| Objective we studied the protective effect of acacetin on cerebral ischemia-reperfusion injury,and to study the effect of acacetin on activation of microglia in cerebral ischemia-reperfusion injury and its effect on the expression of inflammatory cytokines.Methods In this study,adult clean male C57BL/6J mice,weighing 25-30 g,were randomly divided into sham-operated group,ischemia-reperfusion group(MCAO),acacetin treatment group(25mg/kg)(Acacetin +MCAO)according to random number table.MCAO model was prepared by the method of thread occlusion,acacetin was given at the time of reperfusion,and 24 h after reperfusion,the effects of acacetin on cerebral infarction volume and neurological deficit were studied by behavior and TTC staining.Immunohistochemistry was used to observe the proliferation and activation of microglia cells 24 hours later after reperfusion,and the levels of inflammatory mediators such as TNF-α,IL-6 and IL-1β were determined by Elisa method.Results 1.The effect of acacetin on neurological function score of mice after ischemia-reperfusion: No neurological deficit was observed in sham-operated group,the score of neurological function of mice in MCAO group was 2.83 ± 0.41,while the score of neurological function in MCAO + Acacetin group was 1.67 ± 0.52,which was significantly lower than that in MCAO group,and the difference has statistical significance(F = 84.231,P = 0.000).2.Effect of acacetin on cerebral infarction volume in mice after ischemia / reperfusion: No TTC staining was observed in the sham-operated group,that is,no infarction was observed in the sham-operated group.However,the infarct volume in MCAO + Acacetin group was 22.15 ± 3.85mm3,which was significantly lower than that in MCAO group(70.48 ± 12.57mm3).There was a significant statistical difference(F = 135.309,P = 0.000).The results showed that acaciacin significantly reduced the infarct volume of mice after ischemia-reperfusion injury.3.Effects of acacetin on activation of microglia in brain of mice after ischemia-reperfusion: The morphological and quantitative changes of Iba-1-positive microglia in hippocampus and cortex were detected in this study.(1)Cerebral ischemia increased the number of Iba1 positive cells in the hippocampus(3.67 ± 0.79 / HP in sham-operated group and 12.37 ± 2.15 / HP for MCAO group),(P <0.01).The acacetin treatment significantly reduced the number of Iba1 positive cells after cerebral ischemia and reperfusion(MCAO + Acacetin group was 8.48 ± 1.63/ HP),There were significant differences between the 3 groups(F = 43.18,P = 0.00),The differences between MCAO+ Acacetin group and MCAO group(P=0.001)and MCAO group compared with sham operation group(P=0.00)were statistically significant.(2)The same changes were observed in the cortical area.The number of Iba-1 positive cells in the sham-operated group was 4.47 ± 0.37 / HP and significantly increased after the ischemia / reperfusion 13.13 ± 1.86 / HP,while the Iba-1 The number of positive cells decreased significantly in MCAO+Acacetin group(8.33 ± 0.98/ HP),There were significant differences between the 3 groups(F = 74.67,P = 0.00),The differences between MCAO+ Acacetin group and MCAO group(P=0.00)and MCAO group compared with sham operation group(P=0.00)were statistically significant.4.The effect of acacetin on expression of the inflammatory cytokines after cerebral ischemia-reperfusion injury in mice.The results showed that the expression of TNF-α,IL-1βand IL-6 was least in the sham-operated group(199.32 + 17.86 pg/mg,225.8 + 33.1 pg/mg and 195.57 + 54.39 pg/mg respectively).After ischemia reperfusion,the expression of TNF-α,IL-1βand IL-6 increased significantly in group MCAO(402.87 + 73.88 pg/mg,376.89 + 76.28 pg/mg and 514.05 + 60.3 pg/mg),respectively.The expression of TNF-α,IL-1βand IL-6 in MCAO+Acacetin group decreased significantly(282.09 + 53.03 + 46.2 pg/mg,280.56 pg/mg and 259.11 + 50.13 pg/mg)compared with MCAO group,and the decline was statistically significant(P<0.05).conclusion 1:Acacetin can reduce the infarct volume and improve the neurological deficits after ischemia-reperfusion in mice.2:Microglia can be proliferated and activated after cerebral ischemia-reperfusion injury,and acacetin can inhibit this proliferation and activation of microglia.3:Acacetin can inhibit the expression of inflammatory cytokines TNF-α,IL-1β and IL-6 in brain tissue after cerebral ischemia-reperfusion in mice.4:The protective effect of acacetin on brain tissue after cerebral ischemia-reperfusion may be achieved by inhibiting the proliferation and activation of microglia,thereby reducing the expression of inflammatory cytokines.Acacetin can be used as a potential neuroprotective agent for clinical ischemic stroke. |
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