Dihydroartemisinine Enhances Dictamnine-induced Apoptosis via a Caspase Dependent Pathway in A549 Cells

Dictamnine (Dic), a natural alkaloid, was isolated from the root of Dictamnus dasycarpus Turcz, and has been reported to possess anti-platelet aggregation, fungal activity and vascular-relaxing effects (Huang et al., 2005; Huang et al., 2007; Guo et al., 2008). Recently, it was reported that Dic could induce cytotoxicity in human cervix, colon, and oral carcinoma cells (Huang et al., 2005). In addition, derivatives from Dic have been exhibited anticancer activity (Huang et al., 2007). However, the characteristics and molecular mechanism of Dic-induced cell death are still poorly understood. Apoptosis, one of the programmed cell death, plays an essential role in regulating growth, development and immune response by clearing redundant or abnormal cells in organisms (Fan et al., 2005). Apoptotic cells undergo various cellular morphological changes, including cell shrinkage, chromatin condensation, membrane blebbing, oligonucleosomal DNA cleavage and translocation of phosphatidylserine (PS) from the inner to the outer leaflet of the plasma membrane and activation of a