Carcinogenesis initiation phase

Tanaka, T. et al., Suppression of azoxymethane-induced rat colon carcinogenesis by dietary administration of naturally occurring xanthophylls astaxanthin and canthaxanthin during the post-initiation phase, Carcinogenesis, 16, 2957, 1995. 

As previously mentioned, carcinogenesis is a complex process and it would be naive to believe that dietary protein alters only the initiation phase. A series of eloquent studies by Appleton and Campbell (22, 23, 24) have indicated that the effects exerted by dietary protein during the promotional phase of AFBi hepatocar-cinogenesis are as important, if not more so, than the effects seen during the initiation phase. 

Inhibition of the initiation phase of carcinogenesis does not appear to totally explain the anticarcinogenicity of selenium. 

The effects of dietary fat and protein on the initiation phase of DMBA carcinogenesis were examined by feeding the 9 different diets for the 4 weeks prior to carcinogen administration. Four hours... 

Garlic oil also exhibits an antagonistic effect on benzo[a]pyrene by inhibiting benzo[a]pyrene-induced skin carcinogenesis in Swiss mice during the initiation phase (Sadhana et al. 1988). A primary constituent of garlic oil. allyl methyl trisulfide (ATM), has also demonstrated an inhibitory effect on benzo[a]pyrene induced neoplasia of the forestomach in mice (Sparnins et al. 1986). 

From our observations, it was also apparent that the tumors appeared at essentially the same time in the hamsters in the two experimental groups. These results indicate that 3-methoxybenzamide is not a promoter, but an initiator. If this proves to be true, then it is possible that the activity of poly(ADP-ribose) polymerase may be critical during the initiation phase of carcinogenesis. 

Ip, C., Jiang, C., Thompson, H.J., and Scimeca, J.A. (1997) Retention of Conjugated Linoleic Acid in the Mammary Gland Is Associated with Tumor Inhihition During the Post-Initiation Phase of Carcinogenesis, Carcinogenesis 18, 755-759. 

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