Pharmacological Effects and Candidate Bioactive Constituents of Huanglian Wendan Decoction in Experimental Metabolic Syndrome: Multi-Omics Analysis of Gut-Liver Metabolism and NLRP3 Signaling

Background: Chronic low-grade inflammation and gut microbiota dysbiosis contribute to metabolic syndrome (MS). Huanglian Wendan Decoction (HLWDD) is a defined multi-herbal formulation used in Chinese medicine, but its effects on gut microbiota-associated metabolism and NLRP3 inflammasome signaling remain unclear. Objective: This study evaluated the pharmacological effects and candidate absorbed bioactive constituents of HLWDD in experimental MS. Methods: A high-fat, high-sugar diet-induced rat model of MS was assessed using metabolic, biochemical, histological, molecular, and multi-omics endpoints. Gut metagenomics, untargeted metabolomics of liver and colonic contents, liver transcriptomics, and UPLC-HRMS/MS analysis of serum-absorbed constituents were integrated with network pharmacology and molecular docking. Baicalin was further evaluated in PA-BSA-treated HepG2 cells. Results: HLWDD ameliorated obesity, dyslipidemia, hepatic steatosis, and systemic inflammation and attenuated NLRP3 inflammasome-related signaling. Multi-omics analysis identified nine shared differential metabolites and a strong positive association between Faecalibacterium and butyrate. Thirty-two serum-absorbed constituents were tentatively identified. Baicalin showed favorable predicted interactions with NLRP3 (-5.82 kcal/mol) and CASP1 (-5.41 kcal/mol) and concentration-dependently suppressed NLRP3 inflammasome-related signaling in HepG2 cells; the highest concentration increased intracellular butyrate. Conclusion: HLWDD ameliorated metabolic and inflammatory abnormalities in experimental MS in association with restoration of gut-liver metabolic homeostasis and attenuation of NLRP3 inflammasome signaling. Baicalin emerged as a candidate absorbed bioactive constituent.