STUDIES OF CHEMOPREVENTIVE EFFECTS OF MYOINOSITOL ON BENZO[A]PYRENE-INDUCED NEOPLASIA OF THE LUNG AND FORESTOMACH OF FEMALE A/J MICE

There is a continuing effort at identifying chemopreventive agents that might be useful in preventing cancer of the lung. In the present study, the effects of myo-inositol and dexamethasone on benzo[a]pyrene (B[a]P)-induced pulmonary adenoma formation in female A/J mice was investigated. A diet containing 3% myo-inositol fed beginning 1 week after B[a]P administration reduced the number of pulmonary adenomas by 40% but did not prevent forestomach tumors, which also occur in this experimental model. Under the same conditions, dexamethasone, 0.5 mug/g diet, inhibited pulmonary adenoma formation by 57% and also inhibited forestomach tumor formation to a similar extent. Feeding a diet containing both myo-inositol and dexamethasone resulted in an additive effect on the inhibition of pulmonary adenoma formation. The combination of myoinositol plus dexamethasone produced almost identical inhibition of forestomach tumor formation to that of dexamethasone alone. The results of the present study are preliminary, but may provide a basis for future investigation into strategies for chemoprevention of pulmonary neoplasia.