田蓟苷对脑小血管病大鼠模型认知功能受损和神经细胞凋亡的影响

Effects of Tilianin on Cognitive Impairment and Neuronal Apoptosis in a Rat Model of Cerebral Small Vessel Disease

目的:探讨田蓟苷对脑小血管病(cerebral small vessel disease,CSVD)大鼠模型认知功能受损和神经细胞凋亡的影响及机制。方法:将SD大鼠分为Sham组、CSVD组、低剂量田蓟苷组(L-Til组,5 mg/kg/d)、中剂量田蓟苷组(M-Til组,10 mg/kg/d)和高剂量田蓟苷组(H-Til组,20 mg/kg/d)。通过同种系微栓子体外注入法建立CSVD大鼠模型,各组大鼠均治疗4周。治疗结束后对各组大鼠进行Morris水迷宫测试,分离海马组织并进行HE染色、TUNEL染色和尼氏染色。通过免疫组化染色或Western blot检测大鼠海马组织中Bax、Bcl2、cleaved caspase-3、VEGF和细胞核NF-κB p65的表达。使用相应试剂盒检测血清炎症指标(TNF-α和IL-1β)和氧化应激指标(SOD和MDA)水平。结果:与CSVD组比较,L-Til组、M-Til组和H-Til组的逃避潜伏期均缩短,而穿越平台次数均增加(P<0.05)。与CSVD组比较,L-Til组、M-Til组和H-Til组大鼠海马组织TUNEL阳性率降低,而尼氏体光密度增加(P<0.05);Bax和cleaved caspase-3的表达水平降低,Bcl2水平升高(P<0.05)。与CSVD组比较,L-Til组、M-Til组和H-Til组大鼠血清中TNF-α、IL-1β和MDA水平降低,SOD升高(P<0.05)。与CSVD组比较,L-Til组、M-Til组和H-Til组大鼠海马组织中细胞核NF-κB p65蛋白表达水平降低,细胞质VEGF蛋白表达水平升高(P<0.05)。结论:本研究证明田蓟苷可减轻CSVD大鼠的认知功能障碍并抑制神经细胞凋亡,田蓟苷对CSVD的治疗机制部分通过减少炎症和氧化应激、促进VEGF的表达和抑制NF-κB信号通路来实现。

Objective:To investigate the effect and mechanism of tericin on cognitive impairment and neuronal apoptosis in a rat model of cerebral small vessel disease(CSVD).Methods:SD rats were divided into Sham group,CSVD group,low-dose tilianin group(L-Til group,5 mg/kg/d),middle-dose tilianin group(M-Til group,10 mg/kg/d)and high-dose tilianin group(H-Til group,20 mg/kg/d).The CSVD rat model was established by in vitro injection of the same germline microemboli,and the rats in each group were treated for4 weeks.After the treatment,Morris water maze test was performed on the rats in each group,and the hippocampal tissue was separated and stained with HE,TUNEL and Nissl.The expressions of Bax,Bcl2,cleaved caspase-3,VEGF and nuclear NF-κB p65 in hippocampus were detected by immunohistochemical staining or Western blot.The levels of serum inflammatory indexes(TNF-αand IL-1β)and oxidative stress indexes(SOD and MDA)were detected by corresponding kit.Results:Compared with that in the CSVD group,the escape latency decreased in L-Til group,M-Til group and H-Til group,and the number of crossing the platform increased(P<0.05).Compared with that in the CSVD group,the positive rate of TUNEL decreased in hippocampus of L-Til group,M-Til group and H-Til group,while Nissl body optical density increased(P<0.05);The expression levels of Bax and cleaved caspase-3 decreased,while Bcl2 increased(P<0.05).Compared with that in the CSVD group,the serum levels of TNF-α,IL-1βand MDA decreased in L-Til group,M-Til group and H-Til group,while SOD increased(P<0.05).Compared with that in the CSVD group,the nuclear NF-κB p65protein expression level decreased in hippocampus of L-Til group,M-Til group and H-Til group,while the cytoplasmic VEGF protein expression level increased(P<0.05).Conclusion:This study shows that tilianin can alleviate cognitive impairment and inhibit neuronal apoptosis in CSVD rats.The therapeutic mechanism of tilianin on CSVD is partly achieved by reducing inflammation and oxidative stress,promoting VEGF expression and inhibiting NF-κB signal pathway.