CARCINOGENICITY AND MUTAGENICITY OF BENZ(A)ANTHRACENE DIOLS AND DIOL-EPOXIDES

Abstract

Benz(a)anthracene (BA) and its 5 possible trans-dihydrodiols were evaluated for determination of their mouse skin tumor-initiating activity and mutagenic activity in Chinese hamster V79 cells. The skin tumor-initiating abilities of 5 diol-epoxides of BA were tested. Results showed (.+-.)-trans-3,4-dihydroxy-3,4-dihydrobenz(a)anthracene (BA 3,4-dihydrodiol) to be approximately 10 times more mutagenic than BA and about 20 times more mutagenic than the other possible dihydrodiols in the V79 cells cocultivated with irradiated hamster embryo cells. As a skin tumor initiator, BA 3,4-dihydrodiol was approximately 5 times more active than BA, whereas the other BA dihydrodiols were less active tumor initiators. (.+-.)-trans-3.alpha.,4.beta.-Dihydroxy-1.alpha.,2.alpha.-epoxy-1,2,3,4-tetrahydrobenz(a)anthracene was approximately 20% more active as a tumor initiator than BA 3,4-dihydrodiol, whereas the other diol-epoxides of BA were less active than BA itself. The bay-region diol-epoxide of BA may be the ultimate carcinogenic and mutagenic form of BA.