藏药熏倒牛HPLC特征图谱及4个成分的含量测定

目的:利用高效液相色谱法建立藏药熏倒牛的特征图谱，同时测定伞形花内酯、异槲皮苷、木犀草素、芹菜素4个成分的含量。方法:以伞形花内酯、异槲皮苷、木犀草素、芹菜素为目标化合物，采用CAPCELL PAK-C₁₈色谱柱(250 mm×4.6 mm, 5μm),以甲醇(A)-0.1%磷酸水(B)为流动相进行梯度洗脱(0～25 min, 16%A→40%A;25～30 min, 40%A;30～45 min, 40%A→62%A;45～51 min, 62%A→80%A;51～55 min, 80%A;55～56 min, 80%A→16%A;56～60 min, 16%A),流速为1 mL·min^-1,柱温为30℃,检测波长为320 nm,利用“中药色谱指纹图谱相似度评价系统(2012.130723版本)”建立9批熏倒牛的特征图谱，同时对熏倒牛中的4个成分进行测定。结果:建立的HPLC熏倒牛特征图谱中共有27个共有峰，9批熏倒牛样品的相似度介于0.612～0.985之间。9批样品中伞形花内酯、异槲皮苷、木犀草素、芹菜素4个成分的含量分别在63.986...     

HPLC法测定通便宁片中8种成分及其化学计量学综合评价

目的 建立HPLC法测定通便宁片中咖啡酸、儿茶素、表儿茶素、芹菜素-6,8-二-C-葡萄糖苷、异鼠李素-3-O-β-龙胆二糖苷、番泻苷B、番泻苷A、丁内未利葡萄糖苷,结合化学计量学综合评价产品质量。方法 采用Discovery C₁₈色谱柱（250 mm×4.6 mm,5μm）,流动相0.3%冰醋酸–乙腈,梯度洗脱;检测波长为325 nm（0～13 min检测咖啡酸）、270 nm（13～55 min检测儿茶素、表儿茶素、芹菜素-6,8-二-C-葡萄糖苷、异鼠李素-3-O-β-龙胆二糖苷、番泻苷B、番泻苷A和丁内未利葡萄糖苷）;柱温30℃;体积流量1.0 mL/min;进样量10 μL。运用聚类分析（CA）、主成分分析（PCA）、正交偏最小二乘判别分析法（OPLS-DA）对测定结果进行综合分析。结果 咖啡酸、儿茶素、表儿茶素、芹菜素-6,8-二-C-葡萄糖苷、异鼠李素-3-O-β-龙胆二糖苷、番泻苷B、番泻苷A、丁内未利葡萄糖苷分别在0.49～12.25、0.36～9.00、1.08～27.00、4.15～103.75、39.47～986.75、43.71～1092.75、29.20～730.00、8.57～214.25 μg/mL线性关系良好,平均回收率分别为96.99%、97.28%、98.01%、99.33%、100.03%、99.74%、100.10%、98.85%,RSD值分别为1.43%、0.89%、1.55%、0.72%、0.58%、0.66%、0.82%、1.31%。12批通便宁片样品可聚为3类,不同的生产周期呈现一定的差异性;番泻苷B、异鼠李素-3-O-β-龙胆二糖苷和番泻苷A是影响通便宁片产品质量的主要潜在标志物。结论 所建立的方法简单可行,结合化学计量学可用于通便宁片质量的综合评价,可为通便宁片的质量标准提升提供参考。     

莲须的UPLC指纹图谱及异槲皮苷含量分析

目的 建立莲须的超高效液相色谱法(UPLC)指纹图谱，并建立其异槲皮苷的含量测定方法。方法 色谱柱为Waters Acquity UPLCHSS T3,1.8μm, 2.1×100 mm;以乙腈(A)-0.2%乙酸(B)为流动相进行梯度洗脱；流速0.2 mL·min^-1;柱温：30℃;进样量3μL;检测波长300 nm。建立莲须药材的指纹图谱和异槲皮苷含量分析方法，并对19批不同产地莲须药材进行测定。结果 指纹图谱及含量测定方法的各项方法学验证均良好，19批莲须与对照指纹图谱的相似度在0.883～0.995,标定了7个共有峰。主要成分异槲皮苷线性关系良好(R²>0.999),加样回收率在91.58%～99.70%,RSD为3.54%,19批莲须异槲皮苷含量在0.011%～0.033%。结论 所建立的莲须UPLC指纹图谱及异槲皮苷含量分析方法专属性强、分离度好、灵敏度高，可为莲须药材的质量控制与评价提供参考。     

高效液相色谱法同时测定田基黄注射液中槲皮苷、异槲皮苷的含量

目的:建立以高效液相色谱法同时测定田基黄注射液中槲皮苷、异槲皮苷含量的方法。方法:色谱柱为MerckLichrospher RP18,流动相为乙腈-(pH=3.0)磷酸盐缓冲液(18∶82),流速为1ml/min,柱温为25℃,检测波长为350nm。结果:槲皮苷、异槲皮苷进样量分别在0.278μg～4.440μg(r=0.9991)、0.315μg～2.520μg(r=0.9991)范围内与峰面积积分值线性关系良好;平均加样回收率分别为98.60%(RSD=2.23%)、97.79%(RSD=1.74%)。结论:本方法准确可靠、应用性强,可用于本品的质量控制。     

HPCE测定保健品及中药中的多种黄酮类化合物

目的 分离测定中药和保健品中黄芩素、异鼠李素、芦丁、儿茶素、槲皮苷、木樨草素、芹菜素等7种黄酮类化合物.方法 采用高效毛细管区带电泳紫外检测法.运行缓冲液为50 mmol·L~(-1) Na_2BO_4·10H_2O-50 mmol·L~(-1) H_3 BO_3(pH9.5),分离电压20 kV,温度20 ℃,检测波长245 nm.结果 黄芩素、异鼠李素、芦丁、儿茶素、槲皮苷、木樨草素、芹菜素分别在2.79～33.5、12.2～244、68.5～1370、4.70～470、5.75～345、2.33～28、19.9～398 μg·mL~(-1)与各自的峰面积成良好的线性关系,r分别为0.9980、0.9940、0.9974、0.9990、0.9986、0.9996、0.9979,检出限分别为1.340、0.976、0.685、2.350、1.725、0.244、0.398μg·mL~(-1).结论 7种物质在16 min内可得到良好的分离.     

HPLC法同时测定杜仲叶中8种成分的含量

目的:建立同时测定杜仲叶中桃叶珊瑚苷、京尼平苷酸、儿茶素、绿原酸、车叶草苷、芦丁、异槲皮苷和紫云英苷等8种成分的含量测定方法。方法:采用高效液相色谱法。色谱柱为Agilent ZORBAX SB-C18,流动相为乙腈-0.1%磷酸溶液(梯度洗脱),流速为1.0 mL/min,检测波长为203 nm(桃叶珊瑚苷、儿茶素)、239 nm(京尼平苷酸、车叶草苷)、220 nm(绿原酸)、354 nm(芦丁、异槲皮苷)、266 nm(紫云英苷),进样量为5μL。结果:桃叶珊瑚苷、京尼平苷酸、儿茶素、绿原酸、车叶草苷、芦丁、异槲皮苷和紫云英苷的线性范围分别为0.812～6.090μg(r=0.999 3)、0.438～3.285μg(r=0.999 2)、0.045～0.336μg(r=0.999 2)、0.882～6.615μg(r=0.999 3)、0.097～0.726μg(r=0.999 1)、0.064～0.483μg(r=0.999 3)、0.048～0.360μg(r=0.999 1)、0.014～0.108μg(r=0.999 7);精密度、重复性和稳定性试验的RSD均小于3.5%(n=6);平均加样回收率分别为101.60%、103.06%、99.77%、96.93%、98.17%、96.75%、98.97%、99.60%,RSD分别为1.42%、2.65%、2.78%、2.05%、2.26%、0.93%、2.79%、3.08%(n=6)。不同采集时间、不同种植品种的12批杜仲叶样品中桃叶珊瑚苷、京尼平苷酸、儿茶素、绿原酸、车叶草苷、芦丁、异槲皮苷和紫云英苷的含量范围分别为10.903～17.245、5.578～7.892、0.198～0.440、13.890～19.782、1.008～1.547、1.102～2.396、0.267～0.701、0.150～0.412 mg/g,含量波动较大;杜仲皮样品中桃叶珊瑚苷、京尼平苷酸、儿茶素、绿原酸、芦丁、松脂醇二葡萄糖苷的含量分别为0.299、0.123、0.580、0.112、0.026、1.961 mg/g。结论:本方法操作简便、重复性好、准确度高,可用于评价杜仲叶的质量;不同采集时间、不同种植品种的杜仲的不同药用部位(皮、叶)中的成分组成及含量存在明显的差异。     

高效液相梯度洗脱法同时测定情安喘定片5种成分

目的：采用高效液相梯度洗脱法,同时测定情安喘定片中芸香苷、槲皮苷、补骨脂素、佛手柑内酯和芹菜素含量。方法采用依利特Hypersil C18色谱柱(200 mm×4.6 mm,5μm);流速：0.9 mL·min-1;以甲醇( A)-0.1％磷酸溶液( B)为流动相进行梯度洗脱;检测波长：芸香苷和槲皮苷为254 nm,补骨脂素、佛手柑内酯和芹菜素为269 nm,柱温为35℃。结果芸香苷、槲皮苷、补骨脂素、佛手柑内酯和芹菜素质量浓度分别在6.06~121.20μg·mL-1(r=0.9999)、5.80~116.00μg·mL-1(r=0.9992)、4.65~93.00μg·mL-1(r=0.9997)、7.10~142.00μg·mL-1(r=0.9995)、6.30~126.00μg·mL-1(r=0.9993)时与其峰面积呈良好的线性关系;芸香苷、槲皮苷、补骨脂素、佛手柑内酯和芹菜素的平均加样回收率分别为99.26％,98.28％,97.12％,98.05％,96.72％,RSD(n=6)分别为0.76％,1.54％,0.64％,0.87％,0.61％。结论该方法是一种快速、灵敏、准确的分析方法,可用于情安喘定片的质量控制。     

UPLC法测定郁舒片中5种药效成分含量

目的:建立UPLC法同时测定郁舒片中芍药内酯苷、芍药苷、芦丁、金丝桃苷、异槲皮苷的含量。方法:采用Waters Acquity UPLCTMBEH-C18(100 mm×2.1 mm,1.7μm)色谱柱,以0.1%磷酸水溶液(A)-乙腈(B)为流动相,梯度洗脱,流速0.4m L·min-1,检测波长203 nm,柱温30℃。结果:芍药内酯苷、芍药苷、芦丁、金丝桃苷、异槲皮苷5种成分在相应的范围内,呈良好的线性关系(r≥0.999 0);方法的平均加样回收率(n=6)分别为101.4%(RSD=0.82%)、101.9%(RSD=1.0%)、99.0%(RSD=2.6%)、98.9%(RSD=2.0%)、100.0%(RSD=2.4%)。3批样品的测定结果分别是芍药内酯苷3.53~3.80 mg·片-1,芍药苷9.33~10.01 mg·片-1,芦丁0.89~0.98 mg·片-1,金丝桃苷0.72~0.76 mg·片-1,异槲皮苷0.82~0.86 mg·片-1。结论:该方法分析时间短,操作简单,可以作为郁舒片的质量控制方法。     

HPLC梯度洗脱法测定抗饥消渴片中7种成分的含量

目的建立HPLC梯度洗脱法同时测定抗饥消渴片中原儿茶醛、儿茶素、表儿茶素、毛蕊花糖苷、焦地黄苯乙醇苷B1、麦冬甲基黄烷酮A和甲基麦冬二氢高异黄酮B的含量,为抗饥消渴片质量标准提升提供数据支持。方法采用Diamonsil C18色谱柱(4.6 mm×250 mm,5μm),柱温35℃;流动相:乙腈-0.2%磷酸溶液,梯度洗脱,流速1.0 mL·min-1;检测波长分别为280 nm(0～24.0 min检测原儿茶醛、儿茶素和表儿茶素)、330 nm(24.0～36.0 min检测毛蕊花糖苷和焦地黄苯乙醇苷B1)和296 nm(36.0～50.0 min检测麦冬甲基黄烷酮A和甲基麦冬二氢高异黄酮B)。结果原儿茶醛、儿茶素、表儿茶素、毛蕊花糖苷、焦地黄苯乙醇苷B1、麦冬甲基黄烷酮A和甲基麦冬二氢高异黄酮B分别在5.96～119.20、1.18～23.60、8.76～175.20、2.87～57.40、1.59～31.80、1.26～25.20、0.88～17.60μg·mL-1内与峰面积线性关系良好(r≥0.9991);7种测定成分的平均回收率均> 96.0%,RSD均≤2.0%。结论该方法操作简便、重复性好,可用于抗饥消渴片中多种指标性成分的质量控制。     

萹蓄中杨梅苷和槲皮苷的含量测定

目的:采用反相高效液相色谱法(RP-HPLC)分析萹蓄中杨梅苷和槲皮苷的含量。方法:Agilent LC-C18(250 mm×4.6 mm,5μm)色谱柱,以乙腈-0.1%磷酸溶液(18︰82)作为流动相,流速为1.0 mL/min,柱温30℃,检测波长256 nm。结果:杨梅苷和槲皮苷分别在1.22～24.30μg/mL和0.77～15.40μg/mL范围内有良好的线性关系,平均加样回收率分别为98.9%、99.6%,RSD分别为1.11%和1.09%。结论:该方法准确,简便,重复性好,可用于萹蓄中杨梅苷和槲皮苷的定量分析。     

Antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of ethanol extract and pure flavonoids from Adinandra nitida leaves

Context: Adinandra nitida Merr. ex. H.L. Li (Theaceae) is an indigenous plant in south China. Its leaves have been reported to have many curative effects such as reducing blood pressure, as well as antibacterial, antioxidant, and analgesic properties, which could be used in foods and medicines.

Objective: The antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of the main flavonoids and ethanol extract (EE) of A. nitida leaves were investigated for the first time.

Materials and methods: The main flavonoids of A. nitida leaves (camellianin A, camellianin B) were prepared and their contents in EE were determined by HPLC. The antioxidant activities of the samples were measured by DPPH radical scavenging assay and Rancimat test. The ACE inhibitory activities of the samples were carried out by using an assay kit with hippuryl-glycyl-glycine as substrate.

Results: The contents of camellianin A, camellianin B and apigenin in EE were determined as 41.98, 2.67, and 1.73%, respectively. The antioxidant activities of the flavonoids were far lower than that of EE in DPPH radical scavenging and Rancimat assays. However, the ACE-inhibitory activities of camellianin A, camellianin B and apigenin were higher than that of EE.

Discussion and conclusion: The flavonoid content of EE was more than 45%. The high activities of EE in DPPH scavenging and Rancimat assay could be mainly attributed to compounds other than flavonoids. However, the ACE-inhibitory activity of EE could be mainly attributed to the presence of the flavonoids.     

Flavonoids in the flowers of Primula officinalis

From methanolic extracts of fresh flowers of PRIMULA OFFICINALIS 19 flavonoids were isolated or detected: quercetin, luteolin, kaempferol, isorhamnetin, apigenin; quercetin 3-O-glucoside, -rutinoside, -robinobioside, -gentiobioside, -(glucosyl-(1-->2) -glucosyl-(1-->6))-glucoside, -(rhamnosyl)-robinobioside; isorhamnetin 3-O-glucoside, -rutinoside, -robinobioside, -(rhamnosyl) -robinobioside; kaempferol 3-O-rutinoside, -robinobioside; limocitrin 3-O-glucoside; 3', 4'-dihydroxyflavonglucoside. Other compounds isolated were epicatechin, epigallocatechin, and proanthocyanidin B 2.     

UPLC-QTOF-MS法同时测定春季文冠果叶中11种黄酮类化合物的含量

目的建立UPLC-QTOF-MS法同时测定春季文冠果叶中11种黄酮类化合物的含量。方法采用ACQUITY UPLC HSS T3色谱柱(100 mm×2.1 mm,1.8μm),以体积分数0.05%甲酸水为流动相A,体积分数0.05%甲酸乙腈为流动相B,梯度洗脱,流速0.4 mL·min-1,电喷雾离子源(ESI),负离子全扫描模式,选择性离子监测定量方式进行。结果表没食子儿茶素,表儿茶素,杨梅素-3-O-芸香糖苷,芦丁,杨梅苷,山柰酚-3-O-芸香糖苷,槲皮苷,杨梅树皮素,山柰酚-3-O-α-吡喃鼠李糖苷,木犀草素和槲皮素质量浓度分别在0.38~38.00、0.46~46.00、0.90~90.00、0.75~75.00、1.60~160.00、0.45~45.00、0.60~60.00、0.016~1.60、0.30~30.00、0.010~1.00、0.010~1.00 g·L-1内与峰面积呈良好的线性关系,相关系数r均大于0.999。精密度、稳定性和重复性的RSD值均小于15%,平均回收率在91.5%~110.4%内,RSD小于6.5%。结论所建立的UPLC-QTOF-MS法适用于文冠果叶中黄酮类化合物的含量测定,为文冠果叶的合理应用提供依据。     

Inhibition of human cytochrome CYP 1 enzymes by flavonoids of St. John's wort

CYP 1B1 is involved in metabolizing both polycyclic aromatic hydrocarbons and estradiol to potentially carcinogenic intermediates, and it is also over-expressed in human cancer cells. In order to investigate whether flavonoids could specifically inhibit CYP 1B1, seven flavonoids in St. John's wort and apigenin were screened for their inhibition of recombinant human CYP 1B1 and CYP 1A1. While seven flavonoids (myricetin, apigenin, kaempferol, quercetin, amentoflavone, quercitrin and rutin) were slightly more selective for CYP 1B1 EROD inhibition (K(i)s 0.06-5.96 microM) compared to CYP 1A1 (K(i)s 0.20-1.6 microM) the difference in K(i)s for the P450s were not significantly different. Rutin did not inhibit CYP 1A1 at concentrations up to 10 microM. Kinetic analyses determined that apigenin and amentoflavone were competitive inhibitors of CYP 1B1, while quercetin showed mixed type inhibition. To characterize the inhibition potential of these flavonoids, five were studied further for their ability to inhibit TCDD-induced EROD activity in 22Rv1 human prostate cancer cells. 22Rv1 cells express constitutive and TCDD-inducible CYP 1A1 and CYP 1B1 mRNA. In the cells, the IC(50)s were similar to those measured for the recombinant CYP 1A1 except for amentoflavone. Quercetin (IC(50): 4.1 microM), kaempferol (3.8 microM), myricetin (3.0 microM) and apigenin (3.1 microM) caused significant inhibition of EROD activity whereas amentoflavone did not cause inhibition. Depending on their bioavailability, flavonoids that can selectively inhibit CYP1 enzymes may be useful as chemoprotective agents in prostate cancer prevention.     

Differential effects of dietary flavonoids on reactive oxygen and nitrogen species generation and changes in antioxidant enzyme expression induced by proinflammatory cytokines in Chang Liver cells.

This study was aimed to investigate the differential protective effect of dietary flavonoids against oxidative stress induced by proinflammatory stimuli in parenchymal liver cells. Chang Liver cells were incubated with a cytokine mixture (CM) supplemented with the flavonols quercetin and kaempferol, the flavanone taxifolin and the flavone apigenin (5-50 microM). Concentrations of oxidised and reduced glutathione, generation of different ROS/RNS, and expression of antioxidant enzymes were measured. Oxidised glutathione concentration and the oxidised/reduced glutathione ratio were increased by the CM. These effects were significantly prevented by quercetin, kaempferol and taxifolin at all tested concentrations. Effects of apigenin reached a lesser extent and were not significant at 25 microM. Treatment with quercetin and kaempferol prevented the production of peroxides, superoxide anion and nitric oxide induced by CM. Taxifolin 50 microM and apigenin 25-50 microM caused a significant increase in peroxides and nitric oxide generation. Protein concentration of the different antioxidant enzymes was generally reduced by kaempferol and quercetin in comparison to CM, although quercetin 25 and 50 microM increased Mn SOD protein concentration. GPx protein level was significantly increased by apigenin 25 and 50 microM. Changes in mRNA tended to be parallel to those in protein concentration. Our study reveals that important differences exist between flavonoids with different structural features in their capacity to abrogate the generation of different ROS/RNS, and suggests that the modulation of antioxidant enzymes by flavonoids may be also important in their antioxidant effects in liver cells.     

高效液相色谱法同时测定醉鱼草中五种黄酮成分

目的：建立同时测定中药材醉鱼草中黄酮成分蒙花苷、芦丁、木犀草素、槲皮素和芹菜素含量的方法,为醉鱼草的质量控制提供理论依据。方法：采用高效液相色谱法对醉鱼草中五种黄酮类有效成分进行同时测定。色谱柱型号：Hypersil ODS色谱柱（200 mm×4.6 mm,5 μm）,柱温：25℃;流速：1.0 mL·mL^-1;流动相：甲醇-0.2%磷酸水溶液;检测波长：256 nm,梯度洗脱。结果：中药材醉鱼草中的黄酮成分蒙花苷、芦丁、木犀草素、槲皮素和芹菜素在质量浓度为1.63~75 μg·mL^-1（r=0.999 5）,0.42~26 μg·mL^-1（r=0.999 7）,0.77~152 μg·mL^-1 （r=0.999 4）,1.02~108 μg·mL^-1（r=0.999 6）,0.91~99 μg·mL^-1（r=0.999 2）范围内与峰面积线性相关,醉鱼草样品加标回收率均值分别为99.7%,97.9%,99.7%,99.5%,99.1%,RSD分别为1.3%,1.7%,0.7%,1.1%,1.0%。结论：该测定方法适用性强、快捷,重复性好,适用于中药材醉鱼草的质量控制。     

Production of Cytokine and NO by RAW 264.7 Macrophages and PBMC In Vitro Incubation with Flavonoids

Flavonoids, a group of low molecular weight phenylbenzopyrones, have various pharmacological properties including antioxidant activity, anticancer, and immunomodulatory effects. In the present study, lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate/phytohemagglutinin (PMA/PHA) were used as stimulants for RAW 264.7 macrophages and human peripheral blood mononuclear cell (hPBMC), and tumor necrosis factor (TNF)-alpha and interleukin (IL)-2 productions were measured. In addition, flavonoids were examined for their effects on LPS-induced NO production in RAW 264.7 macrophages. The results showed that all compounds were not strongly cytotoxic at the tested concentrations on hPBMC and RAW 264.7 macrophages. On immunomodulatory properties, catechin, epigallocatechin (EGC), naringenin, and fisetin repressed NO production and TNF-alpha secretion. Furthermore, catechin, epigallocatechin gallate (EGCG), epicatechin (EC), luteolin, chrysin, quercetin, and galangin increased IL-2 secretion while EGC, apigenin, and fisetin inhibited the secretion. These results indicated that flavonoids have the capacity to modulate the immune response and have a potential anti-inflammatory activity. There was no obvious structure-activity relationship regard to the chemical composition of the flavonoids and their cell biological effects.     

车前子中槲皮素、木犀草素、山柰酚、芹菜素的含量测定

目的建立车前子的槲皮素、山柰酚、木犀草素、芹菜素含量测定方法。方法采用反相高效液相色谱（RP—HPLC）法,色谱柱为Zorbax SB—C18柱（150mm×4．6mm,5μm）;检测波长360nm,流动相为甲醇-0．2％磷酸（45：55）,柱温30℃,流速1．0mL／min。结果槲皮素、山柰酚、木犀草素、芹菜素的回归方程分别为Y=1504．412X＋9．9756,Y=1991．745X＋8．6051,Y=567．591X＋2．5397,Y=1811．803X＋0．3074;质量浓度线性范围分别是0．05522～0．1933μg／mL,0．0461—0．1613μg／mL,0．1255～0．4393μg／mL,0．0603～0．211μg／mL,r在0．9999．1．0000之间;槲皮素、山柰酚的加样回收率分别为92．87％和102．95％,RSD分别为0．28％和1．08％;样品分别含槲皮素、山柰酚、木犀草素、芹菜素0．81,0．634,0,0．08mg／g。结论RP—HPLC法分析车前子中黄酮化合物的含量,方法简便可行,重复性好,结果可靠。     

松嫩草原罗布麻各器官总黄酮和槲皮素的含量测定及药材抗氧化活性评价

目的:测定松嫩草原罗布麻各器官总黄酮和槲皮素含量并评价其体外抗氧化活性,为有效利用罗布麻资源提供参考。方法:以超声波辅助提取罗布麻中总黄酮,用比色法和高效液相色谱法分别测定罗布麻中总黄酮和槲皮素的含量,DPPH.和.OH清除法评价其抗氧化活性。结果:松嫩草原罗布麻花和叶中总黄酮、槲皮素含量较高,其次为茎;叶和花中总黄酮提取液抗氧化活性较强,茎次之。结论:松嫩草原罗布麻叶、花和茎均可以作为天然抗氧化剂原料。     

Influence of the flavonoids apigenin, kaempferol, and quercetin on the function of organic anion transporting polypeptides 1A2 and 2B1

OATP1A2 and OATP2B1 are uptake transporters of the human organic anion transporting polypeptide (OATP) family with a broad substrate spectrum including several endogenous compounds as well as drugs such as the antihistaminic drug fexofenadine and HMG-CoA reductase inhibitors. Both transporters are localized in the apical membrane of human enterocytes. Flavonoids, abundantly occurring in plants, have previously been shown to interact with drug metabolizing enzymes and transporters. However, the impact of flavonoids on OATP1A2 and OATP2B1 transport function has not been analyzed in detail. Therefore, HEK293 cell lines stably expressing OATP1A2 and OATP2B1 were used to investigate the influence of the Ginkgo flavonoids apigenin, kaempferol, and quercetin on the transport activity of OATP1A2 and OATP2B1. K_i values of all three flavonoids determined from Dixon plot analyses using BSP as substrate indicated a competitive inhibition with quercetin as the most potent inhibitor of OATP1A2 (22.0 μM) and OATP2B1 (8.7 μM) followed by kaempferol (OATP1A2: 25.2 μM, OATP2B1: 15.1 μM) and apigenin (OATP1A2: 32.4 μM OATP2B1: 20.8 μM). Apigenin, kaempferol, and quercetin led to a concentration-dependent decrease of the OATP1A2-mediated fexofenadine transport with IC₅₀ values of 4.3 μM, 12.0 μM, and 12.6 μM, respectively. The OATP1A2- and OATP2B1-mediated transport of atorvastatin was also efficiently inhibited by apigenin (IC₅₀ for OATP1A2: 9.3 μM, OATP2B1: 13.9 μM), kaempferol (IC₅₀ for OATP1A2: 37.3 μM, OATP2B1: 20.7 μM) and quercetin (IC₅₀ for OATP1A2: 13.5 μM, OATP2B1: 14.1 μM). These data indicate that modification of OATP1A2 and OATP2B1 transport activity by apigenin, kaempferol, and quercetin may be a mechanism for food-drug or drug-drug interactions in humans.