白藜芦醇通过PI3K/Akt通路及线粒体途径抑制软骨肉瘤

 目的：探讨白藜芦醇抑制软骨肉瘤的机制及对线粒体途径和PI3K/Akt通路的影响。方法：SW1353软骨肉瘤细胞培养至对数生长期后设对照组和白藜芦醇处理组,药物处理组用25、50和100 μmol/L白藜芦醇处理24 h、48 h或72 h。采用CCK8法检测SW1353软骨肉瘤细胞的活力,Hoechst 33258荧光染色观察细胞凋亡,Western blotting检测activated caspase-3、Bcl-2、Bax、Akt和p-Akt蛋白在细胞中表达情况,细胞划痕实验观察细胞迁移情况。结果：白藜芦醇处理后细胞活力下降,呈时间-剂量依赖性（P<0.01）。Hoechst  33258染色检测可见药物处理组有明显的细胞凋亡核象。Western blotting检测显示药物处理组activated caspase-3和Bax蛋白表达上调,Bcl-2蛋白和p-Akt蛋白表达下调,总Akt改变不显著。细胞划痕试验显示,白藜芦醇能显著抑制SW1353细胞的迁移。结论：白藜芦醇能够诱导软骨肉瘤凋亡,部分是通过线粒体途径及PI3K/Akt信号通路发挥作用。     

2型糖尿病大鼠心肌缺血再灌注损伤转录因子E2相关因子2/血红素氧合酶1信号通路的表达及白藜芦醇的干预研究

目的探讨白藜芦醇在糖尿病心肌缺血再灌注（I/R）损伤中对转录因子E2相关因子2（Nrf2）/血红素氧合酶1（HO-1）信号通路的影响。 方法将2型糖尿病模型制备成功的60只大鼠分成假手术组、I/R组、白藜芦醇（R）组、白藜芦醇+ EX527（RE）组,每组各15只。采用结扎左冠状动脉前降支30 min、恢复灌注120 min的方法制备心肌I/R损伤模型。R组及RE组大鼠于术前7 d连续腹腔注射白藜芦醇15 mg/kg,假手术组及I/R组大鼠腹腔注射等容量的等渗NaCl溶液,RE组大鼠于缺血前15 min尾静脉注射EX527 1 μg/kg。于再灌注120 min末,采用酶联免疫吸附测定法检测血清乳酸脱氢酶（LDH）及肌酸激酶同工酶（CK-MB）。随后处死大鼠取心肌组织,采用苏木素-伊红（HE）染色观察心肌病理学变化,采用2,3,5-氯化三苯基四氮唑法检测心肌梗死面积百分比,并检测心肌组织丙二醛含量及超氧化物歧化酶（SOD）活性。采用Western-blotting法检测各组大鼠心肌沉默信息调节因子1（SIRT1）、Nrf2及HO-1蛋白表达水平。 结果HE染色可见,假手术组大鼠心肌细胞轻度断裂、水肿,少量炎症细胞浸润;I/R组大鼠心肌纤维排列杂乱,心肌间质充血水肿伴大量炎症细胞浸润;R组大鼠心肌组织结构相对整齐,偶见核固缩;RE组大鼠心肌纤维排列杂乱,核固缩现象明显,炎症细胞浸润明显。假手术组大鼠无心肌梗死发生,I/R组大鼠心肌梗死面积占比为（51 ± 6）%,R组大鼠占比为（37 ± 4）%,RE组大鼠占比为（41 ± 3）%,各组间比较差异有统计学意义（F = 160.703,P < 0.001）,R组及RE组大鼠心肌梗死的占比面积均显著小于I/R组大鼠,且R组大鼠心肌梗死面积的占比更小（P均<0.05）。各组大鼠血清LDH、CK-MB、丙二醛、SOD、SIRT1、Nrf2及HO-1表达水平比较,差异均有统计学意义（F = 144.101、158.545、53.682、99.273、50.121、59.153、143.702,P均< 0.001）。进一步两两比较发现,与假手术组比较,I/R组、R组、RE组大鼠的LDH、CK-MB及丙二醛含量均显著升高,SOD活性、SIRT1、Nrf2及HO-1蛋白表达水平均显著降低（P均<0.05）;与I/R组比较,R组及RE组大鼠的LDH、CK-MB及丙二醛含量均显著降低,SOD活性、SIRT1、Nrf2及HO-1蛋白表达水平均显著升高,且LDH、CK-MB及丙二醛含量在R组大鼠更低,SOD活性、SIRT1、Nrf2及HO-1蛋白表达水平在R组大鼠更高（P均<0.05）。 结论白藜芦醇可通过促进SIRT1激活Nrf2/HO-1信号通路来减轻2型糖尿病大鼠心肌的氧化应激反应及心肌I/R损伤。     

Graptopetalum paraguayense and resveratrol ameliorates carboxymethyllysine (CML)-induced pancreas dysfunction and hyperglycemia

Hyperglycemia is associated with advanced glycation end products (AGEs). Recently, AGEs were found to cause pancreatic damage, oxidative stress, and hyperglycemia through the AGE receptor. Carboxymethyllysine (CML) is an AGE but whether it induces pancreatic dysfunction remains unclear. Graptopetalum paraguayense, a vegetable consumed in Taiwan, has been used in folk medicine and is an antioxidant that protects against liver damage. We investigated the protective properties of G. paraguayense 95% ethanol extracts (GPEs) against CML-induced pancreatic damage. The results indicated that resveratrol, GPE, and gallic acid (the active compound of GPE) increased insulin synthesis via upregulation of pancreatic peroxisome proliferator activated-receptor-γ (PPARγ) and pancreatic-duodenal homeobox-1 (PDX-1) but inhibited the expression of CML-mediated CCAAT/enhancer binding protein-β (C/EBPβ), a negative regulator of insulin production. Moreover, resveratrol and GPE also strongly activated nuclear factor-erythroid 2-related factor 2 (Nrf2) to attenuate oxidative stress and improve insulin sensitivity in the liver and muscle of CML-injected C57BL/6 mice and resulted in reduced blood glucose levels. Taken together, these findings suggested that GPE and gallic acid could potentially be used as a food supplement to protect against pancreatic damage and the development of diabetes.     

Colon carcinogenesis: Influence of Western diet-induced obesity and targeting stem cells using dietary bioactive compounds

Colon cancer strikes more than 1 million people annually and is responsible for more than 500,000 cancer deaths worldwide. Recent evidence suggests that the majority of malignancies, including colon cancer are driven by cancer stem cells (CSCs) that are resistant to current chemotherapeutic approaches leading to cancer relapse. Wnt signaling plays a critical role in colon stem cell renewal and carcinogenesis. Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), a Wnt target gene, and aldehyde dehydrogenase 1 B1 (ALDH1B1) are good markers for normal and malignant human colon stem cells. Diet contributes to 20% to 42% of all human cancers and 50% to 90% of colon cancer. Recent evidence shows that the Western diet has a causative link to colon cancer; however, mechanisms of action are not fully elucidated. Western diet-induced obesity elevates systemic insulin-like growth factor-1 and insulin levels, which could lead to elevated proliferation and suppressed apoptosis of CSCs through PI3K/AKT/Wnt pathway. Although conventional chemotherapy targets the PI3K/AKT pathways and can significantly reduce tumor size, it fails to eliminate CSCs and has serious side effects. Dietary bioactive compounds such as grape seed extract, curcumin, lycopene, and resveratrol have promising chemopreventive effects, without serious side effects on various types of cancers due to their direct and indirect actions on CSC self-renewal pathways such as the Wnt pathway. Understanding the role of CSCs in diet-induced colon cancer will aid in development of evidence-based dietary chemopreventive strategies and/or therapeutic agents targeting CSCs.     

白藜芦醇诱导MDA-MB-231细胞凋亡及其对活性氧和Caspase-3的影响

目的探讨白藜芦醇对MDA-MB-231细胞的凋亡诱导效应和对细胞内活性氧水平(reactive oxygen species,ROS)及Caspase-3的影响。方法用不同浓度的白藜芦醇诱导培养MDA-MB-231细胞24h后,采用流式细胞术(FCM)和DNA琼脂糖凝胶电泳检测细胞凋亡,FCM测定细胞内活性氧(ROS)水平,免疫组织化学法检测Caspase-3蛋白的变化。结果白藜芦醇能诱导MDA-MB-231细胞凋亡,DNA电泳可见梯状条带出现,并呈现典型的凋亡改变,60μmol/L白藜芦醇作用MDA-MB-231细胞4、12和24h后细胞ROS生成量分别为:50.0±5.7、115.0±10.6、79.2±6.9;Caspase-3蛋白活性逐渐增加。结论白藜芦醇诱导MDA-MB-231细胞凋亡与细胞ROS水平升高和Caspase-3活化有关,可能是白藜芦醇诱导MDA-MB-231细胞凋亡机制之一。     

白藜芦醇抑制人脑胶质瘤细胞生长及诱导凋亡比较

 目的 探讨白藜芦醇（Resveratrol，Res）体外抑制U251、U87和SHG-44脑胶质瘤细胞生长及诱导凋亡的不同作用比较，验证Re8确可导致U251细胞凋亡。方法 MTT比色法测量不同剂量的Res作用U251、U87和SHG-44胶质瘤细胞24h后对增殖的影响及不同剂量的Res作用U251、U87和SHG-44细胞6h、24h、48h后的影响。流式细胞仪用Annexin V-FITC和PI双染检测U251、U87和SHG-44细胞凋亡率。HE染色、Hoechst 33342荧光染色、透射电镜（TEM）观察U251细胞形态改变，流式细胞仪测定U251细胞的细胞周期改变。结果 Res明显抑制U251、U87和SHG-44细胞的生长和增殖（P〈0．01）且对U87细胞的抑制作用最强，U251和SHG-44细胞次之；对U251细胞的抑制作用呈浓度及时间依赖性反应；Re8所致的U251、U87和SHG-44胶质瘤细胞凋亡为浓度依赖关系，且对U87细胞的凋亡作用强于U251和SHG-44细胞。U251凋亡细胞的细胞周期主要发生G，期阻滞。结论 Res对U251、U87和SHG-44细胞生长抑制及凋亡作用以U87细胞更明显，对U251细胞的抑制作用呈浓度及时间依赖性反应并引起了其细胞周期改变。     

17种国产菝葜属植物中白藜芦醇含量比较

目的测定17种国产菝葜属植物样品中白藜芦醇的含量。方法以活性成分白藜芦醇为指标,采用HPLC法对采自我国17种菝葜属植物样品进行含量测定。结果不同品种菝葜中白藜芦醇的含量有显著差异。小果菝葜、长托菝葜、黑果菝葜等含量较高,而短梗菝葜、尖叶菝葜、土茯苓等不能检测出。结论该研究为菝葜属植物资源的深入开发利用提供了一定的科学依据。     

白黎芦醇体外抗肝纤维化实验研究

目的:探讨白黎芦醇体外抗肝纤维化的作用机制。方法:原位灌流分离大鼠肝细胞,以维生素E作阳性对照,检测不同浓度白黎芦醇对四氯化碳(CCl4)损伤后肝细胞中丙二醛(MDA)、丙氨酸氨基转移酶(ALT)活性和肝细胞存活率的影响;并用肝星状细胞(HSC)与次氮基三醋酸铁共同培养产生氧应激后,检测不同浓度白黎芦醇对HSC增殖和Ⅰ型胶原生成的影响,并测定细胞培养液中MDA、超氧化物歧化酶(SOD)活性。结果:白黎芦醇明显改善CCl4损伤后肝细胞存活率,抑制CCl4引起的ALT、MDA活性升高,并能明显抑制HSC氧应激后MDA活性升高和SOD活性的降低,抑制HSC增殖和Ⅰ型胶原的生成。结论:白黎芦醇抗肝纤维化作用可能与其抗脂质过氧化有关。