Structural characteristics and wound-healing effects of Bletilla striata fresh tuber polysaccharide

A homogeneous polysaccharide from Bletilla striata fresh tuber (BSPS) was prepared and extensively characterized using HP-GPC, colorimetry, FT-IR, methylation, GC-MS, NMR, Congo red experiment, SEM, and AFM. The molecular weight of BSPS was 722.90 kDa. BSPS consisted of glucose and mannose in the molar ratio of 1 : 2.5. BSPS had a linear chain structure consisting mainly of →4)-β-d-Glc_p-(1→ and →4)-β-d-Man_p-(1→ residues. O-acetyl group linked to C₂ of →4)-β-d-Man_p-(1→ residue. Its monosaccharide molar ratio, molecular weight, and O-acetyl substituted position were different from that of the polysaccharide from B. striata dried tuber reported previously. Furthermore, BSPS at concentrations of 3.125-25 μg/mL significantly promoted the viability (ca. 10%), differentiation (1.5-4 folds), migration (15%-70%), and invasion (1.84-4.65 folds) of C2C12 cells. Of note, BSPS remarkably accelerated the epidermal regeneration and wound healing in mice. This study for the first time reported the structure of polysaccharides in B. striata fresh tubers. The results demonstrated that BSPS could be explored as a novel natural wound-healing drug.