The anti-tumor activity and mechanism of alkaloids from Aconitum szechenyianum Gay.

In the current study, the anti-tumor activity of Aconitum szechenyianum Gay alkaloids (ASA) and its mechanism of action were investigated. The result showed that ASA could induce apoptosis in HepG-2, Hela and A549 cells but not in normal human embryonic kidney 293A cells, and its apoptotic effect on A549 cells was stronger than those of HepG-2 and Hela cells. Moreover, the following study showed that ASA could up-regulate the expression levels of p38 and phosphorylated p38 MAPK, suggesting ASA-induced apoptosis was associated with the p38 MAPK mediated pathway. Furthermore, ASA could up-regulate TNF-R1 and DR5 via activation of p38 MAPK, thereby activating caspase 8, revealing the death receptor pathway was also involved in this process. In addition, ASA could led to a loss in the mitochondrial out membrane potential, up-regulate p53, phosphorylated p53 and Bax, down-regulate Bcl-2, release cytochrome c from the mitochondria to the cytoplasm, and activate caspase-9 and caspase-3 in A549 cells, which revealed that ASA could also induce apoptosis through the mitochondria mediated pathway. These results suggested that ASA played the anti-tumor role through the activation of p38 MAPK-, death receptor-, mitochondria- and caspase-dependent apoptotic pathways.