Table1_Comparative pharmacokinetics of four major compounds after oral administration of Mori Cortex total flavonoid extract in normal and diabetic rats.DOC

Introduction: Mori Cortex has been used in traditional Chinese Medicine as an antidiabetic agent. The aim of this study was to establish a UPLC-MS/MS method for simultaneous determination of morin, morusin, umbelliferone and mulberroside A in rat plasma and investigate the pharmacokinetics differences between normal and diabetic rats following oral administration of Mori Cortex total flavonoid extract.
Methods: Samples were pre-treated by protein precipitation and genkwanin was used as internal standard. Chromatographic separation was performed using a Hypersil GOLD C18 column (50 mm × 2.1 mm, 3 μm). The mobile phase consisted of acetonitrile and water (containing 0.1% formic acid) in gradient mode at a flow rate of 0.5 ml/min. The transitions of m/z 300.9→107.1, m/z 419.3→297.1, m/z 160.9→77.0, m/z 567.1→243.2 and m/z 283.1→268.2 were selected for morin, morusin, umbelliferone, mulberroside A and internal standard, respectively.
Results: The intra- and inter-day precision for analytes were less than 12.5% and the accuracy ranged from −8.1% to 3.5%. The extraction recovery was >88.5% and no obvious matrix effect was observed. The AUC(0-t) and Cmax of morin were 501.3 ± 115.5 ng/mL*h and 127.8 ± 56.0 ng/mL in normal rats and 717.3 ± 117.4 ng/ml*h and 218.6 ± 33.5 ng/ml in diabetic rats. Meanwhile, the AUC(0-t) and Cmax of morusin were 116.4 ± 38.2 ng/ml*h and 16.8 ± 10.1 ng/mL in normal rats and 325.0 ± 87.6 ng/mL*h and 39.2 ± 5.9 ng/ml in diabetic rats. For umbelliferone and mulberroside A, the AUC(0-t) and Cmax also increased significantly in diabetic rats (p < 0.05).
Discussion: The validated method was successfully applied to the pharmacokinetic study in normal and diabetic rats.

引言：桑白皮（Mori Cortex）在传统中医药中被用作抗糖尿病药物。本研究旨在建立一种超高效液相色谱-串联质谱法（UPLC-MS/MS），同时测定大鼠血浆中的桑色素（morin）、桑根酮（morusin）、伞形酮（umbelliferone）与桑皮苷A（mulberroside A），并探究正常大鼠与糖尿病大鼠口服给予桑白皮总黄酮提取物后的药代动力学差异。
方法：样品经蛋白沉淀法进行前处理，以芫花素（genkwanin）作为内标。色谱分离采用Hypersil GOLD C18色谱柱（50 mm × 2.1 mm，3 μm）；流动相为乙腈-含0.1%甲酸水溶液，采用梯度洗脱模式，流速为0.5 mL/min。分别选取质荷比m/z 300.9→107.1、m/z 419.3→297.1、m/z 160.9→77.0、m/z 567.1→243.2及m/z 283.1→268.2作为桑色素、桑根酮、伞形酮、桑皮苷A与内标的监测离子对。
结果：各分析物的日内、日间精密度均小于12.5%，准确度范围为-8.1%至3.5%。提取回收率大于88.5%，未观察到明显的基质效应。正常大鼠体内桑色素的AUC(0-t)与Cmax分别为501.3 ± 115.5 ng·mL⁻¹·h⁻¹和127.8 ± 56.0 ng·mL⁻¹，糖尿病大鼠体内则分别为717.3 ± 117.4 ng·mL⁻¹·h⁻¹和218.6 ± 33.5 ng·mL⁻¹。与此同时，桑根酮在正常大鼠体内的AUC(0-t)与Cmax分别为116.4 ± 38.2 ng·mL⁻¹·h⁻¹和16.8 ± 10.1 ng·mL⁻¹，糖尿病大鼠体内则分别为325.0 ± 87.6 ng·mL⁻¹·h⁻¹和39.2 ± 5.9 ng·mL⁻¹。对于伞形酮与桑皮苷A，其在糖尿病大鼠体内的AUC(0-t)与Cmax同样显著升高（p < 0.05）。
讨论：本经验证的方法已成功应用于正常与糖尿病大鼠的药代动力学研究。