Anticarcinogens from fried ground beef: heat-altered derivatives of XXXX .

@entity3653 @entity26523 @entity864 @entity19 @entity5 @entity1185 @entity7677 @entity1324 @entity106 @entity105 @entity4722
Fried ground beef contains substances that inhibit mutagenesis in bacteria and the initiation of epidermal @entity105 in @entity19 by @entity3653 ( @entity106 ). The inhibitors apparently act at least in part via inhibition of @entity7677 activity. A highly purified fraction that inhibited @entity7677 activity in vitro was isolated by HPLC and characterized by GC-MS, and by UV and proton NMR spectroscopy. The fraction contained four isomeric derivatives of @entity4722 each containing a conjugated double-bond system (designated @entity26523 ). Synthetically prepared @entity26523 (containing all four isomers) was tested for anti-initiation activity in the two-stage @entity19 epidermal @entity105 system. Seven days, 3 days and 5 min prior to @entity106 application, @entity26523 was applied at doses of 20, 20 and 10 mg respectively. Control @entity19 were treated similarly with @entity4722 or solvent ( @entity1324 ). One week after initiation, and twice weekly thereafter, all @entity19 were treated with @entity864 to effect @entity5 promotion. There was no difference in @entity5 incidence or yield between @entity4722 -treated @entity19 and solvent-treated control @entity19 . By contrast, the @entity26523 -treated @entity19 developed only about half as many @entity1185 and exhibited a lower @entity5 incidence compared with the control @entity19 .
