Experimental studies on mutagenic and carcinogenic effects of tobacco chewing.

The alcoholic extract of the chewing (Pandharpuri) variety of tobacco (Nicotiana tabacum) was subjected to mutagenicity and tumorigenicity studies. The extract was found to be mutagenic in strain TA 98 of Salmonella typhimurium in the presence of S 9 mixture. It also induced 8 AZG-resistant mutation in V 79 Chinese hamster cells. Administration of tobacco extract to male Swiss mice by gavage or mixed with diet resulted in an increased incidence of lung/liver tumors. Further, an additive effect of tobacco extract and hexachlorocyclohexane on liver tumor induction was observed.