注射雪胆乙素在大鼠体内药动学研究

Study on in vivo pharmacokinetics of cucurbitacin injection in rats

建立血浆样品中雪胆乙素的测定方法，研究雪胆乙素在大鼠体内的药动学特征。大鼠经尾静脉注射给药，以苯海拉明为内标（internal standard，IS），采用液相色谱-串联四级杆质谱（liquid chromatography tandem mass spectrometry，LC-MS/MS）法测定不同时间点大鼠血浆中雪胆乙素浓度。质谱采用电喷雾（ESI）离子源，多反应监测模式正离子检测，确定目标化合物及内标的离子对分别为m/z 503.2/113.1和m/z 256.0/167.2。色谱柱为Agilent ZOBAX SB-C18（2.1 mm×50 mm，1.8 μm），甲醇-0.1%甲酸55：45等度洗脱，流速为0.2 mL·min^-1。采用DAS 2.0软件对所得的血药浓度进行拟合，求算相应的药动学参数。大鼠经尾静脉注射雪胆乙素3.0 mg·kg^-1，目标物血浆质量浓度在10.5～3 150 μg·L^-1线性关系良好（R^2=0.996），标准曲线定量下限为10.5 μg·L^-1信噪比S/N=12；日内精密度RSD〈6.9%，日间精密度RSD〈14%；准确度RE在0.20%～3.7%；提取回收率在92.7%～97.1%。尾静脉注射雪胆乙素的药动学参数AUC0-t为（811.615±111.578）μg·h·L^-1t1/2为（1.285±1.390）h，CL为（3.627±0.487）L·h·kg^-1，Vd为（6.721±7.429）L·kg^-1。该研究建立了一种简便准确、灵敏度高、特异性好的测定雪胆乙素血药浓度的方法，首次报道了雪胆乙素在大鼠体内的药物代谢动力学特征。

To establish a method for the determination of cucurbitacin in plasma samples, in order to study the in vivo pharmacokinetic characteristics of cucurbitacin in rats. Rats were intravenously injected with cucurbitacin. With diphenhydramine as the internal standard（IS）, the plasma concentrations of cucurbitacin in rat plasma at different time points were determined by liquid chromatography tandem mass spectrometry （LC-MS/MS）. With electrospray ionization source, the positive ion detection in the multiple reaction monitoring mode was conducted to determine the ion-pairs for target compound and IS were m/z 503.2/113.1 and m/z 256.0/167.2, respectively. Agilent ZOBAX SB-C18 column （2.1 mm×50 mm, 1.8 μm） was adopted and eluted with methanol and 0.1% formic acid（55：45）, and the flow rate was 0.2 mL·min^-1. DAS 2.0 software was applied to fit the blood concentration and calculate corresponding pharmacokinetic parameters. The rats were intravenously injected with cucurbitacin at the concentration of 3.0 mg·kg^-1. The target blood quality concentration show good linear relations within the range of 10.5-3 150 μg·L^-1（R^2=0.996）, the lower limit of the standard curve was 10.5 μg·L^-1 and the signal to noise ratio S/N=12. Intra- and inter-day precisions RSD was less than 6.9% and 14%, respectively; The accuracy RE ranged between 0.20% and 3.7%; The extraction recoveries ranged between 92.7% and 97.1%. Regarding the pharmacokinetic parameters of tail intravenous injection of cucurbitacin, AUC 0-t was （811.615±111.578） μg·h·L^-1 t1/2 was （1.285±1.390） h, CL was （3.627±0.487） L·h·kg^-1, and Vd was （6.721±7.429） L·kg^-1. In this study, researchers established a simple, accurate, sensitive and highly specific method for determining the blood concentration of cucurbitacin, and reported the in vivo pharmacokinetic characteristics of cucurbitacin in rats for the first time.