Effects Of Astragalus Polysaccharide On The Proliferation Ability Of Cervical Carcinoma C-33A Cells

Background and ObjectivesCervical cancer is one of the major malignant tumor that endangers women’s life. It is of important practical significance to explore the feasibility of applying traditional Chinese medicine to the treatment of cervical cancer. Astragalus is a common nourishing Chinese medicinal plant, which was first described in Shen Nong’s Canon of Herbs in Eastern Han dynasty. It was discovered that Astragalus Polysaccharides (APS) is the major active ingredient of Astragalus, which inhibits the growth of tumor cells in liver cancer, breast cancer, gastric cancer, and leukemia and carcinoma cell strain. However, the effects of APS on the proliferation of C-33A cells have not been reported yet. The purpose of this study is to investigate the effect of APS on the proliferation potential of human cervical cancer C-33A cells and its mechanism so as to provide theoretical and experimental basis for the feasibility of APS used in the treatment of cervical cancer.Methods1. APS was extracted and then quantitated.2. The growth rate and doubling time of C-33A cells were detected by methyl thiazolyl tetrazolium (MTT) chromatometry.3. The distribution of cell cycle was analyzed by flow cytometry. The change of clone-forming efficiency was studied by flat clone-forming assay.4. The expression of proliferation-related genes (cyclin A、cyclin B-. cyclin E and p21) were investigated by Western blotting assay.Results 1. The concentration of extracted APS was51.514mg/mL.2. The results of MTT indicated that:compared with control group, the growth rates in the C-33A cells treated with different concentrations (100μg/mL,200μg/mL and400μg/mL) of APS were significantly slowed (P<0.01), and doubling times were significantly prolonged (P<0.01).Combined with cells state, the C-33A cells treated with200μg/mL APS for48h were taken as the experimental group, and the C-33A cells untreated with APS were used as control group in subsequent experiments.3. The data from flow cytometry showed that:compared with control group, The G1phase was blocked, and the proportion of S phase and G2/M phase cells were decreased obviously (P<0.01) in APS group.4. The results of flat clone-forming assay suggested that:compared with control group, clone-forming rate of C-33A cells were significantly lower (P<0.01), and the volume of colonies was smaller in APS group.5. The data from Western blotting displayed that:compared with control group, the expressions of cyclin B (P<0.05)and cyclin E (P<0.01)were significantly lower, the expressions of p21were significantly increased (P<0.01), while the expressions of cyclin A were no significant difference (P>0.05) in APS group.Conclusions1. APS could obviously inhibit the proliferation ability of cervical carcinoma C-33A cells.2. Mechanisms of above-mentioned effect of APS may be related to the down-regulation of cyclin B and cyclin E expressions, and up-regulation of p21expression.