AIM:To investigate the effects of astragalin(AST)on activation status of astrocytes and the ex-pression level of autophagy-related proteins in the cortex of the anterior cingulate cortex of mice with a complete Freund's adjuvant(CFA)-induced inflammatory pain model.METHODS:Twenty-four 6-month-old male C57BL/6 mice were ran-domly divided into four groups:control group,saline group,CFA model group and CFA+60 mg/kg AST administration group,and six mice in each group.Mice in the AST administration group received 60 mg/kg AST by intraperitoneal injec-tion on a body weight basis for 21 d.The paw withdrawal threshold in each group of mice was evaluated by the von Frey test.The expression levels of autophagy-related factors LC3,p62,ATG12 and beclin-1,and astrocyte activation were de-tected by multiplex immunofluorescence staining in the anterior cingulate cortex of mice in each group.Western blot was used to measure the levels of autophagy-related proteins LC3,p62,ATG12 and beclin-1 in the anterior cingulate cortex of mice in each group.RESULTS:Behavioural tests showed that AST significantly increased mechanical pain thresholds in CFA mice(P＜0.05).The results from multiple immunofluorescent staining showed that AST significantly increased the fluorescence intensity of LC3(P＜0.01),ATG12(P＜0.01)and beclin-1(P＜0.05),attenuated the fluorescence intensi-ty of p62(P＜0.05),and inhibited the activation of astrocytes in the anterior cingulate cortex of CFA mice.Western blot results further confirmed that AST significantly increased the expressions of LC3(P＜0.01),ATG12(P＜0.01),beclin-1(P＜0.01),and decreased the expression of p62(P＜0.05)in the anterior cingulate cortex of CFA mice.CONCLU-SION:AST relieves CFA-induced inflammatory pain of mice,and its analgesic mechanism may be related to the inhibi-tion of activation of cortical astrocytes in the anterior cingulate cortex and the promotion of autophagy in CFA mice.

ObjectiveTo explore the effects of astragalin （AST） on autophagy and apoptosis of astrocytes in the L_4-5 dorsal horn of the spinal cord in mice with inflammatory pain induced by complete Freund's adjuvant （CFA）. MethodsTwenty-four male C57BL/6 mice， aged six months， were randomly assigned to four groups： control group， saline group， CFA model group， and CFA+AST group， six mice in each group. The inflammatory pain model was established by injection of 10 µL CFA into the right lateral malleolus fossa. The saline group were injected with an equal amount of normal saline at the same site. The inflammatory pain mice in CFA+AST group were further treated with AST （60 mg/kg） intraperitoneally once a day for 21 consecutive days. Multiplex immunofluorescence staining was used to detect the coexpression of autophagy-related factors including ATG 12 and Beclin-1， apoptosis-related factors including Cleaved-Caspase3 and Caspase9， and the astrocyte marker such as GFAP in the L_4-5 spinal dorsal horn of the mice in each group. Western blot was used to examine the protein expression levels of autophagy-related proteins（ATG12， Beclin-1） and apoptosis-related proteins（Caspase 3， Caspase 9） in the L_4-5 spinal dorsal horn of mice. ResultsImmunofluorescent staining showed that in the L_4-5 dorsal horn of the spinal cord， the fluorescence intensity of ATG12 （P<0.000 1） and Beclin-1 （P<0.000 1） was significantly increased， while that of Cleaved-Caspase 3 （P<0.001） and Caspase 9 （P<0.000 1） was decreased in the CFA+AST group when compared to the CFA model group. Furthermore， AST could inhibit the activation of astrocytes. Western blot further confirmed that AST significantly upregulated the expression of ATG12 （P<0.000 1） and Beclin-1 （P<0.000 1） in the L_4-5 spinal cord of CFA mice， and downregulated the expression of Caspase 3 （P<0.01） and Caspase 9 （P<0.001）. ConclusionsAST promotes autophagy of astrocytes and inhibits their apoptosis in the L_4-5 spinal dorsal horn of CFA mice.