Structure and Wound-Healing Activity of a Branched Levan-Type Fructan from Cyathula officinalis Roots

Cyathula officinalis Kuan, a medicinal plant used in traditional medicine, remains underexplored as a source of structurally defined wound-repair polysaccharides. In this study, a water-soluble polysaccharide fraction, CoPS, was isolated from C. officinalis roots and structurally characterized using methylation analysis and 1D/2D NMR spectroscopy. Purified CoPS had a total carbohydrate content of 94.8%, a weight-average molecular weight (M_w) of 7.491 kDa, and a narrow dispersity (M_w/M_n = 1.04). Monosaccharide composition analysis showed that CoPS was mainly composed of fructose and glucose at a molar ratio of 95.60:4.40. Structural analyses identified CoPS as a branched levan-type fructan with a β-(2→6)-linked fructofuranosyl backbone and β-(2→1)-linked branching motifs. CoPS was incorporated into a Carbomer/alginate topical formulation, termed CoPS-CPG, and evaluated in vitro and in vivo. CoPS-CPG showed good cytocompatibility and promoted HaCaT keratinocyte migration, reducing the residual scratch area to 48.10% at 12 h compared with 70.13% in the control group and 65.18% in the vehicle (Blank-CPG) group. In a murine full-thickness excisional wound model, CoPS-CPG reduced the residual wound area to 8.70 ± 1.20% on day 14, compared with 24.83 ± 1.51% in the control group and 14.20 ± 0.72% in the vehicle group. Histological and immunological analyses further indicated improved tissue reconstruction, a reduced inflammatory burden, enhanced CD206-associated macrophage signals, increased CD31-associated vascular structures, improved α-SMA-associated perivascular coverage, and lower late-stage HIF-1α expression. These findings identify CoPS as a structurally defined plant-derived levan-type fructan that supports cutaneous wound repair.