Material basis of cytotoxicity in polysaccharide from Solanum nigrum

Objective To study the material basis of cytotoxicity in polysaccharide from Solanum nigrum.Methods Crude products of polysaccharide were isolated from S.nigrum fruit with free protein being removed by Sevage method.The crude products were decolored by 10% H2O2 and precipitated by 95% ethanol treatment.Polysaccharide-protein complex was isolated by DEAE-52 fiber column and the relative molecular weight was detected by SDS-PAGE.MTT assay was used in detecting the cytotoxicity of polysaccharide-protein complex for MCF-7 cells in vitro.Then polysaccharide-protein complex was separated by SephadexG-200 gel column and the cytotoxicity was detected by MTT method.Results Polysaccharide-protein complex was isolated by DEAE-52 fiber column and the relative molecular wight was detected by SDS-PAGE as 3.0×104 and 2.5×104 for the two polysaccharide-protein complexes,It suggested that IC50 was 804.51 μg/mL by MTT.Glycoproteins A andd B were gained by Sephadex G-200 gel column from polysaccharide-protein complex.The IC50 of glycoproteins A and B were 532.96 and 613.91 μg/mL,respectively.Conclusion Material basis of cytotoxicity in polysaccharide from S.nigrum is two kinds of glycoproteins whose relative molecular weight are 3.0×104 and 2.5×104.