CHEMICAL AND BIOLOGICAL STUDIES OF A NEW CIGARETTE THAT PRIMARILY HEATS TOBACCO - PART 3 - IN-VITRO TOXICITY OF WHOLE SMOKE

Mainstream smoke from Kentucky reference low ''tar'' (1R4F) and ultra- low ''tar''(1R5F) cigarettes and a test cigarette (TOB-HT), that prima rily heats tobacco, was compared for cytotoxic and genotoxic potential using cellular smoke exposure technology (CSET). CSET includes a comp uter controlled 30-port AMESA/Battelle-Geneva smoke generator which ex poses cultured mammalian Chinese hamster ovary cells (CHO) to whole sm oke. Cytotoxicity was assessed using the neutral red assay and genotox icity was assessed using the sister chromatid exchange (SCE) assay. Co mpared on a per cigarette basis, mainstream smoke from 1R5F and the TO B-HT cigarette was significantly less cytotoxic and genotoxic than the smoke from the 1R4F cigarette. The cytotoxic and genotoxic activity o f smoke from the TOB-HT cigarettes was slightly greater than the smoke from the ultra-low ''tar'' Kentucky 1R5F reference cigarettes. In con clusion, in these assays mainstream whole smoke of the TOB-HT cigarett e had slightly greater cytotoxic and genotoxic potential compared with an ultra-low ''tar'' 1R5F Kentucky reference cigarette and significan tly less activity compared with the whole mainstream smoke from a low ''tar'' 1R4F Kentucky reference cigarette, representative of the US ma rket average cigarette for FTC yields of ''tar'', CO and nicotine. (C) 1998 Elsevier Science Ltd. All rights reserved.