Protective effect of kaempferol, a flavonoid widely present in varieties of edible plants, on IL-1β-induced inflammatory response via inhibiting MAPK, Akt, and NF-κB signalling in SW982 cells

Effects and mechanisms of kaempferol, identified in a wide variety of dietary sources, on the expression of interleukin (IL)-6, IL-8, matrix metallo proteinase (MMP)-1, and cyclooxygenase (COX)-2 were evaluated in IL-1β-induced SW982 cells. The cells were pretreated with kaempferol of various concentrations (2, 10 and 50 µmol/L) followed by IL-1β (10 ng/mL) stimulation. Kaempferol significantly suppressed mRNA and protein levels of IL-6, IL-8, MMP-1, and COX-2 induced by IL-1β. Kaempferol also inhibited mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) phosphorylation and decreased IκB-α degradation and p65 protein translocation into the nucleus. Moreover, adenosine monophosphate-activated protein kinase (AMPK) does not contribute to the anti-inflammatory effects in SW982 cells, although its phosphorylation is significantly increased by kaempferol. These results indicate that kaempferol may have an anti-inflammatory effect by inhibiting expression of IL-6, IL-8, MMP-1 and COX-2 via suppressing MAPK, Akt, and nuclear factor (NF)-κB signalling but not activating AMPK signalling.