Codonopsis lanceolata extract induces G0/G1 arrest and apoptosis in human colon tumor HT-29 cells--involvement of ROS generation and polyamine depletion.

Codonopsis lanceolata (Campanulasea) is widely distributed and grown in Asia and has been in use as traditional medicine for long time. The n-butanol fraction (BF) of C. lanceolata significantly inhibited human colon cancer HT-29 cell growth in a dose- and time-dependent manner by inducing G0/G1 phase arrest and apoptosis. The inhibition was associated with intracellular ROS generation and polyamine depletion as evidenced by HPLC quantitatively. Additionally, semi-quantitative RT-PCR revealed enhanced expression of caspase-3, p53, and the Bax/Bcl-2 ratio and reduced expression of survivin in HT-29 cells treated with BF. Furthermore, western blot analysis of p53, JNK, and caspase-3 showed that ROS generation was accompanied by JNK activation. Increase of the Bax/Bcl-2 ratio and activation of caspase-3 might be due to intracellular polyamine depletion. Conclusively, the findings of this study imply a critical role of ROS and polyamine depletion in the anticancer effects of C. lanceolata root extract.