Xiaohui Ma

The effect of Compound Danshen Dripping Pills, a Chinese herb medicine, on the pharmacokinetics and pharmacodynamics of warfarin in rats

AIM OF THE STUDY Significant pharmacokinetic/pharmacodynamic (PK/PD) interactions between various herbal products and warfarin have recently been reported. The present study was conducted to determine whether Compound Danshen Dripping Pills (CDDP), a Chinese herb medicine used for the treatment of cardiovascular diseases, interacts with warfarin when administered concomitantly. MATERIALS AND METHODS Each day for 7 days two groups of rats were treated orally with CDDP (50mg/kg and 250 mg/kg, twice daily), and the control group received similar treatment with appropriate volumes of water only. Sixty minutes after the final daily administration of CDDP or water, an aqueous solution of warfarin (0.2mg/mL) was given to each rat at a dose of 1.0mg/kg, and blood samples were collected at 0, 0.5, 1, 2, 4, 8, 12, 24, 36, and 48 h after warfarin-treatment. The concentration of warfarin in blood plasma was determined by high performance liquid chromatography (HPLC). Prothrombin time (PT) in blood plasma was measured using thromboplastin reagent. RESULTS Excellent linearity was found between 0.05 and 10 μg/mL with a lower limit of quantitation (LLOQ) of 0.05 ng/mL (r>0.999); moreover, all the validation data including accuracy and precision (intra- and inter-day), were within the required limits. No significant differences were found in PT(max) and AUC(PT0-∞) between the two CDDP-treated groups and the control. Besides, there was little alteration in any of the pharmacokinetic parameters of warfarin between the two CDDP-treated groups and the control. CONCLUSION The concomitant application of CDDP and warfarin did not give rise to significant effect on the pharmacodynamics of warfarin, and practically no effect on its pharmacokinetics. It was speculated that the PK/PD interactions between CDDP and warfarin was likely to be negligible as long as the patients took CDDP at a normal dose.

Simultaneous determination of five phenolic components and paeoniflorin in rat plasma by liquid chromatography-tandem mass spectrometry and pharmacokinetic study after oral administration of Cerebralcare granule(®).

A simple, sensitive and selective high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed for simultaneous determination and pharmacokinetic study of six active components, protocatechuic acid, chlorogenic acid, caffeic acid, ferulic acid rosmarinic acid and paeoniflorin in rat plasma after oral administration of Cerebralcare granule(®) for the first time. The method involves a simple liquid-liquid extraction with ethyl acetate. The separation was performed on a Luna C18 column (2.0×100mm i.d., 3.0μm, particle, Phenomenex, USA) with gradient elution using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.2ml/min. Electrospray ionization (ESI) in negative ion mode and selective reaction monitoring (SRM) was used for the quantification of six active components and internal standard (IS, Chloroamphenicol). The method was linear for all analytes over investigated range with all correlation coefficients greater than 0.9914. The lower limits of quantification (LLOQ) were 1.0ng/ml for protocatechuic acid, 1.0ng/ml for chlorogenic acid, 1.0ng/ml for caffeic acid, 5.0ng/ml for ferulic acid, 1.5ng/ml for rosmarinic acid and 6.0ng/ml for paeoniflorin, respectively. The intra- and inter-day precisions (R.S.D.%) were less than 6.60% and 11.68%, and accuracy (RE %) between -3.26% and 1.13% (n=6). The developed method was applied for the first time to the pharmacokinetic study of protocatechuic acid, chlorogenic acid, caffeic acid, ferulic acid, rosmarinic acid and paeoniflorin in rat plasma after oral administration of Cerebralcare granule(®).

The Wyckoff positional order and polyhedral intergrowth in the M3B2- and M5B3-type boride precipitated in the Ni-based superalloys

Ni-based single superalloys play a crucial role in the hottest parts of jet engines. However, due to the complex geometry and macro-segregation during the solidification process, the cast defect such as stray grains is inevitable. Therefore, the transient liquid phase (TLP) bonding which can join several small single crystalline castings together is gradually believed to be an effective method for improving the yields of production of the complex components. The melting point depressant element B is always added into the interlayer filler material. Consequently, borides including the M3B2 and M5B3 phase usually precipitate during the TLP bonding process. So a comprehensive knowledge of the fine structural characteristics of the borides is very critical for an accurate evaluation of the TLP bonding process. In this work, by means of the aberration-corrected transmission electron microscopy, we show, at an atomic scale, the Wyckoff positional order phenomenon of the metal atoms in the unit cell of M3B2- and M5B3-type boride. Meanwhile, the defect along the (001) plane of the above two types of boride are determined to be the polyhedral intergrowth with complex configurations.

Determination of ginsenoside Rc in rat plasma by LC-MS/MS and its application to a pharmacokinetic study.

Ginsenoside Rc (GRc) is a potential pharmacologically active ingredient isolated from ginseng (Panax ginseng C.A. Meyer, Araliaceae). A simple, rapid and sensitive method for determination of GRc in rat plasma was developed based on liquid chromatography-tandem mass spectrometry (LC-MS/MS). The analyte and internal standard (IS), ginsenoside Rb(1) (GRb(1)), were extracted from plasma with n-butanol and chromatographied on a C(18) column eluted with a mobile phase of methanol and water containing 0.1% formic acid. The detection was performed by positive ion electrospray ionization in selective reaction monitoring mode (SRM), monitoring the transitions m/z 1101.6→789.3 and m/z 1131.7→364.7 for GRc and IS, respectively. The assay was linear over the concentration range of 5-5000 ng/mL with a limit of quantitation (LOQ) of 5 ng/mL. The accuracy was between 86.7% and 114.9%, and the precision was less than 9.7%. This method was successfully applied to investigate the pharmacokinetic study of GRc in rats after intravenous (2mg/kg) and oral (20mg/kg) administration, and the result showed that the ginsenoside was poorly absorbed with an absolute bioavailability being approximately 0.17%.

Simultaneous determination of caffeic acid and its major pharmacologically active metabolites in rat plasma by LC-MS/MS and its application in pharmacokinetic study.

A simple, sensitive and selective high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination and pharmacokinetic study of caffeic acid (CA) and its active metabolites. The separation with isocratic elution used a mobile phase composed of methanol and water (containing 0.1% formic acid) at a flow rate of 0.2 mL/min. The detection of target compounds was done in selected reaction monitoring (SRM) mode. The SRM detection was operated in the negative electrospray ionization mode using the transitions m/z 179 ([M - H](-) ) → 135 for CA, m/z 193 ([M - H](-) ) → 134.8 for ferulic acid and isoferulic acid and m/z 153 ([M - H](-) ) → 108 for protocatechuic acid. The method was linear for all analytes over the investigated range with all correlation coefficients 0.9931. The lower limits of quantification were 5.0 ng/mL for analytes. The intra- and inter-day precisions (relative standard deviation) were <5.86 and <6.52%, and accuracy (relative error) was between -5.95 and 0.35% (n = 6). The developed method was applied to study the pharmacokinetics of CA and its major active metabolites in rat plasma after oral and intravenous administration of CA.

Simultaneous determination of creatine phosphate, creatine and 12 nucleotides in rat heart by LC–MS/MS

A simple, rapid and sensitive LC-MS/MS method was developed and validated for simultaneous determination of creatine phosphate (CP), creatine (Cr) and 12 nucleotides in rat heart. The analytes, ATP, ADP, AMP, GTP, GDP, GMP, CTP, CDP, CMP, UTP, UDP, UMP, CP, Cr, were extracted from heart tissue with pre-cooled (0°C) methanol/water (1:1, v/v) and separated on a Hypersil Gold AQ C18 column (150mm×4.6mm, 3μm) using an isocratic elution with a mobile phase consisting of 2mmol/L ammonium acetate in water (pH 10.0, adjusted with ammonia). The detection was performed by negative ion electrospray ionization in selective reaction monitoring mode (SRM). In the assay, all the analytes showed good linearity over the investigated concentration range (r>0.99). The accuracy was between 80.7% and 120.6% and the precision expressed in RSD was less than 15.6%. This method was successfully applied to measure the concentrations of the 12 nucleotides, creatine phosphate and creatine in rat heart for the first time.

Compound danshen dripping pills modulate the perturbed energy metabolism in a rat model of acute myocardial ischemia

The continuous administration of compound danshen dripping pills (CDDP) showed good efficacy in relieving myocardial ischemia clinically. To probe the underlying mechanism, metabolic features were evaluated in a rat model of acute myocardial ischemia induced by isoproterenol (ISO) and administrated with CDDP using a metabolomics platform. Our data revealed that the ISO-induced animal model showed obvious myocardial injury, decreased energy production, and a marked change in metabolomic patterns in plasma and heart tissue. CDDP pretreatment increased energy production, ameliorated biochemical indices, modulated the changes and metabolomic pattern induced by ISO, especially in heart tissue. For the first time, we found that ISO induced myocardial ischemia was accomplished with a reduced fatty acids metabolism and an elevated glycolysis for energy supply upon the ischemic stress; while CDDP pretreatment prevented the tendency induced by ISO and enhanced a metabolic shift towards fatty acids metabolism that conventionally dominates energy supply to cardiac muscle cells. These data suggested that the underlying mechanism of CDDP involved regulating the dominant energy production mode and enhancing a metabolic shift toward fatty acids metabolism in ischemic heart. It was further indicated that CDDP had the potential to prevent myocardial ischemia in clinic.

Qualitative and quantitative analyses of Compound Danshen extract based on 1H NMR method and its application for quality control

In this study, a new approach using 1H NMR spectroscopy combined with chemometrics method was developed for qualitative and quantitative analyses of extracts of Compound Danshen Dripping Pills (CDDP). For the qualitative analysis, some metabolites presented in Compound Danshen extract (CDE, extraction intermediate of CDDP) were detected, including phenolic acids, saponins, saccharides, organic acids and amino acids, by the proposed 1H NMR method, and metabolites profiles were further analyzed by selected chemometrics algorithms to define the threshold values for product quality evaluation. Moreover, three main phenolic acids (danshensu, salvianolic acid B, and procatechuic aldehyde) in CDE were determined simultaneously, and method validation in terms of linearity, precision, repeatability, accuracy, and stability of the dissolved target compounds in solution was performed. The average recoveries varied between 84.20% and 110.75% while the RSDs were below 6.34% for the three phenolic acids. This 1H NMR method offers an integral view of the extract composition, allows the qualitative and quantitative analysis of CDDP, and has the potential to be a supplementary tool to UPLC/HPLC for quality assessment of Chinese herbal medicines.

UFLC–MS/MS determination and pharmacokinetic studies of six Saikosaponins in rat plasma after oral administration of Bupleurum Dropping Pills

A rapid and sensitive ultra fast liquid chromatography tandem mass spectrometry method (UFLC-MS/MS) was developed and validated for the simultaneous determination of six Saikosaponins (SSs) (SSa, SSb1, SSb2, SSd, SSc, SSf) of Bupleurum Dropping Pills (BDP) in rat plasma using chloramphenicol as the internal standard (IS). The SSs were separated using an ACQUITY UPLC(®) BEH C18 column (50 mm × 2.1mm, 1.7 μm) and detection of these compounds were done by using a Qtrap 5500 mass spectrometer coupled with negative electrospray ionization (ESI) source under the multiple reaction monitoring (MRM) mode. According to regulatory guidelines, the established method was fully validated and results were showed within acceptable limits. The lower limit of quantifications (LLOQs) of all analytes were 0.2 ng/mL. The validated method was successfully applied into a pharmacokinetic study of orally administered BDP in rats.

Simultaneous determination of ascaridole, p-cymene and α-terpinene in rat plasma after oral administration of Chenopodium ambrosioides L. by GC-MS

A sensitive and reliable GC-MS method was developed and validated for the simultaneous determination of ascaridole, p-cymene and α-terpinene in rat plasma using naphthalene as internal standard. The plasma samples were extracted with ethyl acetate. Chromatographic separation was carried out on a HP-5MS capillary analytical column (30 m × 0.25 mm, 0.25 µm) and detection was performed on a quadrupole mass spectrometer detector operated under selected ion monitoring mode. The method showed excellent linearity over the investigated concentration range (r > 0.99) with the limit of quantitation down to 50, 10 and 5 ng/mL for ascaridole, p-cymene and α-terpinene, respectively. The intra-day and inter-day precisions (RSD) were <11.3%, and the accuracy was between 90.7 and 113.8%. The method was successfully applied to investigate the pharmacokinetics of Chenopodium ambrosioides L. following oral administration to rats.