Cytotoxic and apoptogenic effect of tea (Camellia sinensis var. assamica) root extract (TRE) and two of its steroidal saponins TS1 and TS2 on human leukemic cell lines K562 and U937 and on cells of CML and ALL patients

The anticancer activity of di- and tri-terpenes and other polyphenolic compounds present in tea is already reported. We evaluated the cytotoxic and apoptogenic effect of tea root extract (TRE) and two of its steroidal saponins named as TS1 and TS2, on human cell lines and on cells from leukemic patients. It was found that TRE, TS1 and TS2 significantly decreased cell count and that TRE caused apoptosis, as confirmed morphologically by confocal microscopy and by flow-cytometric analysis using Annexin-V FITC and propidium iodide (PI). Cell count and MTT assay in normal white blood cells (WBC) of healthy volunteers revealed that TRE produced insignificant reduction in cell count and cytotoxicity.