Inhibition of tumor cell proliferation and induction of apoptosis in human lung carcinoma 95-D cells by a new sesquiterpene from hairy root cultures of Artemisia annua.

Artemisia annua is a rich source of many bioactive substances, and in our recent work, a new sesquiterpene, (Z)-7-acetoxy-methyl-11-methyl-3-methylene-dodeca-1,6,10-triene (AMDT), was isolated and identified from hairy roots culture of A. annua, and its bioactivity was characterized in this work. AMDT showed moderate cytotoxic activities against the human tumor cell lines of HO8910 (ovary), 95-D (lung), QGY (liver) and HeLa (cervix) by MTT assay, whose IC(50) values were ranged within 52.44-73.3 microM. As lung cancer is the No. 1 killer of global cancer patients, our interest is to investigate the ability of AMDT in inducing apoptosis of 95-D tumor cells. The 95-D cell growth was inhibited by AMDT, and the flow cytometry analysis showed its cell cycle was arrested in the G1 phase. The apoptotic rate of the cells increased in a dose-dependent manner. AMDT lowered the mitochondrial membrane potential and increased the expression of caspase-9 and -3. These results revealed that AMDT could efficiently induce 95-D cell apoptosis through mitochondrial dependent pathway, and it may be a potential chemotherapeutic agent.