Carcinogenicity of betel quid ingredients: feeding mice with aqueous extract and the polyphenol fraction of betel nut.

Male mice of inbred strains Swiss and C17 were fed daily 5 times a week by intragastric tube 0.1 ml of betel-nut aqueous extract, betel-leaf aqueous extract and the polyphenol fraction of betel nut. Male mice of corresponding strains fed 0.1 ml of distilled water served as controls. Treated and control mice were kept under observation and killed when moribund. Betel-nut aqueous extract induced tumours of the gastrointestinal tract in 58% Swiss mice and 25% C17 mice. The polyphenol fraction by the same route induced tumours at other sites in 17% of the mice. Betel-leaf aqueous extract failed to induce any tumour in the treated mice, which supports an earlier report of the lack of any carcinogenic principle in betel leaf, an essential constituent of betel quid. Results are discussed in relation to the relevant literature.