Astragaloside IV Ameliorates Colonic Adenomatous Polyps Development by Orchestrating Gut Bifidobacterium and Serum Metabolome.

Abstract

Astragaloside IV (AS-IV), a natural triterpenoid isolated from Astragalus membranaceus, has been used traditionally in Chinese medicine. Previous studies have highlighted its benefits against carcinoma, but its interaction with the gut microbiota and effects on adenomatous polyps are not well understood. This present study investigates the effects of AS-IV on colonic adenomatous polyp (CAP) development in high-fat-diet (HFD) fed [Formula: see text] mice. [Formula: see text] mice were fed an HFD with or without AS-IV or Naringin for 8 weeks. The study assessed CAP proliferation and employed 16S DNA-sequencing and untargeted metabolomics to explore correlations between microbiome and metabolome in CAP development. AS-IV was more effective than Naringin in reducing CAP development, inhibiting colonic proinflammatory cytokines (IL-1β, IL-6, and TNF-α), tumor associated biomarkers (c-Myc, Cyclin D1), and Wnt/β-catenin pathway proteins (Wnt3a, β-catenin). AS-IV also inhibited the proliferative capabilities of human colon cancer cells (HT29, HCT116, and SW620). Multiomics analysis revealed AS-IV increased the abundance of beneficial genera such as Bifidobacterium pseudolongum and significantly modulated serum levels of certain metabolites including linoleate and 2-trans,6-trans-farnesal, which were significantly correlated with the number of CAP. Finally, the anti-adenoma efficacy of AS-IV alone was significantly suppressed post pseudoaseptic intervention in HFD-fed [Formula: see text] mice but could be reinstated following a combined with Bifidobacterium pseudolongum transplant. AS-IV attenuates CAP development in HFD-fed [Formula: see text] mice by regulating gut microbiota and metabolomics, impacting the Wnt3a/β-catenin signaling pathway. This suggests a potential new strategy for the prevention of colorectal cancer, emphasizing the role of gut microbiota in AS-IV's antitumor effects.