Isolation and identification of anti-tumor polysaccharide LSP21 from Limonium sinense (Girard) Kuntze

Limonium sinense (Girard) Kuntze is a traditional Chinese folk medicine used for the treatment of fever, hemorrhage, hepatitis and other disorders. Recently, it was found that the crude polysaccharides from L. sinense (LSP) has significant anti-tumor activity. However, research on the isolation and identification of anti-tumor polysaccharide fractions from LSP has not yet been reported. In this study, three polysaccharides LSP11, LSP21, LSP31 were isolated and purified from LSP by using DEAE-52 cellulose column and Sephadex G-100 column chromatography. It was found that LSP21 exhibited the most significant inhibitory effect on the growth of HepG2 cells in vitro. Further research showed that LSP21 inhibited the growth of HepG2 cells in a dose-dependent manner and could induce cell body shrinkage, chromatin condensation, and reduction in the number of tumor cells with normal morphology which suggested that its cytotoxicity on tumor cell might be related to both inhibition on cell proliferation and inducement of cell death. Finally, the structural characteristics of LSP21 were analyzed by high performance liquid chromatography (HPLC) and gas chromatography (GC). The results showed that LSP21 is a heteropolysaccharide with an average molecular weight of 1.31×10(6) Da and consists of glucose, galactose and mannose in the ratio of 1.77:1:2.38.