Uncaria tomentosa Leaves Decoction Modulates Differently ROS Production in Cancer and Normal Cells, and Effects Cisplatin Cytotoxicity.

is a woody vine with a long history of use in traditional Peruvian medicine and nowadays supplements containing this vine as ingredient are available. Immunomodulating, anti-inflammatory and anticancer properties of have been suggested and attributed mainly to the presence of tetracyclic or pentacyclic oxindole alkaloids. However, the synergic action of different compounds occurring in extracts and modulation of redox processes may significantly influence the anticancer activity of . The aim of the present study was to investigate for the first time the cytotoxic effects of the tetracyclic alkaloids free aqueous extract (decoction) of dried leaf blades in normal and cancer cells, and to assess the effect of the tested extract on cisplatin (CDDP) cytotoxicity. Tested extract was not cytotoxic for NHDF cells, but demonstrated cytotoxic effect against HepG2 cells. The extract increased ROS production in HepG2 cells, which resulted in decreased GSH level, leading to apoptosis of these cells through activation of caspase-3 and caspase-7. A reduction of NF-κB active form was observed in cancer cells. In normal cells the extract did not affect ROS production, GSH level and NF-κB activity, and maintained cell viability. HepG2 cells incubation with decoction and simultaneously with CDDP resulted in an increase in CDPP cytotoxic activity against HepG2, while under the same conditions prevents NHDF cell viability reduction due to CDDP. The results indicate that leaves decoction modulates differently cancer and normal cells oxidative metabolism and, enhanced cytotoxicity of CDDP against cancer cells and at the same time increased normal healthy cells resistance to cisplatin. Further studies are needed to confirm our observations and to describe underlying molecular mechanism, and the potential usefulness of decoction in adjuvant therapy for cancer.