Preliminary Studies On Anti-tumor Effect And Mechanism Of Flavonoids Of Astragalus Complanatus

OBJECTIVE: To screen the effective anti-tumor fractions of Astragalus Complanatus, and to elucidate its anti-cancer effect and mechanism.METHODS: SMMC7721, BGC803, HL60, A549, Hela were intrduced to investigate antitumor effect of fractions of Astragalus Complanatus by MTT assay in vitro. Tumor model was set up by transplanting S180 into KM mice to investigate anti-tumor effect of fractions in vivo. MTT assay,³H-TdR incorporation assay were adopted to study the anti-tumor effect of effective fractions.Tumor model was set up by transplanting H22 into KM mice to study the anti-tumor effect of effective fraction. The change in form of cells treated with effective fraction was observed by Giemsa staining, Hochest staining, transmission electron microscopy. The DNA of cells cultured with effective fraction was extracted, agarose gel electrophoresis was used to observe DNA-ladder. Cell cycle and apoptotic rate were investigated by flow cytometry. The activity of caspase-3 was investigated,too. The change of spleen index and thymus index of mice bearing tumor was observed. Routine analysis of blood of mice bearing tumor was carried out to investigate the influence of effective fraction on peripheral blood. The transformation efficiency of splenic lymphocyte and cytoactive of NK were investigated by MTT assay.RESULTS: Flavonoids of Astragalus Complanatus(FAC) is considered as one of the main effective anti-tmor fractions of Astragalus Complanatus. It can inhibit markedly the growth of SMMC7721, HepG2, Hepa1-6 in vitro, and the max inhibit rate was 87.15%, 55.93%, 62.22%. It could also inhibit the proliferation of H22 in vivo, and the max inhibit rate was above 60%. Apoptotic features of cells cultured with FAC could be find by Giemsa staining, Hochest staining and transmission electron microscopy. DNA-ladder could also be find by agarose gel electrophoresis. The max apoptotic rate caused by FAC was 18.58% and cells were inhibited in G₀/G₁ and S phase, the activity of caspase-3 was boosted markedly by FAC. FAC could also increase the index of spleen of mice bearing tumor and splenic lymphocyte transformation rate. The activity of NK cells in FAC groups was remarkably higher than that in control group.CONCLUSION: The result confirmed that FAC can effectively inhibit the growth of cancer cells. FAC can induce the apoptosis, which play an important role in its anti-tumor effect. FAC could also enhance the immunologic functions of mice bearing tumor, this is one of its anti-tumor mechanisms, too.