antitumor activity of capsaicin against the pancreatic cancer cell lines. A, equal numbers of AsPC-1 cells were seeded in 6-well plates in triplicates and incubated with various concentrations of capsaicin (10 and 50 μmol/L) for 14 days. The cells were then fixed, stained, and photographed. B, quantitative analysis of cytotoxic activity of capsaicin in AsPC-1 cells analyzed by colony formation assay. The data are shown as the mean ± SD of 3 experiments. C, the treatment with 30 μmol/L capsaicin for 24 hours induced a 2- to 3-fold increase of cellular superoxide in naturally occurring pancreatic cancer Capan-1, Panc-1, and AsPC-1 cells. D, effect of capsaicin on the invasion of naturally occurring pancreatic cancer cells analyzed by BD BioCoat Chamber as described in the Methods section. Cells were seeded onto the chamber insert with or without 30 μmol/L capsaicin treatment. After 24 hours of treatment, cells that had migrated to the lower surface of the insert were subjected to staining and photographed (magnification, ×400). Ctrl, control.