• The flavouring phytochemical 2-pentanone reduces prostaglandin production and COX-2 expression in colon cancer cells.

      Pettersson, Jenny; Karlsson, Pernilla Christina; Goransson, Ulf; Rafter, Joseph James; Bohlin, Lars (2008-03)
      Many phytochemicals found in the diet may prevent colon carcinogenesis by affecting biochemical processes in the colonic mucosa. Inflammation and subsequent elevation of the enzyme cyclooxygenase-2 (COX-2) are two such factors involved in the development of colon cancer, and inhibition of these processes could be important targets for chemoprevention. We have previously shown COX-2 inhibitory activity locally in the colon; e.g. in human fecal water from a group of vegetarians. In this study we focus on 2-pentanone, a frequently occurring compound in common foods such as banana and carrot. The aim was to study the inhibitory effects on prostaglandin production and COX-2 protein expression in tumour necrosis factor-alpha stimulated colon cancer cells (HT29) by radioimmunoassay and Western blotting. 2-Pentanone inhibited both prostaglandin production and COX-2 protein expression in human colon cancer cells. A concentration of 400 mumol/l 2-pentanone inhibited the prostaglandin production by 56.9+/-12.9% which is in the same range as the reference compound NS398 (59.8+/-7.6%). The two highest concentrations of 2-pentanone were further analyzed by Western blot, and 400 micromol/l and 200 micromol/l 2-pentanone resulted in a 53.3+/-9.6% and +/-27.1% reduction of the COX-2 protein levels respectively. Further studies on flavouring compounds, for example 2-pentanone, as colon cancer chemopreventives would be very valuable, and such results may contribute to future dietary recommendations.