Cytotoxic effects of the Viscum album L. extract on Ehrlich tumour cells in vivo

To date most pharmacological studies on mistletoe (Viscum album L.) have focused on the therapeutic properties of its polar extracts. This study examined the non-polar constituents of Viscum album and their biological activities. Supercritical CO, extraction coupled with gas chromatography/mass spectrometry (GC/MS) was used to selectively extract and identify compounds in Viscum album leaves. Several non-polar classes of compounds were identified in the extract. In addition, a volatile fraction was identified that contained several novel terpene molecules. The hypothesis was tested that the Viscum album extract exhibits cytotoxic properties in Ehrlich carcinoma (EAC) cells in vivo due to the induction of oxidative stress. A significant reduction in the incidence of cancer was observed in all groups that received the Viscum album extract compared with the EAC control group. The largest decrease was observed in mice pretreated with the Viscum album extract, although significantly reduced numbers of EAC cells were also observed in animals with developed carcinoma. The activities of antioxidative enzymes in the EAC cells suggested the absence of oxidative stress. However, changes in the antioxidative enzymes activities observed after administration of the Viscum album extract might be due to the induction of oxidative stress in the EAC cells. Copyright (C) 2008 John Wiley & Sons, Ltd.