Indole-3-carbinol (I3C) found in various cruciferous vegetables has been shown to exert anti-carcinogenic activity in several target organs. Our study was conducted to assess the modifying effect of I3C on the development of colon tumor induced by azoxymethane (AOM). Eighty-seven male F344 rats were divided into 5 groups and were treated with AOM followed by I3C 100 or 300 ppm, AOM alone, I3C alone, and non-treatment, respectively. The animals were subcutaneously injected with AOM. Then diet containing I3C were fed to the rats for 37 weeks. All rats were sacrificed at 40 weeks. Liver and kidney weights of rats treated with I3C at doses of 100 or 300 ppm were significantly increased compared to those of the control group. Colonic tumor incidence and multiplicity of rats treated with I3C at doses of 100 and 300 ppm were not significant compared to those of AOM alone group. In the pathological examination, most of tumors were classified with adenoma and adenocarcinoma in the small and large intestine. These results demonstrated that I3C may have not chemopreventive effect on the rat colon carcinogenesis.
Adenocarcinoma ; Adenoma ; Animals ; Azoxymethane ; Colon ; Diet ; Humans ; Incidence ; Indoles ; Intestine, Large ; Kidney ; Liver ; Male ; Rats ; Rats, Inbred F344 ; Vegetables ; Weights and Measures

BACKGROUND: The effects of diallyl disulfide (DADS), a garlic derived compound, on the viability and cell signaling- like the downstream signaling through cytochrome c, caspase-3, poly (ADP-ribose) polymerase (PARP) during an oxidative-stress induced injury were studied using H2O2 treated neuronal-differentiated PC12 cells by a nerve growth factor. METHODS: To evaluate the toxicity of the DADS itself, the viability of the differentiated PC12 cells treated with several concentrations of DADS was evaluated with 3, (4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays. To evaluate the protective effect of the low concentration of DADS from oxidative stress, the viability of the cells (DADS pretreated vs. not pretreated) was evaluated following the exposure to 100 micro M H2O2. Additionally, the expression of caspase-3, PARP, and cytochrome c was examined using western blot analyses. RESULTS: The viability was not affected at low concentrations of DADS, up to 20 micro M, but, over this concentration, it was decreased. Compared with the cells treated with only 100 micro M H2O2, the pretreatment with low concentrations of DADS before exposure to 100 micro M H2O2 increased the viability and induced the inhibition of caspase-3 activation, PARP cleavage, and cytochrome c release. CONCLUSIONS: These results show that low concentrations of DADS shows neuroprotective effects by affecting the downstream signaling through cytochrome c, caspase-3, and PARP pathway and may be a new potential therapeutic strategy for neurodegenerative diseases associated with oxidative injury.
Animals ; Apoptosis* ; Blotting, Western ; Caspase 3 ; Cytochromes c ; Cytochromes* ; Garlic ; Nerve Growth Factor ; Neurodegenerative Diseases ; Neuroprotective Agents ; Oxidative Stress ; PC12 Cells*