The Study Of The Anticancer Effect Of Sporamin

Sweet potato (Ipomoea batatas) originated from south American, and is widely planted in china, which yields (about 120 million tons per year, more than 80% of the sweet potato protein's content is 1.2 to 10 g/100g dry substance, and its'main storage protein is Sporamin which was found in 1985 by Maeshima. Some research In addition, Sporamin was a Kunitz type trypsin inhibitor. Trypsin inhibitor with the similar structure of Sporamin was proved to have anticancer activity, but there was no research of that of Sporamin.In this research, we used the method of ammonium sulfate precipitation to get the Sporamin crude protein;used ion-exchange(DEAE-52) and gel chromatography(Serphedex G-75) methods to get and purify Sporamin. We used purified Sporamin to incubate with SW480 cell to test its'anticancer activity to SW480 cell, and used crude protein to feed the mouse to measure this anticancer ability to tumor-bearing mice.MTT assay was used to measure the anti-proliferation effect of different concenctration(0, 0.05, 0.1, 0.25, 0.5, 1, 2.5mg/ml) of Sporamin to SW480 cell,and the cytotoxicity of Sporamin was also tested by trypan blue method.The influence of different concenctration(0, 0.02, 0.2, 1mg/ml)Sporamin to the migration and invasion of SW480 cell was tested by transwell cabin and ECM550 invasion kit respectively. The results showed that there was no cytotoxicity when the concentration of Sporamin was below 1mg/ml; the Sporamin could suppress the proliferation of SW480 when the concentration was more than 0.05mg/ml,and the effect was dose dependent; Sporamin could inhibit the invasion of SW480 at the concentration of 0.02mg/ml, and could inhibit the migration at the concentration of 0.2mg/ml, both of them were dose dependent.The modifying effect of peritoneal injection(50mg/kg animal weight) and intragastric administration (2g/kg animal weight)of Sporamin on peritoneal disseminated metastasis model in human colon cancer HCT-8 cells was investigated, the results suggested that Sporamin could decrease the weight of tumor, reduce the CEA concentration of blood and the content of ascitic in peritoneal disseminated metastasis model C57BL/6-nu mice, and the peritoneal injection of Sporamin effect was better than intragastric administration; the effect of peritoneal injection(50mg/kg animal weight) and intragastric administration (3g/kg animal weight)of Sporamin on spontaneous pulmonary metastasis of murine Lewis lung carcinoma 3LL cells was also investigated, Sporamin could depress the weight of tumor and reduce the pulmonary metastasis in spontaneous pulmonary metastasis c57 mice. Finally, the anti-proliferation effect determination of Sporamin (1mg/ml) with different trypsin inhibitor activity(heating treatment in different temperature: 70℃, 90℃, 100℃and 127℃for 30 miniters) to SW480 cells was used MTT mthod, the results demostrates that the effect was not diminish with the lose of trypsin inhibitor activity(TIA), it may means that there was no connection between the TIA of Sporamin and anti-proliferation effect to tumor cells.The research was the first time to investigate the anticancer effect of Sporamin, Sporamin was lost with the discharge exhaust of pruducing waste water, which was good for the developing and utilizing of Sporamin.