The potential efficacy of 3,3'-diindolylmethane in prevention of prostate cancer development.

The objective of this study was to examine the efficacy of 3,3'-diindolylmethane (DIM) in prevention of prostate cancer tumor development in an animal model. Mouse prostate cancer cells (TRAMP-C2, 2x10) were injected subcutaneously into three groups of C57BL/6 mice (10 mice in each group). Two groups were treated earlier with DIM; 2 or 10 mg/kg each, and an additional control group was injected with medium. Animals were treated for five more weeks until sacrificed. Tumor sizes were measured biweekly. At the end of the experiment, mice were sacrificed, and tumors were excised, weighed, measured and tested using immunohistochemical studies. In addition blood samples were collected for biochemical analysis. The results indicated that DIM significantly reduced tumor development in treated animals when compared with controls. Tumors developed in 80% of controls and 40% and 60% of animals treated with 10 or 2 mg/kg of DIM, respectively. Moreover, tumors that developed in treated animals were significantly (P<0.001) smaller than in controls. Additionally, our results indicated that DIM has no effect on animal weight or liver and kidney functions. These results indicated that the DIM agent is not toxic and has an in-vivo preventive effect against the development of prostate cancer in a mouse model.