Animals
The C57BL/6 male mice were obtained from Nanjing University’s Model Animal Research Center, while the COX-2KO mice were kindly provided by the Chinese Academy of Sciences. All mice were bred in the Experimental Animal Center of Shanghai University of Traditional Chinese Medicine’s Experimental Animal Center. The following two groups were established with fifteen mice each: WT group and COX-2KO group, both at 9 months old. During the 12-hour light/dark cycle (lights on 7:00-19:00), all mice were housed in an environment with a temperature of 22 °C and a humidity of 55%. Water and food are available ad libitum. In accordance with the guidelines of the National Institutes of Health for the care and use of laboratory animals, all experimental protocols were strictly complied with, and were approved by Shanghai University of Traditional Chinese Medicine Animals Research Ethics Committee (No.PZSHUTCM200821019) based on the guidelines provided by the Ministry of Science and Technology of the People’s Republic of China.