摘要
目的:积雪草苷(Asiaticoside,AS)属中药积雪草的主要活性成分,本实验采用急性脊髓损伤大鼠模型,探讨AS对大鼠神经元损伤的保护作用,并初步探讨作用机制,为AS治疗ASCI提供理论依据。
方法:大鼠随机分为模型组、甲基强的松龙(methylprednisolon,MP)组、AS高、低剂量(45mg/kg、15mg/kg)组及假手术组,用改良Allen’s打击法建立大鼠急性脊髓损伤模型。术后24h、72h、7d、14d和28d各时间点BBB评分法检测大鼠后肢运动功能,用苏木精-伊红染色对损伤脊髓组织进行病理检查,黄嘌呤氧化酶法检测大鼠损伤脊髓组织SOD活性改变,TBA法检测MDA含量变化,RT-PCR检测大鼠脊髓COX-2 mRNA表达,免疫组织化学法检测大鼠脊髓COX-2蛋白表达及原位末端标记法(TUNEL)检测大鼠脊髓神经元凋亡。
结果:与假手术组相比,术后24h急性脊髓损伤模型组大鼠BBB评分明显降低,脊髓有广泛灶性出血,大量的红细胞渗出,间质性水肿严重,核固缩,脊髓MDA含量增加、SOD活性明显降低,脊髓神经元出现大量凋亡,COX-2 mRNA和蛋白表达明显增强;术后72h、7d、14d和28d以上指标逐步改善。与模型组相比,术后24h、72h、7d、14d和28d各时间点,AS高、低剂量治疗组(45mg/kg、15mg/kg)和MP组(30mg/kg)均能改善大鼠BBB评分,降低MDA含量,提高SOD活性,减轻大鼠脊髓神经元凋亡,下调脊髓COX-2蛋白及mRNA的表达(P﹤0.05)。
结论:改良Allen’s打击法可致大鼠神经元损伤、后肢运动功能减退,诱导COX-2mRNA和蛋白表达。积雪草苷能减轻脊髓病理损伤,改善运动功能,对脊髓神经元有保护作用。其机制可能与抑制氧化应激和炎症反应,抑制神经元凋亡有关。
Objective: To study the effects of Asiaticoside , the major active component of traditional Chinese herb‘Centella asiatica’, on model of acute spinal cord injury in rats and its possible protective mechanisms, and to provide a theoretical basis of AS for the treatment of ASCI.
Methods : Rat model of acute spinal cord injury was established by modified Allen’s method. One hundred and forty rats were divided randomly into the normal group,the model group , and the groups treated with Asiaticoside (15mg/kg and 45mg/kg) and methylprednisolon (30mg/kg). At 24h, 72h, 7d, 14d and 28d after operation, motor functions of the rat hind limbs were determined by the BBB(Basso Beattie and Bresnahan), morphologic changes of spinal neurons were evaluated by HE staining, the changes of SOD activity and MDA contents in rat spinal cord were measured by xanthinoxidase method and the method of TBA separately. The COX-2 mRNA and COX-2 protein expression in rat spinal cord were detected by RT-PCR and immunohistochemistry, separately. The apoptosis of neural cells was assessed with the terminal deoxynucleotidyl transferase mediated deoxyuredine triphosphate-digoxin nick end labeling (TUNEL)method.
Results: It was observed that at 24h, 72h, 7d, 14d and 28d after operation, the motor functions of the rat hind limbs about the acute spinal cord injury model group were decreased; extensive focal hemorrhage of spinal cord, large quantity of diapedesis of erythrocyte, severe interstitial edema and karyopyknosis were observed; levels of MDA were increased and activities of SOD were decreased in spinal cord tissue; TUNEL positive cells were significantly increased, as well as the protein and mRNA expression of COX-2 in the spinal cord increased,the extreme value of every index presented at 24h after operation. Treatments with AS (45 and 15mg/kg) or MP(30mg/kg)could significantly ameliorate the motor functions of the rat hind limbs, markedly decrease the elevation of MDA levels and increase the activities of SOD in spinal tissue. Meanwhile, TUNEL positive cells were significantly decreased , the damage to nerve cells were alleviated and protein and mRNA expression of COX-2 in spinal tissue induced by the acute spinal cord injury were inhibited,with statistical significance as compared with the model group at 24h, 72h, 7d, 14d and 28d after operation.
Conclusion: Acute spinal cord injury can induce motoneuron damage in rats and decrease the rat hindlimbs locomotor function and induce markedly the expression of COX-2 mRNA and protein. The administration of Asiaticoside possesses neuroprotective effect on ASCI,which can improve neurological function recovery and attenuate secondary spinal cord injury.
引文
[1] Liu C, Jin A, Zhou C, et al. Gene expression of inducible nitric oxide synthase in injured spinal cord tissus [J]. Chin J Traumatol, 2001, 4 (4): 231-233.
[2]赵寅涛,李立新,戴建础.雪旺细胞和纤连蛋白对脊髓损伤后功能恢复的初步研究[J].中国现代医学杂志.2000, 10(2): 3-5
[3]王栋,贺两京.胚胎脊髓移植与甲基强的松龙联合应用治疗脊髓损伤的试验研究[J].中国脊柱脊髓杂志.2002,12(1):35
[4]刘明,刘兴波.三七总皂甙对大鼠脊髓损伤后神经功能恢复作用的研究[J].锦州医学院学报,2006,27(4):29.
[5]李光辉,李锋,陈超,等.川芎嗪对大鼠脊髓损伤后线粒体功能的保护作用[J].中国中医急症,2005,14(10):991-992
[6]沈宁江,王宇田,林庆彪,等.汉防己甲素治疗急性脊髓损伤的实验研究[J].中国骨与关节损伤杂志,2006,21(7):533
[7]尚建伟,孔抗美,齐伟力,等.人参皂甙对大鼠脊髓损伤后神经细胞凋亡的影响[J].广东医学,2006,27(1):37.
[8]王磊,刘云会.复方丹参对大鼠脊髓损伤后髓磷脂碱性蛋白基因表达的影响[J].中医药学刊,2006,24(8):1537
[9]何国,利天增,曾运家等.积雪草苷加中药外洗剂治疗烧伤性增生性瘢痕[J].实用医学杂志,2000,16(8) :690
[10]谢举临,利天增,祁少海,等.积雪草苷对体外培养的成纤维细胞的作用[J].中山医科大学学报,2001,22(1):41
[11] Cheng CL, Koo MWL. Effect of Centella asiatica on ethanolinduced gastric mucosal lesionsin rats[J]. Life Sci,2000,67(21):2647
[12] Babu T.D, Kuttan G, Padikkala J, Cytotoxic and antitumour propertyes of certain taxa of Umbelliferae with special refernce to Centella asiatica (L.) Urban [J]. Joumal of Ethnopharmacology, 1995,48(1):53-57
[13]陈瑶,秦路平,芮耀诚,郑汉臣,殷明.积雪草提取物抗抑郁作用实验研究[J].中国药理学会通讯,2002,19(1) :70
[14]李洪忠,万敬员,周岐新等.积雪草苷对小鼠胶原诱导性关节炎的抑制作用[J].药学学报,2007, 42(7) :698-703
[15]章卓,万敬员,李洪忠等.积雪草苷对脂多糖诱导大鼠发热的预防及对相关炎症因子的影响[J] ,中国药理学与毒理学杂志,2007,21(3):229-234
[1] Bozbuga M,Izgi N,Canbolat A.The effects of chronic alpha—tocopherol administration on lipid peroxidation in an experimental model of acute spinal cord injury[J].Neurosurg Rev,1998,21(1):36-42
[2] Basso D M,Beattie M S,Bresnahan J C.A sensitive and reliable locomtor rating scale for open field testing in rats[J].J Neurotrauma,1995,12(1):1-12
[3] Bardakci H . Kaplan S . Karadeniz U . et al . Methylene blue decreases ischemia-reperfusion (I/R)-induced spinal cord injury:an in vivo study in an I/R rabbit mode1[J].Eur Surg Res 2006;38(5):482-488
[4] Kudo Y.Ohtaki H Dohi K.et al.Neuronal damage in rat brain and spinal cord after cardiac arrest and massive hemorrhagic shock[J].Crit Care Med 2006;34(11):2820-2826
[5] Pineau l,Lacroix S. Proinflammatory cytokine synthesis in the injured mouse spinal cord:Multiphasic expression pattern and identification of the cell types involved.J Comp Neurol 2007;500(2):2672-2685
[6]郭世绂,胥少汀脊髓损伤基础与临床[M].北京:人民卫生出版社,1992
[7]申存英.外伤后脊髓空洞症[J].中华创伤杂志,1994,3:117
[8]郭畹华.胶质细胞与神经再生[J].解剖学报,1993,24(4):424
[9] Basso DM,Beattie MS,Bresnahan J C.Graded histological and locomotor outcomes after spinal cord contusion using the NYU weight-drop device versus transaction[J].Exp Neurol,1996,139(2):244-256
[10]宋焕瑾,刘淼,雷文黎,等.银杏叶提取物对大鼠脊髓损伤下肢运动功能的影响[J].西安交通大学学报(医学版),2005,26(2):166-168.
[11] Sgherza AL, Axen K, Fain R, et al.Effect of naloxone on perceived exertion and exercise capacity during maximal cycle ergometry[J]. Appl Physiol, 2002, 93(6):2023-2028.
[12] Keller JN, Kindy MS, Holtsberg FW, et al.Mitochondrial manganese superoxide dismutase prevents neural apoptosis and reduces ischemic brain injury: suppression of peroxynitrite production, lipid peroxidation, and mitochondrial dysfunction [J]. JNeurosci, 1998, 18(2):687-697.
[13] Kaizer RR, Correa MC, Spanevello RM, et al.Acetylcholinesterase activation and enhanced lipid peroxidation after long-term exposure to low levels of aluminum on different mouse brain regions [J]. J Inorg Biochem, 2005, 99(9):1865-1870.
[14] McCord JM. Free radicals and myocardial ischemia: overview and outlook [J].Free Radic Biol Med, 1988, 4(1):9-14.
[15] Sgherza AL, Axen K, Fain R, et al.Effect of naloxone on perceived exertion and exercise capacity during maximal cycle ergometry [J]. J Appl Physiol, 2002, 93(6):2023-2028.
[16] Keller JN, Kindy MS, Holtsberg FW, et al.Mitochondrial manganese superoxide dismutase prevents neural apoptosis and reduces ischemic brain injury: suppression of peroxynitrite production, lipid peroxidation, and mitochondrial dysfunction [J]. J Neurosci, 1998, 18(2):687-697.
[17] Kaizer RR, Correa MC, Spanevello RM, et al.Acetylcholinesterase activation and enhanced lipid peroxidation after long-term exposure to low levels of aluminum on different mouse brain regions [J]. J Inorg Biochem, 2005, 99(9):1865-1870.
[1] Kawas C, Resnick S, Morrison A, et al. A prospective study of estrogen replacement therapy and the risk of developing Alzheimer's disease: the Baltimore Longitudinal Study of Aging [J]. Neurology, 1997, 48(6):1517-1521
[2] Hoozemans JJ, van Haastert ES, Veerhuis R, et al. Maximal COX-2 and ppRb expression in neurons occurs during early Braak stages prior to the maximal activation of astrocytes and microglia in Alzheimer's disease [J]. J Neuroinflammation, 2005,
[3] Hoozemans JJ, O'Banion MK. The role of COX-1 and COX-2 in Alzheimer's disease pathology and the therapeutic potentials of non-steroidal anti-inflammatory drugs [J]. Curr Drug Targets CNS Neurol Disord, 2005, 4(3):307-315
[4] Consilvio C, Vincent AM, Feldman EL. Neuroinflammation, COX-2, and ALS--a dual role? [J]. Exp Neurol, 2004, 187(1):1-10
[5] Wang T, Pei Z, Zhang W, et al. MPP+-induced COX-2 activation and subsequent dopaminergic neurodegeneration [J]. FASEB J, 2005, 19(9):1134-1136
[6] Lukiw WJ, Percy ME, Kruck TP. Nanomolar aluminum induces pro-inflammatory and pro-apoptotic gene expression in human brain cells in primary culture [J]. J Inorg Biochem, 2005, 99(9):1895-1898
[7] Candelario-Jalil E, Gonzalez-Falcon A, Garcia-Cabrera M, et al. Assessment of the relative contribution of COX-1 and COX-2 isoforms to ischemia-induced oxidative damage and neurodegeneration following transient global cerebral ischemia [J]. J Neurochem, 2003, 86(3):545-555
[8] Aimone JB,Leasure JL,Perreau Vm,et a1.Spatial and temporal gene expression profiling of the contused rat spinal cord.Exp Neurol,2004, 1 89:204—22 1.
[9] Thompson CB Apoptosis in the pathogenesis and treatment of disease.Science,1995,267:1456-1462.
[10] Jan H,Wijsman,Richard R,et al.A new method to detect apoptosis in paraffin sections in situ end labeling of fragmented DNA[J].J Histochem,1993,41(1):7-12
[11] Casha S.Yu W R,Fehlings MG.FAS deficiency reduces apoptosis, spares axons and improves function after spinal cord injury.Exp, Neurol,2005,196:390-400.
[1] Jike Lu,Ken WS Ashwell,Phil Waite.Advances in secondary spinal cord injury:Role of apoptosis Spine,2000,14:1859-1866
[2] Emery E,Aldana P,Bunge MB,et a1.Atx tosis after traumatic pinal cord injury.J Neurosurg,1998,89:911-920
[3] Sharma HS,Westman J,Olsson Y,et a1.Involvement of nitric oxide in acute spinal cord injury : An immunocytochemical study using light and electronmicroscopyinthe rat.NeurosciReS,1996,24:373-384.
[4] Taoka Y,Okajima K,Uchiba M.Role of neutrophils in spinal cord in-jmy in the rat.Neurosci,1997,79:1177-1182.
[5] Uchida K,Baba H, Maezawa Y,et al.Progressive changes in neurofilament proteins an d growth-associated protein-43 immunoreactivities at the site of cervical spinal cord compression in spinal hyperostotic mice.Spine,2002,27:480-486.
[6] Bigini P,Bas tone A, Mennini T. Glutamate transporters in the spinal Cord of the wobbler mouse. Neumrepo rt,2001,12:1815-l820.
[7] Gold BG, Villafranca JE. Neuroimmunophilin ligands: the development of novel neumregenerative/neumpmtective compounds.Curt Top Med Chem ,2003,3:1368-1375
[8] Fitzgerald T , Kim D , Karakozis S , et a1 . Visceral isehaemia after cardiopulmonary bypass.Am J Surg,2000,66:623-626.
[9] Ghosh S,Roberts N,Firmin RK,et a1.Risk factors for intestinal ischaemia in cardiac surgical patients.Eur J Cardiothorae Surg,2002,21:411-4l6
[10] Markov A K, Neely W A,Didlak R H ,et a1. Metabolic responses to Fructose-1,6-diphosphate in health subjects.Metabolism,2000,49:698-703.
[11] Rogido M .Husson I.Bonnier C,et a1.Fructose-1,6-biphosphate prevents excltotoxic neuronal cell death in the neonatal mouse brain[J].Brain Res Dev Brain Res. 2003.140(2):287-97