Bingyu Chen,Ke Liu,Yaya Guo,Jingwei Zhao,Yanhua Wang
The global incidence of ulcerative colitis (UC), a chronic inflammatory bowel disease, is rising. Epi-berberine (EPI), an alkaloid from Coptidis Rhizoma , shows potential for UC treatment. This study aimed to assess EPI's effect on UC and explore the mechanism underlying its UC-alleviating effect. The therapeutic effects of EPI on UC were validated in dextran sulfate sodium (DSS)-induced colitis mice and lipopolysaccharide (LPS)-induced Caco-2 inflammatory models and further investigated the underlying mechanism. In vivo, high-dose EPI (200 mg/kg) attenuated weight loss, reduced disease activity index, increased colon length, lowered colon macroscopic/histological scores, restored intestinal mucosal barrier and inhibited colonic inflammation. EPI (25/50 μM) had similar in vitro effects. mRNA-seq identified EPI-regulated genes in UC mice, revealing six gene clusters with analogous expression patterns. The largest cluster contained genes upregulated by DSS but downregulated by EPI, potentially involved in the MAPK pathway. Key DEGs were enriched in PI3K-Akt and MAPK pathways, verified in vivo and in vitro. Literature retrieval and molecular docking predicted glutaminyl-peptide cyclotransferase (QPCT) as EPI's potential UC therapeutic target. EPI inhibited DSS/LPS-induced QPCT upregulation in vivo and in vitro; QPCT knockdown suppressed inflammation and preserved Caco-2 monolayer barrier function, while QPCT overexpression reversed EPI's therapeutic effects. QPCT mediates PI3K-Akt/MAPK activation, and its overexpression abrogated EPI's inhibitory effects. EPI alleviates murine UC by protecting the intestinal mucosal barrier and inhibiting inflammation, likely via regulating the QPCT-PI3K-Akt/MAPK pathway. It provides a preclinical basis for developing prophylactic strategies for inflammatory bowel disease.
The tuber ofCorydalis yanhusuois a famous traditional Chinese medicine and found to have potent pharmacological effects, such as antinociceptive, antitumor, antibacterial, anti-inflammatory, and anti-depressive activities. Although there are several methods to be developed for the analysis and detection of the bioactive ingredients’ alkaloids, so far, only few prominent alkaloids could be quantified, and in vitro and in vivo changes of comprehensive alkaloids after oral administration are still little known. In this study, we first developed a simple and sensitive high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to quantify the comprehensive alkaloids of extracts ofC. yanhusuoin mouse plasma, using nitidine chloride as an internal standard. As results, at least fourteen alkaloids, including an aporphine (oxoglaucine), a protopine (protopine), five tertiary alkaloids (corydaline, tetrahydroberberine, tetrahydropalmatine, tetrahydrocolumbamine, and tetrahydrocoptisine) and seven quaternary alkaloids (columbamine, palmatine, berberine, epiberberine, coptisine, jatrorrhizine, and dehydrocorydaline) could be well quantified simultaneously in mouse plasma. The lower limits of quantification were greater than, or equal to, 0.67 ng/mL, and the average matrix effects ranged from 96.4% to 114.3%. The mean extraction recoveries of quality control samples were over 71.40%, and the precision and accuracy were within the acceptable limits. All the analytes were shown to be stable under different storage conditions. Then the established method was successfully applied to investigate the pharmacokinetics of these alkaloids after oral administration of the extract ofCorydalis yanhusuoin mice. To the best of our knowledge, this is the first document to report the comprehensive and simultaneous analyses of alkaloids ofC. yanhusuoin mouse plasma. It was efficient and useful for comprehensive pharmacokinetic and metabolomic analyses of these complex alkaloids after drug administration.Keywords:alkaloids;Corydalis yanhusuoextract;pharmacokinetics;HPLC-ESI-MS/MS;oxoglaucine