The Anti-Inflammatory Effect of Kaempferol in Aged Kidney Tissues: The Involvement of Nuclear Factor- <i>κ</i> B via Nuclear Factor-Inducing Kinase/I <i>κ</i> B Kinase and Mitogen-Activated Protein Kinase Pathways

Abstract

Kaempferol, one of the phytoestrogens, is found in berries and Brassica and Allium species and is known to have antioxidative and anti-inflammatory properties. In the present study, we examined the molecular mechanisms underlying the anti-inflammation effect of kaempferol in an aged animal model. To examine the effect of kaempferol in aged Sprague-Dawley rats, kaempferol was fed at 2 or 4 mg/kg/day for 10 days. The data show that kaempferol exhibited the ability to maintain redox balance. Kaempferol suppressed nuclear factor-kappaB (NF-kappaB) activation and expression of its target genes cyclooxygenase-2, inducible nitric oxide synthase, monocyte chemoattractant protein-1, and regulated upon activation, and normal T-cell expressed and secreted in aged rat kidney and in tert-butylhydroperoxide-induced YPEN-1 cells. Furthermore, kaempferol suppressed the increase of the pro-inflammatory NF-kappaB cascade through modulation of nuclear factor-inducing kinase (NIK)/IkappaB kinase (IKK) and mitogen-activated protein kinases (MAPKs) in aged rat kidney. Based on these results, we concluded that anti-oxidative kaempferol suppressed the activation of inflammatory NF-kappaB transcription factor through NIK/IKK and MAPKs in aged rat kidney.