姜黄素对大鼠脊髓损伤后后肢功能恢复的作用机制

Effects of curcumin on the recovery of hind limb function after spinal cord injury in rats and its mechamism

目的:观察姜黄素(CUR)对大鼠脊髓损伤后的运动功能的影响,并探讨其对大鼠脊髓损伤的神经保护作用机制,为临床治疗脊髓损伤提供理论和实验依据。方法:采用HI-0400脊髓打击器制备脊髓急性打击损伤动物模型。将105只SD健康清洁级大鼠随机分为3组:假手术组(Sham)、脊髓损伤组(SCI)、姜黄素组(SCI+CUR),在脊髓损伤模型建立后30 min灌胃,以后每天灌胃1次,直到处死为止。SCI+CUR组0.5%羧甲基纤维素钠制备姜黄素(100 mg/kg)灌胃,Sham组与SCI组同等剂量的0.5%羧甲基纤维素钠灌胃。应用BBB评分评估大鼠术后3d,7 d,14 d,21 d和28 d后肢运动功能恢复的情况;分别在术后12 h、1 d、3 d和7 d天取脊髓组织和血液,通过免疫荧光法检测NF-κB,免疫组化发检测Bcl-2、Bax及Caspase-3蛋白,Elisa法检测Bcl-2、Bax蛋白的表达。结果 :BBB评分中3 d时SCI+CUR组与SCI组时无明显差异,7 d、14 d、21 d和28 d SCI+CUR组得分高于SCI组,其差异具有统计学意义(P<0.05);炎症因子NF-κB的表达于脊髓损伤后12 h出现,1 d达高峰,3 d下降。SCI+CUR组中NF-κB在各个时间点的表达与SCI组出现的时间点相对应,SCI+CUR组少于SCI组;Sham组无明显的Bax及Bcl-2蛋白染色。SCI+CUR组中Caspase-3及Bax染色明显较SCI组减弱,而Bcl-2较SCI组增强。结论:姜黄素可以促进大鼠脊髓损伤后后肢运动功能的恢复,其作用机制是通过抑制NF-κB而阻止炎症发生;并通过抑制Bax、Caspase-3的表达,促进Bcl-2的表达来抑制细胞凋亡,从而促进了大鼠脊髓损伤后的运动功能恢复。

Objective： To investigate the effects of curcumin on motor function, and to explore the neuroprotective mechanism of curcumin after the spinal cord injury in rats. The study will theoretical and experimental evidence for curcumin＇ s clinical treatment. Methods： HI-0400 spinal cord impactor was used to prepare animal models of acute of spinal cord injury. One hundred and five clean and healthy rats were randomly divide into three groups： sham operation group （Sham） spinal cord injury group （SCI） and curcumin group （SCI ＋ CUR）. Intragastrie administration was administrated after 30min of the spinal cord injury model, after 1 time a day, until the death. SCI ＋ CUR group was intragastric administration with curcumin （100 mg/kg） of 0.5% carbexymethyl cellulose sodium, and Sham and SCI group were treated with the same dose of 0.5 % carbexymethyl cellulose sodium. The motor function recovery of 3,7,14,21 and 28 days after spinal cord injury were evaluated by basso,beaflie,bresnahan （BBB） score. The spinal cord tissue and blood samples were collected at postoperative 12 h, 1 d, 3 d and 7 d respectively, NF- kappa B was detected by immunofluorescence, Bcl-2, Bax and Caspase-3 were detected by inununohistochemistry expression of Bcl-2 and Bax was detected by Elisa. Results： The statistic difference of BBB score between SCI group and CUR group in 3 day was not statistically significant. It was found that the 7,14,21 and 28 days BBB score in CUR group were statistically significant higher than that in SCI group（ P 〈 0.05） .The expression of inflammatory factor NF- kappa B appeared in 12 h after spinal cord injury, 1 day peaked and 3 days decreased. In SCI ＋ CUR group, the expression of NF- kappa B at each time point was similar to the SCI group , and there was a difference between group SCI ＋ CUR and SCI group in lday . There was no obvious staining of Bax and Bcl-2 in Sham group . The staining of Caspase-3 and Bax in SCI ＋ CUR group was significantly weaker than that in SCI group, while Bcl-2 was stronger. Conclusion： Curcumin can promote the recovery of hindlimb motor function after spinal cord injury in rats. The mechanism is through inhibition of NF- K B to prevent inflammation; And inhibition the expression of Bax and Caspase-3, and promotion the expression of Bcl-2 to prevent apoptosis, so as to accelerate the recovery of motor function in the rats after spinal cord injury.