Luteolin alleviates neuroinflammation

A study published in the May 19 issue of the Proceedings of the National Academy of Sciences found that the naturally-occurring compound luteolin could help alleviate brain inflammation.

Found in high concentrations in celery and green pepper, this flavanoid has been shown to reduce production of pro-inflammatory mediators in several different cell types stimulated with the commonly-used experimental toxin lipopolysaccharide. Because excessive production of pro-inflammatory cytokines by activated brain microglia can cause behavioral pathology and neurodegeneration, a team of US researchers sought to determine whether luteolin also regulates microglial cell production of a prototypic inflammatory cytokine, interleukin-6.

Led by Rodney Johnson, the University of Illinois scientists provided mice with drinking water supplemented with luteolin for 21 days and then injected them with LPS. Luteolin consumption reduced LPS-induced IL-6 in plasma four hours after injection and decreased the induction of IL-6 mRNA by LPS in the hippocampus but not in the cortex or cerebellum. "Taken together, these data suggest luteolin inhibits LPS-induced IL-6 production in the brain by inhibiting the JNK signaling pathway and activation of AP-1 in microglia. Thus, luteolin may be useful for mitigating neuroinflammation," wrote Dr Johnson.