Studies Of In Vitro Anti-tumor Activities Of Glycosides And Ginseng Pectin

Plant polysaccharides, the primary metabolic products of photosynthesis, are the storage substance and support substance of plants, as well as the precursors of many natural compounds. It has been reported that some saccharides possess remarkable biological activities. Besides, some glycoside compounds, especially the steroidal saponins have good biological activities, such as anti-tumor activity. In this experiment, the in vitro anti-tumor activities of baicalin and its esterified products were investigated. The synergetic anti-tumor activities of solamargine, solasonine, chaconine and dioscin were examined. Besides, the in vitro anti-tumor activities of ginseng pectin were studied.The effects of baicalin and its esterified products on the proliferation of L929, Hela and H7402 cells were measured. The results showed that baicalein 7-O-β-D-glucuronide n-butyl ester exerted good inhibitory effect, followed by baicalein 7-O-β-D-glucuronide isopropyl ester, while baicalein 7-O-β-D-glucuronide benzyl ester showed no inhibition. These results suggested that the polarity of the componds were important to their inhibitory effects. After the carboxyl of C-6 site in glucuronic acid of baicalin was esterified, the water-solubility of the products decreased and liposolubility increased, thus the esterified products might become easier to enter cells. Further studies indicated that the effects of baicalin and its esterified products had cell selectivity. Their effects on H7402 and L929 cells were higher than that on Hela cells.The synergistic effects of solamargine, solasonine, chaconine and dioscin on the proliferation of L929, Hela and H7402 cells were measured by MTT assay. Results indicated that dioscin was synergistic either with solamargine, solasonine or chaconine. The inhibitory effect on H7402 cells was low when solamargine alone was applied, but increased significantly when combined with dioscin, solasonine, or chaconine. The effect of chaconine itself is high, but it had no additive or synergistic effects with others. Chaconine, solamargine and dioscin selectively inhibited the proliferation of Hela and H7402 cells, but showed nearly no effects on L929 cells.In the last part of the thesis, the in vitro antitumor activities of ginseng pectin were investigated using Hela,HT-1080,HT-29,U251,and U87 cells. Cells were treated with ginseng pectin for 72 h and then examined for their morphologies using a phase contrast microscope, proliferation by MTT assay, apoptosis and necrosis by staining with typan blue, AO/PI, and Hoechst 33342 dyes. Results showed that ginseng pectin altered cell morphologies and inhibited cell proliferation, but did not induce apoptosis and necrosis. Cell cycle analysis using a FACScan flow cytometer after propidium iodide staining indicated that ginseng pectin caused HT-29 cell cycle arrest in G2/M phase. Thus we proposed that the effect of ginseng pectin on cell cycle, which led to the inhibition of cell proliferation, might be the underlying mechanism by which ginseng pectin inhibited tumor growth in vivo.