Purification, physicochemical characterisation and anticancer activity of a polysaccharide from Cyclocarya paliurus leaves

A Cyclocarya paliurus (Batal.) Iljinskaja polysaccharide (CPP) was isolated and purified by hot water extraction, ethanol precipitation, deproteinisation and anion-exchange chromatography. Its physicochemical properties were characterised by gel permeation chromatography (GPC), gas chromatography–mass spectrometry (GC–MS), thermal gravimetric analysis (TGA), Fourier transform infrared spectrometry (FTIR), UV–visible spectrophotometry, dynamic light scattering (DLS) and viscometry analysis. The anticancer effect of CPP in human gastric cancer HeLa cells was also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the molecular weight of CPP was 900 kDa, and it contained 64.8% total sugar, 23.5% uronic acid, 9.26% protein, and six kinds of monosaccharides, including glucose, rhamnose, arabinose, xylose, mannose and galactose, with molar percentages of 32.7%, 9.33%, 30.6%, 3.48%, 10.4%, and 13.5%, respectively. Furthermore, the results showed that CPP exhibited a strong inhibition effect on the growth of human gastric cancer HeLa cells.