In Vitro Anticancer Screening Of Extracts From 45 Medicinal Plants

In this research,we collected and identified 45 medicinal plants in total.By means of systematic solvent extraction,we aquired 6 solvent extracts from each plant,namely petroleum ether extract,chloroform extract,ethyl acetate extract,n-butanol extract,the remaining part of extraction and water extract,then each plant extract part was dissolved in DMSO solution to make the stock solution with final concentration of 100mg/ml.Through this process,we established a library of 270 medicinal plant extracts.Firstly,we evaluated the proliferation inhibition ability of all extracts in the library against MCF-7(human breast carcinoma cell line),Huh-7(human hepatocellular carcinoma cell line),HeLa(human cervical carcinoma cell line)and BALL-1(human acute lymphoblastic leukemia cell line)by MTT assay.At the same time,MCF-10A(human breast epithelial cell line)was used to assess the cytotoxicity of each plant extract against normal cell line.From this screening procedure,we acquired a few plant extracts possessing general anticancer acti'vity.Six of out of these active plant extracts which showed strong activity(IC50<30?g/ml)against MCF-7 cell line were selected to assay their dose effects after treating MCF-7 cells for 24h,48h and 72h.They were petroleum ether extract of Artemisia argyi H.Lev.&Vaniot.(IC50=16.43?g/ml),petroleum extract of Fatsia japonica(Thunb.)Decne.et Planch.(IC50=29.34?g/ml),petroleum ether extract of Pittosporum tobira(Thunb.)Ait.(IC50=24.42?g/ml),petroleum ether extract of Bougainvillea spectabilis Willd.(IC50=26.25?g/ml),petroleum ether extract of Alternanthera philoxeroides(Mart.)Gri.(IC50=19.19?g/ml)and chloroform extract of Conyza canadensis(L.)Cronq.(IC50=14.32?g/ml).Petroleum ether extract of Artemisia argyi H.Lev.&Vaniot.was selected for a further bio-active-guided constituent isolation against MCF-7 cell growth.We then acquired 14 fractions in total by a phyto-chemical separation procedure.Fraction No.6 showed the strongest proliferation inhibition ability against MCF-7 cell line among the fractions.When the concentration of Fraction No.6 was 10?g/ml,it showed 43.11%proliferation inhibition rate against MCF-7 cells.We selected petroleum ether extract of Alternanthera philoxeroides(Mart.)Gri and chloroform extract of Conyza canadensis(L.)Cronq to do further research on their molecule mechanism against MCF-7 cell line.The following experiments were carried out:the observation of the morphology of MCF-7 cells under optical microscope;the observation of morphology changes of nucleus of MCF-7 cells by Hoechst33342 staining assay;the examination of the colony formation ability of MCF-7 cells by colony formation assay;the examination of apoptosis of MCF-7 cells by AnnexinV-FITC/PI assay.The results were as follows:(1)we observed that MCF-7 cells rounded up and shrinked after exposed to petroleum ether extract of Alternanthera philoxeroides(Mart.)Gri and chloroform extract of Conyza canadensis(L.)Cronq and these phenotypic responses were in a dose-dependent manner.(2)According to the Hoechst33342 staining assay,nucleus of MCF-7 cells were damaged to different extent and the morphology presented abnormal changes under above mentioned extracts' treatment.(3)According to the colony formation assay,petroleum ether extract of Alternanthera philoxeroides(Mart.)Gri and chloroform extract of Conyza canadensis(L.)Cronq both were able to inhibit colony formation of MCF-7 cells in a dose-dependent manner.(4)According to the AnnexinV-FITC/PI assay,petroleum ether extract of Alternanthera philoxeroides(Mart.)Gri could induce early apoptosis of MCF-7 cells and chloroform extract of Conyza canadensis(L.)Cronq could promote necrosis of MCF-7 cells.