Neferine, an alkaloid from lotus seed embryo targets HeLa and SiHa cervical cancer cells via pro-oxidant anticancer mechanism

Apoptosis and autophagy are important processes that control cellular homeostasis and have been highlighted as promising targets for novel anticancer drugs. This study aims to investigate the inhibitory effects and mechanisms of Neferine (Nef), an alkaloid from the lotus seed embryos of Nelumbo nucifera (N. nucifera), as a dual inducer of apoptosis and autophagy through the reactive oxygen species (ROS) activation in cervical cancer cells. Nef and N. nucifera extract suppressed the cell viability of HeLa and SiHa cells in a dose-dependent manner. Importantly, Nef showed minimal toxicity to normal cells. Furthermore, Nef inhibited anchorage-independent growth, colony formation and migration ability of cervical cancer cells. Nef induces mitochondrial apoptosis by increasing pro-apoptotic protein bax, cytochrome-c, cleaved caspase-3 and caspase-9, poly-ADP ribose polymerase (PARP) cleavage, DNA damage (pH(2)AX) while downregulating Bcl-2, procaspase-3 and procaspase-9, and TCTP. Of note, apoptotic effect by Nef was significantly attenuated in the presence of N-acetylcysteine (NAC), suggesting pro-oxidant activity of this compound. Nef also promoted autophagy induction through increasing beclin-1, atg-4, atg-5 and atg-12, LC-3 activation, and (P)62/SQSTM1 as determined by western blot analysis. Collectively, these results demonstrate that Nef is a potent anticancer compound against cervical cancer cells through inducing apoptosis and autophagic pathway involving ROS.