Cytoprotective Effect of two Flavanoids ‐ Catechin and Epicatechin, Against Oxidative Stress Induced by Cumene Hydroperoxide, in MCF‐7 Cells

Abstract

Reactive Oxygen Species (ROS) are generated during normal cellular metabolic activity, especially in the electron transport chain and in biological redox reactions. Cumene Hydroperoxide, (CHP) a potent source of ROS, is commonly used in the chemical manufacture of phenols, acetone and polymers and can result in inadvertent exposure to individuals working in this chemical industry. CHP is known to initiate lipid peroxidation and increase ROS levels in membranes, which can lead to oxidative stress and cell death. The aim of the study was to investigate the cytoprotective activity of two flavonoids, catechin and epicatechin against the oxidative stress induced by CHP. The method involved comparing the % cell viability between cells treated with CHP for 4h alone and cells pretreated with catechin or epicatechin for 24 or 48 hr prior to treatment with CHP. MTS cell proliferation assays (Abcam) was used to determine cell viability after exposure. Approximately 1×104 cells/100μL/well of MCF‐7 cells were seeded in a 96‐well plates. After 24 hours, the cells were treated with CHP (50–350 μM) for 2h, 4h or 24h to determine viability. Cells were also treated with catechin (100–500μM), epicatechin (100–500μM), DMSO or control for 24 or 48 hr. Additionally, cells were pretreated with catechin (100–500μM) or epicatechin (100–500μM) and then exposed to 100μM CHP for 4 hours. % cell viability was then determined by the MTS assay system. The results of individual treatments indicated that there was a concentration dependent cell toxicity of CHP at concentrations > 50μM CHP compared to control when cells were exposed for 4 hr to CHP (IC50 = 100 μM). All concentrations of catechin and epicatechin showed no significant loss of cell viability as compared to the control after both 24 and 48h hr exposure. In the pre‐treatment studies, 100μM of CHP showed 50% decrease in cell viability after 4h of treatment, however when the cells were pretreated for 24 hr with catechin (400–500 μM) or epicatechin (400–500 μM) there was protection of 10–20% from the cytotoxic effects of CHP. Concentrations lower than 400 μM of catechin and epicatechin did not show protection. At 48h of pretreatment with catechin and epicatechin, enhanced protection (20 – 30 %), compared to the 24 hr pre‐treatment, was observed with 300–500 μM concentrations of catechin and epicatechin. The results clearly demonstrate that catechin and epicatechin at concentrations of 300 – 500 μM are cytoprotective to MCF‐7 cells against oxidative stress induced by exposure to 100 μM CHP.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.