Bioavailability of glycyrrhizin from Shaoyao-Gancao-Tang in laxative-treated rats

Quality consistency evaluation of chemical composition and pharmacology of Shaoyao-Gancao decoction dispensing granules and traditional decoction

Dispensing granules of Chinese medicine (DGCM) have emerged as a more convenient alternative to traditional decoction (TD) of Chinese medicine, gaining popularity in recent years. However, the debate surrounding the consistency of DGCM compared to TD remains unresolved. In this study, three batches of Baishao and Gancao DGCM were obtained from manufacturers A, B, and C, and 15 batches of crude drugs were procured from hospital pharmacies for the preparation of dispensing granule decoction (DGD) and TD of Shaoyao-Gancao decoction (SGD). The HPLC-UV method was employed to determine the levels of gallic acid, paeoniflorin, albiflorin, liquiritin, liquiritin apioside, isoliquiritin apioside, isoliquiritin, glycyrrhizic acid, and isoliquiritigenin. The analgesic and antispasmodic effects were assessed using the hot plate and acetic acid writhing test in mice. To evaluate the consistency of chemical constituents and pharmacological effects between the two decoctions, the Criteria Importance Though Intercriteria Correlation (CRITIC) method combined with chemometrics was employed. Grey relation analysis (GRA) was used to assess the comprehensive quality consistency of the two decoctions. The CRITIC results revealed certain differences in chemical constituents and pharmacological effects between the selected DGCM and TD. Notably, DGD-A/C exhibited a significant difference from TD (p > 0.05), whereas DGD-B demonstrated no significant difference from TD (p > 0.05). The GRA analysis demonstrated that the overall quality consistency between DGD-B and TD was the highest among the three manufacturers. This study presents a method for evaluating the quality consistency of DGCM and TD of SGD, offering novel insights into the evaluation of consistency between DGCM and TD.

Quantitative Analysis of the Multicomponent and Spectrum-Effect Correlation of the Antispasmodic Activity of Shaoyao-Gancao Decoction

Shaoyao-Gancao Decoction (SGD) is a well-known classic traditional Chinese medicine (TCM) with antispasmodic, anti-inflammatory, and analgesic effects. This preparation has been widely used to treat spasticity diseases in the clinic. To date, the material basis of SGD remains unclear, and the spectrum-effect correlation of its antispasmodic activity has not been reported yet. In this study, high-performance liquid chromatography (HPLC) was used to establish the fingerprint and determine the multiple components of SGD. The common peaks of fingerprints were evaluated by the similarity with the chromatographic fingerprints of the TCM. Meanwhile, the multiple components were quantified and analysed using the heatmap and box size analysis. Furthermore, data on the antispasmodic effect were extracted through in vitro smooth muscle contraction assay. Grey relational analysis combined with partial least square regression was used to study the spectrum-effect correlation of SGD. Finally, the potential antispasmolytic components were validated using an isolated tissue experiment. The HPLC fingerprint was established, and 20 common peaks were identified. The similarities of 15 batches of SGD were all above 0.965. The HPLC method for simultaneous determination of the multiple components was accurate and reliable. The contents of albiflorin, paeoniflorin, liquiritin, and glycyrrhizic acid were higher than the other components in SGD. The heatmap and box size also showed that X3 (albiflorin), X4 (paeoniflorin), X5 (liquiritin), X11 (liquirtigenin), and X16 (glycyrrhizic acid) could be used as quality indicators in the further establishment of quality standards. The spectrum-effect correlation results indicated that X4, X11, and X16 were highly correlated with antispasmolytic activity. Verification tests showed that paeoniflorin (11.7-29.25 μg/mL) and liquirtigenin (17.19-28.65 μg/mL) could significantly reduce the maximum contractile (P < 0.01). These compounds exerted concentration-dependent spasmolytic effects with the inhibitory response for acetylcholine (Ach)-evoked contraction. Thus, SGD had a significant antispasmodic effect, which resulted from the synergistic activity of its multiple components. These findings can be used for the pharmacodynamics study of SGD and are of great significance for the determination of quality markers and quality control.

Da-Chaihu-Tang alters the pharmacokinetics of nifedipine in rats and a treatment regimen to avoid this

Objectives

To investigate the influence of co-administrated Da-Chaihu-Tang (DCT; a traditional Chinese formulation) on the pharmacokinetics of nifedipine, as well as the safe optimal dosing interval to avoid the adverse interactions.

Methods

A single dose of DCT was administered with nifedipine simultaneously, 2 h before, 30 min before or 30 min after nifedipine administration. Pharmacokinetics of nifedipine with or without DCT were compared. The influences of DCT on nifedipine intestinal mucosal and hepatic metabolism were studied by using rat in-vitro everted jejunal sac model and hepatic microsomes.

Key findings

A simultaneous co-administration of DCT significantly increased the area under concentration-time curve from time zero to infinity (AUC0-inf) of nifedipine. In-vitro mechanism investigations revealed that DCT inhibited both the intestinal and the hepatic metabolism of nifedipine. Further study on the optimal dosing interval for nifedipine and DCT revealed that administration of DCT 30 min before or after nifedipine did not significantly change the AUC of nifedipine.

Conclusions

The bioavailability of nifedipine is significantly increased by a simultaneous oral co-administration of DCT. This increase is caused by the inhibitory effect of DCT on both the intestinal mucosal and the hepatic metabolism of nifedipine. The dose interval between DCT and nifedipine needs to be set for over 30 min to avoid such drug–drug interactions.

Deciphering the combination principles of Traditional Chinese Medicine from a systems pharmacology perspective based on Ma-huang Decoction

ETHNOPHARMACOLOGY RELEVANCE

The main therapeutic concept in Traditional Chinese Medicine (TCM) is herb formula, which treats various diseases via potential herb interactions to maximize the efficacy and minimize the adverse effects. However, the combination principle of herb formula still remains a mystery due to the lack of appropriate methods.

METHODS

A systems pharmacology method integrating the pharmacokinetic analysis, drug targeting, and drug-target-disease network is developed to dissect this rule embedded in the herbal formula. All these are exemplified by a representative TCM formula, Ma-huang decoction, made up of four botanic herbs.

RESULTS

Based on the deep investigation of the function and compatibility of each herb, in a molecular/systems level, we demonstrate the different pharmacological roles that each herb might play in the prescription. By the way of enhancing the bioavailability and/or making the pharmacological synergy among different herbs, the four herbs effectively combine together to be suitable for treating diseases.

CONCLUSIONS

The present work lays foundations for a more comprehensive understanding of the combination rule of TCM, which might also be beneficial to drug development and applications.

Interaction between Shaoyao-Gancao-Tang and a laxative with respect to alteration of paeoniflorin metabolism by intestinal bacteria in rats

Shaoyao-Gancao-Tang (SGT), a traditional Chinese herbal medicine (Kampo formulation) containing Shaoyao (Paeoniae Radix) and Gancao (Glycyrrhizae Radix), is co-administered with laxative sodium picosulfate as a premedication for relieving the pain accompanying colonoscopy. Paeoniflorin (PF), an active glycoside of SGT, is metabolized into the antispasmodic agent paeonimetabolin-I (PM-I) by intestinal bacteria after oral administration. The objective of the present study was to investigate whether the co-administered laxative (sodium picosulfate) influences the metabolism of PF to PM-I by intestinal bacteria. We found that the PF-metabolizing activity of intestinal bacteria in rat feces was significantly reduced to approximately 34% of initial levels by a single sodium picosulfate pretreatment and took approximately 6 days to recover. Repeated administration of SGT after the sodium picosulfate pretreatment significantly shortened the recovery period to around 2 days. Similar results were also observed for plasma PM-I concentration. Since PM-I has muscle relaxant activity, the present results suggest that repetitive administration of SGT after sodium picosulfate pretreatment might be useful to relieve the pain associated with colonoscopy.