TNF and colonic neoplasm: The bioactivity of specific phenolic acids is less well defined, with examples including 3,4diOHPAA an inhibitor of enzymes involved in detoxification (GSTT2), inflammation (COX-2) and anti-proliferative activity in HCT-116 colon cancer cells [67, 70]; 3,4-diOHPPA (3 μM) and 3,4-diOHPAA (3 μM), inhibitors of the pro-inflammatory cytokines such as TNF-a, IL-1b and IL-6 in lipopolysaccharide-stimulated peripheral blood mononuclear cells [70, 71]; and gallic acid (882 μM) inhibitor of Clostridium histolyticum in in vitro faecal fermentation [65, 72].