Induction of Apoptosis of A549 Lung Cancer Cell Line by Dehydrocostus Lactone Isolated from Glossogyne Tenuifolia
Hsia-Fen Hsu1, Yang-Chang Wu1*, Lei-Chin Chen2 AND Jer-Yiing Houng2,3*
1. Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan (R.O.C.)
2. Department of Medical Nutrition, I-Shou University, Kaohsiung County, Taiwan (R.O.C.)
3. Department of Chemical Engineering, I-Shou University, Kaohsiung County, Taiwan (R.O.C.)
(Received: August 19, 2008; Accepted: November 19, 2008)
ABSTRACT
Glossogyne tenuifolia is a traditional antipyretic and hepatoprotective herb used in Taiwan. In this study, dehydrocostus lactone (DL, 6-hydroxy-guaia-4(15), 10(14), 11(13)-trien-12-oic acid lactone) and mokko lactone (ML, 4(15), 10(14)-guaiadien-12,6-olide lactone) were isolated from the crude extract of G. tenuifolia. Structures of these two compounds were elucidated by spectroscopic evidence. These two sesquiterpene lactones were identified for the first time from G. tenuifolia. From cytotoxicity tests, DL inhibited the proliferation of human lung cancer A549 cells in a time- and dose-dependent manner, whereas the cytotoxicity of ML on A549 cells was unimportant. The cytometric analysis showed that the A549 cells were arrested at the sub-G1 phase by the treatment of DL. The evidence of the activation of caspase-9 and -3 verified that the death of A549 cells was through the apoptosis pathway. Other than A549 cells, DL also exhibited strong cytotoxicity on MDA-MB-231 (breast cancer) and Hep G2 (hepatoma) cells. Although DL is a known compound, to our knowledge, this work is the first to investigate its cytotoxicity on A549 cells.
Key words: dehydrocostus lactone, mokko lactone, Glossogyne tenuifolia, cytotoxicity, apoptosis, lung cancer cell line A549