Inhibition of human tumor growth by 2 '-hydroxy- and 2 '-benzoyloxycinnamaldehydes

2'-Hydroxycinnamaldehyde (HCA) was isolated from Cinnamomum cassia Blume (L auraceae) and 2'-benzoyloxycinnamaldehyde (BCA) was prepared by the reactio n of HCA and benzoyl chloride. HCA and BCA strongly inhibited in vitro grow th of 29 kinds of human cancer cells and in vivo growth of SW-620 human tum or xenograft without the loss of body weight in nude mice. HCA prevented ad herence of SW-620 cells to the culture surface but did not inhibit oncogeni c K-Ras processing, implying its antitumor mechanisms at the cellular level .