槲皮素对衰老机体抗氧化能力的研究进展

采用文献资料法对槲皮素与自由基的研究现状及其进展进行概述,分析了自由基在衰老过程中的作用。对槲皮素清除自由基和抗氧化系统的影响作一综述。     

紫叶小檗叶片色素成分分析

以紫叶小檗叶片为试材,用薄层层析色谱法(TLC)、颜色特征反应、紫外—可见分光光度计(UV)和高效液相色谱仪—二极管阵列检测器(HPLC-DAD)对其色素进行定性分析;用HPLC-DAD法对其叶片单体酚质量分数进行定量分析。结果表明:紫叶小檗叶片主要含有叶绿素A、类胡萝卜素、矢车菊素、矢车菊素半乳糖苷、矮牵牛素、二氢槲皮素、二氢杨梅素、芦丁、槲皮素、绿原酸、杨梅素、表儿茶素、芹菜素;其叶片呈现紫红色是矢车菊素、矢车菊素半乳糖苷、矮牵牛素、叶绿素A、类胡萝卜素和槲皮素共同作用的结果。     

槲皮素促进拟南芥生长素极性运输的研究

用含有外源槲皮素的培养基种植拟南芥，探讨槲皮素对拟南芥生长素极性运输的影响。     

Quercetin inhibits endothelin-1-induced T-type Ca2+ channel expression in human umbilical arterial smooth muscle cells

AIM: To investigate the effect of quercetin on endothelin-1-induced T-type calcium channel(TCC) expression in primary cultured human umbilical arterial smooth muscle cells for exploring the protective role of quercetin in cardiovascular system. METHODS: Human umbilical arterial smooth muscle cells were verified by immunocytochemistry. The cells in 2-3 passages were used and randomly divided into control group, quercetin alone group, model group and experimental group. The cells in control group were cultured without any drugs for 24 h. The cells in quercetin alone group were cultured with 80 μmol/L quercetin for 24 h. The cells in model group were cultured with ET-1 at the concentration of 100 nmol/L for 24 h. The cells in experimental groups were pretreated with quercetin for 1 h, then coincubated with 100 nmol/L ET-1 for 24 h. The concentrations of quercetin used in this study were 20, 40and 80 μmol/L, respectively. The expression of α_1G, a TCC major subunit, was assayed at mRNA and protein levels by RT-PCR and Western blotting, respectively. The TCC currents(I_caT) were detected by the technique of whole-cell patch-clamp. RESULTS: Compared with control and experimental group, I_CaT density (P<0.01) and the expression of α_1G at mRNA (P<0.05) and protein (P<0.01) levels in model group were significantly increased. No significant difference in the results of quercetin alone group and control group was observed. CONCLUSION: The protective roles of quercetin in cardiovascular functions are related to the depressive effects of quercetin on ET-1-induced increase in both I_CaT density and the expression of α_1G at mRNA and protein levels in cultured human vascular smooth muscle cells.     

槲皮素对CBRH-7919细胞增殖及线粒体膜电位的影响(英文)

[目的]探讨槲皮素对肝癌细胞株CBRH-7919增殖及线粒体膜电位的影响。[方法]体外培养肝癌CBRH-7919细胞,以不同浓度槲皮素处理细胞后,采用酸性磷酸酶(APA)法检测OD405nm;倒置显微镜观测CBRH-7919细胞形态变化;Rhodamine123染色后流式细胞仪检测线粒体膜电位(△ψm)变化。[结果]槲皮素对肝癌CBRH-7919细胞有明显的增殖抑制作用,并与剂量和时间成正比。光学显微镜下可见槲皮素作用后细胞密度明显降低。经10μg/ml槲皮素作用12、24、48h后,流式细胞术检测到Rhodamine123染色弱荧光细胞百分比逐步增加,线粒体膜电位下降。[结论]槲皮素体外能抑制肝癌细胞株CBRH-7919增殖,引起线粒体膜电位下降。     

Inhibitory effect of quercetin on apoptosis of PC12 cells induced by rotenone

AIM: To observe the effects and mechanisms of quercetin on the apoptosis of PC12 cells induced by rotenone. METHODS: PC12 cells were used in the study. Quercetin at the concentration of 300 μmol/L was added into the PC12 cells cultured in DMEM-F12 medium with 10% fetal calf serum. The morphological changes of the cells were observed under fluorescence microscope. The apoptotic rate was determined by flow cytometry assay. The protein levels of Bax and Bcl-2 were determined by Western blotting, and the mitochondrial membrane potential was measured by ratiometric probe JC-1.RESULTS: In the cells treated with rotenone+quercetin, the morphology of the cells was significantly improved, and the apoptotic rate was decreased to 6.7%, significantly lower than that in the cells treated with rotenone alone (P<0.01). The expression of Bcl-2 was up-regulated and Bax was down-regulated in rotenone+quercetin group (P<0.01), while the mitochondrial membrane potential was also increased (P<0.01) as compared to those in rotenone group.CONCLUSION: Pretreatment of quercetin inhibits the development of apoptosis in PC12 cells induced by rotenone. One of the mechanisms may be correlated with up-regulating the expression of Bcl-2 and down-regulating the expression of Bax, thus maintaining mitochondrial membrane potential.     

Quercetin attenuates cardiomyocyte hypertrophy through proteasome inhibition

AIM: To investigate the protective effect of quercetin on angiotensin Ⅱ (AngⅡ)-induced cardiomyocyte hypertrophy and its possible mechanism. METHODS: Cardiomyocyte hypertrophy was induced by AngⅡ (100 nmol/L) in primary neonatal cardiomyocytes and H9c2 cells. The cells were treated with different concentration of quercetin (10 μmol/L, 20 μmol/L and 40 μmol/L) for 48 h and then the cardiomyocyte surface areas were measured by immunofluorescence. Proteasome activity was detected by fluorescent peptide substrate. The phosphorylated levels of GSK-3α/β and Akt in H9c2 cells were determined by Western blot. RESULTS: Compared with control group, the cardiomyocyte surface areas were both increased in primary cultured neonatal cardiomyocytes and H9c2 cells, while the surface areas were significantly decreased by quercetin, especially at concentration of 20 μmol/L compared with Ang Ⅱ group (P<0.05). Compared with control group, the chymotrypsin-like, trypsin-like and caspase-like activities of proteasome were all increased in H9c2 cells (P<0.05). The trypsin-like and caspase-like activities of proteasome were inhibited by 20 μmol/L and 40 μmol/L quercetin, while chymotrypsin-like activity was inhibited only at 20 μmol/L of quercetin compared with Ang Ⅱ group (P<0.05). In addition, phosphorylated levels of GSK-3α-Ser21, GSK-3β-Ser9 and Akt-Ser473 in Ang Ⅱ group were all increased compared with control group, which were obviously inhibited by in 20 μmol/L and 40 μmol/L quercetin (P<0.05). CONCLUSION: Quercetin decreases cardiomyocyte hypertrophy through proteasome inhibition, which may be related to the inhibition of Akt and therefore increasing activation of GSK-3α/β in H9c2 cells.     

The influence of exposure to light on the phenolic content of ‘Fuji’ apple

In this study, the influence of changes in fruit lighting on individual and total phenols in ‘Fuji’ apple, as well as color development was studied. Content levels of eight quercetin glycosides, five anthocyanins, two catechins and a hydroxycinnamic acid in the skin of apples were analyzed, using high-performance liquid chromatography, tandem mass spectrometry (HPLC-MS). Total phenol, chlorophyll and carotenoid contents were determined by spectrometry. The purpose of this study was to compare content levels of those compounds in apple skin of fruit grown in different parts of the tree canopy, under and outside of the hail net. Lighting of fruit was measured during the last month before harvest. The lowest values were measured in the inner fruit and higher ones in the outer parts of the canopy, while the highest values were measured in fruit growing at the top of the tree. The hail net had no influence on the decrease of lighting in comparison to the control. Light conditions in the tree canopy influenced lower content levels of quercetin glycosides and most anthocyanins in the fruit skin in the inner part of the tree canopy, whereas fruit from the canopy top contained the highest levels of quercetin glycosides and cyanidin glycosides. Catechin, epicatechin and chlorogenic acid content levels in apple skin were independent of fruit position in the canopy or hail net usage, except for chlorogenic acid, where the content level was higher in cases when the orchard was covered with a hail net. Fruit from the top and outer parts of the canopy had a darker and redder coloration than inner fruit, while no influence of canopy position on chlorophyll and carotenoids was detected. Since quercetin glycosides and cyanidin glycosides are influential in red skin color development, better coloration of fruit from the outer and top canopy was observed. More intensive lighting stimulated a higher content level of flavonoids and, consequently, better coloration, which is an important factor in fruit quality.     

槲皮素对BEL-7402细胞生长抑制作用的研究

[目的]探讨槲皮素对人肝癌细胞株BEL-7402的增殖抑制及凋亡诱导作用。[方法]体外培养BEL-7402细胞,以不同浓度槲皮素处理细胞后,采用酸性磷酸酶（APA）法检测细胞增殖抑制率;光镜观测BEL-7402细胞形态变化;流式细胞仪检测细胞凋亡率。[结果]槲皮素对人肝癌BEL-7402细胞有明显的增殖抑制作用,其72h的IC50为4μg/ml。光学显微镜下可见细胞密度明显降低。经槲皮素作用6、12h后,流式细胞术检测到细胞凋亡率显著增加。[结论]槲皮素对人肝癌细胞的增殖抑制呈浓度相关性,可诱导肝癌细胞凋亡。     

落叶松树皮乙醚萃取物组份的分离与鉴定

落叶松树皮丙酮浸提物的乙醚萃取液,经聚己内酰胺、硅胶柱色谱分离,得到三个纯化合物。对它们进行化学分析和光谱分析,确定它们为:( )-儿茶素;槲皮素;一个新的黄烷-3-醇化合物(C_(30)H_(22)O_(10))