The anticancer effects of Saccharina japonica on 267B1/K-ras human prostate cancer cells

Abstract

Saccharina japonica (S. japonica), a brown macroalga, has been used as a traditional medicine in Korea for thousands of years. In this study, the potential anticancer effects of S. japonica were evaluated on 267B1/K-ras human prostate cancer cells. The exposure of cells to the extract induced inhibition of cell growth by increasing the number of apoptotic cells with cell shrinkage and inhibition of cell cycle progression. The effects of the extract on the cells were assessed by studying the cleavage of caspases and the target proteins of caspases. The increased expression of various cleaved caspases and changed expression of other proteins related in the apoptosis pathway were observed. 4′-6-Diamidino-2-phenylindole (DAPI) and immunofluorescence staining showed the cells undergoing apoptosis. Apoptosis induced changes in the expression of proteins involved in a variety of signaling pathways such as endocellular reticulum (ER) stress, death receptor and mammalian target of rapamycin (mTOR)-FoxO-mediated pathways. The data suggest that the extract (n-hexane sub-fraction) of S. japonica, induces apoptosis and cell cycle arrest in 267B1/K-ras human prostate cancer cells, and has potential as a complementary agent for cancer prevention.