Han Li-Kun, Sumiyoshi Maho, Zheng Yi-Nan, Okuda Hiromichi, Kimura Yoshiyuki
Second Department of Medical Biochemistry, School of Medicine, Ehime University, Shigenobu-cho, Onsen-gun, Ehime 791-0295, Japan.
Phytother Res. 2003 Dec;17(10):1195-8. doi: 10.1002/ptr.1405.
Previously, it was reported that polyphenol fractions prepared from the leaves of Salix matsudana reduced the elevation of the rat plasma triacylglycerol level at 3 and 4 h after oral administration of a lipid emulsion containing corn oil, at a dose of 570 mg/kg. Moreover, body weights at 2-9 weeks and the fi nal parametrial adipose tissue weights were significantly lower in mice fed the high-fat diet with 5% polyphenol fractions of S. matsudana leaves than in those fed the high-fat diet alone. The polyphenol fractions of S. matsudana leaves also significantly reduced the hepatic total cholesterol content, which was elevated in mice fed the high-fat diet alone. In addition, the polyphenol fractions of S. matsudana leaves inhibited palmitic acid uptake into brush border membrane vesicles prepared from rat jejunum and alpha-amylase activity, and their fractions enhanced norepinephrine-induced lipolysis in fat cells. To clarify the active substances inhibiting the palmitic acid uptake into small intestinal brush border membrane, the alpha-amylase activity or enhancing the norepinephrine-induced lipolyis in fat cells, the isolation of the active substances from polyphenol fraction was attempted using the above three assay systems. Compounds 1, 2 and 3 were isolated from the polyphenol fractions and identified as apigenin-7-O-d-glucoside, luteolin-7-O-d-glucoside and chrysoeriol-7-O-d-glucoside, respectively. Among three flavonoids, apigenin-7-O-d-glucoside inhibited alpha-amylase activity, and luteolin-7-O-d-glucoside and chrysoeriol-7-O-d-glucoside inhibited palmitic acid uptake into small intestinal brush border membrane. Furthermore, three flavonoid glucosides enhanced norepinephrine-induced lipolysis in fat cells.
此前有报道称，以570 mg/kg的剂量口服含有玉米油的脂质乳剂后，从旱柳叶片中制备的多酚组分在3小时和4小时时可降低大鼠血浆甘油三酯水平的升高。此外，在高脂饮食中添加5%旱柳叶片多酚组分的小鼠，其2至9周龄时的体重以及最终子宫旁脂肪组织重量均显著低于单纯高脂饮食喂养的小鼠。旱柳叶片的多酚组分还显著降低了仅喂食高脂饮食的小鼠肝脏中总胆固醇的含量。此外，旱柳叶片的多酚组分抑制了棕榈酸进入大鼠空肠制备的刷状缘膜囊泡的摄取以及α-淀粉酶活性，并且它们的组分增强了去甲肾上腺素诱导的脂肪细胞脂解作用。为了阐明抑制棕榈酸摄取到小肠刷状缘膜、α-淀粉酶活性或增强去甲肾上腺素诱导的脂肪细胞脂解作用的活性物质，尝试使用上述三种检测系统从多酚组分中分离活性物质。从多酚组分中分离出了化合物1、2和3，分别鉴定为芹菜素-7-O-β-D-葡萄糖苷、木犀草素-7-O-β-D-葡萄糖苷和 Chrysoeriol-7-O-β-D-葡萄糖苷。在这三种黄酮类化合物中，芹菜素-7-O-β-D-葡萄糖苷抑制α-淀粉酶活性，木犀草素-7-O-β-D-葡萄糖苷和 Chrysoeriol-7-O-β-D-葡萄糖苷抑制棕榈酸摄取到小肠刷状缘膜。此外，三种黄酮糖苷增强了去甲肾上腺素诱导的脂肪细胞脂解作用。
