Induction of apoptosis by l-carnitine through regulation of two main pathways in Hepa1c1c 7 cells

This study shows the effects of l-carnitine treatment on cell proliferation with hepa1c1c7 mouse cancer cells and NCTC 1469 normal cells. In an MTT assay, l-carnitine increased the number of dead hepa1c1c7 cells, while there was no difference in the number of NCTC 1469 cells. mRNA and protein levels of TNF-α, Fas, and caspase-8, which are closely related to cell apoptosis by a death ligand/receptor-dependent apoptosis pathway, were increased by l-carnitine treatment. In addition, l-carnitine treatment regulated mitochondria-dependent apoptosis pathways by inducing the up-regulation of caspase-9 and caspase-3 and the down-regulation of Bcl-2 in hepa1c1c 7 cells. Taken together, the findings of this study have demonstrated that l-carnitine could induce apoptosis in hepa1c1c7 cells by regulating Fas ligands and inhibiting the expression of Bcl-2. These results suggest that l-carnitine treatment could be related to both a mitochondrion-dependent and a death ligand/receptor-dependent apoptosis pathway in hepa1c1c7 cells. Our results could give information for understanding the l-carnitine-induced apoptosis mechanism in some cancer cells.