An inulin-type fructan (AMP1-1) from Atractylodes macrocephala with anti-weightlessness bone loss activity

Atractylodes macrocephalon polysaccharides of alleviating weightlessness-induced bone loss (WIBL) are rarely reported. In this study, a neutral polysaccharide fragment named AMP1-1 was isolated and purified. Monosaccharide composition and gel permeation chromatography analysis indicated that AMP1-1 was composed of glucose and fructose with molecular weight of 1.433 kDa. Based on data of gas chromatography-mass spectrometer (GCMS), a linear backbone consisted of α-d-Glcp-(1→ and →1)-β-d-Fruf-2→ was discovered. Combining results from nuclear magnetic resonance (NMR), the inulin-type fructan AMP1-1 was identified as α-d-Glcp-1→(2-β-d-Fruf-1)₇. Anti-WIBL activity of AMP1-1 was evaluated though analyzation of mechanical properties, BALP and TRAP 5b activities on femur. In vitro mRNA expression indicated that anti-WIBL activity of AMP1-1 was achieved by promote bone formation and inhibit bone resorption in primary osteoblasts and RAW264.7 cell lines under simulated weightlessness. In conclusion, the inulin-type fructan AMP1-1 with α-d-Glcp-1→(2-β-d-Fruf-1)₇ had anti-WIBL activity via remodeling bone homeostasis.