Integrated analysis of gut microbiota and metabolomics reveals the laxative mechanism of Sauropi Folium aqueous extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Sauropi Folium (Longliye), the dried leaf of Sauropus spatulifolius Beille, is a traditional medicine for cough and constipation. However, its chemical profile and laxative mechanism remain unclear, limiting clinical use.

AIM OF THE STUDY: The purpose of this study was to investigate the mechanism of Sauropi Folium aqueous extract (SSAE) in alleviating constipation.

METHODS

The chemical profile of SSAE was analyzed by UPLC-Q-TOF-MSeng. Network pharmacology was employed to predict key targets and pathways. A slow transit constipation (STC) rat model was established using loperamide hydrochloride. Serum biochemical indexes and cytokines were measured. Serum and fecal metabolomics and 16S rDNA amplicon sequencing were performed, and integrated analysis was conducted to reveal the mechanism.

RESULTS

UPLC-Q-TOF-MS identified 55 components. Network pharmacology indicated that SSAE might exert anti-constipation effects through cancer, HIF-1 and PI3K-AKT signaling pathways. SSAE effectively alleviated constipation symptoms in STC rats, affected gastrointestinal hormones and neurotransmitters, and improved colonic pathological morphology. Integrated metabolomics and 16S rRNA gene sequencing revealed that SSAE exerted laxative effects by modulating gut microbiota and its metabolic network: at the microbiota level, SSAE increased beneficial bacteria such as Lachnospiraceae_NK4A136_group and decreased potential pathogenic bacteria including Allobaculum, Bifidobacterium, Desulfovibrio and HT002; at the metabolic level, SSAE upregulated serum glutamine and fecal riboflavin, synergistically regulated glutamate metabolism, primary bile acid biosynthesis and purine-polyamine metabolism pathways, promoted 5-HT synthesis, and improved intestinal motility and mucosal barrier function.

CONCLUSIONS

SSAE effectively treats STC through multi-level integrated mechanisms involving chemical constituents, target pathways, gut microbiota and metabolic networks.