Background and Purpose Ischemic stroke is a destructive cerebrovascular disease and a leading cause of death. Yet, no ideal neuroprotective agents are available, leaving prevention an attractive alternative. The extracts from the fruits of Lycium barbarum (LBP), a Chinese anti-aging medicine and food supplement, showed neuroprotective function in the retina when given prophylactically. We aim to evaluate the protective effects of LBP pre-treatment in an experimental stroke model. Methods C57BL/6N male mice were first fed with either vehicle (PBS) or LBP (1 or 10 mg/kg) daily for 7 days. Mice were then subjected to 2-hour transient middle cerebral artery occlusion (MCAO) by the intraluminal method followed by 22-hour reperfusion upon filament removal. Mice were evaluated for neurological deficits just before sacrifice. Brains were harvested for infarct size estimation, water content measurement, immunohistochemical analysis, and Western blot experiments. Evans blue (EB) extravasation was determined to assess blood-brain barrier (BBB) disruption after MCAO. Results LBP pre-treatment significantly improved neurological deficits as well as decreased infarct size, hemispheric swelling, and water content. Fewer apoptotic cells were identified in LBP-treated brains by TUNEL assay. Reduced EB extravasation, fewer IgG-leaky vessels, and up-regulation of occludin expression were also observed in LBP-treated brains. Moreover, immunoreactivity for aquaporin-4 and glial fibrillary acidic protein were significantly decreased in LBP-treated brains. Conclusions Seven-day oral LBP pre-treatment effectively improved neurological deficits, decreased infarct size and cerebral edema as well as protected the brain from BBB disruption, aquaporin-4 up-regulation, and glial activation. The present study suggests that LBP may be used as a prophylactic neuroprotectant in patients at high risk for ischemic stroke.
References
[1]
Latour LL, Kang DW, Ezzeddine MA, Chalela JA, Warach S (2004) Early blood-brain barrier disruption in human focal brain ischemia. Ann Neurol 56: 468–477.
[2]
Ballabh P, Braun A, Nedergaard M (2004) The blood-brain barrier: an overview: structure, regulation, and clinical implications. Neurobiol Dis 16: 1–13.
[3]
Balami JS, Chen RL, Grunwald IQ, Buchan AM (2011) Neurological complications of acute ischaemic stroke. Lancet Neurol 10: 357–371.
[4]
Freeman WD, Dawson SB, Flemming KD (2010) The ABC's of stroke complications. Semin Neurol 30: 501–510.
[5]
Taniguchi M, Yamashita T, Kumura E, Tamatani M, Kobayashi A, et al. (2000) Induction of aquaporin-4 water channel mRNA after focal cerebral ischemia in rat. Brain Res Mol Brain Res 78: 131–137.
[6]
Kimelberg HK (1995) Current concepts of brain edema. Review of laboratory investigations. J Neurosurg 83: 1051–1059.
[7]
Spatz M (2010) Past and recent BBB studies with particular emphasis on changes in ischemic brain edema: dedicated to the memory of Dr. Igor Klatzo. Acta Neurochir Suppl 106: 21–27.
[8]
Huang Z, Huang PL, Panahian N, Dalkara T, Fishman MC, et al. (1994) Effects of cerebral ischemia in mice deficient in neuronal nitric oxide synthase. Science 265: 1883–1885.
[9]
Lo EH, Dalkara T, Moskowitz MA (2003) Mechanisms, challenges and opportunities in stroke. Nat Rev Neurosci 4: 399–415.
[10]
Lo AC, Chen AY, Hung VK, Yaw LP, Fung MK, et al. (2005) Endothelin-1 overexpression leads to further water accumulation and brain edema after middle cerebral artery occlusion via aquaporin 4 expression in astrocytic end-feet. J Cereb Blood Flow Metab 25: 998–1011.
[11]
Asahi M, Asahi K, Wang X, Lo EH (2000) Reduction of tissue plasminogen activator-induced hemorrhage and brain injury by free radical spin trapping after embolic focal cerebral ischemia in rats. J Cereb Blood Flow Metab 20: 452–457.
[12]
Zivin JA, Mazzarella V (1991) Tissue plasminogen activator plus glutamate antagonist improves outcome after embolic stroke. Arch Neurol 48: 1235–1238.
[13]
Sumii T, Lo EH (2002) Involvement of matrix metalloproteinase in thrombolysis-associated hemorrhagic transformation after embolic focal ischemia in rats. Stroke 33: 831–836.
[14]
Kondoh T, Ueta Y, Torii K (2011) Pre-treatment of adrenomedullin suppresses cerebral edema caused by transient focal cerebral ischemia in rats detected by magnetic resonance imaging. Brain Res Bull 84: 69–74.
[15]
Schmerbach K, Pfab T, Zhao Y, Culman J, Mueller S, et al. (2010) Effects of aliskiren on stroke in rats expressing human renin and angiotensinogen genes. PLoS One 5: e15052.
[16]
Elango C, Devaraj SN (2010) Immunomodulatory effect of Hawthorn extract in an experimental stroke model. J Neuroinflammation 7: 97.
[17]
Chang RC, So KF (2008) Use of anti-aging herbal medicine, Lycium barbarum, against aging-associated diseases. What do we know so far? Cell Mol Neurobiol 28: 643–652.
[18]
Yu MS, Leung SK, Lai SW, Che CM, Zee SY, et al. (2005) Neuroprotective effects of anti-aging oriental medicine Lycium barbarum against beta-amyloid peptide neurotoxicity. Exp Gerontol 40: 716–727.
[19]
Yu MS, Lai CS, Ho YS, Zee SY, So KF, et al. (2007) Characterization of the effects of anti-aging medicine Fructus lycii on beta-amyloid peptide neurotoxicity. Int J Mol Med 20: 261–268.
[20]
Li SY, Yang D, Yeung CM, Yu WY, Chang RC, et al. (2011) Lycium barbarum polysaccharides reduce neuronal damage, blood-retinal barrier disruption and oxidative stress in retinal ischemia/reperfusion injury. PLoS One 6: e16380.
[21]
Lo AC, Cheung AK, Hung VK, Yeung CM, He QY, et al. (2007) Deletion of aldose reductase leads to protection against cerebral ischemic injury. J Cereb Blood Flow Metab 27: 1496–1509.
[22]
Chan HC, Chang RC, Koon-Ching Ip A, Chiu K, Yuen WH, et al. (2007) Neuroprotective effects of Lycium barbarum Lynn on protecting retinal ganglion cells in an ocular hypertension model of glaucoma. Exp Neurol 203: 269–273.
[23]
Li SY, Fu ZJ, Ma H, Jang WC, So KF, et al. (2009) Effect of lutein on retinal neurons and oxidative stress in a model of acute retinal ischemia/reperfusion. Invest Ophthalmol Vis Sci 50: 836–843.
[24]
Khan M, Im YB, Shunmugavel A, Gilg AG, Dhindsa RK, et al. (2009) Administration of S-nitrosoglutathione after traumatic brain injury protects the neurovascular unit and reduces secondary injury in a rat model of controlled cortical impact. J Neuroinflammation 6: 32.
[25]
Yeung CM, Lo AC, Cheung AK, Chung SS, Wong D, et al. (2010) More severe type 2 diabetes-associated ischemic stroke injury is alleviated in aldose reductase-deficient mice. Journal of neuroscience research 88: 2026–2034.
[26]
Moskowitz MA, Lo EH, Iadecola C (2010) The science of stroke: mechanisms in search of treatments. Neuron 67: 181–198.
[27]
Li JJ, Xing SH, Zhang J, Hong H, Li YL, et al. (2011) Decrease of tight junction integrity in the ipsilateral thalamus during the acute stage after focal infarction and ablation of the cerebral cortex in rats. Clin Exp Pharmacol Physiol 38: 776–782.
[28]
Badaut J, Lasbennes F, Magistretti PJ, Regli L (2002) Aquaporins in brain: distribution, physiology, and pathophysiology. J Cereb Blood Flow Metab 22: 367–378.
[29]
Potterat O (2010) Goji (Lycium barbarum and L. chinense): Phytochemistry, pharmacology and safety in the perspective of traditional uses and recent popularity. Planta medica 76: 7–19.
[30]
Hu C, Li J, Yang D, Pan Y, Wan H (2010) A neuroprotective polysaccharide from Hyriopsis cumingii. J Nat Prod 73: 1489–1493.
[31]
Zhou ZY, Tang YP, Xiang J, Wua P, Jin HM, et al. (2010) Neuroprotective effects of water-soluble Ganoderma lucidum polysaccharides on cerebral ischemic injury in rats. J Ethnopharmacol 131: 154–164.
[32]
Huang X, Li Q, Li H, Guo L (2009) Neuroprotective and antioxidative effect of cactus polysaccharides in vivo and in vitro. Cell Mol Neurobiol 29: 1211–1221.
[33]
Ho YS, Yu MS, Yang XF, So KF, Yuen WH, et al. (2010) Neuroprotective effects of polysaccharides from wolfberry, the fruits of Lycium barbarum, against homocysteine-induced toxicity in rat cortical neurons. J Alzheimers Dis 19: 813–827.
[34]
Brouns R, Wauters A, De Surgeloose D, Marien P, De Deyn PP (2011) Biochemical markers for blood-brain barrier dysfunction in acute ischemic stroke correlate with evolution and outcome. Eur Neurol 65: 23–31.
[35]
Zhao BQ, Wang S, Kim HY, Storrie H, Rosen BR, et al. (2006) Role of matrix metalloproteinases in delayed cortical responses after stroke. Nat Med 12: 441–445.
[36]
Romanic AM, White RF, Arleth AJ, Ohlstein EH, Barone FC (1998) Matrix metalloproteinase expression increases after cerebral focal ischemia in rats: inhibition of matrix metalloproteinase-9 reduces infarct size. Stroke 29: 1020–1030.
Simard JM, Kent TA, Chen M, Tarasov KV, Gerzanich V (2007) Brain oedema in focal ischaemia: molecular pathophysiology and theoretical implications. Lancet Neurol 6: 258–268.
[39]
Yeung PK, Lo AC, Leung JW, Chung SS, Chung SK (2009) Targeted overexpression of endothelin-1 in astrocytes leads to more severe cytotoxic brain edema and higher mortality. J Cerebral Blood Flow Metab 29: 1891–1902.
