Structural characterization and in vitro evaluation of the hypolipidemic activity of the HSP-Ia, a bioactive polysaccharide derived from hemp (Cannabis sativa L.) seeds.

A novel polysaccharide, HSP-Ia, with a molecular weight of 973.6 kDa, was isolated from hemp (Cannabis sativa L.) seed residues using sequential aqueous extraction, ethanol-induced precipitation, and chromatographic fractionation. Its structural attributes were determined through methylation profiling and nuclear magnetic resonance spectroscopy. The physicochemical characteristics were examined using X-ray diffraction, atomic force microscopy, scanning electron microscopy, and circular dichroism spectroscopy. The hypolipidemic potential of HSP-Ia was assessed using oxidized low-density lipoprotein-induced RAW264.7 macrophages. HSP-Ia was predominantly comprised of glucose, with minor proportions of arabinose and galactose. It had a backbone of →6)-α-D-Glcp-(1 → residues with side chains attached at the O-2 and O-3 positions. HSP-Ia possessed an amorphous, nonuniform, and discontinuous morphology, with height distributions ranging from 0.7 to 10.5 nm. It exhibited a zeta potential of -7.4 mV and retained a triple-helix conformation in aqueous media. Notably, HSP-Ia facilitated lipid efflux in foam cells in a dose-dependent manner, associated with the upregulation of Liver X receptor α/ATP-binding cassette transporter signaling pathway. Overall, these findings enhance the current knowledge of the structural features of hemp seed-derived polysaccharides and underscore the potential application of HSP-Ia as a lipid-modulating agent in the development of functional food products and pharmaceutical formulations.