Ethanol Extract of Hizikia fusiforme Induces Apoptosis in B16F10 Mouse Melanoma Cells through ROS-Dependent Inhibition of the PI3K/Akt Signaling Pathway.
BACKGROUND
Previous studies have reported that Hizikia fusiforme, an edible brown seaweed, has diverse health-promoting effects; however, evidence for its anti-cancer potential is still lacking. In this study, we examined the effect of ethanol extract of H. fusiforme (EHF) on the proliferation of B16F10 mouse melanoma cells.


METHODS
Analyses of cell viability and apoptosis were performed to study the actions of EHF on B16F10 cells. Cellular reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were measured using a flow cytometer. Western blot analysis was carried out to measure apoptosis and phosphoinositide 3-kinase (PI3K)/Akt signaling related proteins.


RESULTS
EHF treatment significantly decreased B16F10 cell viability, which was associated with induction of apoptosis. EHF activated caspase-8 and caspase-9, which are involved in the initiation of extrinsic and intrinsic apoptosis pathways, respectively, and also increased caspase-3 activity, a typical effect caspase, subsequently leading to poly (ADP-ribose) polymerase cleavage. In addition, EHF destroyed the integrity of mitochondria and increased Bax/Bcl-2 ratio, which contributed to cytosolic release of cytochrome c. EHF further enhanced intracellular levels of ROS and the addition of N-acetyl cysteine (NAC), a ROS inhibitor, significantly diminished EHF-induced mitochondrial dysfunction and growth inhibition. Moreover, EHF inactivated the PI3K/Akt signaling pathway and LY294002, a PI3K/Akt inhibitor, increased the apoptosis-inducing effect of EHF. However, increased apoptosis and reduced cell viability by simultaneous treatment of EHF and LY294002 were significantly attenuated in the presence of NAC.


CONCLUSION
These results indicate that EHF induces apoptosis through activation of extrinsic and intrinsic apoptotic pathways and ROS-dependent inactivation of PI3K/Akt signaling in B16F10 cells.<br />.
['Park|Cheol|C|', 'Lee|Hyesook|H|', 'Hwangbo|Hyun|H|', 'Ji|Seon Yeong|SY|', 'Kim|Min Yeong|MY|', 'Kim|So Young|SY|', 'Hong|Su Hyun|SH|', 'Kim|Gi-Young|GY|', 'Choi|Yung Hyun|YH|0000-0002-1454-3124']
D000818:Animals D017209:Apoptosis D049109:Cell Proliferation D000431:Ethanol D008546:Melanoma, Experimental D053078:Membrane Potential, Mitochondrial D051379:Mice D000459:Phaeophyta D058539:Phosphatidylinositol 3-Kinase D010936:Plant Extracts D051057:Proto-Oncogene Proteins c-akt D017382:Reactive Oxygen Species D014407:Tumor Cells, Cultured
Hizikia fusiforme Apoptosis PI3K/Akt B16F10 cells ROS