Study on biomarker of Tripterygium wilfordii in treatment of rheumatoid arthritis based on PK/PD / 中国中药杂志

To observe the serum samples and the anti-inflammatory effect of Tripterygium wilfordii in treating RA by using the pharmacokinetic-pharmacodynamic model, make a correlation analysis on concentration-time and effect-time curves, and explore RORγt, IL-17, STAT3, IL-6 mRNA transcriptional levels in rats by PCR. Methotrexate, tripterine and high-dose T. wilfordii could down-regulate RORγt, IL-17, STAT3, IL-6 mRNA transcriptional levels in AA rat lymph nodes. The study on PK-PD model showed correlations between inflammatory factors and blood concentration of T. wilfordii. T. wilfordii and its main active constituent tripterine could show the inflammatory effect and treat RA by inhibiting IL-17 cytokine.

Study of change in activity of hepatic drug metabolism enzymes in rat model of chronic unpredictable mild stress / 药学学报

This study aimed to explore the impact of depression caused by chronic unpredictable mild stress (CUMS) on in vivo activity of six kinds of CYP450 isoforms in rats. According to 'Katz' method, the model of CUMS was established. Tolbutamide, chlorzoxazone, theophylline, midazolam, omeprazole and dextromethorphan were chosen as probe substrates of CYP2C6, CYP2E1, CYP1A2, CYP3A2, CYP2D1 and CYP2D2 of rats. Plasma concentration of six kinds of CYP450 in control group and model group were determined by LC-MS/MS and computed pharmacokinetic parameters. Consequently, metabolism of theophylline and chlorzoxazone accelerated significantly (P < 0.01), but tolbutamide, dextromethorphan, omeprazole and midazolam had no significant difference. The present study proved that depression caused by CUMS had strong induction to CYP1A2 and medium induction to CYP2E1.

Effect of clopidogrel on plasma protein binding rate of ginsenosides: a liquid chromatography-mass spectrometry-based study / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of clopidogrel on the binding rate of ginsenosides with rat serum proteins (RSA).</p><p><b>METHODS</b>Equilibrium dialysis and liquid chromatography-mass spectrometry were employed to quantify the concentration of ginsenoside Rg1 and Rb1. The protein-binding rates of Rg1 and Rb1 in the presence or absence of clopidogrel (1.0 mg/L) were determined. A molecular simulation model (consisting of homology modeling and molecular docking interaction) was used to reveal the target protein-compound interactions.</p><p><b>RESULTS</b>The binding rates of ginsenosides Rg1 (0.4, 1.0, and 2.0 mg/L) with RSA were (30.16∓2.82)%, (33.42∓4.21)%, and (34.61∓3.42)%, and those of and Rb1 were (50.13∓2.34)%, (51.23∓3.23)%, and (53.11∓3.26)%, respectively. In the presence of clopidogrel, the binding rates of Rg1 decreased to (22.13∓2.72)%, (21.42∓3.22)%, and (25.45∓3.52)%, and those of Rb1 to (40.13∓3.24)%, (41.25∓4.15)%, and (43.11∓3.31)%, receptively. The molecular docking suggested that these compounds competed to bind with RSA.</p><p><b>CONCLUSION</b>Clopidogrel can competitively bind to RSA with ginsenosides to lower the plasma protein binding rates of ginsenosides.</p>

Determination of plasma concentration of five phenolic acid by LC-MS/MS and study of pharmacokinetics in rats after Mailuoning injection / 中国中药杂志

To establish a LC-MS/MS method for quantification of chlorogenic acid, caffeic acid, 3,4-DCQA, ferulic acid and cinnamic acid in rats plasma and study its pharmacokinetics after administration of Mailuoning injection at a single dose to rats. Plasma samples were acidified with hydrochloric acid and extracted with ethyl acetate. The analytes were determined by LC-MS-MS using a ZOBAX SB C18 column with a mobile phase of methanol-water (containing 2 mmol x L(-1) ammonium acetic) (60:40)at a flow rate of 0.5 mL x min(-1) and detected using ESI with negative ionization mode. Ions monitored in the multiple reaction monitoring (MRM) mode were m/z 353.1/191.0 [M-H]- for chlorogenic acid, m/z 178.9/134.9 [M-H]- for caffeic acid, m/z 515.2/353.0 [M-H]-for 3,4-DCQA, m/z 193.0/133.9 [M-H]-for ferulic acid, m/z 146.9/102.9 [M-H]- for cinnamic acid and m/z 246.0/125.8 [M-H]- for tinidazole (IS). After administration of Mailuoning injection at a single dose to eight Sprague-Dawley rats, the concentrations of chlorogenic acid, caffeic acid, 3,4-DCQA, ferulic acid and cinnamic acid in plasma were determined by LC-MS/MS method. The main pharmacokinetics parameters of measured data were caluculated by using DASver 1.0 software. The linear concentration ranges of the calibration curves for chlorogenic acid, caffeic acid, 3,4-DCQA and cinnamic acid were 2.006-1,027 microg x L(-1) (r = 0.999 6), 1.953-1,000 microg x L(-1) (r = 0.999 7), 28.51-1.459 x 10(4) microg x L(-1) (r = 0.998 9), 1.836-940.0, g x L(-1) (r = 0.997 7) and 4.780-2,447 microg x L(-1) (r = 0.998 6) respectively. The inner and inter-days relative standard deviations were both less than 5.0%, indicating legitimate precise and accuracy to the requirement of biological sample analysis. For chlorogenic acid, the pharmacokinetic parameter t1/2, AUC0-t, and CL were (49.78 +/- 12.81) min, (123.55 +/- 14.82) mg x min x L(-1) and (0.004 3 +/- 0.000 5) L x min(-1), respectively. For caffeic acid, the pharmacokinetic parameter t1/2, AUC0-t, and CL were (36.65 +/- 10.59) min, (91.67 +/- 11.77) mg x min L(-1) and (0.005 7 +/- 0.000 7) L x min(-1), respectively. For 3,4-DCQA, the pharmacokinetic parameter t1/2, AUC0-t, and CL were (50.08 +/- 13.78) min, (278.34 +/- 31.82) mg x min x L-1 and (0.001 6 +/- 0.000 2) L x min(-1), respectively. For ferulic acid, the pharmacokinetic parameter t1/2, AUC0-t, and CL were (51.39 +/- 15.52) min, (34.72 +/- 4.67) mg x min x L(-1) and (0.000 4 +/- 0.0001) L x min(-1), respectively. For cinnamic acid, the pharmacokinetic parameter t1/2, AUCo-t, and CL were (74.42 +/- 18.32) min, (34.63 +/- 4.82) mg x min x L(-1) and (0.007 7 +/- 0.001 1) L x min-', respectively. The assay method is proved to be sensitive, accurate and convenient. It can be applied to the pharmacokinetic study of chlorogenic acid, caffeic acid, 3,4-DCQA, ferulic acid and cinnamic acid.

Study on determination of caffeic acid, chlorogenic acid in rat plasma and their pharmacokinetics with LC-MS/MS / 中国中药杂志

To establish a LC-MS/MS method to determine caffeic acid, chlorogenic acid in rat plasma and study their pharmacokinetics in rats. Six Sprague-Dawley rats were intravenously injected with 4 mL x kg(-1) of Dengzhanxixin injection, respectively. Their drug plasma concentration was determined by LC-MS/MS, with tinidazole as an internal standard. The pharmacokinetic parameters were calculated by DAS 1.0. The linear concentration ranges of caffeic acid, and chlorogenic acid were 2-128 microg x L(-1) (r = 0.998 1) and 3-384 microg x L(-1) (r = 0.998 7), respectively. The methodological test showed conformance to the requirements. The intraday and inter-day variable coefficients were both less than 10.0%, indicating that both of legitimate precise and accuracy were in conformity with the requirements of biological sample analysis. For caffeic acid, the pharmacokinetic parameter t1/2beta AUC0-t, and CL were (130.91 +/- 38.77) min, (4.89 +/- 0.96) mg x min x L(-1) and (0.12 +/- 0.02) L x min(-1) x kg(-1), respectively. For chlorogenic acid, the pharmacokinetic parameter t1/2beta , AUC0-t, and CL were (49.38 +/- 8.85) min, (9.54 +/- 0.95) mg x min x L(-1) and (0.09 +/- 0.003) L x min(-1) x kg(-1), respectively. The LC-MS/MS analysis method established in this study was proved to be so accurate and sensitive that it can be applied to the pharmacokinetic study of caffeic acid and chlorogenic acid.

Simultaneous determination of baicalin and chlorogenic acid in human plasma by UPLC-MS/MS / 药学学报

To develop and validate an ultra performance liquid chromatography tandem mass spectrometric (UPLC-MS/MS) method for the simultaneous quantification of baicalin and chlorogenic acid in human plasma after iv infusion of Yinhuang injection, the analytes were isolated from plasma by protein precipitation with methanol. Then they were chromatographied on an Acquity UPLC BEH C18 column (50 mm x 2.1 mm ID, 1.7 microm) at 40 degrees C. The mobile phase A consisted of water and 0.1% formic acid. The mobile phase B consisted of methanol and 0.1% formic acid. The analytes were eluted from the column with a linear gradient from 5% B to 80% B in 5 min, then hold for 0.5 min before returning to initial condition. The flow rate was 0.35 mL x min(-1). A tandem mass spectrometer equipped with electrospray ionization source was used as detector. Multiple reaction monitoring (MRM) using the precursor to product ion pairs of m/z 447-->271 (for baicalin), m/z 353-->191 (for chlorogenic acid) and m/z 287-->287 (for internal standard) were used to quantification. The linear concentration ranges of the calibration curves for baicalin and chlorogenic acid ranged from 9.6 to 1540 ng x mL(-1) and from 7.5 to 1200 ng x mL(-1), respectively. The intra- and inter-day relative standard deviation (RSD) across three validations run over the entire concentration range was less than 10.2% for both baicalin and chlorogenic acid. After iv infusion of Yinhuang injection to the volunteers, the concentration-time curves of baicalin and chlorogenic acid fitted the two-compartment and three-compartment model. T(1/2)alpha were (4.47 +/- 0.89) and (7.65 +/- 4.42) min, T(1/2)beta were (46.22 +/- 10.03) and (34.40 +/- 19.16) min, respectively. The method was proved to be highly sensitive, selective, and suitable for pharmacokinetic investigations of both baicalin and chlorogenic acid.

Albumin kinetics in patients with severe sepsis / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the mechanism of hypoalbuminemia in patients with severe sepsis.</p><p><b>METHODS</b>I(125)-labeled albumin was administered intravenously to 10 health volunteers and 10 patients with severe sepsis. Blood samples were taken at 0, 1, 2, 4, 8, 12, 24 hours and 2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 18, 22, 25 days for the measurement of the dose of gamma-radiation and the curve of concentration and time. Then the half-life time (t(1/2)), apparent volume of distribution (V(d)) and transportation rate (K(12)) from center compartment to side compartment of albumin were calculated.</p><p><b>RESULTS</b>The half-life time in septic group was obviously shorter than that in control group (8.2 +/- 1.4 vs. 12.5 +/- 1.7, P < 0.01). The transportation rate in the septic group was higher than that in the control group [(4.4 +/- 1.9) x 10(-2)/h vs. (2.4 +/- 0.6) x 10(-2)/h, P < 0.05]. There was no significant difference in apparent volume of distribution between the two groups.</p><p><b>CONCLUSIONS</b>In patients with severe sepsis, the distribution rate of albumin from vessel to tissue was obviously increased and the decomposition rate of albumin was markedly improved.</p>