Ethanol extracts of Hizikia fusiforme induce apoptosis in human prostate cancer PC3 cells via modulating a ROS-dependent pathway

• Published in: Asian Pacific Journal of Tropical Biomedicine
• Main Authors: Eun Ok Choi, Hyesook Lee, Cheol Park, Gi-Young Kim, Hee-Jae Cha, Suhkmann Kim, Heui-Soo Kim, You-Jin Jeon, Hye Jin Hwang, Yung Hyun Choi
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wolters Kluwer Medknow Publications 2020
• Subjects: hizikia fusiforme; apoptosis; prostate cancer cells; caspase; reactive oxygen species; Arctic medicine. Tropical medicine; RC955-962; Biology (General); QH301-705.5; Arctic
• Online Access: https://doi.org/10.4103/2221-1691.275422; https://doaj.org/article/67c836122c124979a5b335d810331001

Objective: To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells. Methods: Cell viability was evaluated using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide. Apoptosis and mitochondrial membrane potential (MMP) were measured using flow cytometry in PC3 cells. DNA damage was assessed by nuclear staining and DNA fragmentation assay. Expressions of apoptosis-associated proteins were determined by Western blotting assays. Activities of caspase-3, -8, and -9 were determined by colorimetric assay. Moreover, intracellular reactive oxygen species (ROS) generation was detected using a flow cytometer and fluorescence microscope. Results: Treatment of PC3 cells with ethanol extracts of Hizikia fusiforme inhibited proliferation, which was associated with induction of apoptosis, and accompanied by increased expression of Fas, Fas-ligand (FasL), Bax and tBid, and decreased expression of Bcl-2. In addition, ethanol extracts of Hizikia fusiforme reduced c-Flip expression and activated caspase-8, -9 and -3, resulting in an increase in poly (ADP-ribose) polymerase (PARP)cleavage. However, in the presence of a pan-caspase inhibitor, ethanol extracts of Hizikia fusiforme-mediated growth inhibition and apoptosis were significantly attenuated. Ethanol extracts of Hizikia fusiforme also destroyed the integrity of mitochondria due to the loss of MMP, leading to cytosolic release of cytochrome c. Moreover, the levels of ROS were markedly increased by treatment with ethanol extracts of Hizikia fusiforme, which was significantly suppressed by the ROS scavenger N-acetyl-L-cysteine. Further investigation of whether ethanol extracts of Hizikia fusiforme-induced apoptosis was related to the generation of ROS was conducted and the results showed that N-acetyl-L-cysteine fully blocked ethanol extracts of Hizikia fusiforme-induced apoptotic events including loss of MMP, activation of caspase-3, the cytosolic release of cytochrome c and cytotoxicity. Conclusions: ...