Jiangsu Provincial Academy of Chinese Medicine, 100 Shizi Road, Nanjing 210028, Jiangsu, China.
Molecules. 2012 Dec 13;17(12):14908-17. doi: 10.3390/molecules171214908.
Shaoyao-Gancao (Paeoniae Radix Alba and Glycyrrhizae Radix et Rhizoma) is a traditional Chinese drug pair widely used in decoctions for relieving pains, especially abdominal pain. We aimed to determine the intestinal absorption and interaction of three active compounds (glycyrrhizic acid, liquiritin, and paeoniflorin) in this drug pair. We investigated the transport of these compounds across intestinal epithelial cells by using the Caco-2 cell monolayer in both the apical-to-basolateral (A-B) and B-A directions. All compounds could only travel through the Caco-2 cell monolayer at a low level when the cells were treated with single component solutions. In the presence of verapamil, an inhibitor of P-glycoprotein (P-gp), the absorptive permeability (P(AB)) of paeoniflorin and liquiritin increased significantly (p < 0.05) and efflux ratios decreased, while the absorption of glycyrrhizic acid did not change significantly, which indicated that paeoniflorin and liquiritin might be P-gp substrates. In addition, when liquiritin and glycyrrhizic acid in Gancao extract and paeoniflorin in Shaoyao extract were examined, P(AB) of paeoniflorin and liquiritin were significantly higher, while glycyrrhizic acid retained the same absorption level compared to the corresponding single component solutions, which suggested that some certain ingredients in the extracts can promote the absorption of paeoniflorin and liquiritin, but not that of glycyrrhizic acid. Furthermore, compared to the results of treatment with individual extracts, treatment of cells with a mixture of the two extracts considerably increased (p < 0.05) the absorption of glycyrrhizic acid and paeoniflorin and showed no change in the absorption of liquiritin, which implied that the transport of glycyrrhizic acid and paeoniflorin is increased by some ingredients from the complementary drug in the drug pair, while that of liquiritin remains unaffected.
芍药甘草（白芍和甘草）是一种传统的中药对，广泛用于缓解疼痛的方剂中，尤其是腹痛。我们旨在确定该药物对中三种活性化合物（甘草酸、甘草苷和芍药苷）的肠吸收和相互作用。我们通过 Caco-2 细胞单层在顶侧到基底侧（A-B）和 B-A 方向上研究了这些化合物在肠道上皮细胞中的转运。当细胞用单一组分溶液处理时，所有化合物都只能以低水平穿过 Caco-2 细胞单层。在 P 糖蛋白（P-gp）抑制剂维拉帕米存在的情况下，芍药苷和甘草苷的吸收渗透性（P(AB)）显著增加（p<0.05），外排比降低，而甘草酸的吸收没有明显变化，这表明芍药苷和甘草苷可能是 P-gp 的底物。此外，当甘草提取物中的甘草苷和甘草酸以及白芍提取物中的芍药苷进行检查时，芍药苷和甘草苷的 P(AB)显著升高，而甘草酸的吸收水平与相应的单一组分溶液相同，这表明提取物中的某些成分可以促进芍药苷和甘草苷的吸收，但不能促进甘草酸的吸收。此外，与单独处理提取物的结果相比，用两种提取物的混合物处理细胞显著增加（p<0.05）了甘草酸和芍药苷的吸收，而甘草苷的吸收没有变化，这表明甘草酸和芍药苷的转运是由药物对中的互补药物中的某些成分增加的，而甘草苷的转运不受影响。
