AIMTo investigate the effects of curcumin on the behavior of chronic constrictive injury (CCI) rats and the p-ERK, p-CREB, c-fos expression in dorsal root ganglion.

METHODS108 male SD rats were randomly divided into 6 groups: (1) Control group (treated with CCI); (2) Sham operation group; (3) Solvent contrast group; (4) Curcumin treated group(Cur 30, Cur 100, Cur 300), treated with CCI, intraperitoneal injected with curcumin 30 mg x kg(-1) x d(-1), 100 mg x kg(-1) x d(-1), 300 mg x kg(-1) x d(-1) for 14 days after operation respectively. Thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) of rats were determined, respectively. Rats were killed on the 3th, 7h, 14th day after operation. The expression of p-ERK, p-CREB, c-fos in dorsal root ganglion were assessed by immunohistochemical analysis.

RESULTSIn Con group, the MWT and TWL declined gradually after operation. On the 3rd day, the rats represented the severest mechanical and thermal hyperalgesia(MWT was 15.3 +/- 3.0 g, TWL was 4.6 +/- 1.0 s). The expression of p-ERK, p-CREB, c-fos neurons were markedly increased in dorsal root ganglion. In Cur group, the MWT and TWL were also declined gradually, which were higher than Con group. On the 3rd day, the rats represented the severest mechanical and thermal hyperalgesia (MWT was 22.6 +/- 4.0 g, TWL was (5.6 +/- 1.1l)s in Cur 100 group), the expression of p-ERK, p-CREB, c-fos in dorsal root ganglion were lower than control group at each timepoint in each group.

CONCLUSIONCurcumin could attenuate the activation of p-ERK, p-CREB, c-fos in dorsal root ganglion to ameliorate the CCI-induced neuropathic pain.