Carbamazepine, a Histone Deacetylase Inhibitor Induces Apoptosis in Human Colon Adenocarcinoma Cell Line HT-29.

Abstract

Colon cancer ranks fourth and is responsible for causing 10% cancer-related mortalityin western countries. Its incidence is rising in many countries due to widespread adoption of the Western diet and lifestyle. Carbamazepine (CBZ) is a FDA-approved antiepileptic drug and a histone deacetylase inhibitor. The aim of this study is to evaluate the cytotoxic potentials of CBZ in human colon cancer cells (HT-29 cells). HT-29 cells were treated with 36 and 76μg/ml of CBZ for 24h. The cytotoxic effect was evaluated by MTT assay. The intracellular reactive oxygen species (ROS) expression was evaluated through dichloro-dihydro-fluorescein diacetate staining. Morphological changes related to apoptosis were evaluated by dual staining with acridine orange and ethidium bromide. Mitochondrial membrane potential was evaluated by rhodamine 123 staining. Immunofluorescence analysis of caspase 3 was done with confocal microscopy. CBZ caused significant cytotoxicity in HT-29 cells and the effect was concentration dependent. CBZ treatments also caused significant expression of ROS in HT-29 cells. Dual staining showed early and late apoptotic cells and morphological alterations induced by the CBZ. Confocal microscopic studies confirmed the increased caspase 3 expression in CBZ-treated cells. CBZ induced apoptosis in HT-29 cell through ROS generation and caspase 3 expression and these results pave the way for further in vivo studies.