Proteomic analysis of β-asarone induced cytotoxicity in human glioblastoma U251 cells.

Though rhizoma acori graminei (RAG) is frequently prescribed in formulations for brain tumor in traditional Chinese medicine, the potential mechanisms are still unclear. The aim of this study is to determine the effect of β-asarone, a major component in the volatile oil of RAG, against brain tumor and elucidate the underlying molecular mechanisms. The results showed that β-asarone significantly inhibited the cell viability of human glioblastoma U251 cells. Moreover, YO-PRO-1/PI staining revealed that cells treated with β-asarone underwent apoptotic and necrotic death. Then, the two-dimensional gel electrophoresis (2-DE)-based proteomics was applied to investigate the different protein profiles of U251 cells treated with vehicle or β-asarone. Sixteen proteins affected by β-asarone were successfully identified by MALDI-TOF/TOF mass spectrometry. Gene ontology analysis showed that those proteins participated in several important biological processes and exhibited diverse molecular functions. Importantly, four proteins (heterogeneous nuclear ribonucleoprotein H1 (H), isoform CRA_b, heterogeneous nuclear ribonucleoprotein A2/B1, isoform CRA_a, ubiquitin carboxyl-terminal hydrolase isozyme L1 and cathepsin D) acting as either oncoproteins or tumor suppressors draw our special attention. Finally, the effect of β-asarone on these four genes was confirmed at transcriptional level by semi-quantitative RT-PCR. Collectively, a variety of proteins affected by β-asarone were identified by 2-DE coupled with MALDI-TOF/TOF MS/MS analysis. Four potential protein targets were proposed, which will enable a better understanding of the anti-tumor activity of β-asarone.