槲皮素联合顺铂诱导宫颈HeLa细胞凋亡的实验研究

目的探讨槲皮素对HeLa细胞增殖和凋亡的影响以及联合顺铂的化疗效应。方法分别用不同浓度槲皮素、顺铂及不同浓度槲皮素联合顺铂处理HeLa细胞24 h;采用MTT法检测药物对HeLa细胞增殖的影响;流式细胞仪和Hochest 33258检测药物作用后的细胞凋亡情况;荧光显微镜观察用PI荧光标记的细胞核形态学变化。结果槲皮素能抑制HeLa细胞增殖,且呈剂量依赖性;槲皮素联合顺铂与相同浓度槲皮素单用及顺铂单用处理HeLa细胞相比,前者对HeLa细胞的抑制作用更显著(p<0.01);不同浓度槲皮素与顺铂联合处理HeLa细胞与槲皮素单用及顺铂单用相比,前者显著提高了HeLa细胞的凋亡率(p<0.01)。结论槲皮素联合顺铂比槲皮素单用及顺铂单用对HeLa细胞的抑制作用更显著,因而产生更强的抗肿瘤效果。     

榭皮黄酮通过抑制Traf6/NF-κB信号转导通路增强5-氟尿嘧啶对HepG2的化疗作用

目的 研究榭皮黄酮（quercetin,Qu）影响肝癌细胞HepG2对5-氟尿嘧啶（5-fluorouracil,5-FU）的敏感性及Traf6/NF-κB信号转导通路。方法 体外培养HepG2细胞,取对数期细胞进行后续实验,将细胞分为对照组（不含任何药物的培养基孵育细胞24 h）、单独Qu组（含40μg/ml Qu的培养基孵育细胞24 h）、单独5-FU组（含50μmol/L 5-FU的培养基孵育细胞24 h）、Qu+5-FU联合处理组（含40μg/ml Qu和50μmol/L 5-FU的培养基共同孵育细胞24 h）、单独Traf6抑制剂C25-140组（2μmol/L C25-140的培养基孵育细胞8 h）、C25-140+Qu+5-FU组（C25-140预处理细胞8 h,然后含40μg/ml Qu和50μmol/L 5-FU的培养基共同处理细胞24 h）。采用CCK8法检测细胞活力,采用倒置显微镜记录细胞克隆数,采用流式细胞术检测细胞凋亡率,采用Western blot检测剪切的半胱氨酸蛋白酶-7(cleaved-caspase 7,Cle-caspase 7)、Clecaspa...     

槲皮素与芦丁对离体大鼠主动脉环的舒张作用及机制

目的:比较研究槲皮素与芦丁对离体大鼠胸主动脉环的作用及其可能的途径。方法:采用累积加药法,检测槲皮素和芦丁对去氧肾上腺素(pheny lephrine,PE)预收缩的胸主动脉环张力的影响。结果:槲皮素对离体大鼠内皮完整和去内皮的胸主动脉环均有浓度依赖性的舒张作用,而芦丁对PE预收缩血管的舒张作用是内皮依赖性的。槲皮素和芦丁对内皮完整的胸主动脉环的最大舒张反应分别为(77.20±6.11)%和(44.28±7.48)%,但两者对内皮完整的胸主动脉环最大舒张的半数有效浓度无明显差异。用一氧化氮合酶抑制剂L-NAM E(0.1 mm o l/L)预处理后,可阻断芦丁诱导的舒张血管作用,但不能阻断槲皮素引起的舒张血管作用;用鸟苷酸环化酶抑制剂亚甲蓝(10μm o l/L)预处理后,两者的血管舒张作用均被阻断。用环氧合酶抑制剂吲哚美辛(10μm o l/L)预处理后可减弱槲皮素诱导的舒张血管作用,但不能阻断芦丁引起的舒张血管作用。结论:槲皮素的舒血管作用强于芦丁,槲皮素可能是通过鸟苷酸环化酶和环氧合酶途径产生非内皮依赖性的血管舒张作用,而芦丁可能是通过NO-鸟苷酸环化酶途径产生内皮依赖性的血管舒张作用。     

高效液相色谱法同时测定大庆马齿苋中山奈酚和槲皮素的含量

目的建立采用高效液相色谱法同时测定大庆马齿苋中山奈酚和槲皮素含量的方法。方法采用Agilent1200 Series,Eclipse XDB-C18色谱柱(150 mm×4.6 mm,5μm),甲醇-0.2%磷酸(45∶55),流速1.0 mL/min,柱温25℃,检测波长360 nm。结果山奈酚进样量在0.448~2.240μg范围内线性关系良好(r=0.9997),平均回收率为96.90%,RSD=0.63%(n=6);槲皮素进样量在0.496~2.480μg范围内线性关系良好(r=0.9997),平均回收率为98.10%,RSD=0.45%(n=6)。结论此方法重复性好,精确可靠。     

吉西他滨联合槲皮素对胰腺癌细胞Panc-1凋亡的影响研究

目的研究吉西他滨联合槲皮素抑制胰腺癌细胞Panc-1增殖,促进其凋亡的效果.方法设立槲皮素(终浓度为50μM)、吉西他滨(50μg/ml)、吉西他滨联合槲皮素和对照组4组,MTS法检测药物对Panc-1细胞凋亡的影响,流式细胞仪检测联合药物处理对细胞凋亡和细胞周期的影响,最后应用荧光定量PCR法测定凋亡相关基因BCL-2家族蛋白的相对表达.结果吉西他滨联合槲皮素后,对胰腺癌促凋亡效果增强,同时改变细胞周期,使其S期减少,BCL-2家族促凋亡基因表达上调.结论槲皮素能够显著增强吉西他滨抑制胰腺癌恶性增殖的作用.     

Synergistic effect of quercetin and quinic acid by alleviating structural degeneration in the liver,kidney and pancreas tissues of STZ-induced diabetic rats: A mechanistic study

The aim of this study was to investigate the synergistic effects of quercetin (QE) and quinic acid (QA) on a STZ-induced diabetic rat model to determine their potential role in alleviating diabetes and its associated complications. In our study design, diabetic rats were treated with single and combined doses of QE and QA for 45 days to analyse their effects on liver, kidney and pancreas tissues. The study result showed that QE and QA treated groups down-regulated hyperglycaemia and oxidative stress by up-regulating insulin and C-peptide levels. Moreover, histological observations of the liver, kidney and pancreas of diabetic rats treated with single and combined doses of QE and QA showed a significant improvement in the structural degeneration. Interestingly, the combination dose of QE and QA (50 mg/kg) exhibited maximum inhibition of the pro-apoptotic protein Bax expression and demonstrate enhancement of the anti-apoptotic protein Bcl-2 expression in the kidney tissues, suggesting a protective role in the kidneys of diabetic rats. Taken together, these results indicates the synergistic effects of QE and QA in ameliorating hyperglycaemia, hyperlipidemia and insulin resistance in diabetic rats and therefore, open a new window of research on the combinatorial therapy of flavonoids.     

Iron oxide nanoparticles mediated cytotoxicity via PI3K/AKT pathway: Role of quercetin

Recently Fe₂O₃ NPs (iron oxide nanoparticles) have been extensively used in medical imaging and in industry also. As a result, people are increasingly exposed day by day to those nanoparticles. The adverse effect of Fe₂O₃ NPs is not so significant at lower doses but at higher doses Fe₂O₃ NPs causes significant damage to cells. The present study investigates the cell signaling mechanism of Fe₂O₃ NPs induced oxidative stress and cytotoxicity in vitro using murine hepatocytes as the working model. In addition, the cytoprotective action of quercetin in this pathophysiology has also been investigated. Dose-dependent studies suggest that incubation of hepatocytes with 250 μg/ml Fe₂O₃ NPs for 4 h significantly decreased the cell viability and intra-cellular antioxidant ability. This study also showed that exposure to Fe₂O₃ NPs caused hepatocytes death via apoptotic pathway. Incubation of hepatocytes with quercetin (50 μmol/L) prior to 1 h of Fe₂O₃ NPs exposure protects the cells from the altering activities of antioxidant indices, cytotoxicity and apoptotic death. Results suggest that Fe₂O₃ NPs induced cellular damage and quercetin plays a protective role in Fe₂O₃ NPs induced cytotoxicity and apoptotic death.     

Quercetin对人气道平滑肌细胞增殖和迁移的影响及机制

目的 体外培养人气道平滑肌细胞(human airway smooth muscle cells,HASMCs),探讨槲皮素(Quercetin,Que)对血小板源性生长因子BB(PDGF-BB)刺激的HASMCs增殖和迁移的影响及其机制.方法体外培养HASMCs,分为六组；对照组、PdGF-BB组、Que与PDGF-BB联合干预组、Que组、U0126组、U0126与PDGF-BB联合干预组.四甲基偶氮唑蓝(MTT)微量比色法测定HASMCs增殖,transwell法观察细胞迁移,Western blot法检测ERK的磷酸化及Cyclin D1表达水平.结果 与对照组相比,PDGF-BB(20μg/L)显著诱导HASMCs增殖和迁移(P＜0.05),Que(20～80μmol/L)呈浓度依赖性抑制PDGF-BB诱导的HASMCs的增殖和迁移(P＜0.05).PDGF-BB组ERK磷酸化及Cyclin D1 表达水平较对照组明显增高(P＜0.05).Que(80μmol/L)及PDGF-BB干预组其表达量低于PDGF-BB组,此抑制作用与ERK特异性拮抗剂U0126作用相当(P＞0.05).结论 Que抑制PDGF-BB诱导的HASMCs的增殖和迁移,可能是通过调节ERK/Cyelin D1通路起作用.     

银杏叶提取物中槲皮素体外经皮渗透的研究

摘 要 目的： 研究银杏叶提取物中槲皮素体外经皮渗透情况。方法: 用50%乙醇溶解银杏叶提取物,采用改良Franz扩散池进行体外透皮试验,用HPLC法测定接收池中槲皮素的渗透量。结果: 槲皮素体外经皮渗透近似于零级动力学特征。结论:银杏叶提取物中的槲皮素能够经皮渗透。