A novel polysaccharide from Qamgur (Brassica rapa L.) mitigates pulmonary fibrosis by regulating inflammatory, epithelial-mesenchymal transition, and fibrotic pathways.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Qamgur (Brassica rapa L.) has been utilized for an extended period in Uyghur traditional medicine in Xinjiang, China, for treating respiratory diseases. This study validates the efficacy of its polysaccharide component (BRP) against pulmonary fibrosis. AIM OF THE STUDY: To explore extraction and purification methods of Qamgur polysaccharides (BRP) and characterize their composition and molecular features. Furthermore, to evaluate the therapeutic effect of BRP in a bleomycin-induced pulmonary fibrosis mouse model. MATERIALS AND METHODS: BRP was extracted and purified from Qamgur, followed by analysis of polysaccharide content, monosaccharide composition, molecular weight, and polydispersity. Structural characterization included FT-IR, UV spectroscopy, microscopic observation, glycosidic linkage analysis, and NMR. Animal studies involved histopathological examination, Western blot, PCR, and transcriptomics related to pulmonary fibrosis. RESULTS: BRP-1-1 was identified as a heteropolysaccharide (12.55 kDa) composed mainly of glucose (94.04%), with a → 4 -α-D-Glcp-(1→ backbone and branched structures at → 4,6)-α-D-Glcp-(1→ ; twelve glycosidic linkages were detected by methylation analysis and GC-EI-MS. BRP treatment alleviated pulmonary fibrosis, reduced histopathological damage, downregulated TGF-β and α-SMA, suppressed NF-κ B and NLRP3, and modulated EMT markers (E-cadherin, N-cadherin) and fibrosis indicators (α-SMA, collagen I). Transcriptomics revealed differential gene expression between groups, and GSEA confirmed BRP reduced pro-fibrotic gene expression. CONCLUSION: This research provides a comprehensive analysis of the structure of Qamgur (Brassica rapa L.) polysaccharide and examines its potential therapeutic benefits, thereby establishing a theoretical basis for the advancement of treatments aimed at combating pulmonary fibrosis.