The antitumor effect of formosanin C on HepG2 cell as revealed by 1H-NMR based metabolic profiling

Formosanin C (FC) is a pure compound isolated from Rhizoma Paridis. In the past years, antitumor effects of FC have been observed in several cultural cells and animal systems. However, there was no research particular on liver cancer. In this experiment, 3-(4, 5-dimethylthiazol diphenyltetrazolium bromide (MTT) dye reduction assay was used to evaluate cell viability of HepG2 cells with FC-treatment. 4', 6-diamidino-2-phenylindole (DAPI) staining, Annexin V-FITC/PI assay and DNA fragment assay were applied to observe FC-induced apoptosis. Cell cycle analysis and NMR metabolic profiles were used to identify molecular mechanisms of FC in HepG2 cells. As a result, FC inhibited the growth of HepG2 cells through inducing apoptosis and S phase arrest. Cells cultured in the presence or absence of FC was different in metabolic profiles. The treatment decreased acetate, ethanol, choline and betaine, and increased butyrate, fatty acids, leucine and valine in HepG2 cells. In conclusion, metabolomic analysis of the exometabolome of FC-treated HepG2 cells, together with traditional methods such as apoptosis test and cell cycle analysis provided a holistic method for elucidating mechanisms of potential anti-cancer drug, FC.