Classification Of Lycium Barbarum Polysaccharide And Its Effect On The Apoptosis Of Human Hepatoma Cells

Lycium Barbarum Polysaccharide (LBP) was extracted from the fruit of Chinese wolfberry, and five polysaccharide fractions were obtained using four ultra filtration membranes (80K,30K,10K and 4K). Their physicochemical properties and the effect on human hepatoma SMMC-7721 cells were studied to investigate structure-bioactivity relationship of lycium barbarum polysaccharide.The optimum reaction conditions are determined and the average molecular weight of LBP-80, LBP-30, LBP-10, LBP-4 and LBP-4p are 2.04×106 Da,5.48×105 Da,3.62×106 Da,5.5×104 Da and 1.02×104 Da.Compared with each other, the content of uronic acid, protein, neutral sugar of each fraction was different. They were consisted of the same kinds of monosaccharides with a different molar ratio, mainly were fucose, rhamonose, arabinose, xylose, glucose, mannose and galactose, with different molar ratio, however, the content of rhamonose in LBP-80 LBP-4p and LBP-4 were below detectable limit, glucose in LBP-80 was not detected either. The images revealed that LBP-30 particles appeared as flocculent structure or spherical shape, the size of spherical molecular was relatively uniform with a big thickness while LBP-4p particles were spherical molecular of uniform size, the thickness of LBP-30 was higher than that LBP-4p, while the diameter was smaller than that LBP-4p.The results of DSC showed that the endothermic peak of LBP-30 and LBP-4 were narrow, while the LBP-80 and LBP-10 were width and flat, it might due to the molecular weight range of LBP-30 and LBP-4 were relatively concentrated, the component were more uniform.ln the heat absorption curve of LBP-4p, irregular subtle curve slope appeared, which might caused by the absorption of moisture, that moisture content changes affect the thermodynamic changes of temperature.And the effects of these fractions on human liver cancer cells (SMMC-7721) were observed by MTT assay, cell morphology observation and flow cytometry (FCM). The results showed that LBP-80, LBP-10, LBP-4 and LBP-4p could inhibit the proliferation of SMMC-7721 cells in a concentration and time dependent manner. LBP-4p and LBP-10 showed better inhibition,and the best inhibition ratio was 56.1%±1.4%. The cells’ morphology were also changed, it could arrest SMMC-7721 cells at the G0/G1 phase and enhance the intracellular Ca2+ concentration significantly. Nevertheless, the fraction of LBP-30 could promote the growth of SMMC-7721 cells significantly, the highest cell survival rate was 183.5%±4.7%, it also shift the cell population of G2/M phase to G0/G1 and S phases, and no enhance of the intracellular Ca2+ concentration was detected.