Extracts from Viscum and Crataegus are cytotoxic against larynx cancer cells.

The effects of hexanoic extracts of Viscum cruciatum Sieber parasitic on Crataegus monogyna Jacq. (I), Crataegus monogyna Jacq. parasitized with Viscum cruciatum Sieber (II), and Crataegus monogyna Jacq. non-parasitized (III), and of a triterpenes enriched fractions isolated from I, II and III (CFI, CFII, CFIII respectively), on the growth of HEp-2 cells have been evaluated. All the samples demonstrated significant cytotoxic activity against cultured HEp-2 cells, and all of them showed a stronger in vitro activity than 6-mercaptopurine solution used as a positive control. With the hexanoic extracts I, II and III almost similar activity was obtained, but the hexanoic extract I showed comparably better results. Almost complete inhibition was observed with triterpenes-enriched fractions CFI, CFII and CFIII, at the dose 6 micrograms/ml, after 72 h of treatment. The most intense response was obtained with the triterpenes-enriched fraction CFIII (from Crataegus monogyna non-parasitized), where the inhibition was 93%, but the fraction CFI and CFII showed similar inhibition (92% and 83%).