The value of flavonoids for the human nutrition: Short review and perspectives

Flavonoids are phytochemicals and belong to the polyphenols. A wide variety of beneficial factors has been attributed to their mode of action. Some of their activities concerns the inhibition of inflammatory pathways and the down regulation of genes involved in chronic inflammatory disease states. These genes enhance the inflammatory signaling pathways leading to expression of inflammatory cytokines and chemokines. Flavonoids from fruits, vegetable and tea compounds can block many proinflammatory proteins and thus function as natural inhibitors of inflammation. Instead of using nonsteroidal anti-inflammatory drugs natural inhibitors could possibly be used to suppress the intensity of the inflammation in the chronically inflamed mucosa in patients with chronic inflammatory bowel disease. Natural inhibitors like flavonoids are xenobiotics which are metabolized by the cytochrome P-450 enzymes and conjugating protective enzymes. Flavonoids can induce these protective enzymes by upregulation and thereby could act as protective metabolic barrier within the intestinal mucosa. The nutritional value of flavonoids is probably related to their anti-inflammatory activity and through this mechanism responsible for prevention of neoplasia. The evidence for their clinical efficacy as essential compounds is still preliminary at best and limited but suggestive.