Butylated hydroxyanisole and lung tumor development in A/J mice.

A diet containing 0.75% butylated hydroxyanisole (BHA) did not enhance the development of lung tumors in A/J mice if fed for 8 weeks after administration of urethan, benzo[a]pyrene (B[a]P), or dimethylnitrosamine (DMN). Prefeeding animals with BHA partially protected animals against the tumorigenic effect of urethan and B[a]P. Partial protection was also seen in animals given B[a]P and then exposed to BHA in the diet. The two isomers of BHA (3-tert.-butyl-4-hydroxyanisole and 2-tert.-butyl-4-hydroxyanisole) were synthesized and injected ip. They failed to enhance lung tumor development. It is concluded that BHA is not a promoting agent as is butylated hydroxytoluene (BHT) for lung tumors in mice. One possible explanation is that BHA in the diet does not produce the extensive cell proliferation seen in the lungs of mice fed BHT.