Anticancer Activity of Tetrahydrocorysamine against Pancreatic Adenocarcinoma Cell Line PANC-1 In vitro and In vivo

Purpose: To investigate the cytotoxic activity of tetrahydrocorysamine (TCSM) from Corydalis Rhizoma W. T. Wang (Papaveraceae) against PANC-1 cells and its possible mechanisms.
Methods: TCSM was isolated from Corydalis Rhizoma by column chromatography and identified by mass spectrometry and nuclear magnetic resonance (NMR). The effects of TCSM on the proliferation and apoptosis of PANC-1 cells were determined by methyl thiazolyl tetrazolium (MTT) and flow cytometry assays. The effect of TCSM on the expressions of mitochondria-mediated apoptotic proteins were investigated by Western blot assay. Xenograft assay was used to evaluate the anticancer activity of TCSM in vivo.
Results: TCSM showed cytotoxic activity against PANC-1 cells with half-maximal concentration (IC₅₀) of 19.16 μM in MTT assay. TCSM (5, 10 and 20 μM) significantly (p < 0.01) increased the apoptosis rates of PANC-1 cells (24.45, 35.26 and 54.16 vs 6.12 %), compared with control group. The results of Western blot suggest that TCSM significantly (p < 0.01) down-regulated the expressions of antiapoptotic proteins (Bcl-2 and Survivin), up-regulated the expressions of pro-apoptotic proteins (Bax, Smac, c-caspase-3 and c-caspase-9) and promoted the release of cytochrome C from mitochondria to the cytoplasm of PANC-1 cells, compared with control. TCSM (20 mg/kg) significantly (p < 0.01) inhibited the growth of PANC-1 cell-induced tumor (384 vs 1138 mm³) by regulating the expressions of mitochondria-mediated apoptotic proteins as stated above for xenograft assay, compared with control.
Conclusion: TCSM induces apoptosis in PANC-1 cells in vitro and in vivo via mitochondria-mediated apoptotic pathway.

Keywords
Corydalis Rhizoma; Tetrahydrocorysamine; PANC-1 cells; Flow cytometry; Western blot; Xenograft