Effects of Kaempferol on Lippolysaccharide-induced Inflammation in Mouse Brain

Abstract

ABSTRACT Objectives : Brain inflammation early activates the microglia and activated microglia secrete a variety of pro-inflammatory cytokines. Kaempferol, which is a flavonoid in Cuscutae Semen, shows a wide range of physiological activities, including neurons protection and anti -inflammatory actions through inhibition of pro-inflammatory mediators. The present study examined the modu latory effect of kaempferol on cytokines 〔tumor necrosis factor- alpha (TNF-α), interleukin-1beta (IL-1β ) and interleukin-6 (IL-6)〕and cyclooxygenase-2 (COX-2) mRNA expression and microglia activation in the brain tissue of the mouse.Methods : Kaempferol was administered orally three doses of 10, 20 and 30 ㎎/㎏ respectively, once 1 hour before the lippolysaccharide(LPS) (3 ㎎/㎏, i.p.) injection. Brai n tissue was removed at 4 hours after LPS injection. Cytokines and COX-2 mRNA expression in the brain tis sue was measured by the quantitative real-time polymerase chain reaction (PCR) method. Iba1 expressi on was calculated by western blotting method. Microglia was observed with immunohistochemistry. Immunohistoch emistry stained microglia was analyzed by using ImageJ software.Results : Kaempferol 20 and 30 mg/kg was significantly attenuated the ex pression of TNF-α, IL-1β and IL-6 mRNA. Kaempfrol 10, 20 and 30 mg/kg significantly attenuated CO X-2 mRNA expression in the brain tissue. Kaempferol 30 mg/kg significantly suppressed the increase of Ib a1 protein expression by LPS. Kaempferol 30 mg/kg significantly decreased the number of microglia in the ce rebral cortex and the number and cell size of microglia in the hypothalamic region and the area percentage of ionized calcium binding adaptor molecule 1(Iba1)-expressed microglia in the hippocampus.Conclusions : This results indicate that kaempferol plays an anti-inflammatory role in the brain.Key words : Kaempferol, TNF-α, IL-1β, IL-6, COX-2, Microglia