Pharmacokinetics of 8-O-acetylharpagide and harpagide after oral administration of Ajuga decumbens extract in beagle dog / 中国中药杂志

8-O-acetylharpagide and harpagide are two kinds of effective component of Ajuga decumbens extract. A sensitive LC-MS/MS method has been established for pharmacokinetics of 8-O-acetylharpagide and harpagide in beagle dog after oral administration of from A. decumbens extract. Female beagle dogs received orally 12.9, 25.7 mg x kg(-1) p. o. Concentrations of 8-O-acetylharpagide and harpagide in plasma were determined by LC-MS/MS method at different time points and all pharmacokinetic parameters were estimated by non-compartment analysis. The mobile phase consisted of 0.1% formic acid in water (A) and acetonitrile (B), which was run at a flow rate of 0.3 mL x min(-1). Chromatographic separation was achieved on an Agilent ZORBAX XDB-C18 column (2.1 mm x 50 mm, 3.5 microm) using a gradient elution of 5% B at 0-2 min, 95% B at 2. 1-5 min and 5% B at 5. 1-10 min. All analytes, including the IS, were monitored under positive ionization conditions and quantified in MRM mode with transitions of m/z 429.2-369.2 for 8-O-acetylharpagide, m/z 387.2-207.2 for harpagide, and m/z 149.2-103.1 for IS. High purity nitrogen was employed as both the nebulizing and drying gas. Other parameters of the mass spectrometer were optimized as follows: drying gas flow 10.0 L x min(-1); drying gas temperature 300 degrees C; capillary voltage 4 000 V. Results showed that 8-O-acetylharpagide and harpagide showed a dose-dependence profile. T(max) of 8-O-acetylharpagide is 1.7 h, and T(max) of harpagide is 1.57 h, which was higher than T(max) of 8-O-acetylharpagide and harpagide after oral administration of from A. decumbens extract in rats. The different pharmacokinetic parameters may be due to the species differences of rat and beagle dog.

Metabolic kinetic of puerarin in beagle liver microsomal by HPLC-ESI-MS / 中国中药杂志

<p><b>OBJECTIVE</b>To develop a HPLC-ESI-MS method for the determination of puerarin and its metabolite and study the metabolic kinetics in beagle dog liver microsomes.</p><p><b>METHOD</b>Beagle dog liver microsomes were prepared by using ultracentrifugation method. Chromatography was performed on a Shimadzu C18 column (2.0 mm x 150 mm, 5 microm). Amethanol-water gradient system was used. ESI interface was applied in the positive, and SIM m/z 417 was puerarin and m/z 531 was daidzein.</p><p><b>RESULT</b>The puerarin was metabolized by NADPH regenerating system in beagle dog microsomes. The Michaelis-Menten parameters Km and Vmax in beagle dog microsomes were initially estimated by analyzing Lineweave-Brurk plot. The Vmax Km of puerarin were (0.047 +/- 0.006) mg x min(-1) x g(-1), (1.22 +/- 0.53) mg x L(-1).</p><p><b>CONCLUSION</b>The puerarin and daidzein can be rapidly determined by HPLC-MS in beagle dog microsomes and the puerarin was metabolized to daidzein by CY P450. The study can give help for Baige capsule.</p>