Characterization using LC/MS of the absorption compounds and metabolites in rat plasma after oral administration of a single or mixed decoction of Shaoyao and Gancao.

Shaoyao-Gancao decoction (SGD), a traditional Chinese formulation containing Paeoniae Radix (SY) and Glycyrrhizae Radix (GC), is commonly used to relieve abdominal pain. However, the absorption and metabolites of the characteristic constituents of the two herbs in vivo have been reported rarely. The purpose of this study was to investigate the compatibility rationality and the mechanism of the enhanced efficiency of SGD. A single or a mixed decoction (SG and S+G, respectively) was orally administered to rats. Blood samples were collected at different intervals following treatment and analyzed by liquid LC/MS. A total of fifteen ingredients (denoted as M1 to M15) were found in both rat plasma after treatment with the two decoctions. Furthermore, the proposed structures of the remained twelve ingredients were obtained except M9, M10 and M15. The quality of the ingredients in the rat plasma showed no significant difference between the two decoctions. However, the quantity of twelve ingredients differed greatly, indicating that the absorption of SG was greater than that of S+G except M7, M12 and M15. As the compositions associated with the efficacy of SG and S+G were inconsistent, the degree of the absorption of the 15 ingredients by the gastrointestinal tract were different, which caused a significantly enhanced efficacy of certain ingredients. This study presents an exploration of the mechanism behind the improved efficacy of individual components in traditional Chinese medicine therapies through combination with other components.

Pharmacokinetics of characteristic effective ingredients from individual and combination Shaoyao and Gancao treatment in rats using HPLC fingerprinting.

Shaoyao-Gancao decoction, a traditional Chinese formulation composed of Paeoniae Radix and Glycyrrhizae Radix, is commonly used to relieve abdominal pain. In this paper, the compatibility rationality of this decoction was investigated. Shaoyao-Gancao decoction, Shaoyao decoction and Gancao decoction were orally administered to rats, respectively. Blood samples were collected at pre-determined times after administration and analyzed by high-performance liquid chromatography (HPLC). The pharmacokinetic parameters of characteristic peaks were analyzed and the statistical significance of the obtained parameters was determined. Paeoniflorin (12.0 min) and compounds at retention times of 4.7 and 5.2 min were all significantly higher in the Shaoyao-Gancao decoction than in the Shaoyao decoction (P < 0.05). In contrast, in the Gancao decoction, the compound at a retention time of 14.6 min was significantly lower than in the Shaoyao-Gancao decoction (P < 0.01). However, the compounds at retention times of 17.1 and 18.1 min were significantly higher in the Gancao decoction than in the Shaoyao-Gancao decoction (P < 0.05). These results indicate that poor compatibility of the compounds in the Shaoyao-Gancao decoction could result in poor absorption. The compatibility of the component compounds of the Shaoyao-Gancao decoction was revealed in the pharmacokinetic characteristics of the decoction. Generally, the absorption of Shaoyao components was increased in the Shaoyao-Gancao decoction, while the absorption of Gancao components was time dependent. In the Shaoyao-Gancao decoction, the increased absorption of some Shaoyao components may be related to a reduction in absorption of some Gancao components.

[Pharmacokinetics study on characteristic ingredients of different-dose herbs of shaoyao-gancao decoction].

The paper is to report the observation of pharmacokinetic changes of the characteristic ingredients in the combinations of different-dose herbs of Shaoyao-Gancao decoction. After the establishment of HPLC analytical method of plasma effective constituents, rats were orally administered with different-dose herbs of Shaoyao-Gancao decoction. Blood samples at different times after administering these decoctions were collected, and then were analyzed by HPLC fingerprints technology. Pharmacokinetic parameters of characteristic peaks were analyzed by SPSS 15.0 software and DAS 2.0. At last, we looked for the correlation of those pharmacokinetic parameters and the dosage of Gancao. The best dose of Shaoyao-Gancao decoction was at the ratio of 4 to 4, which was consistent with the dose commonly used in ancient times. The absorption of characteristic peaks from Shaoyao-Gancao decoction was related with the dosage of Gancao, and there existed interaction between each characteristic ingredients. There existed the right dose-ratio of Shaoyao and Gancao to get the best effect. The absorptions of effective constitutents were mutual waxing and waning in order to increase biological effects together. It's demonstrated the compatibility connotation at a right dose-ratio of Shaoyao-Gancao decoction through the angle of pharmacokinetics.