Abstract: To study the therapeutic effect and mechanism of allicin on experimental colorectal cancer in rats.Experimental rat colon cancer model was successfully established by 30 mg/kg intraperitoneal injection of DMH,injection once a week,continuous application of 20 weeks,and the model was treated with allicin injection at the same time.The changes of general state,spleen index,thymus index,histopathological changes,CD44V6 and VEGF levels in serum and Survivin,Caspase-3 and Caspase-7 protein levels in colorectal tissues were compared before and after the treatment.At the end of the thirty-two weeks,the average weight of the model group was significantly lower than that of the normal group (P<0.05).The average weight of high and low dose allicin groups increased significantly compared with that of the model group (P<0.05).Thymus index and spleen index of high and low dose allicin group significantly increased compared with these of the model group (P<0.05).The thymus index and spleen index in high dose allicin group was significantly higher than that of low dose allicin group (P<0.05).The tumor incidence,tumor number and tumor metastasis rate in the model group were significantly higher than those in the other groups (P<0.05).The serum levels of CD44V6 and VEGF in model group were significantly higher than those in normal group (P<0.05).Serum CD44V6 and VEGF levels of allicin high and low dose group decreased significantly compared with the model group (P<0.05).Compared with the low dose allicin group,CD44V6 and VEGF levels of high dose allicin group increased more significantly (P<0.05).The expression level of survivin,Caspase-3 and Caspase-7 in the model group was significantly higher than that in the normal group (P<0.05).But compared with the model group,the survivin expression levels of high and low dose allicin group were significantly decreased,and expression level of Caspase-3 and caspase-7 were significantly increased (P<0.05).In conclusion,allicin had good prevention and cure function on experimental rats with colorectal cancer induced by dimethylhydrazine,which can effectively inhibit the development and metastasis of colorectal cancer,the mechanism may through enhancing rat physique,improving the immune function of rats and inhibiting tumor vessel formation and invasion and metastasis by regulating the expression of CD44v6 and VEGF,while allicin may inhibit the expression of survivin gene,upregulate Caspase-3 and caspase-7 level,so as to promote the apoptosis of cancer cells.

Key words: allicin, colorectal cancer, pathology, thymus index, spleen index