title: The combination of astragalus membranaceus and ligustrazine ameliorates micro-haemorrhage by maintaining blood-brain barrier integrity in cerebrally ischaemic rats.
abstract: BACKGROUND
  Haemorrhagic transformation is an asymptomatic event that frequently occurs after following ischaemic stroke, particularly when pharmaceutical thrombolysis is used. However, the mechanism responsible for haemorrhagic transformation remains unknown, and therapeutics have not been identified. In this study, we administered a combination of astragalus membranaceus and ligustrazine to rats with cerebral ischaemia that had undergone thrombolysis. We analysed the effect of this combination on the attenuation of haemorrhagic transformation and the maintenance of blood-brain barrier integrity.
  
  
  METHODS
  A rat model of focal cerebral ischaemia was induced with autologous blood clot injections. Thrombolysis was performed via the intravenous injection of rt-PA. Astragalus membranaceus, ligustrazine or a combination of Astragalus membranaceus and ligustrazine was administered immediately after the clot injection. The cerebral infarct area, neurological deficits, blood-brain barrier integrity, and cerebral haemorrhage status were determined after 3, 6 and 24h of ischaemia. The ultrastructure of the blood-brain barrier was examined with a transmission electron microscope. The expression of tight junction proteins, including claudin-1, claudin-5, occludin, and zonula occludens-1, and matrix metallopeptidase-9 activation was further evaluated in terms of their roles in the protective effects of the combination drug on the integrity of the blood-brain barrier.
  
  
  RESULTS
  Ischaemia-induced Evans blue leakage and cerebral haemorrhage were markedly reduced in the combination drug-treated rats compared to the rats treated with either astragalus membranaceus or ligustrazine alone (p<0.05). The disruption of the ultrastructure of the blood-brain barrier and the neurological deficits were ameliorated by the combination treatment (p<0.05). The reductions in the expression of laudin-1, claudin-5, occludin, and ZO-1 were smaller in the rats that received the combination treatment. In addition, MMP-9 activity was suppressed in the combination-treated rats compared to the controls (p<0.05).
  
  
  CONCLUSIONS
  Treatment with a combination of astragalus membranaceus and ligustrazine alleviated ischaemia-induced micro-haemorrhage transformation by maintaining the integrity of the blood-brain barrier.
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China; Post-doctoral Research Center of Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Cai
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China; Post-doctoral Research Center of Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Ruihuan
authors.initials: R
authors.lastname: Pan
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Jia
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
authors.forename: Zijun
authors.initials: Z
authors.lastname: Hou
authors.affiliation: Department of Rheumatism, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Run-Yue
authors.initials: RY
authors.lastname: Huang
authors.affiliation: Department of Radiology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
authors.forename: Shengping
authors.initials: S
authors.lastname: Huang
authors.affiliation: Neuroscience and Neuroengineering Center, Med-X Research Institute, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Guo-Yuan
authors.initials: GY
authors.lastname: Yang
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China. Electronic address: 13642627661@163.com.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Sun
authors.affiliation: Diagnosis and Treatment Center of Encephalopathy, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China. Electronic address: gdszyyhy@163.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000818:Animals; D027883:Astragalus Plant / Q000737:chemistry*; D001812:Blood-Brain Barrier / Q000187:drug effects*; D002545:Brain Ischemia / Q000150:complications / Q000503:physiopathology*; D004195:Disease Models, Animal; D020300:Intracranial Hemorrhages / Q000517:prevention & control*; D008279:Magnetic Resonance Imaging; D008297:Male; D046529:Microscopy, Electron, Transmission; D010936:Plant Extracts / Q000494:pharmacology*; D011719:Pyrazines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D010936:Plant Extracts; D011719:Pyrazines; C017953:tetramethylpyrazine
keywords: Astragalus membranaceus; Brain–blood barrier; Cerebral ischaemia; Haemorrhage transformation; Ligustrazine