Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: January 18, 2007
Publication Date: March 25, 2007
Citation: Manthey, J.A. 2007. In vivo studies of the anti-inflammatory actions of citrus polymethoxylated flavones. American Chemical Society National Meeting. Paper No. AGFD 146. Technical Abstract: Previous in vitro studies have shown that citrus polymethoxylated flavones are inhibitors of the phosphodiesterase-4 of LPS-stimulated cultured human monocytes, and that this inhibition leads to the inhibition of the production of certain proinflammaotry cytokine proteins by the stimulated monocytes. Recent studies now show that the polymethoxylated flavone, 3,5,6,7,8,3',4'-heptamethoxyflavone (HMF), administered by intraperitoneal (ip) injection was active against the production of the cytokine, tumor necrosis factor-alpha, in LPS-challenged mice. A second study has now shown that this inhibition does not occur following oral adimistration of HMF. Likewise, HMF administered ip in rats was a potent inhibitor of inflammation in the carrageenan/paw edema assay, but lacked inhibitory activity when administered orally. Oral administration of HMF in mice produced measurable levels of HMF metabolites, mainly glucuronides, whereas ip injection also produced measureable levels of the free, unmodified HMF in the blood serum. These results suggest the anti-inflammatory actions of HMF may be due to the original compound, but are lost with conjugation with glucuronic acids.