HPLC法同时测定叶下珠中没食子酸、原儿茶醛、柯里拉京、鞣花酸、槲皮素的含量

目的建立HPLC法同时测定叶下珠中5种成分没食子酸、原儿茶醛、柯里拉京、鞣花酸、槲皮素的含量。方法采用RP-HPLC测定叶下珠中5种成分的含量。采用Alltima C18(4.6×150mm,5μm),流动相为甲醇-0.1%磷酸梯度洗脱,流速为1.0mL/min,检测波长为280nm,柱温为30℃,进样体积为10μL。结果没食子酸、原儿茶醛、柯里拉京、鞣花酸、槲皮素线性范围分别为0.198～3.166μg(r=0.9998)、0.195～3.128μg(r=0.9996)、0.235～3.754μg(r=0.9999)、0.140～2.234μg(r=0.9997)、0.179～2.862μg(r=0.9995);平均加样回收率分别为99.82%(RSD=2.48%)、99.68%(RSD=1.48%)、100.43%(RSD=1.49%)、95.21%(RSD=2.42%)、100.34%(RSD=2.27%)。结论本研究所建立的方法方便、结果稳定可靠,可用于叶下珠的质量控制。     

槲皮素固体脂质纳米粒的包封率与载药量测定

目的:建立槲皮素固体脂质纳米粒(SLN)的包封率和载药量测定方法。方法:采用高速离心-高效液相色谱法。色谱柱为DiamonsiL-C18(250mm×4.6mm,5μm),流动相为甲醇-4.3%乙酸溶液(55∶45),流速为1.0mL·min-1,检测波长为254nm,柱温为30℃。结果:槲皮素检测浓度在2.0～200.0μg·mL-1范围内与峰面积积分值呈良好线性关系(r=0.9996);平均回收率为97.83%,RSD=1.03%(n=6)。该条件下,槲皮素SLN的包封率为80.2%,载药量为1.7%。结论:所建方法便捷、可靠,可用于SLN包封率与载药量的测定。     

RP-HPLC法测定小飞蓬总黄酮中野黄芩苷、槲皮素和木犀草素的含量

目的:建立测定小飞蓬总黄酮(总黄酮含量为76.52%)中野黄芩苷、槲皮素和木犀草素含量的方法。方法:采用反相高效液相色谱法。色谱柱为AgilentZORBAXSB-C18(250mm×4.6mm,5μm),流动相为甲醇-0.5%冰醋酸水溶液(梯度洗脱),检测波长为360nm,流速为1mL·min-1,柱温为30℃。结果:野黄芩苷、槲皮素和木犀草素进样量均在0.52～1.17μg范围内与各自峰面积积分值呈良好线性关系(r均为0.9999);三者平均加样回收率分别为97.23%、96.57%和97.33%,RSD分别为1.44%、0.80%和1.72%(n均为6)。结论:本方法简便、快速、准确,可为有效控制小飞蓬总黄酮的质量提供依据。     

HPLC法测定千里光中槲皮素的含量

目的:建立测定千里光药材中槲皮素含量的方法,为千里光的质量控制提供理论依据。方法:采用高效液相色谱法。色谱柱为Agilent Eelipse XDB C18(250mm×4.6mm,5μm),柱温为30℃,流动相为甲醇-0.1%三氟乙酸(65:45),流速为1.0mL·min-1,检测波长为360nm,进样量为20μL。结果:槲皮素进样量在0.2032～1.8288μg范围内与峰面积积分值呈良好线性关系(r=0.9999);平均回收率为98.42%,RSD=4.16%(n=6)。结论:本方法专属性强、准确度高、重复性好,可用于千里光的质量控制。     

不同产地及生长期马鞭草中槲皮素和芹菜素含量变化的比较

目的 研究不同产地及不同生长期马鞭革中槲皮素和芹莱素的含量变化.方法采用高效液相色谱法,ODS-C18,以甲醇-0.1％磷酸溶液(60∶40)为流动相,检测波长350nm.并比较了不同产地及不同生长期马鞭革中槲皮素和芹菜素的含量.结果 槲皮素和芹菜素的线性范围分别在0.016～ 1.0μg、0.01～0.64μg,平均...     

桑树寄主的4种桑寄生科药用植物槲皮素含量测定

目的 对同以桑树为寄主4种桑寄生科药用植物槲皮素含量进行测定,为扩大桑寄生药材来源的可能性提供科学的理论依据.方法 采用RP - HPLC法对4种桑寄生科药用植物槲皮素含量进行测定,并与桑寄生药材对照品槲皮素含量比较,槲皮素采用甲醇-盐酸(4:1)回流提取,用Agilent Eclipse XDB - C18柱,甲醇-0.05％磷酸溶液(47:53)为流动相,流速1.0ml/min,检测波长254 nm.结果 槲皮素的线性范围0.41 ～6.56 mg(r=0.999 9),平均回收率为99.25％,4种桑寄生科药用植物槲皮素含量分别为:三色鞘花0 mg/g,小红花寄生8.01 mg/g,红花寄生7.82 mg/g,广寄生5.27 mg/g.结论 4种药用植物除三色鞘花检测不到槲皮素,不能作为桑寄生药用外,小红花寄生和红花寄生的槲皮素含量较高,提示小红花寄生和红花寄生亦可作桑寄生药材使用.     

壮药依肝达颗粒质量标准研究

目的 建立壮药依肝达颗粒的质量标准.方法 采用薄层色谱法进行定性鉴别,以高效液相色谱法测定槲皮素的含量.结果 薄层色谱分离度好,专属性强.槲皮素的线性范围为0.058～0.58 μg(r=0.999 8,n=6),平均回收率为103.82％,RSD =0.84％ (n=6).结论 所建立的方法简便、准确、专属性强、重复性好,可有效控制壮药依肝达颗粒的质量.     

Quercetin protects neuroblastoma SH-SY5Y cells against oxidative stress by inhibiting expression of Krüppel-like factor 4

Quercetin is one of flavonoids with cyto-protective activities. It has been demonstrated that quercetin inhibits oxidative stress in some animal models and specific cells, but the particular mechanism is known a little. In the present study, we found that quercetin could decrease the expression of Krüppel-like factor 4 (KLF4) induced by hydrogen peroxide (H₂O₂) in human neuroblastoma SH-SY5Y cells, further increase the expression ratio of bcl-2 to bax, which were apoptotic-related target genes of KLF4, thus alleviate the apoptotic rate and caspase-3 enzyme activity of SH-5YSY cells; the overexpression or inhibition of KLF4 demonstrated the mediated role of KLF4 for the protective effect of quercetin on cell damage induced by H₂O₂. All results suggest a potential molecular mechanism of quercetin protecting against the oxidative damage, which may be applied in the treatment of oxidative related diseases, such as neurodegeneration diseases.     

Effect of quercetin on lipopolysaccharide induced-sickness behavior and oxidative stress in rats

Objectives:

Gram-negative infections and control infusion of recombinant cytokines in human have been shown to induce sickness behavior characterized by fever, prolong sleep, decreased food and water intake, reduced mobility, depression, and anxiety. Therefore, the present study was undertaken to investigate the effect of bioflavonoid quercetin in lipopolysaccharide (LPS)-induced sickness behavior.

Materials and Methods:

Wistar albino rats were divided into six groups (n=6). Three groups received vehicle and two doses of quercetin (2 and 25 mg/kg, i.p.) respectively for 2 weeks before being challenged with LPS (1 mg/kg, i.p). One group received vehicle for 2 weeks and was challenged with saline on day 15. The per se effect of quercetin (2 and 25 mg/kg, i.p.) was also seen after 2 weeks of dosing. LPS-induced sickness behavior in rats was quantified by measuring time in social exploration, anxiety, food and water consumption, and weight loss. Levels of cytokines (TNF-α, IL-1β, and IL-6) and oxidative stress in rat brain were also analyzed.

Results:

Quercetin (2 and 25 mg/kg) administration significantly (P<0.05) attenuated LPS-induced sickness behavior by modulating cytokines production as well inhibiting LPS-induced oxidative stress.

Conclusions:

Adequate intake of dietary flavonoids (like quercetin) may help promote recovery from sickness behavior.     

HPLC法测定银杏叶软胶囊中总黄酮的含量

目的：采用RP-HPLC法测定保健食品银杏叶软胶囊中总黄酮的含量。方法：采用Agilent C18（4.6 mm×250 mm,5μm）色谱柱,流动相为甲醇-水（用磷酸调pH为2.5）（50∶50）,流速为1.0 ml/min,检测波长为360 nm,柱温为30℃。结果：槲皮素、山奈素、异鼠李素的线性范围分别为0.050～0.400、0.005～0.040、0.005～0.040μg;3批样品中总黄酮含量分别为6.466、6.455、6.838 mg/粒。结论：本法简便、准确、分离效果好,适合于银杏叶软胶囊总黄酮的含量测定。