A novel cyclic pentapeptide, H-10, inhibits B16 cancer cell growth and induces cell apoptosis.

Sansalvamide A, a cyclic depsipeptide isolated from a marine fungus of the genus, exhibits significant antitumor activity. In the present study, H-10 (molecular formula, CHNO; molecular weight, 677.8732), a novel sansalvamide A derivative, demonstrated an inhibitory effect on the proliferation of murine melanoma B16 cells. It was confirmed that H-10 induced the apoptosis of the B16 cells. The inhibitory rate of various concentrations of H-10 on the B16 cells was measured by sulforhodamine B colorimetric assay, and the results revealed that the inhibitory effect of H-10 on the B16 cells occurred in a concentration-dependent manner. In addition, a growth curve model of the B16 cells treated with 50 μM H-10 revealed that the effect of H-10 also occurred in a time-dependent manner. The apoptotic morphology of the B16 cells was observed using an optical microscope. Following the treatment of the cells with 50 μM H-10 for 24 h, the cell apoptosis rate was analyzed using flow cytometry. The expression levels of caspase-3, -8 and -9 were analyzed by western blot analysis, and the results indicated that H-10 may induce the apoptosis of B16 cells.