Abstract: In order to investigate antitumor effect of polysaccharides from Coelomactra antiquata (PCA) on esophageal cancer,the human esophagus carcinoma transplanted tumor model of Ec-9706 cells in nude mice was established.The nude mice were then divided randomly into 5 groups:Group 1,nude mice treated with normal saline (NS,Control);Group 2,nude mice treated with 5 mg/kg of cyclophosphamide (CTX);Group 3,nude mice treated with 100 mg/kg of PCA;Group 4,nude mice treated with 200 mg/kg of PCA;Group 5,nude mice treated with 300 mg/kg of PCA.The size of tumor was measured every 3 days after 2 weeks transplantation of Ec-9706 cells.All nude mice received ip administration every day for 26 days.All the mice were sacrificed after the last administration.The tumor weight was measured and the tumor inhibition rates were calculated.The results revealed that PCA can inhibit the growth of transplanted tumor in nude mice after administration for 26 d and the inhibitory rate was directly proportional to dose of PCA.When PCA was 300 mg/kg,the inhibitory rate was maximum (28.85%).

Key words: polysaccharides, Coelomactra antiquata, esophagus carcinoma, antitumor activity