β-Ecdysterone and Sarsasapogenin, first isolated from Polygonatum kingianum, reveal its therapeutic potential in MAFLD via 16S rRNA sequencing and metabolomics

Metabolic dysfunction-associated fatty liver disease (MAFLD) is linked to metabolic disorders. Polygonatum kingianum (PK), as a medicinal and edible homologous plant, shows therapeutic potential. β-Ecdysterone (phytosterol) and Sarsasapogenin (steroidal saponin) were first isolated from PK. We evaluated their effects in MAFLD mice via 16S rRNA Sequencing and Metabolomics. Results showed β-Ecdysterone primarily reduced serum LDL-C (by 0.46 mmol/L) and TC (by 1.24 mmol/L). Sarsasapogenin mainly lowered hepatic TG ( by 6 μmol/g tissue). Additionally, the liver injury was alleviated. Mechanistically, 16S rRNA sequencing analysis revealed Sarsasapogenin (90 mg/kg/d) lowered the Firmicutes/Bacteroidetes (F/B) ratio, while β-Ecdysterone (90 mg/kg/d) suppressed Proteobacteria and enriched Actinobacteria and Verrucomicrobia. At the genus level, both treatments reduced the abundance of Allobaculum (β-Ecdysterone: by 18.56–19.25%; Sarsasapogenin: by 8.97%-19.31), and increased Akkermansia , Blautia , Bacteroides , etc. Metabolomics showed they co-regulated Taurine and Tryptophan Metabolism. Besides, β-Ecdysterone affected Thyroid Hormone Synthesis and Steroidogenesis, whereas Sarsasapogenin targeted Arachidonic Acid, Sphingolipid, Glutamate, Pyrimidine, and Purine Metabolism. In β-Ecdysterone groups, Spearman correlation analysis revealed Ruminococcus negatively correlated with serum kynurenine, while Lactobacillus and Parabacteroides positively linked to hepatic taurine. Fecal bile acid metabolites (e.g., cholic acid) showed divergent associations with microbial communities. Sarsasapogenin groups revealed negative correlations between Lactobacillus and sphingolipids metabolites, Bacteroides and Akkermansia positively associated with fluvastatin and taurine. Amino Acids (e.g., L-phenylalanine) and Arachidonic Acid metabolites were also influenced by microbiota. Results highlighted β-Ecdysterone and Sarsasapogenin as pivotal MAFLD-ameliorating components via microbiota and metabolites, while identifying phytosterol as a key bioactive constituent in PK. • β-Ecdysterone and Sarsasapogenin were isolated from PK for the first time. • β-Ecdysterone mainly reduced serum LDL-C and TC, while Sarsasapogenin primarily lowered hepatic TG. • They co-regulate taurine (their common differential metabolite), bile acid, and tryptophan metabolism while targeting distinct pathways in MAFLD mice. • They acted pivotal MAFLD-ameliorate components via microbiota and metabolites, while phytosterol was identified as key bioactive constituents in PK.