[Objective]To investigate the effect of oxidized low-density lipoprotein(ox-LDL)on the expression of PECAM-1 mRNA and protein in cultured human endothelial cells.[Methods]Effects of ox-LDL on expression of platelet endothelial cell adhesion molecule-1(PECAM-1)protein and mRNA in human umbilical vein endothelial cell(HUVEC)were determined with western blotting and reverse transcription polymerase chain reaction(RT-PCR).[Results]ox-LDL up-regulated PECAM-1 mRNA expression and protein synthesis in HUVEC in concentration-dependent manner after incubating with 50 mg/L,100 mg/L and 200 mg/L LDL[(0.54 ± 0.08 vs 0.85 ± 0.07,1.56 ± 0.08,1.39 ± 0.20;P﹤0.05),(880 ± 90 vs 2470 ± 440,2930 ± 470,2850 ± 620;P﹤0.05)].[Conclusion]ox-LDL can up-regulate the expression of PECAM-1 gene at transcription level and increase the expression of PECAM-1 protein in HUVECs.

目的:研究茶多糖体外清除氧自由基与抗脂蛋白氧化作用.方法:对H2O2、O-2·及OH·的清除作用采用化学发光法测定,ROO·的清除作用采用比色法测定.给20名健康受试者空腹食用茶多糖后抽取静脉血,采用超速离心法分离血浆极低密度脂蛋白(VLDL)、低密度脂蛋白(LDL)和高密度脂蛋白(HDL),并观察各血浆脂蛋白过氧化程度以及氧化易感性的变化.结果:茶多糖对R0O·、O-2、OH·及H2O2均有清除作用;食用茶多糖后受试者血浆及VLDL、LDL和HDL过氧化脂质水平明显降低;在体外进行氧化修饰时,LDL氧化延滞时间明显延长,提示LDL氧化易感性下降.结论:茶多糖可增强血浆及脂蛋白抗氧化能力,因此能够起到预防心血管疾病和延缓衰老的积极作用.

OBJECTIVE To study the biochemical effects of two fractions from Codonopsis lanceolata(CL) extractives.METHODS CL was extracted with 70% methanol and isolated into two layers: water layer and butanol layer,then got fraction 1(F1) and fraction 2(F2) by freeze-drying.Human blood platelet aggregate rates were measured when F1 and F2 were added,respectively.Lipid peroxide(LPO) level was tested after F1 and F2 were added into the human low density lipoprotein oxidation reaction system,respectively.Free radical scavenging effect was tested when F1 and F2 reacted with a stable free radical reagent.RESULTS Compared with control group,F1 reduced platelet aggregate rates significantly(P0.01);F1 and F2 showed significant antioxidant effect,the level of LPO in the reaction system was much lower than control group when F1 or F2 were added into reaction system(P0.01);F1 showed significant free radical scavenging effect.CONCLUSION F1 showed significant antioxidant effects and might proved the forming of thrombus,and the antioxidant effects resulted from free radical scavenging function.F2 showed similar effects but weaker than F1.

Total glycosides were extracted from soybean hypocotyl, then soyasaponins were isolated with C18 column chromatography and high-performance liquid chromatography (HPLC). The inhibitory activities of each component of soyasaponins against α-glucosidase were tested by colorimetric method. Soyasaponins showed potent inhibitory activities against α-glucosidase. Group B, Group E and DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) saponins were shown to be reversible inhibitors of α-glucosidase with IC50 values of 10 μmol/L~40 μmol/L, while Group A saponins showed a little lower potency with IC50 values of about 2 mmol/L. The results suggest soyasaponins, which exhibit inhibitory effects on α-glucosidase, seem physiologically useful for suppressing postprandial hyperglycemia in patients with diabetes mellitus.

目的:研究大豆异黄酮(soybean isoflavones,SI)和皂甙(soyasaponins,SS)的降糖作用机制.方法: 普通饲料中添加20 g/kg富含SI和SS的大豆胚轴提取物(soybean hypocotyl extracts,SHE),饲喂Wistar正常大鼠和GK/Jcl(Goto-Kakizaki)2型糖尿病大鼠20 w,观察其血糖和葡萄糖耐量变化及对α-葡萄糖苷酶和α-淀粉酶的抑制活性. 结果: 长期食用SHE能显著降低2型糖尿病大鼠血糖水平,明显改善其葡萄糖耐量,同时能改善正常大鼠葡萄糖耐量.在糖尿病相关酶的抑制试验中,B类、E类和DDMP(2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one)皂甙显示很强的α-葡萄糖苷酶抑制活性,其50%抑制浓度(IC50)值为10～40 (mol/L;异黄酮苷元也有很强的α-葡萄糖苷酶抑制作用,其IC50值为20～150 (mol/L,异黄酮葡萄糖苷形式对α-葡萄糖苷酶的抑制活性则较弱.SI和SS还具有较弱的α-淀粉酶抑制作用,浓度为1 g/L时,抑制率为10%～20%.结论: SHE具有降低糖尿病大鼠血糖水平和改善糖耐量的作用,其部分作用机制可能是通过SI和SS对α-葡萄糖苷酶和α-淀粉酶的抑制作用而实现的.

体外研究新鲜香蕉对活性氧自由基的清除作用,同时给20名健康受试者空腹食用新鲜香蕉,观察其血浆脂蛋白过氧化脂质水平的变化.结果表明,在体外新鲜香蕉对ROO@、O2-@、@OH、H2O2均有清除作用,清除率分别为81.8%、54.5%、72.1%和68.8%;在体内可明显降低人血浆极低密度脂蛋白(VLDL)、低密度脂蛋白(LDL)和高密度脂蛋白(HDL)中过氧化脂质水平.结果提示,香蕉可增强人血浆抗氧化能力,能够起到预防心血管疾病和延缓衰老的积极作用.

[目的]研究大豆异黄酮对血小板聚集性的影响.[方法]普通饲料中添加20 g/kg大豆异黄酮混合物,饲喂GK/Jcl糖尿病大鼠20周,测定其血小板聚集率.利用ODS柱层析和高效液相色谱技术分离大豆异黄酮,体外观察大豆异黄酮单体对人血小板聚集率的影响.[结果]长期食用大豆异黄酮的GK/Jcl糖尿病大鼠血小板聚集率显著降低.在人体外血小板聚集实验中,大豆异黄酮均抑制腺嘌呤核苷二磷酸钠、胶原蛋白和肾上腺素诱导的血小板聚集,大豆异黄酮类型中金雀异黄素的最强,其50%抑制浓度值分别为0.38,0.30,0.23 mmol/L.[结论]大豆异黄酮具有血小板聚集抑制效应,在大豆抗血小板聚集中起着重要作用.

[目的]研究大豆胚轴提取物对糖尿病大鼠血浆脂蛋白脂质过氧化的影响.[方法]给GK/JclⅡ型糖尿病大鼠饲喂添加100 g/kg大豆胚轴提取物的饲料20周,检测其血浆脂蛋白过氧化脂质含量.血浆极低密度脂蛋白、低密度脂蛋白和高密度脂蛋白的分离采用序列超速离心分离法.[结果]长期食用大豆胚轴提取物的GK/Jcl糖尿病大鼠血浆总过氧化脂质和高密度脂蛋白过氧化脂质明显减少,低密度脂蛋白过氧化脂质表观水平有所下降.[结论]大豆胚轴提取物显著降低糖尿病大鼠血浆总过氧化脂质和高密度脂蛋白过氧化脂质,对糖尿病及其并发症的发生和发展起有效的防治作用.

OBJECTIVE To study the influence of methanol extract of soybean hypocotyls on blood glucose, blood lipid and lipidperoxide metabolisms in diabetes of rats. METHODS Extract of soybean hypocotyl rich in isoflavonoids and saponins were isolated with methanol and investigated using TLC and HPLC. GK/Jcl diabetes rats were given feed containing 100g/kg soybean hypocotyl extract and then the biochemical indices were investigated. RESULTS Among the diabetes mellitus rats fed soybean hypocotyl extract, the blood glucose levels were decreased considerably, the serum lipidperoxide was decreased noticeably, the high-density-lipoprotein cholesterol was increased noticeably. However, the serum total cholesterol and triglyceride had no notable changes. CONCLUSION Soybean hypocotyl methanol extract has the function of decreasing blood glucose, improving glucose intolerance, reducing lipidperoxide and increasing the high density hypocotyl-cholesterol level.

OBJECTIVE To study the inhibitory effects of isoflavonoids on alpha-glucosidase (EC 3.2.1.20) and alpha-amylase (EC 3.2.1.1) and supply a scientific basis for the development and use of isoflavonoids for the patient with diabetes mellitus. METHODS The isolation and identification of isoflavonoids were performed by ODS column chromatography, TLC, HPLC and NMR. Assays for inhibition of alpha-glucosidase and alpha-amylase were investigated by colorimetric method. The concentration of the given inhibitor required to inhibit 50% of enzyme activity under the assay conditions was defined as the IC 50value. RESULTS Isoflavone aglycones show strong inhibitory activities against yeast alpha-glucosidase with the IC 50 values of 20～150 μmol/L, whi le isoflavone glycosides showed a little lower potency than their aglycones(IC 50 value was about 200～600 μmol/L). Isoflavones also tended to inhibit porcine pancreatic alpha-amylase activities. The inhibitory activities of isoflavones were about 10%～20% at the concentration of 1 g/L. Malonylated isoflavone glycosides showed no inhibition on both alpha-glucosidase and alpha-amylase. CONCLUSION The isoflavones, which exhibit alpha-glucosidase and alpha-amylase inhibitory activities, seem physiologically useful for suppressing postprandial hyperglycemia in patients with diabetes mellitus.