol (TAG) in the liver. Interestingly, the combination of wx/ae starch plus γ-oryzanol not only prevented a TAG accumulation in the liver, but also partially suppressed the rise in plasma TAG concentration, indicating that wx/ae starch and γ-oryzanol could have a synergistic effect on the lipid metabolism.
蜡质/直链淀粉延伸因子（wx/ae）双突变粳稻（Oryza sativa L.）能产生抗性淀粉（RS）和大量γ-谷维素。我们之前的研究表明wx/ae糙米对小鼠有降血脂作用。为了确定wx/ae水稻中降血脂活性的功能成分，我们从wx/ae水稻中制备了纯wx/ae淀粉和γ-谷维素，并研究了它们对BALB/c.KOR/Stm Slc-Apoe(shl)小鼠脂质代谢的影响。给小鼠喂食含非突变水稻淀粉、非突变水稻淀粉加γ-谷维素、wx/ae淀粉或wx/ae淀粉加γ-谷维素的饲料3周。单独的γ-谷维素对脂质代谢没有影响，而wx/ae淀粉可防止肝脏中三酰甘油（TAG）的积累。有趣的是，wx/ae淀粉加γ-谷维素的组合不仅能防止肝脏中TAG的积累，还能部分抑制血浆TAG浓度的升高，这表明wx/ae淀粉和γ-谷维素对脂质代谢可能具有协同作用。
