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Betel quid, a masticatory widely used in Sri Lanka, consists of Jaffna tobacco, the nuts and leaves of betel plants and calcium hydroxide. An ethyl acetate extract of Jaffna tobacco induced morphological transformation of hamster embryo cells. The extract also induced sister chromatid exchanges in virally transformed and phytohaemagglutinin (PHA)-stimulated human lymphocytes. The induction of sister chromatid exchanges was potentiated by addition of rat liver homogenate. The extract did not induce ouabain-resistant mutation of V79 cells. Extracts of betel nuts and leaves gave negative results in assay of morphological transformation, sister chromatid exchange and mutagenesis.

In vitro carcinogenicity of betel tobacco extracts was examined in a transformation assay with cryopreserved hamster embryo cells. The ethanol extract induced a transformed colony at 100 μg ml and the ethyl acetate extract induced 2 transformed colonies at 5 μg ml and 2 at 100 μg ml .

The in vitro carcinogenic activities of 3-(N-salicyloyl)amino-1,2,4-triazole (SAT) and its two components, 3-amino-1,2,4-triazole and phenyl salicylate were examined in a transformation assay with cryopreserved hamster embryo cells. SAT induced morphological transformation at certain doses between 10 μg ml and 100 μg ml in each of 5 repeated experiments, but gave a negative result in the Salmonella mutation assay. 3-Amino-1,2,4-triazole also induced transformation in 3 repeated experiments. Phenyl salicylate did not induce transformation at any of the doses tested in 3 consecutive experiments.

The mutagenic effects of Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2, Lys-P-1, MeAαC, AαC, MeIQ and IQ on Chinese hamster V79 cells with or without X-irradiated Syrian hamster embryo cells were examined. Of these products, only Trp-P-2 and Lys-P-1 induced ouabain-resistant mutants of Chinese hamster V79 cells in a dose-related fashion; X-irradiated Syrian hamster embryo cells were required for the mutagenicity of Lys-P-1, but not for that of Trp-P-2. None of the other pyrolysis products examined was mutagenic with or without X-irradiated Syrian hamster embryo cells.