Structural analysis and anti-alcoholic liver disease effects of a polysaccharide from Arundo donax L. rhizome.

BACKGROUND: Alcoholic liver disease remains a critical worldwide public health challenge. Arundo donax L. rhizomes are a traditional Chinese medicinal material, however, the structural characteristics and hepatoprotective potential of polysaccharides derived from this medicinal resource remain largely unexplored to date. METHODS: Polysaccharide ADLP was extracted from Arundo donax L. rhizomes, and its hepatoprotective activity and molecular mechanisms were investigated in an alcoholic liver injury murine model. RESULTS: Structural analysis indicated that ADLP (Mw = 22.689 kDa) possesses a linear →4)-α-d-Glcp-(1→ backbone, which is primarily decorated with a side chains of →1)-α-d-Glcp-(6→1)-α-d-Glcp-(6→1)-α-d-Glcp. Activity studies confirmed that ADLP not only improved the viability of ethanol-treated HepG2 cells, but also alleviated ethanol-induced hepatic lipid accumulation. Mechanistic analyses revealed that ADLP facilitates hepatic lipid metabolism by regulating the AMPK-PPARα signaling pathway. Meanwhile, ADLP exerts hepatoprotective effects through modulation of the gut-liver axis. Specifically, ADLP upregulates the expression of tight junction proteins ZO‑1 and Occludin, thereby mitigating alcohol-triggered intestinal barrier injury, restoring dysregulated gut microbiota, and elevating the levels of short-chain fatty acids. CONCLUSION: This study systematically characterized the structural features of Arundo donax L. rhizome polysaccharide ADLP and verified its protective effects against alcohol-induced liver injury both in vitro and in vivo. ADLP exerts its hepatoprotective function via dual regulation of hepatic lipid metabolism and the gut-liver axis. This work fills the blank of structural and anti-alcoholic liver injury activity of polysaccharides derived from Arundo donax L. rhizomes, and provides a novel natural polysaccharide candidate for the intervention of alcoholic liver disease.