Identification and quantification of putative active constituents of huangqin decoction for ulcerative colitis treatment through the integration of chemical profiling, network pharmacology, and bioinformatics.

Introduction: Huangqin decoction (HQD), a traditional Chinese medicine prescription, is used to treat gastrointestinal diseases, including ulcerative colitis (UC). However, systematic research on the components of HQD remains insufficient. Therefore, we aimed to perform chemical profiling, network pharmacology, and bioinformatics analyses of HQD to identify candidate constituents potentially associated with UC and to establish a quantitative method for their determination in HQD. Methods: Qualitative chemical profiling was performed to identify 51 compounds in HQD, and their potential targets were predicted. UC-related target genes were identified by combining results from public and Gene Expression Omnibus (GEO) databases. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to investigate the biological processes and signaling pathways associated with UC. Moreover, protein-protein interaction (PPI) analysis was performed. Based on these results, 15 putative active constituents of HQD were selected and quantified. Molecular docking analysis was then performed to evaluate the binding interactions between these compounds and key target proteins. Results: A total of 947 HQD component-related, 1,868 UC-related, and 2,930 GEO database-related target genes were intersected to obtain 109 common target genes for HQD and UC. GO and KEGG enrichment analyses indicated that these targets were mainly associated with inflammatory and immune-related biological processes and signaling pathways. Among the identified targets, NOS2, AHR, MMP3, MMP9, and PRKCQ were highlighted as potential key targets. The analysis of three batches of HQD samples revealed that baicalin had the highest content. Molecular docking results indicated favorable predicted interactions between the putative active compounds and core target proteins, with several compound-target pairs exhibiting docking scores below -11.0 kcal/mol. Discussion: This study not only provides a comprehensive chemical profile of HQD but also presents a new approach for evaluating and managing quality based on putative active constituents. These findings may serve as a scientific basis for further pharmacological and clinical studies.