Résumé
Objective To study the pharmacokinetics of HMS-01 in mice and provide support for subsequent studies. Methods Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to establish a sensitive and specific method for the determination of the concentration of HMS-01 in plasma and other biological samples. The pharmacokinetics of HMS-01 in C57BL/6J mice were studied by the established method. To obtain the basic pharmacokinetic parameters, three doses of HMS-01 were given orally and one dose of HMS-01 was given intravenously. Results The pharmacokinetic results of mice showed that the intestinal absorption of HMS-01 was fast, the oral bioavailability of HMS-01 in mice was moderate (50% to 70%). The exposure levels (AUC and cmax) of HMS-01 in mice increased with the increase of dosage, while the AUC was linearly correlated with the increase of dosage. After intravenous administration of HMS-01, the half-life period in mice was about 1 h which was not long. The plasma clearance rate (CLtotal.p) was 2.8 L/h·kg, which was similar to the hepatic blood flow of mice. The apparent volume of distribution (VSS) was 5 L/kg, which was much larger than the total mouse fluid. There were significant differences in AUC and F (P<0.05), but no significant differences in parameters such as cmax,AUC0−∞,t1/2,CLtot,p,MRT,Vss in male and female mice which were given 30 and 60mg/kg HWS-01 orally. Conclusion The pharmacokinetic process of HMS-01 in mice showed gender differences, and the area under the curve of blood concentration time and bioavailability of female mice were higher than that of male mice. As oral bioavailability was reasonable, further in vivo studies on HMS-01 in mice with heart failure by oral administration could be considered to provide evidence.
Résumé
Objective To study the pharmacokinetics of HMS-01 in rats and provide support for subsequent study. Methods A sensitive and specific method for the determination of HMS-01 in plasma and other biological samples was established by LC-MS/MS. The pharmacokinetics of HMS-01 in rats was studied by the established method. The pharmacokinetics of one dose of single intragastric administration and one dose of single intravenous administration in SD rats were studied, and the basic pharmacokinetic parameters were obtained. Results After intravenous injection of 1 mg/kg HMS-01, the area under the plasma concentration-time curve AUC0-t of male and female rats was 221 ng·h/ml and 409 ng·h/ml, respectively. The average clearance rates were 4.53 L/h·kg and 2.41 L/h·kg, respectively. The average plasma elimination half-lives were 0.786 h and 1.27 h, and the apparent distribution volume was 5.13 L/kg and 3.82 L/kg, respectively. After intragastric administration of 30 mg/kg HMS-01, the peak time of plasma concentration in rats was 1.17 h, the peak concentration of Cmax was 1 243 ng/ml, and the elimination half-life t1/2 was 2.00 h. The AUC0-t of male and female rats was 2 271 and 8 529 ng·h/ml respectively, and their bioavailability was 34.3% and 69.5% respectively. Conclusion The pharmacokinetics of HMS-01 in rats has significant gender differences. It is well absorbed orally, and the bioavailability of HMS-01 in females is much higher than that in males.
Résumé
Objective To analyze the correlation between LC-MS/MS method and enzymatic cycling assay for determination of homocysteine concentration in human serum,and the application of two methods in the determination of homocysteine concentration.Methods Homocysteine concentrations of 63 serum samples were collected and determined by LC-MS/MS method and enzymatic cycling assay,respectively.The correlation between the concentrations by different methods was analyzed and evaluated.Results The concentrations were(19.11 ± 15.69) μmol/L by LC-MS/MS method and(16.95 ± 14.41) μmol/L by enzymatic cycling assay,the P value evaluated by paired-samples T test showed that there was statistical difference among the concentrations determined by two different methods (t =6.25,P ＜ 0.05).The conversion formula was YLC-MS/MS method =1.074Xenzymatic cycling assay + 0.892,R =0.987.Conclusion There is good correlation between LC-MS/MS method and enzymatic cycling assay for the determination of homocysteine concentration in serum,providing a theoretical basis for estimating the concentrations in the same serum sample by the two methods.
Résumé
The study established a LC-MS/MS method for the simultaneous determination of two active diterpenoids:kirenol and ent-16β, 17-dihydroxy-kauran-19-oic acid (DHKA) from Herba Siegesbeckiae in rat plasma using osthole as an internal standard (IS). Plasma sample pretreatment involved a one-step liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on a Waters Symmetry C18 column (2.1 mm×100 mm, 3.5 μm) with isocratic elution using methanol-5 mmol·L-1 aqueous ammonium acetate (80:20) as mobile phase at a flow rate of 0.2 mL·min-1. The detection was performed on a triple quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode under positive and negative electrospray ionization. Quantification was performed using SRM of the transitions m/z 356.4→321.4 for kirenol, m/z 335.3→335.3 for DHKA, and m/z 245.1→188.9 for the IS, respectively. The calibration curves were linear over the range of 50.0-25000 ng·mL-1 for kirenol, 25.0-12500 ng·mL-1 for DHKA. The extraction recoveries of two analytes and IS were more than 85%. The intra- and inter-day precision (relative standard deviation) values were less than 13.9% and accuracy (relative error) was from -10.7% to 10.3% at four quality control levels. The pharmacokinetic parameters of different medication administration teams were analyzed with SPSS statistics 13.0 software. The validated method was successfully applied to a comparative pharmacokinetic study of the two diterpenoids in rat plasma after intragastric administration of kirenol, DHKA and Herba Siegesbeckiae extract. Kirenol appeared to be both absorbed and eliminated fast in vivo, and DHKA absorbed fast but eliminated slowly in vivo. And there were obvious differences between the pharmacokinetic behaviors after oral administration of Herba Siegesbeckiae extract compared with single substances. Compared with the value after oral administration of kirenol, the extract might inhibit the absorption and postpone the elimination of kirenol in rats after administration of the extract. For DHKA, the absorption rate of DHKA increased rapidly after administration of the extract. This work can provide some experimental basis for the clinical use of Herba Siegesbeckiae. The method is simple, rapid and sensitive, which is suitable for pharmacokinetics study of the two diterpenoids from Herba Siegesbeckiae in rats.