Imperatorin possesses notable anti-inflammatory activity in vitro and in vivo through inhibition of the NF-κB pathway

Imperatorin (IMT) is a furanocoumarin from the root of Phlomis younghusbandii (Lamiaceae) with various activities. In the present study, the anti-inflammatory effects of IMT were evaluated by examining dimethylbenzene-induced ear edema, acetic acid-induced vascular permeability and by performing cotton pellet granuloma assessments in mice. In addition, the expression of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β, were detected using enzyme-linked immunosorbent assay kits in mice and using reverse transcription polymerase chain reaction analysis in RAW 264.7 cells. The expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear p65, cytosolic p65 and inhibitor of nuclear factor (NF)-κB (IκB) in RAW 264.7 cells were determined using western blot analysis. The results showed that the oral administration of IMT significantly inhibited the inflammatory reactions and reduced the release of TNF-α, IL-6 and IL-1β reactions and reduced and suppressed the mRNA expression of TNF-A expressionact1o, and the protein expression of iNOS and COX-2 in the RAW 264.7 cells. The results also indicated that IMT suppressed the activity of NF-κB via upregulating p65 and IκB in the cytoplasm and downregulating p65 in the nucleus. In conclusion, IMT possessed notable anti-inflammatory activities in vitro and in vivo through inhibiting the NF-κB pathway.