Anti-proliferation activities of three bioactive components purified by high-speed counter-current chromatography in essential oil from ginger

Three bioactive components (6-gingerol, zingerone and sesquiterpenes) in essential oil from ginger were successfully separated and purified by high-speed counter-current chromatography (HSCCC), and their proliferation inhibition on cancer cells was further investigated. The HSCCC was performed using n-hexane-ethyl acetate-methanol-water (7:3:5:5, v/v), n-hexane-methanol-water (3:2:1, v/v), and n-hexane-chloroform-acetonitrile (6:2:5, v/v) in 600 mu l samples severally, yielding 35 mg 6-gingerol, 23 mg zingerone, and 105 mg sesquiterpenes with the purities of 98.6%, 99.4%, and 99.2% determined by high-performance liquid chromatography (HPLC). Their relative contents reached 84.07%, 94.67%, and 95.17%. MTT results showed that the three compounds caused cytotoxicity on the A549, HepG2 and MDA-MB-231 cells and 6-gingerol had the strongest anti-proliferation activity. Moreover, Hoechst 33342/PI staining confirmed that 6-gingerol could induce A549 cells to exhibit some typical features of apoptosis and Annexin V-FITC/PI verified that the cells induced by 6-gingerol underwent apoptosis rather than necrosis during this process. The HSCCC could be used to prepare bioactive substance with anti-tumor activities.