Abstract: In this study,we researched the effects of COX-2 specific inhibitor Rofecoxib on A beta deposition in Alzheimer's disease by immunofluorescence,Western blot and ELISA.The experiment was divided into three groups,that is wild type group,AD model group and Rofecoxib treatment group.The results showed that the number of A beta deposition and senile plaques increased,the volume enlarged compared with the wild type group,the contents of A beta 1-40 and A beta 1-42 increased,the expression of β-secretase and γ-secretase (including BACE1,PS1,PS2,NCT) elevated,and the expression of COX-2 in mouse brain increased.After treatment with Rofecoxib,A beta deposition and senile plaques decreased,the expression level of APP lyase and COX-2 were obviously lower than those in AD group.These results suggest that COX-2 specific inhibitor Rofecoxib could inhibit COX-2 expression,indirectly reduce β-secretase and γ-secretase activity,and downregulate PS1,PS2,BACE1 or NCT expressions,ultimately reduce the formation of A beta deposition and senile plaque,alleviate the occurrence and development of Alzheimer's disease.

Key words: Alzheimer’s disease, APP/PS1 transgenic mice, COX-2;Rofecoxib, Aβ, senile plaque, APP lyase