Tumor-Promoting Activity of Extracts of Unburned Tobacco

Abstract
Both an aqueous Bα(OH)2 extract and an acetone-benzene extract of unburned cigarette tobacco produced skin tumors when painted on mice previously treated with 125 µg of7,12-dimethylbenz[a]anthracene. The extract from as little as 0.5 cigarette per day was effective. The data are of interest in connection with epidemiological evidence that tobacco chewing is a cause of oral cancer. The data also suggest that tumor-promoting agents in cigarette smokemay have their source in the unburned tobacco