Identification of Protosappanoside D from Caesalpinia decapetala and Evaluation of Its Pharmacokinetic, Metabolism and Pharmacological Activity

Quantitative analysis of three bioactive components of Biancaea decapetala extracts in rat plasma and RAW264.7 cells using UPLC-MS/MS and its application to comparative pharmacokinetics in normal and diseased states

Biancaea decapetala (Roth) O.Deg. (Fabaceae), traditionally utilized by the Hmong for treating rheumatoid arthritis (RA), has its pharmacokinetic behavior under disease conditions largely unexplored. In view of this, a UPLC-MS/MS method was established for the determination of protosappanin B (PTB), protosappanin B-3-O-β-D-glucoside (PTD), and 3-deoxysappanchalcone (3-DSC), key bioactive components of the herb, in rat plasma and RAW264.7 cells to explore the effect of disease state on the pharmacokinetic profiles changes of these three components in vitro and in vivo. These components were detected using multiple reaction monitoring (MRM) process in positive and negative mode. Each calibration curve had a high R2 value of > 0.99. The intra- and inter-day precisions of PTD, PTB, 3-DSC were all < 15 %, and accuracy ranged from 85 % to 115 %. The RSD values pertaining to stability, recovery, matrix effect, and stability remained below 15.0 %. It was successfully applied for the investigation of the pharmacokinetics of these three components in rat plasma and RAW264.7 cells after administration of Biancaea decapetala extracts (BDE). In rat pharmacokinetic experiments, significant differences were observed in the AUC(0-t), MRT(0-t), and Clz/F values of PTD, PTB, 3-DSC between adjuvant-induced arthritis (AA) and normal rats. In cellular pharmacokinetic experiments, comparison with the normal group revealed increased AUC(0-t) and MRT(0-t) for these three components in the LPS-induced inflammatory cell model, along with decreased Clz/F, which was consistent with in vivo experimental outcomes. These findings suggest an increased absorption rate and a decreased elimination rate of the three components of BDE in AA rats and inflammatory cells, indicating a potential alteration in the rate and extent of drug metabolism. This study provided a theoretical reference for further clarification of its pharmacodynamic basis.

Structural Investigation of Betulinic Acid Plasma Metabolites by Tandem Mass Spectrometry

Betulinic acid (BA) has been extensively studied in recent years mainly for its antiproliferative and antitumor effect in various types of cancers. Limited data are available regarding the pharmacokinetic profile of BA, particularly its metabolic transformation in vivo. In this study, we present the screening and structural investigations by ESI Orbitrap MS in the negative ion mode and CID MS/MS of phase I and phase II metabolites detected in mouse plasma after the intraperitoneal administration of a nanoemulsion containing BA in SKH 1 female mice. Obtained results indicate that the main phase I metabolic reactions that BA undergoes are monohydroxylation, dihydroxylation, oxidation and hydrogenation, while phase II reactions involved sulfation, glucuronidation and methylation. The fragmentation pathway for BA and its plasma metabolites were elucidated by sequencing of the precursor ions by CID MS MS experiments.