Esculetin modulates cytotoxicity induced by oxidants in NB4 human leukemia cells.

Esculetin is a polyphenolic compound with cytoprotective properties. We previously demonstrated the induction of apoptosis by esculetin in NB4 human leukemia cells, as a model, by a mechanism not well understood. To analyse the antioxidant activity of esculetin on apoptosis, we have studied the influence of co-treatments of esculetin at a concentration of 100μM with exogenous ROS donors, namely tert-butyl-hydroperoxide and hydrogen peroxide, on NB4 cells. Esculetin (100μM) exerts a protective effect on cell viability and death necrosis or late apoptosis caused by the oxidant t-BHP whereas it potentiates decrease of cell viability and cell death caused by HO. In the first case, the O scavenging activity of esculetin (100μM) could be implicated. In the last one, cytotoxicity by apoptosis induction seems to be related to the increase in O, among other possible mechanisms. These results contribute to the study of the antitumor properties of esculetin by regulation of redox balance in leukemia cells.