Effects of chemical synthesized curcumin preconditioning on the expression of AQP-4 and cerebral edema after focal cerebral ischemia/reperfusion damage in rats

Aim To explore the effect of chemical synthesized curcumin(Cur) preconditioning on the expression of aquaporin 4(AQP-4) and cerebral edema after focal cerebral ischemia-reperfusion damage in rats.Methods Local ischemia/reperfusion model of middle cerebral artery occlusion(MCAO) was made by inserting a nylon thread into internal carotid artery in rats.72 healthy SD rats weighing 290~310 g were randomly divided into 3 groups: sham operated group(S)(n=18),ischemia/reperfusion group(I)(n=18),Cur group(C1 and C2)(n=18) which were preconditioned with cur 50 or 100 mg·kg-1 intraperitoneally 30 min before focal cerebral ischemia-reperfusion.In I group,NS was given instead of Cur and in S group,the carotid arteries were exposed without performing MCAO.The rats in I group and C1,C2 group were killed 24 hours after cerebral ischemia/reperfusion.Neurological scores were studied,method of dry/wet weight was used to observe water content,and Evans Blue(EB) was collected to observe the changes of blood-brain barrier(BBB) permeability.Expression of AQP-4 and activation of c-Jun N-terminal kinase(JNK) in rat brain were determined by Western blot.Results Sham operated group presented no neurological changes.The water content and EB in C1 and C2 group were significantly lower than those of Ⅰ group(P0.05).Curcumin could also alleviate the expression of AQP-4 and the phosphorylation of JNK(P0.05).The neurological deficiency scores in C1 and C2 groups were obviously higher than those of I group(P0.05).Conclusions Chemical synthesized curcumin can alleviate the expression of AQP-4 and the phosphorylation of JNK,therefore protect the structure of BBB and alleviate the cerebral edema which can exert the neuroprotective effect after focal cerebral ischemia and reperfusion.