Enhanced anticancer activity and endocytic mechanisms by polymeric nanocarriers of n-butylidenephthalide in leukemia cells.

PURPOSE The purpose of this study was to investigate the antitumor mechanisms of n-butylidenephthalide (BP) and to further examine the delivery efficacy of polycationic liposome containing PEI and polyethylene glycol complex (LPPC)-encapsulated BP in leukemia cells. METHODS MTS, flow cytometric and TUNEL assays were performed to assess cell viability and apoptosis. BP and BP/LPPC complex delivery efficiency was analyzed by full-wavelength fluorescent scanner and fluorescence microscope. The expressions of cell cycle- and apoptosis-related proteins were conducted by Western blotting. RESULTS The results showed that BP inhibited leukemia cell growth by inducing cell cycle arrest and cell apoptosis. LPPC-encapsulated BP rapidly induced endocytic pathway activation, resulting in the internalization of BP into leukemia cells, causing cell apoptosis within 1 h. CONCLUSIONS LPPC encapsulation enhanced the cytotoxic activity of BP and did not influence the effects of BP induction that suggested LPPC-encapsulated BP might be developed as anti-leukemia drugs in future.