A validated LC-MS/MS method for the determination of hederasaponin C: Application to pharmacokinetics-pharmacodynamics studies in the therapeutic area of acetic acid-induced ulcerative colitis in rats.

Hederasaponin C (HSC), one of the main components of Pulsatilla chinensis, is considered as a potential drug for the treatment of inflammatory bowel disease. In the present research, we developed a pharmacokinetics-pharmacodynamics model to describe the concentration-effect course of drug action following the intraperitoneal injection of HSC in colitis rats. A sensitive UPLC-MS/MS method was established for the the determination of HSC in rat plasma to explore the pharmacokinetics properties. The separation was performed on an Accucore C18 column (2.1 × 100 mm, 2.6 µm) with a flow phase consisting of acetonitrile and 0.1% formic acid water. The assay method was validated and demonstrated good adaptability for application in the pharmacokinetics study. Then the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) in colon tissues were measured using an ELISA assay. The levels of TNF-α, IL-1ß and IL-6 were decreased after HSC administration, suggesting that HSC can significantly improve the level of inflammatory syndrome factor. The pharmacokinetics study showed that the time to peak concentration of HSC was 1 h. The concentration-effect curves showed a hysteresis loop. There was also a hysteresis between the peaked concentration and the maximum effect of HSC. The present study established in vivo pharmacokinetics-pharmacodynamics models and the results showed a great potential of HSC for treating ulcerative colitis.

[Anti-inflammatory active fraction screening and mechanism of unripe Forsythiae Fructus based on ¹H-NMR metabolomics].

To screen the anti-inflammatory active fraction of unripe Forsythiae Fructus, and elucidate the action mechanism, water decoction, ethyl acetate portion, n-butanol portion and residue water extracts of unripe Forsythiae Fructus were administered into rats for continuously 15 days. The acute lung injury inflammatory model was established to observe the section structure of lung tissues. Levels of IL-6, TNF-α, IL-1ß and IL-10 in bronchoalveolar lavage fluid were determined by ELISA kits, and changes in endogenous metabolites in serum were analyzed based on 1H-NMR metabolomics. The results showed that ethyl acetate portion of unripe Forsythiae Fructus had a better anti-inflammatory activity against acute lung injury, and could suppress the release of inflammatory factors of IL-6, TNF-α, IL-1ß, significantly reduce contents of creatine, ß-OH-butyrate, succinate, lysine, valine, isoleucine and glutamine, and elevate the content of GPC in serum. Ethyl acetate portion was proved to be the main fraction of anti-inflammatory activity from the perspective of endogenous metabolites in serum, and played an anti-inflammatory role by regulating creatine metabolism, choline metabolism, branched-chain amino acid metabolism and TCA cycles. This study could lay a foundation for studying pharmacodynamic material basis of unripe Forsythiae Fructus.