| ABSTRACT: |
|
The ability of six proposed chemopreventive agents to prevent
diethylnitrosamine-induced liver foci and tumors in male C3H mice was
investigated. The test agents were administered by intraperitoneal
injection on days 13, 14 and 15 of age and starting at 21 days of age
continuously in the diet until sacrifice at 161 days of age. The mice were
administered 4.0 mg/kg diethylnitrosamine by intraperitoneal injection on
day 15 of age and two hours after the test agent.
Diethylnitrosamine-induced 62.4 +/- 4.2 foci of altered hepatocytes and
22.1 +/- 2.1 hepatocellular adenomas, which were reduced by diallyl
sulfide to 21.6 +/- 2.4 and 6.73 +/- 1.13 and phenethyl isothiocyanate to
28.2 +/- 3.4 and 5.06 +/- 1.53 foci and adenomas, respectively.
Difluoromethylornithine and ellagic acid only decreased the yield of
adenomas without affecting the yield of foci of altered hepatocytes and of
total lesions. N-Acetyl-l-cysteine and 1,2-oxothiazolidine-4-carboxylate
did not affect the yield of either liver lesion. When administered
starting prior to diethylnitrosamine-initiation and continuing until
sacrifice, diallyl sulfide and phenethyl isothiocyanate demonstrated
chemoprevention of tumorigenesis. |