Purple carrot anthocyanins suppress lipopolysaccharide-induced inflammation in the co-culture of intestinal Caco-2 and macrophage RAW264.7 cells

This study was designed to evaluate the anti-inflammatory effects of purple carrot anthocyanins (PCA) with respect to gut inflammation, simulated in a co-culture system consisting of intestinal epithelial Caco-2 cells and RAW264.7 macrophages. The obtained results indicated that PCA extract down-regulates the mRNA expression of proinflammatory interleukins Il-1 beta (down arrow 91%) and Il-6 (down arrow 69%) as well as inflammatory mediators, such as cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNos), in lipopolysaccharide-activated RAW264.7 cells. The decrease in the generation of prostaglandin E-2 (down arrow 48%) and nitric oxide (down arrow 26%) was observed as a result of the inhibition of Cox-2 (down arrow 25%) and iNos (down arrow 12%) mRNA expressions, respectively. Moreover, the PCA reduced mRNA expression (down arrow 40%) and production (down arrow 17%) of IL-8 in intestinal cells. The anti-inflammatory effect of PCA was contributed to the protection of the intestinal barrier, which was disrupted upon the stimulation of macrophages. These findings may provide preliminary justification for the use of PCA in further studies focused on the prevention and therapy supporting the conventional treatment of inflammatory bowel diseases.