Marchantin C, a macrocyclic bisbibenzyl, induces apoptosis of human glioma A172 cells

Macrocyclic bisbibenzyls, a class of characteristic components derived from liverworts, are attracting more and more attention because of their wide range of biological significance, including anti-bacterial, anti-fungus, anti-oxidation and cytotoxicity. Herein, we investigated the pro-apoptotic effect of marchantin C on human glioma A 172 cells. The results demonstrated that marchantin C conferred dose-dependent inhibitory effects onto cell growth, viability and colony formation ability of A 172 cells. Morphological observation and DNA laddering assay showed that marchantin C-treated A172 cells displayed outstanding apoptosis characteristics, such as nuclear fragmentation, the appearance of membrane-enclosed apoptotic bodies and DNA laddering fragment. Moreover, flow cytometric detection of phosphatidylserine externalization indicated that marchantin C-induced apoptosis occurred in a dose-dependent manner. RT-PCR and western blot assay further substantiated that marchantin C, as a promising pro-apoptotic agent, had strong effects to induce A172 cell apoptosis, suggesting that the action was achieved through up-regulating Bax and down-regulating Bcl-2.