Cytotoxicity of Different Viscotoxins and Extracts from the European Subspecies of Viscum album L.

Six viscotoxins in pure form from Viscum album L. have been isolated and their toxicity compared by using a viscotoxin sensitive Yoshida cell line. Four of them are the known viscotoxins A2, A3, B and 1-PS, whereas the other two appear to be new. The six viscotoxins were cytotoxic but varied in potency. Cytotoxicity of the extracts from the three European subspecies of V. album depended on the qualitative and quantitative composition of these viscotoxins. A good correlation of the cytotoxicity calculated on the basis of the content of viscotoxins present in the extracts with that measured by the Yoshida cell assay was observed. The viscotoxin sensitive Yoshida cell line is a suitable system for detecting the viscotoxin dependent cytotoxicity of mistletoe extracts