Multi-level differential characterization of polysaccharides and the cardiomyocyte protection simultaneously from three raw and processed ginseng varieties

Ginseng is often steamed to enhance the efficacy, however, studies on the induced chemical transformation have seldom focused on the contained polysaccharides, hitherto. Herein, change of ginseng polysaccharides induced by the steaming was studied. Utilizing three ginseng varieties ( Panax ginseng , PG; P. quinquefolius , PQ; P. notoginseng , PN) as the templates, this work was designed to characterize the transformation of polysaccharides induced by steaming at different time (0 −10 h) by three-level fingerprinting, and to visualize them by in situ hydrolysis and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI). After steaming, the total contents of polysaccharides in three ginseng varieties generally increased, but showed indistinctive changes in molecular weight distribution. Five oligosaccharide markers were selected enabling the differentiation of raw and steamed ginseng products. DESI-MSI could distinguish between the raw and steamed samples for each ginseng variety by five differential oligosaccharides, respectively, including the trisaccharide, tetrasaccharide, pentasaccharide, octasaccharide, tridecasaccharide, and pentadecasaccharide. In addition, based on the in vitro oxygen-glucose deprivation (OGD) and oxygen-glucose deprivation and reperfusion (OGD/R) models, examination and comparison among the polysaccharides from the raw materials and steamed products could unveil significant cardiomyocyte protection effect of PN-0h (raw material of P. notoginseng ) and PN-2h (steamed for 2 h), with potential mechanism of inhibiting the mitochondrial dependent pathways to reduce cell apoptosis rate. Conclusively, holistic transformation of polysaccharides during the steaming simultaneously from three ginseng varieties was depicted, for the first time. The obtained results can provide useful information for quality control of the raw and processed ginseng in the polysaccharide perspective.