Abstract

Lycium barbarum polysaccharide is a natural functional component which has a variety of biological activities. The composition and apoptosis inducing activities on human hepatoma SMMC-7721 cells of Lycium barbarum Polysaccharide fraction (LBP1) was investigated. The results showed that LBP1 consisted of neutral sugars, uronic acid and protein. LBP1 was composed of three kinds of monosaccharides including mannose, galactose and glucose. The molecule weight of LBP1 was 367 KDa. SMMC-7721 cells were cultured in the presence of LBP1 at various concentrations (50-400 mg/L) for 2 days, 4 days and 6 days and the percentage of cell viability was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. We found that anti-proliferative effect of LBP1 was associated with apoptosis on SMMC-7721 cells by morphological changes and cell cycle arresting at G0/G1phase. Furthermore, LBP1 could induce cell apoptosis which was closely accompanied with the enhancement of Reactive Oxygen Species (ROS) level, dissipation of Mitochondria Membrane Potential (MMP), increase expression of Bax mRNA and decrease expression of Bcl-2 mRNA. These results suggested that SMMC-7721 cell apoptosis induced by LBP1 mainly was mediated by mitochondrial pathways. However, further research on the molecular mechanisms of LBP1 effecting on the cells’ mitochondria is necessary.

Keywords:

Apoptosis, Bcl-2/Bax, composition, hepatoma SMMC-7721 cells, Lycium barbarum Polysaccharide (LBP), MMP, ROS,

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