黄芩茎叶总黄酮对脑缺血再灌注大脑皮质微血管和氧化应激的预防保护作用

Protective effects on microvessels injury and oxidative stress of cerebral cortex in ischemia reperfusion injured by pretreatment with scutellaria baicalensis stem-leaf total flavonoid

目的探讨黄芩茎叶总黄酮(SSTF)对缺血再灌注大鼠大脑皮质微血管损伤和氧化应激的预防保护作用。方法随机将60只SD大鼠分为假手术对照组(sham组)、缺血再灌注模型组(IR组)、SSTF预处理组(SSTF组)和尼莫地平阳性对照组(NIM组)。术前1周SSTF组和NIM组分别灌胃给SSTF 100 mg/(kg·d)、尼莫地平10 mg/(kg·d),共7 d。线栓法制作大脑中动脉缺血再灌注模型,术后进行神经行为学评分,单宁酸-氯化铁法观测缺血区大脑微血管密度(MVD)和微血管面积比(MVA),光镜观察大脑皮质病理变化,检测SOD、GSH-Px活性和MDA含量的变化。结果 IR组神经功能缺损评分显著增高,MVD、MVA减少,神经元缺失、肿胀,SOD、GSH-Px活性明显降低,MDA量增加;SSTF组、NIM组神经功能评分比IR组明显降低(P<0.001),MVD、MVA增加(P<0.001),神经元和胶质细胞损伤减轻,SOD、GSH-Px活性增高,MDA含量降低(P<0.001);SSTF组与NIM组的组间差异无统计学意义(P>0.05)。结论 SSTF预处理可通过增加大脑皮质微血管再通和相关酶的活性,减轻脑水肿和神经元损伤,预防性保护大脑组织。

Objective To study the protective effects on ischemia reperfusion injury on microvessels injury and ox- idative stress of focal cerebral cortex with scutellaria baicalensis stem-leaf total flavonoid （SSTF） in rats. Methods The 60 Sprage-Dawley rats were divided randomly into four groups：sham group, ischemia reperfusion group, SSTF pretreated group （ SSTF group） and nimodipine group. SSTF group and nimodipine group were respectively admin- istrated with SSTF 100 mg/（kg · d） or nimodipine 10 mg/（kg· d） one week before operation, sham group and model group only administrated with NS 10 mg/（ kg · d） ig for 7 days. The model group, SSTF group and nimodipine group were prepared into the ischemia reperfusion models, and then evaluated the neurological deficit score of the rats, invested the microvessels density（MVD） and microvessel area（MVA） ratio with Tannic acid-fer- ric chloride staining methods （TA-Fe）, tested SOD and GSH-Px activity and MDA containing with biochemical criterion. Results The results showed that the neurological deficit scores were obviously increased in model group compared with that of the sham group,MVD and MVA were reduced（P 〈0. 001 ） ,the activity of SOD and GSH- Px was reduced（P 〈 0. 001 ）, the content of MDA increased, the neurological deficit scores in SSTF group and nimodipine group were obviously decreased compared with that of the IR group （ P 〈 0. 001 ）, MVD and MVA were increased （P 〈 0. 001 ）, neuron and neurogliocyte were decreased, the activity of SOD and GSH-Px was increased,content of MDA was decreased, there was no significant difference between the SSTF group and the nimodipine group （P 〉 0. 05）. Conclusion SSTF pretreatment can exert preventive protective effects on cerebral tissue through relieving brain edema, decrease neural damage, promote microvascular repatency and increase enzyme activity.