金雀异黄素对Raji细胞生长抑制作用及机制的研究

本研究旨在探讨金雀异黄素（Genistein,Gen）对BCL-6阳性的Raji细胞系的生长抑制作用及其机制.用台盼蓝染色法及MTT法分析Gen对BCL-6阳性淋巴瘤细胞系Raji细胞的抗增殖作用,应用PI/AV双染法检测Gen对细胞凋亡的诱导作用,Western blot法检测Gen对BCL-6和NCoR表达的影响,免疫共沉淀（Co-IP）法分析Gen对BCL-6和NCoR蛋白相互作用的影响.结果表明：Gen可时间和剂量赖性地抑制Raji细胞的增殖,同时可诱导其凋亡.研究发现,不同剂量Gen对BCL-6和NCoR表达无明显影响,但可抑制BCL-6和NCoR的结合.结论：Gen对BCL-6阳性B淋巴瘤细胞有明显的抑制作用,这种作用有可能成为联合利妥昔单抗和化疗为基础的辅助治疗.     

染料木素通过TIPE 2负性调控Akt活性促进脂多糖活化的巨噬细胞凋亡

目的探究染料木素(genistein,GEN)对脂多糖(lipopolysaccharide,LPS)活化的RAW264.7细胞凋亡的影响及其可能的药理学作用机制。方法GEN预孵育RAW264.7细胞或慢病毒介导的肿瘤坏死因子α诱导蛋白8样分子2(tumor necrosis factor-α-induced protein 8-like 2,TIPE 2)过表达细胞2 h,再与LPS共孵育24 h,采用CCK 8试剂盒检测细胞活力,Annexin V-FITC/PI试剂盒检测细胞凋亡水平,qRT-PCR检测TNF-α、IL-6、caspase-8、caspase-3和TIPE 2 mRNA,Western blot检测iNOS、COX-2、caspase-8、caspase-3、TIPE 2、Akt和p-Akt蛋白表达。结果LPS促进RAW264.7细胞TNF-α、IL-6、iNOS、COX-2合成;GEN抑制LPS活化的RAW264.7细胞活力,凋亡细胞增多,并上调caspase-8、caspase-3、TIPE 2 mRNA及蛋白表达;TIPE 2过表达上调活化RAW264.7细胞caspase-8、caspase-3 mRNA及蛋白表达,减少Akt磷酸化,且与GEN具有协同作用。结论GEN可能通过上调TIPE 2抑制Akt活性,激活外源性凋亡途径,促进LPS活化的RAW264.7细胞凋亡。     

Regulation of transient outward current in human atrial myocytes by protein tyrosine kinase pathway

INTRODUCTION: Regulation of transient outward current (I(to)) in human myocytes is unclear. The present study investigated the effect of protein tyrosine kinase (PTK) inhibitors on I(to) in human atrial myocytes. METHODS AND RESULTS: Atrial myocytes were isolated enzymatically from biopsies of human right atrial appendage obtained from patients undergoing coronary artery bypass surgery. I(to) was recorded by the whole-cell patch-clamp technique in voltage-clamp configuration. Two groups of PTK inhibitors, the ATP binding site PTK inhibitors genistein and AG957 and the protein substrate PTK inhibitors ST638 and PP2, significantly inhibited I(to) in a concentration-dependent manner, with a potency order of genistein>AG957>ST638>PP2. At test pulse potential of +60 mV, I(to) was inhibited by 28% +/- 3%, 59% +/- 3%, and 89% +/- 3% by 15, 50, and 100 microM genistein, respectively. Daidzein and PP3, inactive analogues of genistein and PP2, respectively, did not produce any inhibitory effects on I(to). In addition to the inhibition of I(to) amplitude, the protein substrate PTK inhibitors ST638 and PP2 significantly accelerated I(to) inactivation (current decay) and delayed recovery from inactivation. Inhibition of protein tyrosine phosphatase partially reversed the effect of genistein. Stimulation or inhibition of serine/ threonine kinases (PKA, PKC, and PKG) did not change I(to) or alter the inhibitory response of PTK inhibitors on I(to). CONCLUSION: In human atrial cells, the PTK pathway plays an important role in the regulation of basal I(to), independent of serine/threonine kinases.     

Effects of genistein and equol on human and rat testicular 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase 3 activities

The objective of the present study was to investigate the effects of genistein and equol on 3β-hydroxysteroid de- hydrogenase （3β-HSD） and 17β-hydroxysteroid dehydrogenase 3 （17β-HSD3） in human and rat testis microsomes. These enzymes （3β-HSD and 17β-HSD3）, along with two others （cytochrome P450 side-chain cleavage enzyme and cytochrome P450 17α-hydroxylase/17-20 lyase）, catalyze the reactions that convert the steroid cholesterol into the sex hormone testosterone. Genistein inhibited 3β-HSD activity （0.2 μmol L^-1 pregnenolone） with half-maximal inhibition or a half-maximal inhibitory concentration （IC50） of 87 ± 15 （human） and 636 ± 155 nmol L^-1 （rat）. Genistein＇s mode of action on 3β-HSD activity was competitive for the substrate pregnenolonrge and noncompetitive for the cofactor NAD＋. There was no difference in genistein＇s potency of 3β-HSD inhibition between intact rat Leydig cells and testis microsomes. In contrast to its potent inhibition of 3β-HSD, genistein had lesser effects on human and rat 17β-HSD3 （0.1 μmol L^-1 androstenedione）, with an IC50 〉 100μmol L^-1. On the other hand, equol only inhibited human 3β-HSD by 42%, and had no effect on 3β-HSD and 17β-HSD3 in rat tissues. These observations imply that the ability of soy isoflavones to regulate androgen biosynthesis in Leydig cells is due in part to action on Leydig cell 3β- HSD activity. Given the increasing intake of soy-based food products and their potential effect on blood androgen levels, these findings are greatly relevant to public health.     

染料木黄酮对小鼠子宫内膜癌c-fos、cj-un mRNA表达的影响

目的探讨染料木黄酮对雌二醇-17β(E2)所诱发的小鼠子宫内膜癌c-fos、c-jun mRNA表达的影响。方法利用免疫组化方法和定量RT-PCR法检测小鼠子宫内膜癌细胞c-fos、c-jun mRNA的表达量。结果E2单独投与群c-fos、c-jun mR-NA表达增强,与E2单独投与群比较,E2和染料木黄酮联合投与群明显抑制E2刺激所诱发的c-jun表达增强。c-fos mRNA表达有减少趋势。结论E2皮下注射的雌性ICR小鼠给予染料木黄酮后c-fos、c-jun mRNA表达减少,对子宫内膜癌的预防有一定的意义。     

Transcellular transport of genistein, a soybean-derived isoflavone, across human colon carcinoma cell line (Caco-2).

Genistein, a soybean-derived isoflavone, is thought to have an anticarcinogenic action, but little is known about the cellular mechanisms of its intestinal absorption. This study was designed to investigate the absorption mechanisms of genistein using human colon carcinoma cell line, Caco-2 cells. The apical-to-basolateral transcellular transport of genistein across a Caco-2 cell monolayer was significantly greater than that in the opposite direction. An uptake experiment revealed that cellular uptake of genistein by Caco-2 cells was concentrative. The transcellular transport of genistein was saturable and temperature-dependent, and was inhibited by other flavonoids such as rutin, quercetin, (+)-catechin and (-)-epicatechin. These results suggest that genistein is transported across Caco-2 cells by a carrier-mediated system, located on the apical membrane.     

金雀异黄酮对大鼠视网膜缺血-再灌注损伤的保护作用

目的　探讨金雀异黄酮（GEN）对大鼠视网膜缺血-再灌注（I/R）损伤的保护作用。方法　选取30只健康SPF级大鼠，按照随机数字表法将其分为假手术组、I/R组和I/R+GEN组，每组各10只。I/R组和I/R+GEN组大鼠采用前房灌注生理盐水升高眼压法制备视网膜I/R损伤大鼠模型，I/R组大鼠术后每天给予注射生理盐水（1 mL·kg^-1·d^-1）；I/R+GEN组大鼠术后每天给予注射GEN （40 mL·kg^-1·d^-1）；假手术组大鼠行相应假手术后每天予以注射生理盐水（1 mL·kg^-1·d^-1），连续7 d后，颈椎脱臼法处死各组大鼠，取眼部组织。HE染色观察各组大鼠视网膜的形态以及内丛状层（IPL）、内核层（INL）和神经节细胞层（GCL）厚度；免疫荧光分析观察各组大鼠视网膜神经节细胞（RGC）的存活率；TUNEL染色检测各组大鼠视网膜细胞凋亡水平；检测各组大鼠视网膜组织中过氧化氢酶（CAT）、丙二醛(MDA)及超氧化物歧化酶(SOD)水平以反映视网膜氧化应激状态；Western blot分析三组大鼠视网膜中NLRP3、ASC、Caspase-1的蛋白表达。结果　I/R组、I/R+GEN组和假手术组大鼠视网膜总厚度分别为(114.37±7.32）μm、（155.31±6.83）μm和（178.98±13.65）μm（t=14.284，P<0.01），I/R组低于假手术组和I/R+GEN组，差异均有统计学意义（均为P<0.01）。I/R组大鼠视网膜IPL、INL和GCL厚度分别为（18.95±5.06）μm、（17.62±4.69）μm和（19.03±4.74）μm，I/R+GEN组大鼠视网膜IPL、INL和GCL厚度分别为（20.69±8.13）μm、（25.74±6.78）μm和（26.71±7.85）μm，假手术组大鼠视网膜IPL、INL和GCL厚度分别为（11.73±3.15）μm、（11.97±3.56）μm和（12.59±3.24）μm（均为P<0.05），I/R组与假手术组和I/R+GEN组三个指标比较差异均有统计学意义（均为P<0.01）。I/R组、I/R+GEN组和假手术组大鼠视网膜中RGC相对存活率分别为（26.87±3.12）%、（73.46±7.80）% 和（100.00±5.64）%（t=16.825，P<0.01），I/R组RGC相对存活率低于假手术组和I/R+GEN组，差异均有统计学意义（均为P<0.01）。I/R组、I/R+GEN组和假手术组大鼠视网膜中CAT、MDA、SOD含量总体比较差异均有统计学意义（均为P<0.01），I/R组与I/R+GEN组和假手术组三个指标比较差异均有统计学意义（均为P<0.05）。Western blot检测结果显示，三组大鼠视网膜中NLRP3、ASC、Caspase-1的蛋白表达总体比较差异均有统计学意义（均为P<0.01），组间两两比较差异均有统计学意义（均为P<0.05）。结论　GEN可通过提高视网膜细胞抗炎和抗氧化能力抑制视网膜细胞凋亡，从而起到对大鼠视网膜I/R损伤的保护作用。     

4,5,7-三羟基异黄酮对子宫内膜癌细胞株shikawa细胞增殖的影响

背景与目的:探讨4,5,7-三羟基异黄酮(Genistein)对子宫内膜癌细胞增殖的影响。材料与方法:采用5-溴-2'-脱氧尿苷细胞增殖酶联免疫测定法,检测浓度为12.5、25、50、100μmol/L的Genistein对体外培养子宫内膜癌细胞的增殖和生长抑制作用。结果:12.5~25μmol/L浓度的Genistein对Ishikawa细胞有增殖作用,当Genistein的浓度达到100μmol/L时则为抑制作用。结论:随着Genistein浓度的变化而对子宫内膜癌细胞起着增殖或生长抑制作用。     

植物性雌激素三羟异黄酮对脑缺血大鼠学习记忆的影响

目的：观察植物性雌激素三羟异黄酮（GST）对脑缺血大鼠学习记忆的影响。方法：雌性大鼠，行双侧卵巢切除手术后，皮下注射三羟异黄酮治疗，10天后结扎双侧颈总动脉，制备脑缺血动物模型。2个月后，用水迷宫法测定大鼠学习记忆能力的改变，并取海马组织作超薄切片电镜分析。结果：①水迷宫测试结果：GST组与去卯巢对照组比较，游完全程的时间明显缩短，错误反应次数明显减少。②形态学观察：去卵巢对照组海马神经元超微结构有明显损害，而GST组能明显改善海马神经元的损伤。结论：GST通过对脑缺血动物脑神经元保护作用，提高卯巢去势大鼠学习记忆的能力。