| ABSTRACT: |
|
Excessive nitric oxide (NO) production in the brain has been
correlated with neurotoxicity and the pathogenesis of several
neurodegenerative diseases. NO production from neuroglial cells
surrounding neurons contributes significantly to the pathogenesis of these
diseases. The suppression of NO production in these cells may be
beneficial in retarding many of these disorders. The present study was
designed to evaluate the capacity of dietary-derived polyphenolic
compounds, flavonoids, crude extracts, oils, and other food constituents
in suppressing the release of NO from lipopolysaccharide
(LPS)/gamma-interferon (IFN-gamma) stimulated C6 astrocyte cells. In this
experiment, 61 compounds were tested, and 36 showed significant
suppressive effects of NO production. The results indicate that the
following compounds exhibited a dose-dependent suppressive effect of NO
production with an IC50 less than 10(-3) M: quercetin,
(-)-epigallocatechin gallate, morin, curcumin, apigenin, sesamol,
chlorogenic acid, fisetin, (+)-taxifolin, (+)-catechin, ellagic acid, and
caffeic acid. Compounds, which reduce NO production at less than 300 ppm,
include milk thistle, silymarin, grapenol, and green tea. These results
demonstrate a possible value for dietary compounds to inhibit the
excessive production of NO. |