Structural Characterization and Anti-Inflammatory Effects in LPS-Stimulated RAW264.7 Macrophages of an Inulin-Type Fructan (AVP-1-2) Isolated from Allium victorialis L.

Abstract

Allium victorialis L. is a significant plant traditionally used as both food and medicine in Northeast China. However, the structural and functional studies of its polysaccharide components remain limited. In the present study, we investigated the anti-inflammatory potential of AVP-1-2 (DP 27), an inulin-type fructan isolated from A. victorialis, using an LPS-induced RAW264.7 macrophage model. Its structural characterization was determined through methylation analysis and nuclear magnetic resonance spectroscopy. AVP-1-2 is an inulin-type fructan composed of fructose and glucose. The backbone consists mainly of →1)-β-D-Fruf-(2→, with minor glucose residues and limited branching. The qPCR and ELISA results indicated that AVP-1-2 effectively suppressed the mRNA expression and protein secretion of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) in a cellular model. Overall, this work provides new structural and functional insights into A. victorialis polysaccharides and offers a theoretical foundation for the comprehensive utilization of A. victorialis resources.