Quantitative Determination of Quercitrin Levels in Rat Plasma Using UHPLC-MS/MS and its Application in a Pharmacokinetic Study after the Oral Administration of Polygoni cuspidati Folium Capsules.

BACKGROUND: Quercitrin is widely found in herbal medicines, and it is particularly important in the design of new therapeutic agents. Because of its wide range of biological activities, methods for detecting quercitrin and its pharmacokinetics in biological samples must be investigated. OBJECTIVES: To develop and validate a sensitive and reliable ultra-high-performance liquid chromatography- tandem mass spectrometry (UHPLC-MS/MS) method for the quantitative determination of quercitrin levels in rat plasma, and test its application in a pharmacokinetic investigation after the oral administration of Polygoni cuspidati folium capsules (HC). METHODS: First, a rapid analytical method implementing UHPLC-MS/MS for the quantification of quercitrin levels in rat plasma was developed and validated. The analyte and internal standard (IS) tinidazole were extracted from rat plasma via protein precipitation with 800 µL of methanol and 50 µL of 1% formic acid solution. Chromatographic separation was performed using an Agilent ZORBAX C18 column within 4 min. Mass spectrometry was performed for quantification using a triple-quadrupole mass spectrometer employing electrospray ionization in the negative ion mode. The MRM transitions for quercitrin and IS were m/z 447.2→229.9 and m/z 246.0→125.8, respectively. The UHPLC-MS/MS method for the quantitative determination of quercitrin levels in rat plasma was then applied to investigate its pharmacokinetics after the oral administration of HC in rats. RESULTS: The developed UHPLC-MS/MS method for detecting quercitrin in rat plasma was linear over the range of 0.1-160 ng/mL. The linear regression equation was Y = (0.7373 ± 0.0023)X - (0.0087 ± 0.0021) (r2 = 0.9978). The intra- and interday precision values were within 7.8%, and the recoveries of quercitrin and IS exceeding 67.3%. The UHPLC-MS/MS method was successfully applied to characterize the pharmacokinetic profile of quercitrin in eight rats after the oral administration of HC. The experimentally obtained values were fit to a one-compartment, first-order pharmacokinetic model, and they appeared to fit the concentration-time curve. CONCLUSION: Quercitrin was proven to be stable during sample storage, preparation, and the analytical procedures. The pharmacokinetic parameters suggested that quercitrin may be present in the peripheral tissues of rats.

[Synergistic Effects of Clopidogrel and Xuesaitong Dispersible Tablet by Modulating Plasma Protein Binding].

Objective: The ginsenoside Rb1,which account for platelet aggregation of Xuesaitong dispersible tablet, was selected to investigate the synergistic effects of clopidogrel( CPG) and Xuesaitong dispersible tablet drug by modulating plasma protein binding rate aspect. Methods: The HPLC and equilibrium dialysis were employed to determine the concentration of Rb1 both in dialysate( PBS) and blank plasma from healthy volunteer blood donors. The differences in protein-binding rate between Xuesaitong dispersible tablet alone( the concentration of ginsenoside Rb1 were 5. 0,1. 0,0. 4 µg / m L,respectively) and combined with CPG( each add CPG 2 µg / m L) were then compared. The three-dimensional spatial structure of the blank plasma albumin( HSA) in the subjects was construct by rabbit plasma albumin( PDB ID 3V09) template and evaluated by PRO-CHECK and ERRAT methods. Molecular simulation technique was used to display the competition mechanism with human plasma protein. Results: The protein binding rate of Xuesaitong dispersible tablet alone group in plasma PBS and human plasma at high( the concentration of ginsenoside Rb1 were 5. 0 µg / m L),middle( the concentred of ginsenoside Rb1 were 1. 0 µg / m L) and low( the concentration of ginsenoside Rb1 were 0. 4 µg / m L) concentrations were( 58. 17 ±3. 82) %,( 57. 43 ± 3. 21) %,( 55. 63 ± 3. 42) % respectively. When combined with CPG( each add CPG 2 µg / m L),the protein binding rate value were decline to( 46. 54 ± 3. 35) %,( 49. 25 ± 3. 56) %,( 48. 15 ± 3. 76) %,respectively. The molecular simulation results suggested that the two compounds have competitive synergistic effects with human plasma protein. Conclusion: The present investigation suggestes that there are synergistic effects of CPG and Xuesaitong dispersible tablet by modulating plasma protein binding rate of ginsenoside Rb1.

[Computational Pharmacological Study on Clopidogrel Metabolism Enzymes Influenced by Fufang Danshen Dripping Pill].

OBJECTIVE: To investigate the effect of Fufang Danshen Dripping Pill on Clopidogrel metabolism enzymes target such as human liver carboxylesterasel (CES1), cytochrome P450 3A4, CYP450 2C19, CYP450 1A2, and CYP450 2B6, and to interpret the interaction effects. METHODS: The CES1, cytochrome P450 3A4, CYP450 2C19, CYP450 1A2 and CYP450 2B6 which involved in Clopidogrel metabolism were selected at first, the chemical ligand database were created then, and finally the interaction effects between the ligand database and Clopidogrel metabolism target were explored. RESULT: 1 MX1 (CES1), 3NXU (CYP450 3A4), 4GQS (CYP450 2C19), 2HI4 (CYP450 1A2) and 3IBD(CYP450 2B6) as well as THA, RIT, OXU, Chlorzoxazone and CPZ were used as receptors and cutoff for each target respectively. The number of hits with potentially positive activities with metabolism enzymes target from the bioactive compounds in the preparation was 29, 8, 31, 51 and 44, respectively. These computational pharmacological docking studies were in accordance with the referenced cocktail experiment results. CONCLUSION: It is suggested that Fufang Danshen Dripping Pill has inhibitory effects on Clopidogrel metabolism enzymes target such as CES1, Cytochrome P450 3A4, CYP450 2C19, CYP450 1A2 and CYP450 2B6.

[Studies on effects of Achyranthes bidentata on tongsaimai pellets main active ingredients chlorogenic acid, isoliquiritin, harpagoside and glycyrrhizin in vivo pharmacokinetics].

To study on the effects of Achyranthes bidentata on Tongsaimai pellets main active ingredients chlorogenic acid, isoliquiritin, harpagoside and glycyrrhizin in rats in vivo pharmacokinetic behaviors, a method for the simultaneous determination of chlorogenic acid, isoliquiritin, harpagoside and liquiritigenin in rat plasma was established by UPLC-MS/MS. The analysis was performed on a waters Acquity BEH C18 column (2.1 mm x 100 mm, 1.7 microm) with the mixture of acetonitrile and 0.1% formic acid/water as mobile phase, and the gradient elution at a flow rate of 0.3 mL x min(-1). The analytes were detected by tandem mass spectrometry with the electrospray ionization (ESI) source and in the multiple reaction monitoring (MRM) mode. It turned out that the analytes of Tongsaimai pellets groups C(max) and AUC(Q-infinity) values were higher than that with A. bidentata group, and the C(max) values of chlorogenic acid had significantly difference (P < 0.05), the AUC(0-infinity) values of chlorogenic acid and glycyrrhizin had significantly difference (P < 0.05); The T(max) and CL values of two groups had no significantly difference. Results showed that the established method was specific, rapid, accurate and sensitive for the studies of Tongsaimai pellets four main active ingredients in rat in vivo pharmacokinetic, and A. bidentata have varying degrees of effects on Tongsaimai pellets four main active ingredients in rat in vivo pharmacokinetic behaviors.

[Application of oral micro-carrier drug delivery system in studies on traditional Chinese medicine].

Drug-loading micro-particles are a targeted, positioned and controlled-release drug delivery carrier with a wide application prospect. Various micro-carrier drug delivery systems have their own advantages in promoting absorption, improving stability, targeting and controlled release. Accordingly, it is of far-reaching significance for the studies on micro carrier drug delivery systems to build oral traditional Chinese medicine (TCM) compound micro-carrier drug delivery systems with effective TCM components and effective fractions. This article introduces several features and advantages of oral micro-carrier drug delivery systems, and summarizes their application in the field of TCMs.

In vitro metabolism in Sprague-Dawley rat liver microsomes of forsythoside A in different compositions of Shuang-Huang-Lian.

Shuang-Huang-Lian (SHL), a traditional Chinese formula containing Lonicerae japonicae flos (LJF), Scutellariae radix (SR) and Forsythiae fructus (FF), is commonly used to treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. Forsythoside A is one of the main active ingredients in Forsythiae fructus, a key herb in SHL. In the present study, effects of different compositions in SHL on the in vitro metabolism in Sprague-Dawley rat liver microsomes of forsythoside A were investigated. The observations from Sprague-Dawley rat liver microsomes in the presence of ß-NADPH or UDPGA that forsythoside A may be the substrates of CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3, UGT1A1 and UGT1A9; Chlorogenic acid may be the substrates of CYP3A4, CYP2C9, CYP1A2, CYP2C19, UGT1A6, UGT1A3 and UGT1A1; Baicalin may be the substrates of CYP3A4, CYP2C19, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; Baicalein may be the substrates of CYP3A4, CYP2E1 and UGT1A6. It was also found that the residue of forsythoside A in SHL, FF+LJF and FF+SR was greatly increased compared with that in FF in Sprague-Dawley rat liver microsomes in the presence of ß-NADPH or UDPGA, which indicated that the metabolism of forsythoside A in SHL may be influenced by chlorogenic acid in LJF acting on the CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3 and UGT1A1; baicalin in SR acting on the CYP3A4, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; baicalein acting on the CYP3A4 and UGT1A6 respectively.

Intestinal absorption of forsythoside A in different compositions of Shuang-Huang-Lian.

Shuang-Huang-Lian (SHL), a traditional Chinese formula containing Lonicerae japonicae flos (LJF), Scutellariae radix (SR) and Forsythiae fructus (FF), is commonly used to treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. Forsythoside A is one of the main active ingredients in Forsythiae fructus, a key herb in SHL. In the present study, effects of different compositions in SHL on the intestinal absorption of forsythoside A were investigated. The observations from in situ intestinal circulation model showed that A/%(h(-1)) of forsythoside A in FF+LSF, FF+SR and SHL were all reduced greatly compared with that in FF. However, in pharmacokinetics study, C(max) and AUC(0→1440) of forsythoside A all increased and T(1/2) prolonged in SHL, FF+LJF and FF+SR compared with FF. The results indicated that the different compositions of SHL decreased absorption but increased bioavailability of forsythoside A, which may be related to its metabolism inhibited in intestine or liver.

[Research on the quality changes in pre- and post-processed pieces of Eucommia ulmoides].

OBJECTIVE: To study the quality changes in pre- and post-processed pieces of Eucommia ulmoides Oliv. METHODS: The changes of the content of pinoresinol diglucoside, extract and fingerprint were studied. RESULTS: Pinoresinol diglucoside contents in post-processed pieces were lower than those in pre-processed and alcohol extract had different changes because of its different habitats. Eucommia ulmoides consists of 11 common peaks, the one processed by salt-water consists of 8 Peaks. CONCLUSION: Processing can reduce the content of pinoresinol diglucoside. Alcohol extract has different changes. Eucommia ulmoides common peaks of its fingerprint reduce and mostly components descend after processed by salt-water.