Sesamol induced apoptotic effect in lung adenocarcinoma cells through both intrinsic and extrinsic pathways.

Sesamol is a phenolic lignan found in sesame seeds (Sesamum indicum L.) and sesame oil. The anticancer effects and molecular mechanisms underlying its apoptosis-inducing effect were investigated in human lung adenocarcinoma (SK-LU-1) cells. Sesamol inhibited SK-LU-1 cell growth with an IC50 value of 2.7 mM and exhibited less toxicity toward normal Vero cells after 48 h of treatment (Selective index = 3). Apoptotic bodies-the hallmark of apoptosis-were observed in sesamol-treated SK-LU-1 cells, stained with DAPI. Sesamol increased the activity of caspase 8, 9, and 3/7, indicating that apoptotic cell death occurred through both extrinsic and intrinsic pathways. Sesamol caused the loss of mitochondrial transmembrane potential signifying intrinsic apoptosis induction. Decreasing Bid expression revealed crosstalk between the intrinsic and extrinsic apoptotic pathways; demonstrating clearly that sesamol induces apoptosis through both pathways in human lung adenocarcinoma (SK-LU-1) cells.