黄连解毒汤中小檗碱及其他成分模拟组合在脑缺血大鼠体内药动学比较研究

目的 比较基于黄连解毒汤原方比例的4种不同模拟组合中主成分小檗碱在脑缺血模型大鼠体内的药动学变化过程。方法 大鼠按体质量分为模型组和假手术组,模型组以线栓法复制大鼠脑缺血模型。每组又分为4个亚组,分别为小檗碱（247.4 mg/kg）组、小檗碱（247.4 mg/kg）＋黄芩苷（190.7 mg/kg）组、小檗碱（247.4 mg/kg）＋栀子苷（149.5 mg/kg）组、小檗碱（247.4 mg/kg）＋栀子苷（149.5 mg/kg）＋黄芩苷（190.7 mg/kg）组。各组分别于ig给药后0.083、0.25、0.5、1、2、3、4、6、8、10、12、24、48、72 h 眼眶取血,HPLC法测定小檗碱在大鼠血浆中的浓度变化,绘制药-时曲线,DAS 2.0计算药动学参数。结果 根据统计矩参数,模型组和假手术组小檗碱的吸收顺序均为小檗碱＋栀子苷组＞小檗碱＋栀子苷＋黄芩苷组＞小檗碱组＞小檗碱＋黄芩苷组。结论 针对脑缺血模型,黄连解毒汤中的栀子苷可促进小檗碱的吸收,黄芩苷则对小檗碱的吸收有一定的抑制作用,而三者组合给药后栀子苷可以降低黄芩苷对小檗碱吸收的抑制作用。     

基于UPLC-Q-TOF-MS分析通络清脑注射剂在大鼠体内的代谢产物

目的:研究大鼠尾静脉注射通络清脑注射剂后尿液中的代谢产物,为该制剂的作用机制分析提供参考。方法:大鼠尾静脉注射通络清脑注射剂,收集0~12 h尿液,采用超高效液相色谱-四级杆-飞行时间串联质谱(UPLC-Q-TOF-MS)分析尿液样品,流动相0.1%甲酸水溶液-乙腈梯度洗脱,流速0.3 m L·min~(-1),电喷雾离子源,正离子模式,扫描范围m/z 100~1 400。结果:检测并鉴定到7个原型成分(黄芩苷,栀子苷,三七皂苷R1,人参皂苷Rg1,Rb1,Rd和Re)及10个可能的代谢产物(其中4个来源于黄芩苷,6个来源于栀子苷)。10个可能的代谢产物分别为葡萄糖基化代谢物(B-M1,G-M2和G-M4),葡萄糖醛酸化代谢物(B-M2),甲基化代谢物(B-M3),水解代谢物(B-M4),去甲基化代谢物(G-M1),脱氢代谢物(G-M3)和羟基化代谢物(G-M5和G-M6),而人参皂苷类成分则暂时未能在尿液中检测到代谢产物。结论:尾静脉注射通络清脑注射剂后,大鼠尿液中能检测到黄芩苷和栀子苷的原型及不同途径的10个代谢产物,而三七总皂苷各成分则只检测到药物原型,暂时未能检测到代谢产物。     

Comparative study on brain pharmacokinetics of Buyang Huanwu Decoction in normal and cerebral ischemia rats using brain microdialysis combined with LC-MS/MS

Objective: To conduct a comparative study on the brain pharmacokinetics of seven ingredients (i. e. senkyunolide A, ferulic acid, formononetin, calycosin, ononin, calycosin-O-β-D-glucopyranoside, and paeoniflorin), which were the compounds of Buyang Huanwu Decoction (BHD), in normal and cerebral ischemia rats administrated intragastrically with BHD. Methods: The samples of normal and permanent middle cerebral artery occlusion (pMCAO) rats were collected by using brain microdialysis technique. The concentrations of seven ingredients were determined by the HPLC-MS/MS method. After the BHD were administrated intragastrically to the rats for seven consecutive days, brain microdialysis probes were inserted into the hippocampus of rats, and then the brain microdialysates were collected at 20 min time intervals for 5 h. The separation of the seven ingredients and internal standard (IS) was carried out on an ACQUITY UPLC BEH C18 (2.1 mm × 100 mm, 1.7 μm) chromatographic column, using a mobile phase consisting of acetonitrile (containing 0.1% formic acid) and water (containing 0.1% formic acid) for gradient elution within 13 min. The ionization was conducted using an ESI source in positive ion mode. Multiple reaction monitoring mode was used for quantification of ingredients in BHD. Results: Linearity, accuracy, precision, matrix effect and stability of LC-MS/MS method were all satisfactory, successfully applied to compare the pharmacokinetics of the analytes between normal and model rats after intragastric administration of BHD. Compared with the normal group, the model group after the administration of the BHD showed that T1/2 of formononetin and ononin were longer, and except for calycosin-O-β-D-glucopyranoside (P < 0.01), there was no significant difference between the normal group and the model group. The Cmax of senkyunolide A and calycosin of model group were increased, while the Tmax of senkyunolide A was decreased, and except for the Tmax of PF, the differences between the two groups were statistically significant (P < 0.01). Conclusion: The LC-MS/MS method combined with microdialysis was successfully applied to the comparative study of brain pharmacokinetics of seven ingredients in BHD. After intragastric administration of BHD, there were differences in the pharmacokinetics of seven ingredients in the brain hippocampus between normal rats and model rats, probably related to the characteristics of the ingredients and the effects of cerebral ischemia on the absorption and distribution of the ingredients.     

针刺对局灶性脑缺血大鼠海马神经元细胞[Ca2+]i的影响

[目的]研究脑缺血不同时点大鼠海马神经元内游离Ca2+浓度[Ca2+]i及醒脑开窍针刺对其影响,探讨醒脑开窍针刺法早期干预对脑缺血的治疗作用。[方法]建立大脑中动脉所致局灶性脑缺血(MCAO)模型,采用醒脑开窍针刺法治疗,采用激光扫描共聚焦显微技术动态观察脑组织海马CA1区锥体细胞[Ca2+]i在不同时间点的变化。[结果]与正常组大鼠相比,模型组大鼠脑组织海马CA1区锥体细胞内游离[Ca2+]i(以细胞内Ca2+相对荧光强度表示)在局灶性脑缺血1 h时升高,持续升高至缺血24 h时(P<0.05)。假手术组与正常组相比[,Ca2+]i变化差异无统计学意义(P>0.05)。相应时间点非穴位针刺组与模型组[Ca2+]i比较,无统计学意义(P>0.05)。在相应时间点,醒脑开窍针刺组[Ca2+]i低于模型组(P<0.01)。[结论]急性局灶性脑缺血后大鼠海马神经细胞[Ca2+]i随缺血时间的延长而持续升高,提示细胞内钙超载;醒脑开窍针刺组能有效调节缺血区的[Ca2+]i,提示在缺血后针刺治疗效果越早越好,为临床及早应用针刺治疗缺血性脑血管病提供了理论依据。     

The effect of stroke and other components in Xing-Nao-Jing on the pharmacokinetics of geniposide

Ethnopharmacological relevance

Geniposide is a bioactive substance derived from gardenia, which has been used in traditional Chinese preparation, such as “Xing-Nao-Jing” (XNJ) for stroke treatment. Stroke and the ingredients of herbal preparation affect the pharmacokinetics of geniposide. A comparative pharmacokinetic study of geniposide in stroke and sham-operated rats after administration of XNJ and geniposide was proceeded to evaluate the effect of stroke on pharmacokinetics of geniposide, while the influence of other components in XNJ was determined by using gardenia extract and geniposide–borneol compounds in rats with stroke to compare.

Materials and methods

Stroke was induced by middle cerebral artery occlusion followed by reperfusion 2 h later. Plasma concentration of geniposide was determined by HPLC. Various pharmacokinetic parameters were estimated from the plasma concentration versus time data using non-compartmental methods.

Results

The maximum plasma concentration (C_max) and area under the curve (AUC_0−t) in stroke after administration of XNJ were 5.97±3.82 μg/mL, and 570.06±274.32 μg·min/mL, respectively, which were 5 times compared with sham-operated rats or the stroke-afflicted rats given geniposide. In stroke, the C_max and AUC_0−t of geniposide–borneol group and gardenia extraction group were close to XNJ group and geniposide group, respectively. The geniposide–borneol group had a higher value.

Conclusion

Stroke improved the absorption of geniposide in XNJ. Borneol may be the key ingredient in XNJ improving the absorption of geniposide.     

黄连解毒汤中9种主要成分在大鼠脑组织中分布特征研究

目的建立灵敏、准确、可靠的小檗碱、小檗红碱、药根碱、巴马汀、黄芩苷、汉黄芩素、千层纸素A、京尼平苷和栀子黄素B在大鼠海马、皮层、纹状体和脑脊液组织中高效液相色谱-串联质谱联用(HPLC-MS-MS)分析方法,用于黄连解毒汤中9种主要成分在大鼠脑组织中分布研究。方法优化黄连解毒汤中9种主要成分及内标克拉霉素和氯霉素的质谱检测条件,确定分析条件并对方法学进行考察。正常大鼠ig给予黄连解毒汤,末次给药1 h后采集脑脊液、海马、皮层和纹状体样品,经处理后将该方法用于9种成分的测定。结果小檗碱、药根碱、巴马汀、黄芩苷、汉黄芩素、千层纸素A、栀子黄素B在1～250 ng/mL呈现良好的线性关系(r~20.99),小檗红碱在1～500 ng/mL具有良好的线性关系(r~2=0.991 2),京尼平苷在5～500 ng/mL具有良好的线性关系(r~2=0.999 5);各成分的日内、日间精密度RSD均小于12.94%,准确度均在-12.71%～6.91%;提取回收率均在88.02%～106.70%,基质效应均在88.92%～105.10%;短期、冻融循环和长期稳定性RSD均小于12.51%。各成分在海马、皮层和纹状体中的含量为小檗碱黄芩苷京尼平苷小檗红碱巴马汀汉黄芩素药根碱千层纸素A栀子黄素B;各成分在脑脊液中的含量为京尼平苷小檗碱小檗红碱巴马汀黄芩苷栀子黄素B药根碱汉黄芩素千层纸素A。结论该方法可用于大鼠脑组织中小檗碱、药根碱等9种成分含量的同时检测,并可用于这9种成分在大鼠脑组织分布研究,为探究黄连解毒汤治疗脑部疾病的物质基础提供依据。     

清开灵注射液生产过程性能指数研究

为科学评价中药产品质量可靠性和批间一致性,该文以清开灵注射液为研究对象,收集一定时期内清开灵注射液产品质量指标历史数据,将过程性能指数P_p和P_pk应用于中药生产过程能力分析,并采用Bootstrap抽样方法计算过程性能指数置信区间。结果P_pk的估计值和置信区间宽度均低于P_p,表明P_pk用于过程性能分析时灵敏度更高。在考察的生产周期内,以黄芩苷、胆酸、栀子苷和总氮浓度为指标计算的P_pk分别为1.122,2.055,1.564,0.891,即胆酸的过程能力最高,其次为栀子苷和黄芩苷,总氮过程能力较低,提示应加强总氮相关工艺质量管理和控制水平。过程性能分析法可对中药生产过程能力和产品质量一致性进行量化研究,可作为生产过程运行质量的控制手段。     

清开灵滴丸质量控制方法的优化研究

目的优化并完善清开灵滴丸的质量控制方法。方法采用高效液相色谱法对清开灵滴丸中的黄芩苷进行鉴别;采用薄层色谱法对清开灵滴丸中金银花及其所含绿原酸、栀子所含栀子苷进行鉴别。采用高效液相色谱法-蒸发光检测器同时测定清开灵滴丸中胆酸和猪去氧胆酸的含量,色谱柱为Phenomenex Gemini 110 C18(4.6 mm×250 mm,5μm),流动相为甲醇-乙腈-0.1%甲酸(68:17:15),流速为1.0 mL·min^-1。采用高效液相色谱法测定清开灵滴丸中扼子苷的含量,色谱柱为Agilent Eclipse XDB-C18(4.6 mm×150 mm,5μm);流动相为乙腈-0.05%磷酸(10:90),流速为1.0 mL·min^-1;检测波长为238 nm。采用高效液相色谱法测定清开灵滴丸中黄芩苷的含量,色谱柱为同栀子苷含量测定;流动相为甲醇-水-鱗酸(47:53:0.2),流速为1.0 mL·min^-1;检测波长为Z75 nmD结果薄层色谱斑点清晰,重现性好。猪去氧胆酸、胆酸、栀子苷和黄芩苷进样量分别在0.5050?6.312μg、0.515?6.440μg、0.02912?0.5824μg和0.1092?1.092μg内与冷面积(或峰面积对数)呈良好线性关系,平均回收率分别为101.5%、101.6%、98.61%和99.77%,RSD分别为1.7%、1.5%、1.42%和0.79%。结论提高后的质量标准分析方法简便、快速、准确且毒性较小,能更全面有效控制清开灵滴丸的质量。     

清开灵注射液中黄芩苷在大鼠体内代谢动力学的研究

目的：研究清开灵注射液中黄芩苷在大鼠体内的代谢动力学,为探索清开灵注射液的体内效应物质基础提供依据。方法：大鼠尾静脉注射清开灵粉针剂后,于不同时间点取血、肝、肺组织,采用高效液相质谱联用法测定样品中黄芩苷含量,并用3P87拟合求算药代动力学参数。结果：静脉给药后,黄芩苷在大鼠体内符合二室模型。45 min时肝组织中分布达峰值,接着肝中浓度急剧下降,120 min后开始缓慢回升,呈现双峰现象。肺组织中黄芩苷浓度远高于肝组织中浓度,且消除较肝脏慢,但达峰时间同肝脏。结论：静注清开灵后,黄芩苷迅速分布至效应器官肺、肝中,黄芩苷为清开灵注射液的肝肺效应物质基础之一。黄芩苷在大鼠体内可能存在一定程度的肝肠循环。     

黄连解毒汤中黄酮成分逆转 K562/ADM多药耐药的实验观察

目的:观察黄连解毒汤中黄酮成分逆转肿瘤多药耐药的作用,探讨本方逆转肿瘤多药耐药的物质基础。方法:以人慢性粒细胞白血病红白血病细胞株K562的耐阿霉素(adriamycin,ADM)细胞株(K562/ADM)为细胞系,通过MTT实验观察黄芩苷、京尼平苷对K562/ADM细胞ADM的敏感性的影响,计算细胞增殖抑制率、半数抑制浓度(IC50)及耐药逆转倍数,并对细胞内ADM浓度变化进行测定。结果:黄芩苷、京尼平苷均能部分逆转K562/ADM细胞。黄芩苷、京尼平苷的IC50值分别为5.06,6.74 mg.L-1。黄芩苷、京尼平苷的耐药逆转倍数分别为1.95,1.46倍。与相应的对照组相比,K562/ADM细胞经黄芩苷(50 mg.L-1)、京尼平苷(100 mg.L-1)作用后,细胞内ADM的荧光强度高于对照组,其中黄芩苷组提高到3.6%,京尼平苷组提高到1.7%。结论:黄连解毒汤逆转肿瘤多药耐药的物质基础可能与其含有的黄芩苷、京尼平苷有关。     

黄芩苷镁盐和黄芩苷的肠吸收动力学和药代动力学比较

目的:比较黄芩苷镁盐和黄芩苷的肠吸收动力学和药代动力学的异同。方法:采用高效液相色谱法(HPLC)测定样品中黄芩苷镁盐和黄芩苷的含量,计算黄芩苷镁盐的吸收速率常数(K_a),每小时单位体积的肠吸收量(Abs),表观渗透系数(P_(app))等肠吸收动力学参数和药时曲线下面积(AUC_(0-t))等药动学参数,明确黄芩苷镁盐的肠吸收动力学和药动学特征。通过SPSS 19.0软件进行数据分析,探讨黄芩苷镁盐与黄芩苷在体和体内的吸收差异。结果:肠吸收动力学结果表明黄芩苷镁盐的K_a为黄芩苷的16.33倍,Abs为黄芩苷的1.78倍,P_(app)为黄芩苷的15.75倍,统计学差异明显(P0.05)。但药动学数据显示黄芩苷镁盐的药峰浓度(C_(max)),AUC0-t,达峰时间(T_(max))和血浆清除率(CL_z)与黄芩苷比较均无统计学差异。结论:与黄芩苷比较,黄芩苷镁盐在大鼠肠道的吸收更好,且吸收迅速。黄芩苷镁盐灌胃给药后药动学特征与黄芩苷无显著性差异,原因是黄芩苷镁盐经体内胃酸的作用被还原成为了黄芩苷。     

高效液相色谱法测定安宫牛黄丸中栀子苷、黄芩苷和盐酸小檗碱的含量

目的：建立同时测定安宫牛黄丸中栀子苷、黄芩苷和盐酸小檗碱含量的反相液相色谱法。方法：采用Agilent ZORBAX SB-C₁₈柱(4.6 mm×250 mm,5 μm),乙腈-6 mmol·L^-1 KH₂PO₄水溶液(pH 4.6)梯度洗脱,检测波长240 nm。结果：栀子苷、黄芩苷和盐酸小檗碱的线性范围分别为4.50～110.00,5.00～153.00,6.40～191.00 mg·L^-1；质量检测下限分别为0.77,1.53,1.43 ng；栀子苷的回收率为104.44%,RSD为1.79%；黄芩苷的回收率为96.98%,RSD为1.76%；盐酸小檗碱的回收率为101.08%,RSD为3.1%。结论：采用该方法同时测定安宫牛黄丸中栀子苷、黄芩苷和盐酸小檗碱含量具有简便﹑快速﹑准确等优点。     

基于方证对应理论的黄连解毒汤肠道吸收分析

目的:基于方证对应理论研究正常和脑缺血病理状态下黄连解毒汤中指标成分肠吸收情况的差异性,探讨临床对症治疗脑缺血疾病的合理性。方法:以黄连解毒汤中盐酸小檗碱、黄芩苷、栀子苷为检测指标,建立在体单向肠灌流模型,考察不同浓度黄连解毒汤在正常和脑缺血大鼠的肠吸收情况。结果:与正常组比较,不同浓度黄连解毒汤中盐酸小檗碱、黄芩苷、栀子苷在脑缺血模型组大鼠不同肠段的肠吸收均有一定程度增加,其中盐酸小檗碱在十二指肠、空肠有显著性增加;黄芩苷在全部肠段的肠吸收均有显著性增加;栀子苷在空肠、回肠、结肠有显著性增加。结论:黄连解毒汤主要药效成分在脑缺血大鼠的肠道吸收情况优于正常组,为该复方临床对症治疗脑缺血疾病的合理性提供实验依据,体现了中医方证对应理论。     

基于计算机仿真技术的中药水提液中药效物质与共性高分子物质“溶液结构”及相互作用初探——以黄连解毒汤为例

目的：分析淀粉、果胶等共性高分子物质与小分子药效物质的共存状态及相互作用。方法：选择黄连解毒汤模拟液为研究对象,使用计算机仿真技术,对分析物质进行建模、体系能量最小化、计算总体系能量、计算共性高分子单独存在时的能量、计算小分子药效物质单独存在时的能量,分析淀粉、果胶等共性高分子物质与小檗碱、巴马丁、黄芩苷、栀子苷的相互作用关系。结果：淀粉、果胶与小檗碱、巴马汀为相互吸引关系,与黄芩苷为弱相互吸引关系,而与栀子苷则为相互排斥作用;淀粉与小檗碱、巴马丁、黄芩苷、栀子苷的平均相互作用能依次为-32.159,-28.630,-5.974,234.295 kcal·mol^-1,果胶与小檗碱、巴马丁、黄芩苷、栀子苷的相互作用能平均值分别为-19.717,-19.804,-1.067,253.258 kcal·mol^-1;淀粉、果胶和小分子药效物质的分离容易顺序依次为栀子苷 >黄芩苷 >巴马汀 >小檗碱。结论：共性高分子和小分子药效物质间的相互作用由范德华力占主导地位,静电作用较小（3%~15%）,相互作用能的大小和正负值与药效物质的空间位置有关。     

黄芩苷纳米晶体微丸的制备及其药代动力学初步研究

目的:该研究制备了黄芩苷纳米晶体(baicalin nanocrystal,BC-NC),并进行了大鼠体内药物动力学研究.方法:采用探头超声结合高压均质法制备黄芩苷纳米混悬剂,然后通过流化干燥工艺将其脱水干燥成固体微丸,考察纳米晶体的形态、粒径分布、Zeta电位.以黄芩苷为指标成分,采用HPLC测定大鼠灌胃给药后的血药浓度,用DAS 2.0药动学软件计算药代动力学参数.结果:黄芩苷纳米晶体在扫描电镜下呈不规则颗粒状,平均粒径(248±6) nm,多分散指数(PI)为(0.181±0.065),Zeta电位为(-32.3±1.8)mV.BC-NC达峰浓度(Cmax)为(16.51±1.73) mg·L-1,0～24h的药时曲线下面积(AUC)增加为(206.96±21.23) mg·L-1·h,与黄芩苷原料药及物理混合物相比均有显湿著性提高(P＜0.0l).结论:通过高压均质及流化干燥工艺制得的黄芩苷纳米晶体能显著提高药物体内生物利用度,有望进一步制成口服固体制剂.     

冰片和熊去氧胆酸对黄芩苷角膜透过性的影响

目的 研究冰片、熊去氧胆酸对黄芩苷离体角膜透过率的影响,探讨其在眼用制剂中的应用.方法 采用离体角膜渗透技术考察不同质量浓度的冰片、熊去氧胆酸对黄芩苷角膜透过率的影响.结果 0.2 mg/mL的冰片使黄芩苷表观渗透系数(Papp)增加了1.36倍,与对照组相比具有显著性差异(P＜0.05);0.3、0.4、0.5、0.7 mg/mL的冰片使黄芩苷Papp分别增加了1.35、1.43、1.51、3.47倍,0.2、0.3、0.4、0.5、0.7 mg/mL的熊去氧胆酸使黄芩苷Papp分别增加了1.19、2.25、1.24、0.35、0.68倍,与对照组相比均具有非常显著性差异(P＜0.01).结论 0.2、0.3、0.4、0.5、0.7 mg/mL的冰片、熊去氧胆酸能够显著增大黄芩苷的Papp,且对角膜无刺激性.     

DBS法与传统采样法用于人体药物代谢动力学试验的比较研究

[目的]探讨干血点采样(DBS)法在热毒宁注射液药物代谢动力学试验中的应用,并与传统的血浆采集方法结果进行比较。[方法]从志愿者肘静脉取血,一部分进行LC-MS/MS定量分析,剩余全血分离血浆,进行栀子苷、山栀苷以及京尼平龙胆双糖苷的血药浓度分析。色谱柱Ecosil C18(150 mm×4.6 mm,5μm),流动相甲醇,20 mmol/L甲酸铵,0.1%甲酸,10%甲醇,流速0.5 m L/min,进样量10μL。质谱检测采用ESI离子源,MRM正离子检测模式,质谱运行采集时间11 min。[结果]单次静脉滴注热毒宁注射液,DBS法测定3种栀子成分全血浓度经血细胞比容校正后,栀子苷、山栀苷、京尼平龙胆双糖苷的达峰时间(Tmax)分别为1.41、1.47、1.47 h。峰浓度(Cmax)分别为4.580、0.285、0.550μg/m L。浓度-时间曲线下的面积(AUC0-t)分别为9.060、0.638、1.200(μg·h)/m L。平均驻留时间(MRT0-t)分别为1.52、1.49、1.45 h。[结论]山栀苷、京尼平龙胆双糖苷血浆法和DBS法(校正后)计算的血药浓度和药代参数较为一致,表明DBS法在药物稳定性成分的药物代谢动力学研究中可替代传统血浆处理方法。     

The effects of notoginsenoside R₁ on the intestinal absorption of geniposide by the everted rat gut sac model

Ethnopharmacological relevance

Geniposide is derived from Gardenia jasminoides Ellis (Rubiaceae). Its anti-inflammatory, antithrombotic effects as well as its preventive effect against ischemic stroke have been reported. Radix notoginseng (Chinese name tienchi or sanqi) is the dried root of Panax notoginseng (Burk.) F.H. Chen, an herb noted for its promotion of blood circulation, blood stasis removal and pain alleviation, and has been widely utilized for the prevention and treatment of microcirculatory disturbances in China and other Asian countries for many years. Notoginsenoside R₁ is an effective and structurally representative bioactive constituent of R. notoginseng. In our preliminary study, notoginsenoside R₁ was able significantly to improve the bioavailability of geniposide in beagle dogs, but the underlying mechanisms remain unknown.

Materials and Methods

The present study aimed to investigate the intestinal kinetic absorptive characteristics of geniposide as well as the absorptive behavior influenced by the co-administration of notoginsenoside R₁ using an in vitro everted rat gut sac model.

Results

The results showed good linear correlation between the geniposide absorption in sac contents and the incubation time from 0 to 120 min. The concentration dependence showed a non-linear correlation between the geniposide absorption and the concentrations 0.356–1.424 mg/mL, the absorption was saturated about 1.424 mg/mL. Notoginsenoside R₁ at 0.1 and 0.2 mg/mL concentrations was able significantly to enhance the absorption of geniposide (1.424 mg/mL) by 1.7- and 1.4-fold. Moreover, verapamil, a well-known P-glycoprotein inhibitor, was able significantly to elevate the absorption of geniposide 2.4-fold. Notoginsenoside R₁ influenced geniposide's absorption in a way similar to that of a P-glycoprotein inhibitor.

Conclusions

In conclusion, notoginsenoside R₁ significantly enhances the intestinal absorption of geniposide. As for the mechanism underlying the improvement of geniposide's bioavailability, it is proposed that notoginsenoside R₁ was able to decrease the efflux transport of geniposide by P-glycoproteins.     

LC-MS/MS研究新型酪氨酸酶抑制剂UP302在大鼠肝微粒体中代谢的酶动力学

 目的 建立并验证测定大鼠肝微粒体孵育液中UP302含量的高效液相色谱-串联质谱法,研究UP302在大鼠肝微粒体中代谢的酶动力学。方法 经大鼠肝微粒体孵育的UP302样品,经色谱柱分离,电喷雾离子化负离子检测,扫描方式为选择反应监测,用于定量分析的离子反应分别为m/z 301.1→135.2（UP302）和m/z 252.9→132.0（内标大豆苷元）。考察不同孵育时间、底物浓度和微粒体浓度对UP302代谢的影响,确定最佳反应条件。结果 标准曲线线性范围为0.1～20 μmol·L-1,线性关系良好,日内日间准确度在86.42%～112.59%,日内日间精密度均小于9.09%,回收率在100.50%～109.91%之间。确定了酶动力学参数,最大反应速度V_max为196.08 μmol·L-1·min-1·g-1 ,米氏常数K_m为14.98 μmol·L-1,内在代谢清除率CL_int为13.09 mL-1·min-1·g-1。结论 该检测方法快速、专属、灵敏度高,可满足酶动力学检测要求。     

Identification and interspecies characterization of UDP-glucuronosyltransferase isoforms catalyzing acacetin glucuronidation using recombinant UGT enzymes and microsomes

ObjectiveTo explore the glucuronic acid metabolism of acacetin in human liver and intestinal microsomes to better characterize human uridine 5′-diphospho (UDP)-glucuronosyltransferase (UGT) isoforms. In addition, interspecies comparisons were performed to identify the most appropriate experimental animal model for an in vivo study.MethodsLiquid chromatography tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) were used to confirm the successful biosynthesis of acacetin-7-O-glucuronide. Human isoforms of UGT and isozyme-specific chemical inhibitors were used for recombinant assays. Acacetin glucuronidation kinetics were assessed by combining acacetin with recombinant human UGT isoforms or with microsomes from humans or experimental animals. Kinetic differences between species were assessed in vitro using the same approach.ResultsWe identified multiple UGT isoforms that facilitated acacetin glucuronidation, and found that UGT1A1 was the major isoform that catalyzed this process. Acacetin-7-O-glucuronide formation exhibited clear substrate inhibition kinetics when combined with recombinant UGTs or with liver/intestinal microsomes derived from humans, monkeys, rats, mice, dogs, or pigs. Intrinsic metabolic clearance values of human intestinal microsomes were two-fold greater than those of human liver microsomes. Among the evaluated species, the K_m value of dog microsomes (0.86 μM) was greatest in acacetin glucuronidation, while mice exhibited the highest CL_int value, 5.05 mL/min/mg. The CL_int values of microsomes derived from monkeys and minipigs were 1.99 mL/min/mg and 2.12 mL/min/mg, respectively, exhibiting similar intrinsic metabolic clearance activity to that observed in humans.ConclusionMonkey may represent a suitable model for experimental studies of acacetin pharmacokinetics owing to a high sequence homology of UGT1A1 and similar UGT1A1 glucuronidation activity to humans.