肉桂醛对脑缺血再灌注损伤后大鼠脑组织自噬的影响

Effect of cinnamaldehyde on autophagy of brain tissue after cerebral ischemia reperfusion injury in rats

目的观察肉桂醛对脑缺血再灌注损伤大鼠脑血流以及脑组织自噬的影响,探讨其对脑缺血再灌注损伤大鼠脑组织保护作用的机制。方法将SD大鼠50只随机分为假手术组、模型组、肉桂醛高剂量组、3-MA组、肉桂醛低剂量组,每组10只。采用改良线栓法制备脑缺血再灌注损伤大鼠模型,肉桂醛组大鼠分别给予腹腔注射肉桂醛75 mg/(kg·d)和25 mg/(kg·d)治疗,3-MA组于造模前1 h腹腔注射3-MA(10 mg/kg),造模成功后与假手术组和模型组每天腹腔注射与高剂量肉桂醛组相同剂量的生理盐水,共治疗7 d。随后采用ZeaLonga评分法进行大鼠神经功能评分,采用激光多普勒血流仪检测大鼠大脑皮质血流速度,应用尼氏染色法观察脑组织神经元损伤情况,使用Western blot方法检测脑组织中自噬相关蛋白Beclin1、LC3II、P62的表达。结果与假手术组比较,模型组大鼠神经功能缺损评分明显增多,脑血流明显降低(P<0.01);与模型组比较,肉桂醛高剂量组大鼠神经功能缺损评分下降明显,而抑制剂组评分亦下降,且与肉桂醛高剂量组接近,差异有统计学意义(P<0.01)。与模型组比较肉桂醛高剂量组和3-MA组脑血流均明显增加(P<0.01),且肉桂醛高剂量组和3-MA组间差异无统计学意义(P>0.05)。缺血侧尼氏染色结果模型组可见尼氏小体数量减少,肉桂醛高剂量组和3-MA组尼氏小体的数量较模型组多(P<0.01)。Western blot结果与假手术组相比,模型组beclin-1和LC3II蛋白表达水平升高,而p62表达水平降低(P<0.05);与模型组比较,肉桂醛高剂量组和3-MA组beclin1、LC3II蛋白表达水平明显减少,而p62的表达水平明显增多(P<0.05)。结论肉桂醛能够改善脑缺血再灌注损伤大鼠的神经功能,且高剂量组效果最为显著,其机制与脑血流速度增加以及抑制自噬有关。

Objective To observe the effect of cinnamaldehyde on cerebral blood flow and autophagy in rats with cerebral ischemia-reperfusion injury,and to explore the mechanism of its protective effect on cerebral tissue.Methods 50 SD rats were randomly divided into sham operation group,model group,high-dose cinnamaldehyde group,3-MA group,and low-dose cinnamaldehyde group,with 10 rats in each group.Modified line bolt of of cerebral ischemia reperfusion injury in rats model of cinnamic aldehyde group rats were given abdominal injection of cinnamaldehyde 75 mg/(kg·d)and 25 mg/(kg·d)treatment,3-MA groupto build model by intraperitoneal injection of 1 h before 3-MA(10 mg/kg),after the success of the building with the control group and model group,intraperitoneal injection with high dose of cinnamic aldehyde group every day the same dose of normal saline,a total of 7 days of treatment.Then,ZeaLonga score was used to score the nerve function of the rats,the blood flow velocity of the cerebral cortex of the rats was detected by laser Doppler blood flow meter,the neuronal damage of the brain tissue was observed by Nysch staining,and the expressions of autophagy related proteins Beclin1,LC3II and P62 were determined by Western blot.Results Compared with the sham operation group,the scores of neurological deficits and cerebral blood flow in the model group were significantly increased(P<0.01).Compared with the model group,the scores of neurological impairment of rats in the high-dose cinnamaldehyde group decreased significantly,and those in the inhibitor group also decreased,and were similar to those in the high-dose cinnamaldehyde group,with statistical difference(P<0.01).Comparison with the model groupcerebral blood flow increased significantly in the high-dose cinnamaldehyde group and 3-ma group(P<0.01),and there was no significant difference between the high-dose cinnamaldehyde group and 3-ma group,with no statistical significance(P>0.05).The results of ischemic side Nissl staining showed that the number of nissl bodies in the model group decreased,while the number of Nissl bodies in the cinnamaldehyde high group and 3-MA group was more than that in the model group(P<0.01).Western blot resultsCompared with the sham group,beclin-1 and LC3II protein expression levels in the model group were increased,while p62 protein expression levels were decreased(P<0.05).Compared with the model group,Beclin-1 and LC3II protein expression levels in the cinnamaldehyde high-dose group and 3-MA group were significantly decreased,while the expression levels of P62 were significantly increased(P<0.05).Conclusion Cinnamaldehyde can improve the neurological function of rats with cerebral ischemia-reperfusion injury,and the effect is most significant in the high-dose group.The mechanism is related to increased cerebral blood flow velocity and inhibition of autophagy.