Studies on oral bioavailability and first-pass metabolism of withaferin A in rats using LC-MS/MS and Q-TRAP
Studies on oral bioavailability and first-pass metabolism of withaferin A in rats using LC-MS/MS and Q-TRAP
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DOI：
10.1002/bmc.4573
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发表时间：
2019-09-01
影响因子：
1.8
通讯作者：
Dai, Renke
中科院分区：
文献类型：
--
作者：
Dai, Tianming;Jiang, Weifan;Dai, Renke
Withaferin A(Withaferin A，Withaferin A)是一种主要的生物活性甾体内酯类化合物，具有广泛的药理活性。Wa的绝对口服生物利用度仍不清楚，也没有与人体相关的体外数据。因此，本研究采用大鼠口服绝对生物利用度、Q-TRAP法和LC-MS/MS联用法对其吸收因子进行体外筛选，以探讨其可能的临床特征。所开发和验证的分析方法已成功地应用于水杨酸的药代动力学研究和体外测定。大鼠静脉给药(5 mg/kg)和口服(10 mg/kg)的生物利用度分别为32.4+/-4.8%。体外实验结果表明，Wa能很好地通过Caco-2细胞，且Wa不是P-糖蛋白的底物。此外，Wa在模拟胃液(稳定)、肠道菌群溶液(缓慢下降)和肝微粒体(快速耗尽，半衰期为5.6min)中的稳定性与人相似。因此，通过大鼠在体肠-肝灌流进一步证实了Wa的首过代谢，发现Wa迅速减少，1h内仍有27.1%，而Q-Trap鉴定的三种主要代谢物(M1、M4、M5)的含量增加。这一灌流结果与体内口服生物利用度结果一致。Wa的首过代谢可能是在雄性大鼠体内获得良好口服生物利用度的主要障碍，预计在人类中也是如此。本研究可能具有临床意义。
Withaferin A (WA) is one of the major bioactive steroidal lactones with extensive pharmacological activities present in the plant Withania somnifera. The absolute oral bioavailability of WA remains unknown and human-related in vitro data are not available. Therefore, in the present study, the absolute oral bioavailability of WA in male rats and the in vitro screening of absorption factors by Q-trap and LC-MS/MS analysis were conducted to explore possible clinical properties of WA. The developed and validated analytical methods were successfully applied to the pharmacokinetic studies and in vitro measurement of WA. The oral bioavailability was determined to be 32.4 +/- 4.8% based on intravenous (5 mg/kg) and oral (10 mg/kg) administrations of WA in male rats. The in vitro results showed that WA could be easily transported across Caco-2 cells and WA did not show as a substrate for P-glycoprotein. Moreover, the stability of WA was similar between male rat and human in simulated gastric fluid (stable), in intestinal microflora solution (slow decrease) and in liver microsomes (rapid depletion, with a half-life of 5.6 min). As such, the first-pass metabolism of WA was further verified by rat intestine-liver in situ perfusion, revealing that WA rapidly decreased and 27.1% remained within 1 h, while the content of three major metabolites (M1, M4, M5) identified by Q-trap increased. This perfusion result is consistent with the oral bioavailability results in vivo. The first-pass metabolism of WA might be the main barrier in achieving good oral bioavailability in male rats and it is predicted to be similar in humans. This study may hold clinical significance.