Study on the structure, cardioprotective function, and mechanism of an inulin-type fructan in Platycodon grandiflorum and its resource development

A fructan, designated Platycodon grandiflorum main peak (PGMP), was isolated and purified from the rhizome of Platycodon grandiflorum (PG), with an average molecular weight of 2,286 Da. Structural analysis revealed that PGMP is an inulin-type fructan composed primarily of fructose, with its backbone mainly consisting of 2,1-β-D-fructofuranose (Fruf). Oral administration of PGMP significantly ameliorated doxorubicin (DOX)-induced cardiotoxicity in a chronic heart failure (CHF) model. The experimental results showed that PGMP exhibited significant antioxidant and cardioprotective effects in a distinct nonmonotonic dose-dependent manner, with the medium-dose PGMP (PGMP-M) demonstrating optimal efficacy. PGMP-M markedly improved cardiac function, elevated left ventricular ejection fraction (LVEF), and fractional shortening (FS); reduced serum levels of myocardial injury biomarkers; and alleviated myocardial inflammation as well as collagen deposition, outperforming the high-dose PGMP (PGMP-H). Combined-omics analysis revealed that PGMP-M reversed DOX-induced myocardial metabolic and transcriptional dysregulation by modulating key metabolites, including oleic acid, L-biopterin, and 3-oxopalmitic acid. In conclusion, PGMP can effectively protect against DOX-induced chronic heart failure by modulating key myocardial metabolic pathways, making it a promising functional food for cardioprotection.