Treatment of cinnamon extract inhibits the growth of various cancer cells. Cinnamon (0.5 mg/ml) was treated for 0, 48 and 72 hrs to cancer cell lines (Hela; cervical cancer, Caco2; colon cancer, Clone M3; melanoma and B16F10; melanoma). After treatment of cinnamon extract, (A) morphological changes of each cancer cell lines were monitored by microscopic observation. (B) Proliferation and viability of cancer cells were measured by cell viability assay at the indicated time points. Error bars indicated SD. Data are representative of three independent experiments.