Vegetarian fecal water inhibits COX-2 in colon cancer cells
The cyclooxygenase-2 enzyme (COX-2) is involved in prostaglandin biosynthesis and plays a significant role in the process of inflammation. Several compounds of plant origin affect the COX-2 enzymatic activity . In recent years it has also been suggested that COX-2 is involved in cancer development . Thus, ingested phytochemicals with anti-inflammatory activity have the potential to act as cancer chemopreventive agents in the human colon. This study has focused on the discovery of natural COX-2 inhibitors present in the colonic contents of human subjects on a vegetarian diet. A number of human fecal water samples from vegetarians were collected and assessed for effects on COX-2 inhibiting activity in human colon cancer cells (HT-29). The fecal waters showed inhibiting effects on the enzymatic level as well as on the protein expression level . By solid phase extraction (SPE) the fecal waters were separated into a water fraction and a lipid fraction. The activity was traced to the water fraction, suggesting that the active compounds most likely are of polar nature. The chemical content of fecal water was further analyzed using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). GC-MS was performed with an emphasis on finding phenolic compounds, whereas NMR was used for a metabolomic analysis of the total fecal water content. A variety of compounds were identified including several phenolic compounds, amino acids and fatty acids [3,4]. NMR metabolomic analysis of human fecal water has the potential to be a useful method for the identification of biomarkers and other colonic metabolites of interest in colon cancer research.
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