Apoptotic effects of ginsenoside Rh2 on human malignant melanoma A375-S2 cells.

AIM: To study the mechanism of ginsenoside-Rh2 (G-Rh2)-induced growth inhibition of A375-S2 cells. METHODS: A375-S2 cell viability and the effect of caspase inhibitors on G-Rh2-induced apoptosis were measured by crystal violet assay. Changes in cellular morphology were observed by phase-contrast microscopy. Apoptosis-specific nucleosomal DNA fragmentation was assayed by agarose gel electrophoresis. Cell cycle distribution was measured by flow cytometry. RESULTS: G-Rh2 inhibited the A375-S2 cell growth in concentration- and time-dependent manners. Caspase family inhibitor, z-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk), caspase-3 inhibitor, z-Asp-Glu-Val-Asp-fluoromethylketone (z-DEVD-fmk), and caspase-8 inhibitor, z-Ile-Glu-Asp-fluoromethylketone (z-IETD-fmk), partially inhibited G-Rh2-induced apoptosis. But caspase-1 inhibitor, Ac-Tyr-Val-Ala-Asp-chloromethyl-ketone (Ac-YVAD-cmk), did not antagonize G-Rh2 induced-cell death. CONCLUSION: G-Rh2 suppresses the growth of A375-S2 cells in vitro by inducing apoptosis. G-Rh2-induced apoptosis is partially dependent on caspase-8 and caspase-3 pathway in A375-S2 cells. Other apoptotic pathways might be also related to the induction of apoptosis by G-Rh2.

Self-Assembly of Uniform Spherical Aggregates of Magnetic Nanoparticles through π-π Interactions.

Nanoparticles of Fe3 O4 coated with 2-carboxyterthiophene (TTP-COOH) self-assemble through π-π interactions to form uniform transparent microspheres. The interaction between individual particles is relatively weak and the spherical aggregates can be destroyed by sonication to leave the monodispersed nanoparticles.