摘要：

目的 探讨盐酸小檗碱对颅脑创伤（TBI）模型小鼠双侧丘脑继发性损伤（炎症反应、氧化损伤和神经元缺失）的神经保护作用。 方法 采用自由落体撞击法制备颅脑创伤模型，盐酸小檗碱组小鼠予以盐酸小檗碱50 mg/（kg·d）灌胃21 d，TBI 组予等量生理盐水灌胃21 d，对照组不予自由落体撞击。免疫组织化学染色计数双侧丘脑诱导型一氧化氮合酶（iNOS）、环氧合酶-2（COX-2）、8-羟基脱氧鸟苷（8-OHdG）和神经元核抗原（NeuN）阳性神经元或胶质细胞数目，免疫荧光染色计数双侧丘脑胶质纤维酸性蛋白（GFAP）阳性星形胶质细胞和离子钙结合蛋白1（Iba1）阳性小胶质细胞数目。 结果 3 组小鼠颅脑创伤同侧丘脑iNOS（P = 0.015）、COX-2（P = 0.022）、8-OHdG（P = 0.000）和NeuN（P = 0.000）阳性神经元或胶质细胞数目以及GFAP 阳性星形胶质细胞数目（P = 0.024）和Iba1 阳性小胶质细胞数目（P =0.000）差异均有统计学意义，其中，TBI 组iNOS（P = 0.005）、COX-2（P = 0.011）和8-OHdG（P = 0.000）阳性神经元或胶质细胞数目以及GFAP 阳性星形胶质细胞数目（P = 0.011）和Iba1 阳性小胶质细胞数目（P =0.000）均高于对照组，而NeuN 阳性神经元数目低于对照组（P = 0.000）；盐酸小檗碱组iNOS（P = 0.031）、COX-2（P = 0.024）和8-OHdG（P = 0.008）阳性神经元或胶质细胞数目以及GFAP 阳性星形胶质细胞数目（P = 0.031）和Iba1 阳性小胶质细胞数目（P = 0.012）均低于TBI 组，仅8-OHdG 阳性神经元数目（P =0.014）和Iba1 阳性小胶质细胞数目（P = 0.024）仍高于对照组，而NeuN 阳性神经元数目高于TBI 组（P =0.016）、仍低于对照组（P = 0.027）。3 组小鼠颅脑创伤对侧丘脑仅COX-2（P = 0.029）和8-OHdG（P =0.000）阳性神经元或胶质细胞数目差异有统计学意义，其中，TBI 组COX-2（P = 0.011）和8-OHdG（P =0.000）阳性神经元或胶质细胞数目高于对照组，盐酸小檗碱组COX-2（P = 0.047）和8-OHdG（P = 0.010）阳性神经元或胶质细胞数目低于TBI 组，仅8-OHdG 阳性神经元数目仍高于对照组（P = 0.004）。结论 颅脑创伤可以引起双侧丘脑继发性损伤，尤以同侧丘脑显著，对侧丘脑仅出现炎症反应和氧化损伤；盐酸小檗碱通过抑制颅脑创伤后双侧丘脑炎症反应和氧化损伤而发挥神经保护作用。

关键词: 小檗碱, 颅脑损伤, 丘脑, 炎症, 氧化性应激, 神经元, 疾病模型, 动物

Abstract:

Objective  To investigate the protective effect of berberine chloride on secondary damage (inflammation, oxidative damage and neuron loss) in bilateral thalami of traumatic brain injury (TBI) model mice.  Methods  Mice were randomly divided into 3 groups: control group (N = 6), TBI group (N = 6) and berberine group (N = 6). TBI model was established by a free-falling hitting device. In control group, mice were not given free-falling hitting. Mice in berberine group were given a gavage of berberine chloride [50 mg/（kg·d)] for 21 d, while mice in TBI group were given the same dosage of normal saline for 21 d. Immunohistochemistry was used to count the number of neurons or gliocytes positive for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), 8-hydroxy deoxyguanosine (8-OHdG) and neuronal nuclei (NeuN), the number of astrocytes positive for glial fibrillary acidic protein (GFAP) and the number of microglias positive for ionized calcium-binding adaptor molecule 1 (Iba1).  Results  The number of neurons or gliocytes positive for iNOS (P = 0.015), COX-2 (P = 0.022), 8-OHdG (P = 0.000) and NeuN (P = 0.000), the number of astrocytes positive for GFAP (P = 0.024) and microglias positive for Iba1 (P = 0.000) in TBI ipsilateral thalamus were significantly different among 3 groups. In TBI group, the number of neurons or gliocytes positive for iNOS (P = 0.005), COX-2 (P = 0.011) and 8-OHdG (P = 0.000), the number of astrocytes positive for GFAP (P = 0.011) and microglias positive for Iba1 (P = 0.000) were significantly higher than those in control group, while the number of neurons positive for NeuN (P = 0.000) was significantly lower than that in control group. In berberine group, the number of neurons or gliocytes positive for iNOS (P = 0.031), COX-2 (P = 0.024) and 8-OHdG (P = 0.008), the number of astrocytes positive for GFAP (P = 0.031) and microglias positive for Iba1 (P = 0.012) were significantly lower than those in TBI group, while the number of neurons positive for 8-OHdG (P = 0.014) and microglias positive for Iba1 (P = 0.024) were significantly higher than those in control group. The number of neurons positive for NeuN in berberine group was significantly higher than that in TBI group (P = 0.016), while lower than that in control group (P = 0.027). Additionally, number of neurons or gliocytes positive for COX-2 (P = 0.029) and 8-OHdG (P = 0.000) in TBI contralateral thalamus were significantly different among 3 groups. The number of neurons or gliocytes positive for COX-2 (P = 0.011) and 8-OHdG (P = 0.000) in TBI group was significantly higher than that in control group, while the number of neurons or gliocytes positive for COX-2 (P = 0.047) and 8-OHdG (P = 0.010) in berberine group was significantly lower than that in TBI group. The number of neurons positive for 8-OHdG in berberine group was significantly higher than that in control group (P = 0.004).  Conclusions  TBI could cause secondary damage of bilateral thalami, especially in ipsilateral thalamus, but only cause inflammation and oxidative damage in contralateral thalamus. Berberine chloride might exert neuroprotective effect on bilateral thalami after TBI by significantly suppressing inflammation and oxidative damage.

Key words: Berberine, Craniocerebral trauma, Thalamus, Inflammation, Oxidative stress, Neurons, Disease models, animal