JoVE Logo
Faculty Resource Center

Sign In





Representative Results






Assessing Neuroprotective Effects of Glycyrrhizae Radix et Rhizoma Extract Using a Transient Middle Cerebral Artery Occlusion Mouse Model

Published: December 9th, 2018



1School of Korean Medicine, Pusan National University, 2College of Medicine, Dongguk University, 3Kyunghee Naseul Korean Medicine Clinic
* These authors contributed equally

In this study, we modify an existing experimental method to obtain more reproducible results, by establishing a middle cerebral artery occlusion (MCAO) mouse model. Oral administration of Glycyrrhizae Radix et Rhizome (GR) methanol extract (GRex), following stroke induction, significantly decreased total infarction volume relative to the untreated control group.

Ischemia followed by reperfusion of cerebral blood flow after a stroke leads to the death of nerve cells and loss of brain tissue. The most commonly used animal model for studying stroke is the middle cerebral artery occlusion (MCAO) model. Previous research studies have reported different infarct sizes even when the same experimental animal species was used under similar MCAO conditions. Therefore, we developed an improved experimental method to address this discrepancy. Mice were subjected to MCAO using a filament as the occlusion material to mimic human stroke conditions and filament thickness was optimized to establish more reproducible infarction volume. Mice treated with a methanol extract of Glycyrrhizae Radix et Rhizome (GRex) following stroke induction showed a significantly decreased total infarction volume and increased number of surviving cells relative to the untreated control group. This modified experimental protocol successfully and reproducibly demonstrated the beneficial effect of GRex on ischemic stroke.

Brain damage caused by ischemia and reperfusion of cerebral blood flow leads to the death of nerve cells and loss of brain tissue. This type of brain damage continues to increase with the increasing prevalence of cerebrovascular diseases due to the spread of metabolic diseases such as obesity, hypertension, and diabetes mellitus1,2. The absolute number of elderly patients with stroke has dramatically increased worldwide, and the cost of medical care for these patients, who are often left with long-term disabilities, is a major societal burden. Therefore, secondary disabilities should be mitigated as much as po....

Log in or to access full content. Learn more about your institution’s access to JoVE content here

All procedures involving animals were approved by the ethics committee of Pusan National University (approval number, PNU-2016-1087). A graphical overview of this study is shown in Figure 1.

1. Preparation and Administration of GRex

NOTE: The GR used in this study was purchased from a commercial pharmaceutical company.

  1. Place 200 g of GR in 2,000 mL of methanol and incubate at room temperature (25 °C) for 5 days.
  2. <.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

In the sham-operated normal group, no cerebral infarct is observed whereas in the control group, a relatively wide range of damaged areas is observed. In the mice administered 300 mg/kg GRex in the MCAO model group, a statistically significant reduction in damaged area is observed (Figure 2).

The histological changes are investigated by staining ischemic brain sections with H&E or cresyl violet........

Log in or to access full content. Learn more about your institution’s access to JoVE content here

With the increasing prevalence of metabolic diseases such as chronic hypertension, diabetes, and hyperlipidemia, which are major risk factors for stroke, stroke prevention and treatment have become an important area of medical research12,13. Deficits in language and movement after a stroke are strongly correlated with the degree of damage to brain tissue14 and result in a poor quality of life for patients and their families

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Not applicable.


Log in or to access full content. Learn more about your institution’s access to JoVE content here

Name Company Catalog Number Comments
Glycyrrhizae Radix et Rhizoma Gwangmyoung Pharmaceuticals Co., Korea Glycyrrhizae Radix et Rhizoma
Qualitative filter paper Advantec Filter paper No. 2 Qualitative filter paper
Dimethyl sulfoxide (DMSO) Sigma D8418-250ML Dimethyl sulfoxide (DMSO)
Syringe filter (0.45 µm) Sigma CLS431220 Syringe filter (0.45 µm)
Stereo Microscope Leica M50 Stereo Microscope
Stereo Microscope Nikon SMZ745 Stereo Microscope
Laser Doppler Moor Instrument moorVMS-LDF Laser Doppler
Anesthesia Tabletop Bracket with N2O&O2 Flowmeter System Harvard Appratus 34-1352 Anesthesia Tabletop Bracket with N2O&O2 Flowmeter System
Homeothermic Monitoring System Harvard Appratus 55-7020 Homeothermic Monitoring System
Digital Camera Canon Eos-M2 Digital Camera
Cryostat Leica CM3050S Cryostat
Microscope Carl Zeiss Zeiss Axio Microscope
Data Analysis Systat Software Inc. SigmaPlot version 12 Data Analysis
Data Analysis NIH Image ImageJ Data Analysis
Mouse diet Doo Yeol Biotech Standard rodent chow Mouse diet
Isoflurane JOONGWAE A02104781 Isoflurane
Isoflurane TROIKAA ISOTROY 100 Isoflurane
Silk suture (4-0 Black silk)  AILEE SK47510 Silk suture (4-0 Black silk) 
Silk suture (3-0 White silk)  Baekjae 57 Silk suture (3-0 White silk) 
Nylon suture (8-0 monofilament)  AILEE NB825 Nylon suture (8-0 monofilament) 
2,3,5-triphenyltetrazolium chloride (TTC) Sigma T8877-25G 2,3,5-triphenyltetrazolium chloride (TTC)
Formalin (Formaldehyde solution) JUNSEI 69360-1263 20KG Formalin (Formaldehyde solution)
Hematoxylin (Harris Hematoxylin) YD Diagnostics EasyStain Hematoxylin (Harris Hematoxylin)
Eosin (1% Eosin Y Solution) MUTO PURE CHEMICALS 3200-2 Eosin (1% Eosin Y Solution)
Cresyl violet (acetate) Sigma C5042-10G Cresyl violet (acetate)
Paraformaldehyde  Sigma-Aldrich P6148-1KG Paraformaldehyde 
Sucrose JUNSEI 31365-0350 1KG Sucrose
Optimum cutting temperature (OCT) compound Scigen 4583 Optimum cutting temperature (OCT) compound
Disecting Knife Fine Science Tools 10055-12 Disecting Knife
#4 Forcep Fine Science Tools 11241-30 #4 Forcep
#5 Forcep Fine Science Tools 11254-20 #5 Forcep
#6 Forcep Fine Science Tools 11260-20 #6 Forcep
#7 Fine Forcep Fine Science Tools 11274-20 #7 Fine Forcep
Surgical Scissors Fine Science Tools 14001-12 Surgical Scissors
Extra Fine Bonn Scissors Fine Science Tools 14084-08 Extra Fine Bonn Scissors
Moria Pascheff-Wolff Spring Scissors Fine Science Tools 15371-92 Moria Pascheff-Wolff Spring Scissors
Vessel Dilating Forcep Fine Science Tools 18153-11 Vessel Dilating Forcep

  1. Bejot, Y., Delpont, B., Giroud, M. Rising stroke incidence in young adults: more epidemiological evidence, more questions to be answered. Journal of the American Heart Association. 11 (5), (2016).
  2. Hadadha, M., Vakili, A., Bandegi, A. R. Effect of the inhibition of hydrogen sulfide synthesis on ischemic injury and oxidative stress biomarkers in a transient model of focal cerebral ischemia in rats. Journal of Stroke and Cerebrovascular Diseases. 24 (12), 2676-2684 (2015).
  3. Durukan, A., Tatlisumak, T. Animal models of ischemic stroke. Article in Handbook of Clinical Neurology. 92, 43-66 (2009).
  4. Kim, D. Animal Models of Stroke. Brain and Neurorehabilitation. 4 (1), 1-11 (2011).
  5. Rizzato, G., Scalabrin, E., Radaelli, M., Capodaglio, G., Piccolo, O. A new exploration of licorice metabolome. Food Chemistry. 221, 959-968 (2017).
  6. Zhu, Z., et al. Rapid determination of flavonoids in licorice and comparison of three licorice species. Journal of Separation Science. 39 (3), 473-482 (2016).
  7. Ota, M., Mikage, M., Cai, S. Q. Herbological study on the medicinal effects of roasted licorice and honey-roasted licorice. Yakushigaku Zasshi. 50 (1), 38-45 (2015).
  8. Lim, C., et al. Licorice pretreatment protects against brain damage induced by middle cerebral artery occlusion in mice. Journal of Medicinal Food. 21 (5), 474-480 (2018).
  9. Koizumi, J. Y., Nakazawa, T., Ooneda, G. Experimental studies of ischemic brain edema. Nosotchu. 8 (1), 1-8 (1986).
  10. Fischer, A. H., Jacobson, K. A., Rose, J., Zeller, R. Hematoxylin and eosin staining of tissue and cell sections. Cold Spring Harbor Protocols. 2008, (2008).
  11. Zhu, Y., Liu, F., Zou, X., Torbey, M. Comparison of unbiased estimation of neuronal number in the rat hippocampus with different staining methods. Journal of Neuroscience Methods. 254, 73-79 (2005).
  12. Alberts, M. J., Ovbiagele, B. Current strategies for ischemic stroke prevention: role of multimodal combination therapies. Journal of Neurology. 254 (10), 1414-1426 (2007).
  13. Pinto, A., Tuttolomondo, A., Di Raimondo, D., Fernandez, P., Licata, G. Cerebrovascular risk factors and clinical classification of strokes. Seminars in Vascular Medicine. 4 (3), 287-303 (2004).
  14. Barlow, S. J. Identifying the brain regions associated with acute spasticity in patients diagnosed with an ischemic stroke. Somatosensory and Motor Research. 33 (2), 1-8 (2016).
  15. Roth, S., Liesz, A. Stroke research at the crossroads - where are we heading. Swiss Medical Weekly. 146, 14329 (2016).
  16. Feuerstein, G. Z., Wang, X. Animal models of stroke. Molecular Medicine Today. 6 (3), 133-135 (2000).
  17. Herson, P. S., Traystman, R. J. Animal models of stroke: translational potential at present and in 2050. Future Neurology. 9 (5), 541-551 (2014).
  18. Kumar, A., Gupta Aakriti, V. A review on animal models of stroke: an update. Brain Research Bulletin. 122, 35-44 (2016).
  19. O'Collins, V. E., Donnan, G. A., Howells, D. W. History of animal models of stroke. International Journal of Stroke. 6 (1), 77-78 (2011).
  20. Ji, S., et al. Bioactive constituents of Glycyrrhiza uralensis (licorice): discovery of the effective components of a traditional herbal medicine. Journal of Natural Products. 79 (2), 281-292 (2016).
  21. Yang, R., Wang, L. Q., Yuan, B. C., Liu, Y. The pharmacological activities of licorice. Planta Medica. 81 (18), 1654-1669 (2015).
  22. Yang, R., Yuan, B. C., Ma, Y. S., Zhou, S., Liu, Y. The anti-inflammatory activity of licorice, a widely used Chinese herb. Pharmaceutical Biology. 55 (1), 5-18 (2017).

This article has been published

Video Coming Soon

JoVE Logo


Terms of Use





Copyright © 2024 MyJoVE Corporation. All rights reserved