Development and application of a rapid and sensitive LC-MS/MS method for simultaneous quantification of six diterpene lactones in rats after oral administration of Rhizoma Dioscoreae Bulbiferae extract.

Diterpene lactones have been considered as the main therapeutic and hepatotoxic constituents of Rhizoma Dioscoreae Bulbiferae in recent years. In this work, a simple, rapid and accurate LC-MS/MS method was established and validated to determine six diterpene lactones in rat plasma simultaneously, including Diosbulbin B (DIOB), Diosbulbin C (DIOC), Diosbulbin D (DIOD), Diosbulbin G (DIOG), Diosbulbin J (DIOJ) and Diosbulbin L (DIOL), after oral administration of Rhizoma Dioscoreae Bulbiferae extract. The six diterpene lactones, with the inclusion of two pairs of isomer (DIOB & D, DIOC & L), and Buspirone (internal standard, IS) were successfully separated using an XDB-C18 column with the gradient elution, consisting of water with 0.1% (v/v) FA and methanol with 0.1% (v/v) FA, under a flow rate of 0.50 mL/min in 5.8 min. Precursor-product ion transitions were optimized to be m/z 362.1 → 317.1, 363.1 → 207.1, 345.0 → 299.2, 364.3 → 347.0, 396.3 → 379.3, 363.2 → 345.1 and 386.3 → 122.2 for DIOB, DIOC, DIOD, DIOG, DIOJ, DIOL and buspirone at positive ion mode with an electrospray ionization source (ESI), respectively. The linearity ranges of this present method were 0.50 to 500 µg/L for DIOB, 20.0 to 20,000 µg/L for DIOC and 2.00 to 2000 µg/L for DIOD, DIOG, DIOJ and DIOL, respectively. And the LLOQs were as low as 0.20 µg/L for DIOB, 20.0 µg/L for DIOC and 2.00 µg/L for DIOB, D, G, J and L. The accuracy of each analyte was within the range of 95.8% to 101.0% and the precision was <11.3%. No matrix effect and carry over was observed, and the recovery of the six analytes ranged from 87.3% to 109% with the RSD <11.4% within the concentrations range. The validated method was further applied to the pharmacokinetics investigation of DIOB, DIOC, DIOD, DIOG, DIOJ and DIOL successfully after oral administration of Rhizoma Dioscoreae Bulbiferae extract at 1.53 g/kg in rats.

Quality Evaluation of Andrographis paniculata Capsules Based on Rapid and Accurate LC-ESI-MS/MS Assay of Three Diterpenoids.

Andrographis paniculata is an important traditional Chinese herbal material widely used for treatment of fever and diarrhea. The three diterpenoids [andrographolide (AP), dehydroandrographolide (DP) and neoandrographolide (NP)] in A. paniculata were characterized as the key active components for its extractive and related medicinal preparations. A rapid and accurate quantitative analysis of these three diterpenoids in A. paniculata capsules was accomplished by means of a valid and reliable high-performance liquid chromatography with tandem mass spectrometric (HPLC-MS/MS) analytical method. An optimized gradient elution method, which under the mobile phase consisting of methanol and water, was established successfully. An XDB C18 column (3.5 µm, 2.1 mm × 50 mm) was successfully applied to separate these three diterpenoids at the flow rate of 0.55 mL/min. A triple quadrupole mass spectrometer with multiple reaction monitoring (MRM) mode using an electrospray ionization source was served for analytical detection. The linearity, specificity, accuracy, recovery, precision, stability and repeatability were demonstrated to fully confirm the validity of this study. Good linear regression relationships for the three analytes were obtained over the range of 0.50-1000 ng/mL. Intra-day and inter-day precisions were evaluated with relative standard deviation < 7.62%, and the extraction recovery varied from 93.8% to 102.0%. The rapid and accurate HPLC-MS/MS analytical method was developed for the quality evaluation of A. paniculata capsules successfully. The content of AP, DP and NP obtained were 3.90-4.08, 4.77-5.04, 4.32-4.48 mg/g in A. paniculata capsules, respectively. Moreover, it is expected that this analytical technique can be applied to detect three effective components rapidly and accurately in other different medicinal preparations of A. paniculata as a method for their quality control.

Pharmacokinetic and Toxicological Characteristics of Tripterigium Glycosides and Their Derivatives.

BACKGROUND: Tripterigium wilfordii glycosides (TWG) demonstrate paramount bioactive effectiveness in the management of many autoimmune diseases. However, its side effects on the hepatic, nephrotic, reproductive, and cardiovascular systems have limited its immense therapeutic potentials. Triptolide (TP) and Celastrol (CL), the leading bioactive as well as toxic constituents of TWG, have been widely studied. This review aims to summarize the key mechanisms that TWG trigger the toxic reactions and the precautionary measures that could prevent and reduce such reactions. METHOD: We undertook a systemic search of bibliographic databases for peer-reviewed research literature about the toxic mechanisms and pharmacokinetic profiles of TWG. The key points of screened papers were described and combined together to make up whole. RESULTS: Totally 125 papers were referred in this paper, the majority were from Chinese academic associations. It has been reported that reactive oxygen species generation, mitochondrial respiratory chain inhibition, and metabolizing enzyme inhibition are the leading factors of the toxic reactions. The bioactive effects and toxicities of TWG are closely related to its metabolic profiles. It has been confirmed that TP and CL inhibit CYP450 and the transporters. This paper reviews and summarizes the pharmacokinetic parameters of TWG. Antioxidants, polymeric micelle and topical nanoparticle formulations have exhibited potentials in toxicity circumvention. CONCLUSION: A thorough understanding of the pharmacokinetic and toxicological characteristics of TWG combined with further in-depth study will enhance the efficacy and safety in using TWG, which would augment and improve its clinical application in the future.