Simple and rapid high-performance liquid chromatography methods were developed for the determination of berberine (BB) in various rat tissues so as to evaluate a P-gp inhibitor, glycyrrhetinic acid (GA), on BB’s oral bioavailability. Acetonitrile was used to extract BB from tissues and showed different extraction recoveries in diverse tissues. The intra- and interday precision and accuracy were less than 10%. Long-term stability, pre (post) -preparative stability, and freeze-thaw stability were evaluated, and the results showed it could meet the need of this study. The proposed methods were subsequently applied to investigate the possible drug-drug interaction of GA and BB in vivo from the aspect of tissue distribution. The results showed that no significant difference was found between the group of low dose and high dose at the same time point. The tissue distributions show a saturated model, i.e., the content of BB in tissue tends to be constant while its dose is more than 200 mg/kg. Besides, the contents of BB ranged from high to low according to the order of the liver, kidney, and spleen. The BB content in the liver is especially high as compared to other tissues.

中文翻译：

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一种用于组织中小Ber碱分析的有效液相色谱方法及其应用

开发了一种简单快速的高效液相色谱方法，用于测定各种大鼠组织中的小ber碱（BB），以便评估BB的口服生物利用度，从而评价P-gp抑制剂甘草次酸（GA）。乙腈用于从组织中提取BB，并在不同组织中显示出不同的提取回收率。日内和日间精度和准确度均低于10％。评价了长期稳定性，制备前（制备后）稳定性和冻融稳定性，结果表明该稳定性可以满足本研究的需要。随后，从组织分布的角度出发，将提出的方法用于研究GA和BB在体内可能的药物相互作用。结果表明，低剂量和高剂量组在同一时间点之间没有发现显着差异。组织分布显示出饱和模型，即，当其剂量超过200 mg / kg时，组织中的BB含量趋于恒定。此外，BB的含量根据肝脏，肾脏和脾脏的顺序从高到低不等。与其他组织相比，肝脏中的BB含量特别高。