Inhibition of rat mammary carcinogenesis by inositol hexaphosphate (phytic acid). A pilot study.
Since phytic acid (inositol hexaphosphate, InsP6) and inositol (Ins) have been demonstrated to have anti-tumor and anti-cell proliferative action in several experimental models of carcinogenesis, in a pilot study we have examined their effect on 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumor model. Starting a week prior to induction with DMBA, the drinking water of female Sprague-Dawley rats was supplemented with either: 15 mM InsP6, 15 mM Ins, or 15 mM InsP6 + 15 mM Ins; a control group received no inositol compounds. Animals (55-day-old) were given a single dose of DMBA (20 mg) in 1 ml of sesame oil by oral intubation. Four additional groups not receiving DMBA, but drinking tap water, InsP6, Ins, or InsP6 + Ins of the same molarity as experimental groups were observed for the duration of the study to monitor for any putative toxicity following this long-term treatment. As opposed to the DMBA-only group, rats treated with InsP6 +/- Ins showed a 48% reduction in the number of tumors/tumor bearing animal (tumor multiplicity) and a 40% reduction in the number of tumors/rat. In contrast to 20% rats in DMBA-only group, only 0-8% animals in the treatment group had 5 or more tumors. Likewise, the tumor incidence was reduced by 19% in InsP6 +/- Ins as compared to control untreated animals. The tumors in the treated groups were also 16% smaller in size. Data from this pilot study suggest that in addition to being effective against colon cancer, InsP6 +/- Ins may be protective against mammary carcinoma as well; additional studies are however warranted.
Vucenik
I
I
Department of Medical and Research Technology, University of Maryland School of Medicine, Baltimore 21201-1192.
Sakamoto
K
K
Bansal
M
M
Shamsuddin
A M
AM
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D016009:Chi-Square Distribution; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000517:prevention & control*; D010833:Phytic Acid / Q000494:pharmacology*; D010865:Pilot Projects; D051381:Rats; D017207:Rats, Sprague-Dawley
D016588:Anticarcinogenic Agents; D015127:9,10-Dimethyl-1,2-benzanthracene; D010833:Phytic Acid