Apoptosis of hepatoma cells SMMC-7721 induced by Ginkgo biloba seed polysaccharide

AIM: To study the apoptosis of hepatoma cells SMMC-7721 induced by polysaccharide isolated from Ginkgo biloba seed. METHODS: Ginkgo biloba seed polysaccharide (GBSP) was isolated by ethanol fractionation of Ginkgo biloba seed and purified by Sephadex G-200 chromatography. The purity of GBSP was verified by reaction with iodine-potassium iodide and ninhydrin and confirmed by UV spectrophotometer, cellulose acetate membrane electrophoresis and Sepharose 4B gel filtration chromatography. The Scanning Electron Microscope (SEM) and Flow Cytometry (FCM) were used to examine the SMMC-7721 cells with and without GBSP treatment at 500 mg/ml for 36 h. RESULTS: GBSP product obtained was of high purity with the average molecular weight of 1.86 x 10(5). Quantitative analysis of SMMC-7721 cells in vitro with FCM showed that the percentages of G(2)-M cells without and with GBSP treatment were 17.01+/-1.28 % and 11.77+/-1.50% (P<0.05), the debris ratio of the cells were 0.46+/-0.12% and 0.06+/-0.06% (P<0.01), and the apoptosis ratio of cells was 3.84+/-0.55% and 9.13+/-1.48% (P<0.01) respectively. Following GBSP treatment, microvilli of SMMC-7721 cells appeared thinner and the number of spherical cells increased markedly. Most significantly, the apoptosis bodies were formed on and around the spherical cells treated with GBSP. CONCLUSION: GBSP could potentially induce the apoptosis of SMMC-7721 cells.