Extraction, structural characterization, and therapeutic efficacy of Bletilla striata glucomannan against cholestatic liver fibrosis in vivo

Bletilla striata, a traditional Chinese medicinal herb, is well known for its bioactive polysaccharides, particularly glucomannan. In this study, a homogeneous glucomannan (BSP) was isolated and characterized from B. striata cultivated in Zhejiang, China, and its therapeutic potential against cholestatic liver fibrosis (CLF) was evaluated. Structural analyses revealed that BSP has a 746.2 kDa molecular weight and consists of mannose and glucose in a 7.19:2.81 M ratio, forming a linear backbone composed predominantly of β-1,4-linked D-glucosyl and D-mannosyl residues. In a 0.1 % DDC-induced CLF mouse model, BSP treatment significantly alleviated hepatic injury, as indicated by reductions in serum (ALP, ALT, TBiL) and fibrosis (α-SMA, COL1A1, Hyp) indicators, as well as proinflammatory cytokines (IL-1β, TNF-α). Mechanistic studies further demonstrated that BSP downregulated SASP markers (p16, p21), and restored the balance of lipid mediators (ARA/ω-3 FA metabolites). This study for the first time unveils the therapeutic potential of BSP in CLF, highlighting its novel role as a promising intervention. The findings particularly emphasize the critical role of anti- senescence in mediating this efficacy, revealing how BSP modulates SASP-related phenotype to alleviate CLF pathology, supporting the application of B. striata in functional medicine.