黄芪甲苷对大鼠创伤性脑损伤后脑水肿、炎症反应、细胞凋亡的影响

Effects of astragaloside IV on brain edema,inflammatory response and cell apoptosis after traumatic brain injury in rats

目的探讨黄芪甲苷对大鼠创伤性脑损伤后脑水肿、炎症反应、细胞凋亡的影响。方法将120只SD大鼠随机分为假手术组、模型组和黄芪甲苷组,每组40只。模型组和黄芪甲苷组运用Feeney DM法制作创伤性脑损伤模型,假手术组不进行击打。造模成功后,黄芪甲苷组给予黄芪甲苷20 mg/(kg·d)腹腔注射,假手术组和模型组每天给予等量0.9%NaCl腹腔注射直至处死。分别于造模后12 h、1 d、3 d、5 d、7 d进行改良大鼠神经功能缺损严重程度评分(mNSS)和脑组织含水量检测;取造模后3 d脑组织,HE及尼氏染色观察脑组织神经细胞病理形态学变化,TUNEL法检测损伤灶周围脑组织神经元细胞凋亡情况,ELISA法测定损伤灶及周围脑组织炎症因子白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)含量。结果造模后12 h、1 d、3 d、5 d、7 d,模型组、黄芪甲苷组mNSS评分和脑组织含水量均明显高于同期假手术组(P均<0.05),且mNSS评分造模后12 h最高,脑组织含水量造模后3 d达到峰值,此后均逐渐降低;黄芪甲苷组造模后12 h mNSS评分和造模后12 h、1 d脑组织含水量与模型组比较差异均无统计学意义(P均>0.05);黄芪甲苷组造模后1 d、3 d、5 d、7 d mNSS评分及造模后3 d、5 d、7 d脑组织含水量均明显低于同期模型组(P均<0.05)。HE及尼氏染色显示模型组大鼠有明显脑组织细胞变性坏死、炎性细胞浸润等病变,神经元细胞大量减少、排列紊乱,尼氏体明显减少;与模型组比较,黄芪甲苷组神经元细胞和尼氏体增多,神经元损伤轻。造模3 d后,模型组和黄芪甲苷组大鼠脑组织神经细胞凋亡率、损伤灶及周围脑组织中TNF-α、IL-6、IL-1β含量均明显高于假手术组(P均<0.05),黄芪甲苷组均明显低于模型组(P均<0.05)。结论黄芪甲苷可以通过减轻脑组织水肿及神经细胞损伤,抑制神经细胞凋亡及中枢性炎症反应而起到神经保护作用。

Objective It is to investigate the effects of astragaloside IV on brain edema,inflammatory response and cell apoptosis after traumatic brain injury(TBI)in rats.Methods One hundred and twenty SD rats were randomly divided into sham operation group,model group and astragaloside IV group,with 40 rats in each group.Traumatic brain injury models were made by Feeney DM method in the model group and astragaloside IV group,while the sham operation group was not subjected to beating.After successful modeling,the astragaloside IV group was given astragaloside IV 20 mg/(kg·d)by intraperitoneal injection,and the sham operation group and model group were given the same amount of 0.9%NaCl by intraperitoneal injection every day until sacrificed.At 12 h,1 d,3 d,5 d,and 7 d after modeling,the modified neurological severity score(mNSS)was evaluated and the water content of brain tissue was detected in the rats.The brain tissue was taken in 3 days after modeling,the pathological changes of nerve cells in the brain tissue were observed by HE and Nissl staining,the apoptosis of neurons in the brain tissue around the injury focus was detected by TUNEL method,and the contents of inflammatory factors interleukin-6(IL-6),IL-6 and IL-1β,tumor necrosis factor-α(TNF-α)were detected by ELISA method.Results At 12 h,1 d,3 d,5 d,and 7 d after modeling,the mNSS score and water content of brain tissue in the model group and astragaloside IV group were significantly higher than those in the sham-operated group at the same period(all P<0.05),and the mNSS score was the highest at 12 h after modeling,the water content of brain tissue reached the peak at 3 d after modeling,and then both gradually decreased.There was no significant difference in the mNSS score at 12 hours after modeling and water content of brain tissue at 12 hours and 1d after modeling between astragaloside IV group and model group(all P>0.05);the mNSS scores at 1 d,3 d,5 d,and 7 d after modeling,and water content of brain tissue at 3 d,5 d,and 7 d after modeling in the astragaloside IV group were significantly lower than those in the model group at the same period(all P<0.05).HE and Nissl staining showed that the rats in the model group had obvious brain tissue cell degeneration and necrosis,inflammatory cell infiltration and other lesions,and their neuron cells were greatly reduced and disordered,and their Nissl bodies were significantly reduced.Compared with the model group,the number of neurons and Nissl bodies in the astragaloside IV group increased,and the neuron damage was milder.After 3 days of modeling,the apoptosis rate of nerve cells in the brain tissue of the rats in the model group and the astragaloside IV group,and the contents of TNF-α,IL-6 and IL-1βin the injury focus and surrounding brain tissue were significantly higher than those in the sham operation group(all P<0.05),while the astragaloside IV group was significantly lower than the model group(P<0.05).Conclusion Astragaloside IV can play a neuroprotective role by relieve brain tissue edema and nerve cell damage,inhibiting nerve cell apoptosis and central inflammatory response.