Resveratrol protects against 4-hydroxynonenal-induced apoptosis by blocking JNK and c-JUN/AP-1 signaling.

In the present study we have studied the effect of resveratrol in signal transduction mechanisms leading to apoptosis in 3T3 fibroblasts when exposed to 4-hydroxynonenal (HNE). In order to gain insight into the mechanisms of apoptotic response by HNE, we followed MAP kinase and caspase activation pathways; HNE induced early activation of JNK and p38 proteins but downregulated the basal activity of ERK (1/2). We were also able to demonstrate HNE-induced release of cytochrome c from mitochondria, caspase-9, and caspase-3 activation. Resveratrol effectively prevented HNE-induced JNK and caspase activation, and hence apoptosis. Activation of AP-1 along with increased c-Jun and phospho-c-Jun levels could be inhibited by pretreatment of cells with resveratrol. Moreover, Nrf2 downregulation by HNE could also be blocked by resveratrol. Overexpression of dominant negative c-Jun and JNK1 in 3T3 fibroblasts prevented HNE-induced apoptosis, which indicates a role for JNK-c-Jun/AP-1 pathway. In light of the JNK-dependent induction of c-Jun/AP-1 activation and the protective role of resveratrol, these data may show a critical potential role for JNK in the cellular response against toxic products of lipid peroxidation. In this respect, resveratrol acting through MAP kinase pathways and specifically on JNK could have a role other than acting as an antioxidant-quenching reactive oxygen intermediate.     

红膜处理对毛脉酸模根中白藜芦醇、白藜芦醇苷的影响

目的:探讨红膜处理对一年生毛脉酸模(Rumex gmeliniTurcz.)根中白藜芦醇及其苷的含量和产量的影响。方法:2005年7月1日至9月13日在黑龙江中医药大学药用植物园,利用红色滤光膜对一年生毛脉酸模进行不同时间遮光处理。采用高效液相色谱法对毛脉酸模根中的白藜芦醇及其苷的含量进行测定,并计算其产量。结果:红膜处理时间对白藜芦醇及其苷的含量和产量影响较大,红膜处理30d,并在9月中旬采收时即能显著性增加白藜芦醇及其苷的含量,又能大幅度提高白藜芦醇及其苷的产量。     

白藜芦醇对白血病细胞增殖的抑制作用及机制

目的:探讨白藜芦醇(Res)对K562细胞的作用及机制。方法:对体外培养的K562细胞体系,采用MTT,放免的测定方法。结果:Res对K562细胞有明显的抑制作用,其抑制增殖作用呈时间、剂量依赖性。Res作用48h后细胞上清液中血管紧张素Ⅱ(AngII)含量明显降低。结论:Res可能通过抑制AngII的生成而抑制K562细胞的增殖。     

高效液相色谱荧光光谱法测定虎杖中的白藜芦醇及白藜芦醇苷含量

目的建立高效液相色谱(HPLC)法,分离和测定虎杖中的白藜芦醇的含量.方法采用NUCLEODUR 100-5 C18柱(250 mm×4.6 mm,5μm);流动相异丙醇和水二元梯度洗脱系统;流速0.6 mL·min-1;荧光检测器激发波长334 nm;发射波长404 nm.结果在选定色谱条件下其白藜芦醇苷和白藜芦醇的线性范围良好,样品加样回收率在96.5%～101.4%,相对标准偏差在0.75%～1.42%.结论本方法精密度好,结果可靠,适合虎杖中白藜芦苷和白藜芦醇的定量分析.     

白藜芦醇和抗坏血酸对预防非典型肺炎方剂Ⅰ和Ⅵ所致小鼠外周血液淋巴细胞DNA损伤的保护作用

目的研究白藜芦醇和抗坏血酸对预防非典型肺炎方剂Ⅰ和Ⅵ致小鼠外周血液淋巴细胞DNA损伤的保护作用.方法采用单细胞凝胶电泳方法研究白藜芦醇和抗坏血酸对预防非典型肺炎方剂Ⅰ和Ⅵ致小鼠外周血液淋巴细胞DNA损伤的保护作用.结果白藜芦醇(50,100,200 mg/kg×3 d)和抗坏血酸(50,100,200 mg/kg×3 d)对方剂Ⅰ和Ⅵ(临床等效量×3 d)所致的小鼠外周血液淋巴细胞DNA损伤呈剂量依赖性的保护作用(P＜0.05).结论白藜芦醇和抗坏血酸能够保护预防非典型肺炎方剂J和Ⅵ对小鼠外周血液淋巴细胞DNA的损伤.     

虎杖中白藜芦醇和白藜芦醇苷的提取及含量测定

目的:建立同时测定白藜芦醇和白藜芦醇苷含量的高效液相色谱法,优化虎杖中有效成分白藜芦醇和白藜芦醇苷的提取工艺.方法:采用梯度法建立同时测定白藜芦醇和白藜芦醇苷的高效液相色谱方法,以白藜芦醇和白藜芦醇苷总量为考察指标,设计以乙醇浓度、溶剂倍数及醇提温度等为影响因素的4因素3水平的正交实验,确定虎杖中上述有效成分的最佳提取工艺.结果:在选定的色谱条件下,虎杖提取物中白藜芦醇和白藜芦醇苷可以达到基线分离. 检测白藜芦醇及其苷的线性回归方程分别为Y=0.0006X-0.183(r=0.9996),Y=0.0011X-0.478(r=0.9993);线性范围分别为0.48～38.4 mg/L和0.47～38.2 mg/L. 日内、日间精密度都小于5%,回收率在90%～105%之间,样品分析时间小于7 min. 虎杖中有效成分白藜芦醇和白藜芦醇苷的最佳提取工艺为乙醇浓度80%,溶剂倍数15,醇提温度70℃,提取时间2 h.结论:建立了准确可靠、分析速度快可同时检测虎杖提取物中白藜芦醇和白藜芦醇苷的分析方法,优化了质量可控的提取工艺.     

白藜芦醇对纤维蛋白上调大鼠脑血管内皮细胞基质金属蛋白酶9表达的影响

目的 观察白藜芦醇(resveratrol,Res)对纤维蛋白诱导的体外大鼠脑血管内皮细胞基质金属蛋白酶 9(ma-trix metalloproteinases9,MMP9)高表达的影响.方法 将大鼠脑血管内皮细胞分离后培养,培养液中加入1.0 mg/ml纤维蛋白和不同浓度的白藜芦醇,通过 RT-PCR 检测脑血管内皮细胞中 MMP9 转录水平,应用明胶酶谱法(gelatin zy-mography)定量检测培养液中的 MMP9 水平.结果 加入不同浓度(0、1、5、10、25和50μmol/L)的白藜芦醇 24 h后,25μmol/L和50μtmol/L 白藜芦醇组的培养液中 MMP9 水平显著降低(P<0.01);RT-PCR 结果显示,25μmol/L 和 50/μmol/L 白藜芦醇组的大鼠脑血管内皮细胞中的 MMP9 显著下调(P0.01).结论 白藜芦醇通过降低纤维蛋白导致的大鼠脑血管内皮细胞中 MMP9 的表达,在神经系统炎性病变中发挥抑制性保护作用.     

Resveratrol modulates the phosphoinositide 3-kinase pathway through an estrogen receptor alpha-dependent mechanism: relevance in cell proliferation

Resveratrol (RES), a natural phytoalexin, has antiproliferative activity in human-derived cancer cells and in rodent models of tumor development. We have previously shown that RES induced apoptotic death in estrogen-responsive MCF-7 human breast cancer cells. Recent data have indicated that the estrogen receptor-alpha (ERalpha), through interaction with p85, regulates phosphoinositide 3-kinase (PI3K) activity, revealing a physiologic, nonnuclear function of the ERalpha potentially relevant in cell proliferation and apoptosis. In our study, using MCF-7, we have analyzed the ability of RES to modulate the ERalpha-dependent PI3K pathway. Immunoprecipitation and kinase activity assays showed that RES increased the ERalpha-associated PI3K activity with a maximum stimulatory effect at concentrations close to 10 microM; concentrations >50 microM decreased PI3K activity. Stimulation of PI3K activity by RES was ERalpha-dependent since it could be blocked by the antiestrogen ICI 182,780. RES did not affect p85 protein expression but induced the proteasome-dependent degradation of the ERalpha. Nevertheless, the amount of PI3K immunoprecipitated by the ERalpha remained unchanged in presence of RES, indicating that ERalpha availability was not limiting PI3K activity. Phosphoprotein kinase B (pPKB/AKT) followed the pattern of PI3K activity, whereas RES did not affect total PKB/AKT expression. PKB/AKT downstream target glycogen synthase kinase 3 (GSK3) also showed a phosphorylation pattern that followed PI3K activity. We propose a mechanism through which RES could inhibit survival and proliferation of estrogen-responsive cells by interfering with an ERalpha-associated PI3K pathway, following a process that could be independent of the nuclear functions of the ERalpha.     

白藜芦醇对U937细胞基质金属蛋白酶-9转录的抑制作用

目的:观察白藜芦醇对佛波酯诱导的U937细胞中基质金属蛋白酶-9活性的影响,并从蛋白、mRNA及核转录因子激活蛋白-1(AP-1)水平对其影响进行分析。方法:酶谱法测定U937细胞培养上清中MMP-9的活性;Western blot法考察MMP-9蛋白的生成;RT-PCR法检测MMP-9 mRNA的表达;电泳迁移率变动分析法(EMSA)研究核转录因子SP-1的活性。结果:PMA 10nmol/L 可显著诱导无血清培养的U937细胞中MMP-9活性(P<0.01);白藜芦醇在1和10 μmol/L浓度下可抑制 PMA 10 nmol/L诱导的MMP-9活性(P<0.05 和P<0.01);PMA 10 nmol/L可显著诱导U937细胞中MMP-9蛋白生成(P<0.01)和MMP-9 mRNA的表达(P<0.01),白藜芦醇在1、10μmol/L浓度下可抑制PMA 10 nmol/L诱导的MMP-9蛋白生成和MMP-9 mRNA的表达(P<0.05);白藜芦醇在10、1和0.1μmol/L浓度下可抑制PMA诱导的U937细胞中AP-1的活化。结论:白藜芦醇可有效地抑制PMA诱导的U937细胞中MMP-9的活性,其作用可能是通过抑制PMA诱导的U937细胞核转录因子AP-1活化,进而降低MMP-9 mRNA表达,减少MMP-9蛋白生成而实现的。