ARS | Publication request: Attenuation of iNOS and COX2 by blueberry polyphenols is mediated through the suppression of NF-KB activation

Submitted to: Journal of Functional Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 4, 2009
Publication Date: July 1, 2009
Citation: Lau, F., Joseph, J.A., Mcdonald, J.E., Kalt, W. 2009. Attenuation of iNOS and COX2 by blueberry polyphenols is mediated through the suppression of NF-KB activation. Journal of Functional Foods. 1(3):274-283.

Interpretive Summary: Treatment of brain cells (specifically, BV2 microglial cells) with blueberry extracts has been shown to be effective in reducing factors that cause inflammation. The current study explored the possibility that the down-regulation of two specific factors, iNOS and COX2, by blueberry extracts was mediated through NF-kB signaling pathway. A purified fraction of polyphenol-enriched blueberry extract (PC18) was used to treat previously-stimulated BV2 cells. The results thus far showed that blueberry polyphenols significantly suppressed iNOS and COX2 activity. In addition, blueberry polyphenols inhibited production of NF-kB protein in these stimulated cells. These findings suggested that the beneficial effects of blueberrys may involve direct modulation of oxidative stress and/or inflammatory signaling cascades.

Technical Abstract: Treatment of BV2 microglial cells with blueberry extracts has been shown to be effective in reducing lipopolysaccharide (LPS)-induced pro-inflammatory mediators such as nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1Beta), inducible NO synthase (iNOS), and cyclo-oxygenase 2 (COX2). The current study explored the possibility that the down-regulation of iNOS and COX2 by blueberry extracts was mediated through NF-kB signaling pathway. A column-purified fraction of polyphenol-enriched blueberry extract (PC18) was used to treat LPS-activated BV2 cells. The results thus far showed that blueberry polyphenols significantly suppressed iNOS and COX2 promoter activities. In addition, blueberry polyphenols inhibited NF-kB nuclear translation in LPS-activated BV2 cells. These findings suggested that the beneficial effects of blueberries may involve direct modulation of oxidative stress and/or inflammatory signaling cascades.