A novel protein C-phycocyanin plays a crucial role in the hypocholesterolemic action of Spirulina platensis concentrate in rats
A novel protein C-phycocyanin plays a crucial role in the hypocholesterolemic action of Spirulina platensis concentrate in rats
复制标题
DOI：
10.1093/jn/135.10.2425
复制
发表时间：
2005-10-01
影响因子：
4.2
通讯作者：
Kato, Toshimitsu
中科院分区：
文献类型：
--
作者：
Nagaoka, Satoshi;Shimizu, Kazuo;Kato, Toshimitsu
本研究旨在阐明钝顶螺旋藻浓缩物（SPC）降胆固醇作用的机制，并从SPC中筛选新的降胆固醇蛋白。我们研究了酪蛋白或SPC对胆固醇溶解度、体外牛磺胆酸结合力、Caco-2细胞胆固醇吸收和大鼠胆固醇代谢的影响。我们还评估了SPC，C-藻蓝蛋白（PHY），和PHY残留对大鼠胆固醇代谢的影响，喂养高胆固醇饮食5天，SPC或SPC-丙酮提取物10天。SPC在体外具有比酪蛋白更大的胆汁酸结合能力。与酪蛋白相比，SPC存在下，胶束胆固醇溶解度和Caco-2细胞的胆固醇摄取显著降低。粪便排泄的胆固醇和胆汁酸是显着更大的大鼠喂养SPC补充饮食比那些喂养酪蛋白对照饮食。饲喂SPC的大鼠血清和肝脏胆固醇浓度显著低于饲喂酪蛋白的大鼠。因此，SPC的降胆固醇作用可能涉及抑制空肠胆固醇吸收和回肠胆汁酸重吸收。虽然没有研究到目前为止已经发现了一个低胆固醇血症的蛋白质之间的藻类蛋白质，我们在这里报告发现的一个新的蛋白质C-藻蓝蛋白的低胆固醇血症的效果。这项研究提供了第一个直接的证据，PHY，一种新的降胆固醇蛋白来自螺旋藻，可以有力地影响血清胆固醇浓度，并赋予更强的降胆固醇活性比SPC在动物中。
This study was designed to clarify the mechanisms of the hypocholesterolemic action of Spirulina platensis concentrate (SPC) and identify the novel hypocholesterolemic protein derived from SPC. We investigated the effects of casein or SPC on the solubility of cholesterol, taurocholate binding capacity in vitro, cholesterol absorption in Caco-2 cells, and cholesterol metabolism in rats for 10 d. We also evaluated the effects of SPC, C-phycocyanin (PHY), and PHY residue on cholesterol metabolism in rats fed a high-cholesterol diet for 5 d, and SPC or SPC-acetone extract for 10 d. SPC had a significantly greater bile acid-binding capacity than casein in vitro. Micellar cholesterol solubility and cholesterol uptake by Caco-2 cells was significantly lower in the presence of SPC compared with casein. Fecal excretion of cholesterol and bile acids was significantly greater in rats fed the SPC-supplemented diet than in those fed the casein control diet. Serum and liver cholesterol concentrations were significantly lower in rats fed SPC than in those fed casein. Thus, the hypocholesterolemic action of SPC may involve the inhibition of both jejunal cholesterol absorption and ileal bile acid reabsorption. Although no studies to date have found a hypocholesterolemic protein among the algal proteins, we report here the discovery of a hypocholesterolemic effect in the novel protein C-phycocyanin. This study provides the first direct evidence that PHY, a novel hypocholesterolemic protein derived from Spirulina platensis, can powerfully influence serum cholesterol concentrations and impart a stronger hypocholesterolemic activity than SPC in animals.