Inhibitory effects of 17β-estradiol on inflammatory cytokines released from lipopolysaccharide stimulated microglia

Acute brain insults are decribed to be associated with activation of microglia, which produces cytokines. Inappropriate activation of microglia contributes to progressive neuronal damage and neurodegeneration. 17β-estradiol (17β-EST) is reported to be effective to prevent or to treat neurodegenerative diseases. Microglia have estrogen receptors, so that 17β-EST might affect inflammatory cytokines. In the present study, the concentration of cytokines in the supernatant of microglial culture activated by lipopolysaccharide with or without 17β-EST was measured. Interleukin-1β, tumor necrosis factor α and interleukin-6 were increased in the supernatant steeply from 3 hrs after lipopolysaccharide stimulation. Estrogen could restrain the release of those cytokines to approximately half of each level at least for 24 hrs, respectively. In conclusion, 17β-EST inhibited the release of inflammatory cytokines from lipopolysaccharide stimulated microglia. 17β-EST might play important roles in preventing acute brain damages via suppression of inflammatory cytokines.

estrogen

inflammatory cytokines

acute brain insults

neuro-immuno modulation