New analytical method for determination of epimer metabolites in rat plasma after oral administration of Paeoniflorin by UPLC-TOF-MS following picolinoyl derivatization

Comparative pharmacokinetics of six bioactive components of Shen-Wu-Yi-Shen tablets in normal and chronic renal failure rats based on UPLC-TSQ-MS/MS

ETHNOPHARMACOLOGICAL RELEVANCE

Shen-Wu-Yi-Shen tablets (SWYST), a Chinese patent medicine consisting of 12 herbal medicines, was formulated by a famous TCM nephrologist, Zou Yunxiang. It is clinically used to improve the symptoms of nausea, vomiting, poor appetite, dry mouth and throat, and dry stool in patients with chronic renal failure (CRF) accompanied by qi and yin deficiency, dampness, and turbidity. SWYST can reduce urea nitrogen, blood creatinine, and urinary protein loss, and increase the endogenous creatinine clearance rate. However, little is known about its pharmacokinetics.

AIM OF STUDY

To compare the pharmacokinetics of six bioactive components after oral administration of SWYST in normal and adenine-induced CRF rats.

MATERIALS AND METHODS

A method based on ultra-performance liquid chromatography coupled with a triple-stage quadrupole mass spectrometer (UPLC-TSQ-MS/MS) was developed and validated to determine the six bioactive compounds (albiflorin, paeoniflorin, plantagoguanidinic acid, rhein, aloe-emodin, and emodin) in rat plasma. Rat plasma samples were prepared using protein precipitation. Chromatography was performed on an Agilent Eclipse Plus C18 column (3.0 × 50 mm, 1.8 μm) using gradient elution with a mobile phase composed of acetonitrile and water containing 0.1% (v/v) formic acid, while detection was achieved by electrospray ionization MS under the multiple selective reaction monitoring modes. After SWYST administration, rat plasma was collected at different time points, and the pharmacokinetic parameters of six analytes were calculated and analyzed based on the measured plasma concentrations.

RESULTS

The UPLC-TSQ-MS/MS method was fully validated for its satisfactory linearity (r ≥ 0.9913), good precisions (RSD <11.5%), and accuracy (RE: -13.4∼13.1%), as well as acceptable limits in the extraction recoveries, matrix effects, and stability (RSD <15%). In normal rats, the six analytes were rapidly absorbed (Tmax ≤ 2 h), and approximately 80% of their total exposure was eliminated within 10 h. Moreover, in normal rats, the AUC0-t and Cmax of albiflorin, plantagoguanidinic acid, and rhein exhibited linear pharmacokinetics within the dose ranges, while that of paeoniflorin is non-linear. However, in CRF rats, the six analytes exhibited reduced elimination and significantly different AUC or Cmax values. These changes may reflect a decreased renal clearance rate or inhibition of drug-metabolizing enzymes and transporters in the liver and gastrointestinal tract caused by CRF.

CONCLUSIONS

A sensitive UPLC-TSQ-MS/MS method was validated and used to investigate the pharmacokinetics of SWYST in normal and CRF rats. This is the first study to investigate the pharmacokinetics of SWYST, and our findings elucidate the causes of their different pharmacokinetic behaviors in CRF rats. Furthermore, the results provide useful information to guide further research on the pharmacokinetic-pharmacodynamic correlation and clinical application of SWYST.

A pharmacokinetics-pharmacodynamics study of single-dose total glucosides of paeony capsule on reducing serum total bile acid in hepatic injury rats

CONTEXT

Total Glucosides of Paeony (TGP) capsule possesses various hepatoprotective activities. No study is available concerning TGP's concentration-effect relationship on hepatoprotection.

OBJECTIVE

To establish a pharmacokinetics-pharmacodynamics (PK-PD) modelling on TGP capsule's hepatoprotection after a single oral administration in hepatic injury rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats were divided into five groups (n = 6): control, model (hepatic injury), treated-H (2.82 g/kg), treated-M (1.41 g/kg), and treated-L (0.705 g/kg) groups. All treated groups rats were intragastrically administered a single dose. An LC-MS/MS method was applied to determine paeoniflorin (Pae) and albiflorin (Alb) in rat serum. The effects of single-dose TGP on serum alanine transaminase (ALT), aspartate transaminase (AST) and total bile acid (TBA) were evaluated in hepatic injury rats.

RESULTS

Single dose (2.82, 1.41, or 0.705 g/kg) TGP capsule could real-time down-regulate serum TBA but not ALT and AST in hepatic injury rats within 20 h. An inhibitory effect Sigmoid E_max of PK-PD modelling was established using Pae and Alb as PK markers and serum TBA as effect index. Pharmacodynamic parameters were calculated. For treated-H, treated-M and treated-L group, respectively, E₀ were 158.1, 226.9 and 245.4 μmol/L for Pae, 146.1, 92.9 and 138.4 μmol/L for Alb, E_max were 53.0, 66.0, and 97.1 μmol/L for Pae, 117.4, 249.7 and 60.0 μmol/L for Alb, and EC₅₀ were 9.3, 5.2 and 2.7 μg/mL for Pae, 2.3, 0.8, and 0.8 μg/mL for Alb.

DISCUSSION AND CONCLUSIONS

Serum TBA is a sensitive effect index for TGP's single dose PK-PD modelling, and it is potential for further multi-dose studies of TGP' effect on hepatic injury. The study provides valuable information for TGP's mechanistic research and rational clinical application.

Paeoniflorin attenuates the allergic contact dermatitis response via inhibiting the IFN-γ production and the NF-κB/IκBα signaling pathway in T lymphocytes

Paeoniflorin (PF) has been demonstrated to have an anti-allergic and anti-inflammatory effect in the treatment of allergic contact dermatitis (ACD). However, its clinical application is hampered by the lacking of comprehensive mechanical explanation. This research aimed to study the effect of PF on the proliferation, apoptosis and cytokines secretion as well as the expression of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways of T lymphocytes activation in vitro and in vivo. We found that PF depressed human T lymphocytes activation via inhibition ofinterferon-gamma (IFN-γ) production and NF-κB/IκBα and p38 MAPK signaling pathway in vitro, also PF could attenuate such ACD responses by inhibiting the production of IFN-γ and NF-κB/IκBα pathway in T lymphocytes of ACD mouse model, suggesting that PF might be useful for the treatment of T cell-mediated allergic inflammatory disorders such as ACD. This would make PF a promising T cell-targeted drug candidate for further study because of its immunosuppressive and anti-inflammatory effects.

A review on the pharmacokinetics of paeoniflorin and its anti-inflammatory and immunomodulatory effects

Increasing pharmacological evidence supports that paeoniflorin, a water-soluble monoterpene glycoside isolated from Paeonia lactiflora Pall. (Shaoyao in Chinese), has a wide range of medicinal properties including anti-inflammatory, antioxidant, antithrombotic, anticonvulsive, analgesic, cardioprotective, neuroprotective, hepatoprotective, antidepressant-like, antitumoral, and immune-regulatory activities; as well as enhancing cognition and attenuating learning impairment. In addition to pharmacodynamic studies, information on pharmacokinetics is also significant for the further development and utilization of paeoniflorin. The present review focuses on the absorption, distribution, metabolism, and excretion of paeoniflorin, especially main pharmacological activities of paeoniflorin on inflammation and immune function. According to the findings obtained both in vitro and in vivo, a broad application prospect has been opened for paeoniflorin. However, further studies are needed to clarity the direct molecular mechanisms and key targets underlying the beneficial effects of paeoniflorin on inflammation and immunity.

Advancement in the chemical analysis of Paeoniae Radix (Shaoyao)

Paeoniae Radix Alba (baishao or white peony root) and Paeoniae Radix Rubra (chishao or red peony root) are two highly valuable traditional Chinese medicines (TCMs) usually indicated for painful conditions, menstrual disorders and viral infections. These two TCMs are collectively referred to as shaoyao (Paeoniae Radix) due to their close origins and similar chemical compositions. Modern research indicates that monoterpene glycosides, polyphenols and paeonols are the three main types of compounds related to the pharmacological activities of Paeoniae Radix. This review summarizes recent advances in the chemical analysis of Paeoniae Radix and the related traditional Chinese medicine formulas/preparations, including methods used for sample pretreatment, qualitative analysis, quantitative analysis and biological sample analysis. More than 120 papers are discussed in this review, focusing on the chemical analysis of Paeoniae Radix, and various analytical techniques (such as HPLC, LC-MS, IR, near IR and quantitative NMR), as well as their advantages/disadvantages, are described. It is our hope that this paper can provide necessary information for improving the quality evaluation methods currently available for Paeoniae Radix and offer a scientific basis for the future in-depth study of the pharmacokinetics and pharmacodynamics of Paeoniae Radix.