ABSTRACT
Objective To construct a rat model of inflammatory pain by injecting complete Freund' adjuvant (CFA) to study effects of volatile oil of Acori Graminei Rhizoma on the expression of glial fibrillary acidic protein (GFAP) and immediate early gene c-fos in the basal lateral amygdale (BLA) of the inflammatory pain rats. Methods Thirty-six adult male SD rats were randomly divided into 6 groups; control group, sham group, CFA group, CFA+ 5 g/( kg · day) volatile oil of Acori Graminei Rhizoma group, CFA+10 g/(kg · day) volatile oil of Acori Graminei Rhizoma group, CFA+20 g/(kg · day) volatile oil of Acori Graminei Rhizoma group, six rats in each group were taken gavage for 21 days. Immunofluorescence and Western blotting methods were used to detect the expressions of GFAP and c-fos in the BLA of all rats. Results Immunofluorescence and Western blotting results showed that compared with the control group, the positive expression of GFAP and c-fos in the BLA of the CFA rats were significantly increased (P<0.01). After treatment of the volatile oil from Acori Graminei Rhizoma, the positive expressions of GFAP and c-fos were reduced compared to the CFA group, as well as the expression levels were decreased in the dose-dependent manner (P<0.01). Compared with the low dose group, the positive expression of GFAP and c-fos of high dose group were decreased significantly (P<0.01). Conclusion The volatile oil fraction from Acori Graminei Rhizoma could reduce the expressions of GFAP and c-fos the BLA of CFA-induced chronic inflammatory pain model rats.