Study On Antitumor Effects Of Extract From Cruciferous Vegetables

Previous epidemiologic studies indicate that high cruciferous vegetables intakes are associated with decreased risks of many cancers, such as prostate cancer, lung cancer, bladder cancer, esophageal cancer and colon cancer. Isothiocyanates are the product of glucosinolates, a group of naturally occurring compounds in cruciferous vegetables. A large amount of data demonstrated that isothiocyanates act as cancer chemopreventive agents by favorably modifying carcinogen metabolism via inhibition of Phase 1 enzymes and/or induction of Phase 2 enzymes. In this paper, antitumor effects of Extract 6320 from cruciferous vegetables (isothiocyanate, mainly) in vitro and in vivo, and the mechanism of antitumor were studied systematically.The inhibitory activity of Extract 6320 on tumor cells growing, its antitumor chart, and its cytotoxic effect on human liver cell L-02 were studied with MTT assay .The results showed that the proliferation of tumor cells in vitro may be significantly inhibited by Extract 6320 with a manner of dose-dependence. The IC50 of Extract 6320 on different tumor cell lines were 9～28μmol/L, the therapeutic index of which were 3～10 respectively. But the toxicity of Extract 6320 on normal cells had been observed and accordingly decreased the therapeutic index. Extract 6320 exhibited excellent inhibition activity to many kinds of tumors, especially the B16 cells.In vivo, the antitumor effect of Extract 6320 was evaluated by observation of growth inhibition of B16 melanoma inoculated into mice, including tumor weight and the change of tumor volume. The results suggest that Extract 6320 had obvious inhibited the growth of tumor in vivo i.g. The groups treated with Extract 6320 had the smaller tumor volume and the slower proliferative velocity of tumor volume than negative control. The inhibitory rate at the high dose (120mg/kg/d) was 57.61%, had no evidently difference compared with positive control, Cyclophosphamide (P>0.05). But the toxicity on groups treated with Extract 6320 had been exhibited. At the dose of 120 mg/kg, the body weight was lighter than control, spleen index had differences compared with negative control significantly (P<0.05), however had no effect on thymus.The primary investigation of mechanism demonstrated that Extract 6320 can inhibit B16 melanoma growth via cell apoptosis. B16 cells treated with Extract 6320 for 48h showed significant morphological changes under microscope. The cells under the scan electron microscopy presented the same results as the morphological changes. The villus were disappeared partially at lower concentration and totally at higher. The surface of membrane was smooth and shrinkage to form apoptotic bodies. The cell...