RESUMO
OBJECTIVE To explore the effect mechanism of ethanol extract from Atractylodes macrocephala （EEAM） on microglial phagocytosis and degradation of amyloid β （Aβ） based on peroxisome proliferator-activated receptor γ （PPAR- γ） signaling pathway. METHODS Taking neuromicroglial cell BV2 as subjects， confocal microscopy was used to observe the effects of EEAM （0.3， 0.4， 0.5 mg/mL， similarly hereinafter） on phagocytosis and degradation of Aβ in microglia. Human embryonic kidney cell HEK293 was used to investigate the effects of EEAM on luciferase transcriptional activity of PPAR-γ. The effect of EEAM on nuclear translocation of PPAR-γ was investigated by immunofluorescence. Alzheimer’s disease BV2 cell model was induced by Aβ1-42， and quantitative polymerase chain reaction was used to investigate the effects of EEAM on mRNA expressions of PPAR-γ downstream target genes （Lxra， Lxrb， Abca1， Abcg1， Cd36， Sra and Apoe）. RESULTS The results of Aβ uptake experiment showed that after the intervention of medium and high doses of EEAM， fluorescence intensity of Aβ in BV2 cells increased significantly （P＜0.05）. The degradation experiment of Aβ showed that after the intervention of medium and high doses of EEAM， fluorescence intensity of Aβ in BV2 cells decreased significantly （P＜0.05）. After the intervention of different doses of EEAM， luciferase transcriptional activity of PPAR-γ in HEK293 cells increased significantly （P＜0.05）； fluorescence intensity of PPAR-γ in BV2 cells and nuclei （except for low-dose group） increased significantly （P＜0.05）. mRNA expressions of Lxra， Lxrb， Abca1， Abcg1， Cd36， Sra and Apoe in BV2 cells were increased significantly （P＜0.05）. CONCLUSIONS EEAM can promote the uptake and degradation of Aβ in microglia by activating PPAR-γ signaling pathway， thus improving Alzheimer’s disease.