Ginkgo biloba leaf extract (EGb-761) elicits neuroprotection against cerebral ischemia/reperfusion injury by enhancement of autophagy flux in neurons in the penumbra

Document Type : Original Article

Authors

Department of Basic Medicine, Medical School, Kunming University of Science and Technology, Kunming 650500, China

Abstract

Objective(s): Ginkgo biloba leaf extract (EGb-761) injection has been widely used as adjuvant therapy for cerebral stroke in China. However, its underlying pharmacological mechanism is not completely understood. The present study aimed to investigate whether the therapeutic effects of EGb-761 are exerted by modulating autophagy flux.
Materials and Methods: Ischemic cerebral stroke was prepared in male Sprague-Dawley rats by middle cerebral artery occlusion (MCAO) followed by reperfusion. The MCAO/reperfusion rats were then treated with EGb-761 injection once daily for 7 days. Thereafter, the brain tissues in the ischemic penumbra were obtained to detect the key proteins in the autophagic/lysosomal pathway with Beclin1, LC3, (SQSTM1)/p62, ubiquitin, LAMP-1, cathepsin B, and cathepsin D antibodies by western blot and immunofluorescence. Meanwhile, the infarct volume, neurological deficits, and neuronal apoptosis were assessed to evaluate the therapeutic outcomes.
Results: The results illustrated that EGb-761 treatment was not only able to promote the autophagic activities of Beclin1 and LC3-II in neurons, but also could enhance the autophagic clearance, as indicated by reinforced lysosomal activities of LAMP-1, cathepsin B, and cathepsin D, as well as alleviating autophagic accumulation of ubiquitin and insoluble p62 in the MCAO+EGb-761 group, compared with those in the MCAO+saline group. Meanwhile, cerebral ischemia-induced neurological deficits, infarct volume, and neuronal apoptosis were significantly attenuated by 7 days of EGb-761 therapy.
Conclusion: Our data suggest that EGb-761 injection can elicit a neuroprotective efficacy against MCAO/reperfusion injury, and this neuroprotection may be exerted by enhancement of autophagy flux in neurons in the ischemic penumbra.

Keywords


1. Feigin VL, Vos T. Global burden of neurological disorders: from global burden of disease estimates to actions. Neuroepidemiology 2019;52:1-2.
2.    Meschia JF, Brott T. Ischemic stroke. Eur J Neurol 2018;25:35-40.
3.    Sun H, Zou X, Liu L. Epidemiological factors of stroke: A survey of the current status in China. J Stroke. 2013;15:109-114.
4.    Bano D, Ankarcrona M. Beyond the critical point: An overview of excitotoxicity, calcium overload and the downstream consequences. Neurosci Lett. 2018;663:79-85.
5.    Radak D, Katsiki N, Resanovic I, Jovanovic A, Sudar-Milovanovic E, Zafirovic S, et al. Apoptosis and acute brain ischemia in ischemic stroke. Curr Vasc Pharmacol 2017;15:115-122.
6.    Khoshnam SE, Winlow W, Farzaneh M, Farbood Y, Moghaddam HF. Pathogenic mechanisms following ischemic stroke. Neurol Sci 2017;38:1167-1186.
7.    Leng T, Xiong ZG. Treatment for ischemic stroke: From thrombolysis to thrombectomy and remaining challenges. Brain Circ 2019;5:8-11.
8.    Yuh WT, Alexander MD, Ueda T, Maeda M, Taoka T, Yamada K, et al. Revisiting current goldens rules in managing scute ischemic stroke: evaluation of new dtrategies to further improve treatment selection and outcome. AJR Am Roentgenol 2017;208:32-41.
9.    Nash KM, Shah ZA. Current perspectives on the beneficial role of Ginkgo biloba in neurological and cerebrovascular disorders. Integr Med Insights 2015;10:1-9.
10.    Chau FT, Chan HY, Cheung CY, Xu CJ, Liang Y, Kvalheim OM. Recipe for uncovering the bioactive components in herbal medicine. Anal Chem 2009;81:7217-7225.
11.    Van Beek TA, Montoro P. Chemical analysis and quality control of Ginkgo biloba leaves, extracts, and phytopharmaceuticals. J Chromatoqr A 2009;1216:2002-2032.
12.    Mohanta TK, Tamboli Y, Zubaidha PK. Phytochemical and medicinal importance of Ginkgo biloba L. Nat Prod Res 2014;28:746-752.
13.    Liu H, Ye M, Guo H. An updated review of randomized clinical trials testing the improvement of cognitive function of Ginkgo biloba extract in healthy people and alzheimer’s patients. Front Pharmacol. 2020;10:1688.
14.    Savaskan E, Mueller H, Hoerr R, von Gunten A, Gauthier S. Treatment effects of Ginkgo biloba extract EGb 761® on the spectrum of behavioral and psychological symptoms of dementia: meta-analysis of randomized controlled trials. Int Psychogeriatr 2018;30:285-293.
15.    Hosseini-Sharifabad M, Anvari M. Effects of Ginkgo biloba extract on the structure of Cornu Ammonis in aged rat: a morphometric study. Iran J Basic Med Sci 2015;18:932–937.
16.    Zhou X, Qi Y, Chen T. Long-term pre-treatment of anti-oxidant Ginkgo biloba extract EGb-761 attenuates cerebral ischemia-induced neuronal damage in aged mice. Biomed Pharmacother 2017;85:256-263.
17.    Chandrasekaran K, Mehrabian Z, Spinnewyn B, Chinopoulos C, Drieu K, Fiskum G.  Neuroprotective effects of bilobalide, a component of Ginkgo biloba extract (Egb 761) in global brain ischemia and in excitotoxicity-induced neuronal death. Pharmacopsychiatry 2003;36:89-94.
18.    Liu Y, Wu X, Yu Z. Ginkgo leaf extract and dipyridamole injection as adjuvant treatment for acute cerebral infarction: Protocol for systemic review and meta-analysis of randomized controlled trials. Medicine (Baltimore). 2019;98:e14643.
19.    Oskouei DS1, Rikhtegar R, Hashemilar M, Sadeghi-Bazargani H, Sharifi-Bonab M, Sadeghi-Hokmabadi E, et al. The effect of Ginkgo biloba on functional outcome of patients with acute ischemic stroke: a double-blind, placebo-controlled, randomized clinical trial. J Stroke Cerebrovasc Dis 2013;22:e557-563.
20.    Doherty J, Baehrecke EH. Life, death and autophagy. Nat Cell Biol 2018;20:1110-1117.
21.    Glick D, Barth S, Macleod KF. Autophagy: cellular and molecular mechanisms. J Pathol 2010;221:3-12.
22.    Hou K, Xu D, Chen S. The progress of neuronal autophagy in cerebral ischemia stroke: Mechanisms, roles and research methods. J Neurol Sci 2019;400:72-82.
23.    Chen W, Sun Y, Liu K, Sun X. Autophagy: A double-edged sword for neuronal survival after cerebral ischemia. Neural Regen Res 2014;9:1210-1216.
24.    Beard DJ, Hadley G, Thurley N, Howells DW, Sutherland BA, Buchan AM. The effect of rapamycin treatment on cerebral ischemia: A systematic review and meta-analysis of animal model studies. Int J Stroke 2019;14:137-145.
25.    Ni Y, Gu WW, Liu ZH, Zhu YM, Rong JG, Kent TA, et al. RIP1K contributes to neuronal and astrocytic cell death in ischemic stroke via activating autophagic-lysosomal pathway. Neuroscience 2018;371:60-74.
26.    Zhi X, Feng W, Rong Y, Liu R. Anatomy of autophagy: from the beginning to the end. Cell Mol Life Sci. 2018;75:815-831.
27.    Lahiri V, Hawkins WD, Klionsky DJ. Watch what you (self-) eat: Autophagic mechanisms that modulate metabolism. Cell Metab 2019;29:803-826.
28.    Yu L, Chen Y, Tooze SA. Autophagy pathway: Cellular and molecular mechanisms. Autophagy 2018;14:207-215.
29.    Liu Y, Xue X, Zhang H, Che X, Luo J, Wang P, et al. Neuronal-targeted TFEB rescues dysfunction of the autophagy-lysosomal pathway and alleviates ischemic injury in permenent cerebral ishcemia. Autophagy 2019;15:493-509.
30.    He HY, Ren L, Guo T, Deng YH. Neuronal autophagy aggravates microglia inflammatory injury by downregulating CX3CL1/fractalkine after ischemic stroke. Neural Regen Res 2019;14:280-288.
31.    Zheng Y, Wu Z, Yi F, Orange M, Yao M, Yang B, et al. By Activating Akt/eNOS Bilobalide B inhibits autophagy and promotes angiogenesis following focal cerebral ischemia reperfusion. Cell Physio Biochem 2018;47:604-616.
32.    Chen XP, Zhang X, Liao WJ, Wang Q. Effect of physical and social components of enriched environment on astrocytes proliferation in rats after cerebral ischaemia/reperfusion injury. Neurochem Res 2017;42:1308-1316.
33.    Li MZ, Zhang Y, Zou HY, Ouyang JY, Zhang Y, Yang L, et al. Investigation of Ginkgo biloba extract (Egb 761) promotes neurovascular restoration and axonal remodeling after embolic stroke in rat using magnetic resonance imaging and histopathological analysis. Biomed Pharmacother 2018;103:989-1001.
34.    Zeng GR, Zhou SD, Shao YJ, Zhang MH, Dong LM, Lv JW, et al. Effect of Ginkgo biloba extract-761 on motor functions in permanent middle cerebral artery occlusion rats. Phytomedicine 2018;48:94-103.
35.    Yin B, Xu Y, Wei R, Luo B. Ginkgo biloba on focal cerebral ischemia: a systematic review and meta-analysis. Am J Chin Med 2014;42:769-783.
36.    Li S, Zhang X, Fang Q, Zhou J, Zhang M, Wang H, et al. Ginkgo biloba extract improved cognitive and neurological functions of acute ischemic stroke: a randomised controlled trial. Stroke Vasc Neurol 2017;2:189-197.
37.    Chong PZ, Ng HY, Tai JT, Lee SWH. Efficacy and safety of Ginkgo biloba in patients with acute ischemic stroke: A systematic review and meta-analysis. Am J Chin Med 2020;48:513-534.
38.    Liang ZH, Jia YB, Wang ML, Li ZR, Li M, Yun YL, et al. Efficacy of ginkgo biloba extract as augmentation of venlafaxine in treating post-stroke depression. Neuropsychiatr Dis Treat 2019;15:2551-2557.
39.    Wolf MS, Bayir H, Kochanek PM, Clark RSB. The role of autophagy in acute brain injury: A state of flux? Neurobiol Dis 2019;122:9-15.
40.    Sun Y, Zhu Y, Zhong X, Chen X, Wang J, Ying G, et al. Crosstalk between autophagy and cerebral ischemia. Front Neurosci 2019;12:1022.
41.    Zhang X, Yan H, Yuan Y, Gao J, Shen Z, Cheng Y, et al. Cerebral ischemia-reperfusion-induced autophagy protects against neuronal injury by mitochondrial clearance. Autophagy 2013;9:1321-1333.
42.    Morselli E, Tasdemir E, Maiuri MC, Galluzzi L, Kepp O, Criollo A, et al. Mutant p53 protein localized in the cytoplasm inhibits autophagy. Cell Cycle 2008;7:3056-3061.
43.    Mo Y, Sun YY, Liu KY. Autophagy and inflammation in ischemic stroke. Neural Regen Res 2020;15:1388-1396.
44.    Parzych KR, Klionsky DJ. An overview of autophagy: morphology, mechanism, and regulation. Anti-oxid Redox Signal 2014;20:460-473.
45.    Dai S, Xu Q, Liu S, Yu B, Liu J, Tang J. Role of autophagy and its signaling pathways in ischemia/reperfusion injury. Am J Transl Res 2017;9:4470-4480.
46.    Eskelinen EL. Roles of LAMP-1 and LAMP-2 in lysosome biogenesis and autophagy. Mol Aspects Med 2006;27:495-502.
47.    Kaminskyy V, Zhivotovsky B. Proteases in autophagy. Biochim Biophys Acta 2012;1824: 44-50.
48.    Wang T, Zhao N, Peng L, Li Y, Huang X, Zhu J, et al. DJ-1 regulates microglial polarization through P62-mediated TRAF6/IRF5 signaling in cerebral ischemia-reperfusion. Front Cell Dev Biol 2020;8:593890.
49.    Hochrainer K. Protein modifications with ubiquitin as response to rerebral ischemia-reperfusion injury. Transl Stroke Res 2018;9:157-173.
50.    Cui DR, Sun DW, Wang XT, Yi LY, Kulikowicz E, Reyes M, et al. Impaired autophagyosome clearance contributes to neuronal death in a piglet model of neonatal hypoxic-ischemic encephalopathy. Cell Death Dis 2017;8:e2919.
51.    Zhang Y, Liu J, Yang B, Zheng Y, Yao M, Sun M, et al. Ginkgo biloba extract inhibits astrocytic lipocalin-2 expression and alleviates neuroinflammatory injury via the JAKS/STAT3 pathway after ischemic brain stroke. Front Pharmacol 2018;9:518.
52.    Demarin V, BasicKes V, Trkanjec Z, Budisic M, Bosniak Pasic M, CmacP, et al. Efficacy and safety of Ginkgo biloba standardized extract in the treatment of vascular cognitive impairment: a randomized, double-blind, placebo-controlled clinical trial. Neuropsychiatr Dis Treat 2017;13:483-490.