Structure features, selenylation modification, and improved anti-tumor activity of a polysaccharide from Eriobotrya japonica

A homogeneous polysaccharide, EJP90-1, was isolated from the leaves of E. japonica by hot water extraction in this study. EJP90-1 (7702 Da) was a heteropolysaccharide mainly consisting of -> 5)-linked-alpha-L-Araf-(1 ->, -> 4)-linked-beta-D-Manp-(1 ->, -> 2,4)-linked-alpha-L-Rhap-(1 ->, -> 4)-linked-alpha-D-Xylp-(1 ->, -> 4)-linked-beta-D-Galp-(1 ->, -> 2)-linked-beta-D-Galp-(1 ->, -> 6)-linked-beta-D-Glcp-(1 ->, alpha-D-Glcp-(4 ->, and t-linked-alpha-L-Araf. EJP90-1 was found to show moderate anti-tumor activity at the cellular level. In order to improve the anti-tumor activity and the potential applications of EJP90-1, a typical sodium selenite-nitric acid (Na2SeO3-HNO3) modification on EJP90-1 was carried out. X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS) analysis confirmed that Se was successfully introduced into the polymer chain of EJP90-1. The subsequent in vitro cytotoxicity evaluation showed the selenylation modification derivative (EJP90-1-Se) possessed significant antiproliferative activity against cancer cells (HepG2 and A549 cells) through inducing cell apoptosis. The antitumor activity of EJP90-1-Se was further confirmed by zebrafish models, which inhibited the proliferation and migration of HepG2 cells and the angiogenesis.

Automated summary

A homogeneous polysaccharide EJP90-1 was extracted from the leaves of E. japonica, and further modified with sodium selenite-nitric acid to enhance its anti-tumor activity. The selenylation modification derivative EJP90-1-Se exhibited significant antiproliferative activity against cancer cells, and was confirmed to inhibit cell proliferation, migration, and angiogenesis through zebrafish models.