Purification and characterization of a chicory polysaccharide and its application in stabilizing genistein for cancer therapy

Genistein is an isoflavone with chemopreventive and therapeutic effects on various types of cancers. Apparently, in contrast to the advantages of multi-target therapy, the poor water solubility of this molecule is a major obstacle to its clinical application. In this work, zein/chicory polysaccharide nanoparticles (G-zein-P NPs) were prepared by pH-induced antisolvent precipitation method for the encapsulation of genistein. Firstly, an acidic polysaccharide (CIP70-2) with a molecular weight of 66.7 kDa was identified from the roots of chicory (Cichorium intybus). This natural macromolecule was identified as a plant pectin, for which the structure included RG-I (rhamnogalacturonan I) and HG (homogalacturonan) regions. Using this polysaccharide, G-zein-P NPs were prepared, in which the water solubility of genistein was improved by encapsulation. The encapsulation efficiency and loading efficiency of genistein by composite nanoparticles reached 99.0 % and 6.96 %, respectively. In vitro tumor inhibition experiments showed that the inhibitory effect of G-zein-P NPs on HepG2 cells was twice that of unencapsulated genistein. Moreover, the significant inhibition of tumor development and metastasis by G-zein-P NPs was observed in zebrafish xenograft models. The results suggested that zein/chicory polysaccharide nanoparticles may be a promising delivery carrier for genistein application in cancer prevention and therapy.