Lab Anim Res.  2012 Jun;28(2):77-82. 10.5625/lar.2012.28.2.77.

Ginkgo biloba extract (EGb 761) prevents the ischemic brain injury-induced decrease in parvalbumin expression

• Sung JH
• Shah FA
• Cho EH
• Gim SA
• Jeon SJ
• Kim KM
• Kim YM
• Kim MO
• Koh PO

• KMID: 1436697
• DOI: http://doi.org/10.5625/lar.2012.28.2.77

Abstract

Ginkgo biloba extract (EGb 761) exerts a neuroprotective effect against ischemic brain injury through an anti-apoptotic mechanism. Parvalbumin is a calcium buffering protein that plays an important role in modulating intracellular calcium concentration and regulating apoptotic cell death. The aim of this study was to investigate whether EGb 761 affects parvalbumin expression in cerebral ischemic injury. Adult male Sprague-Dawley rats were treated with vehicle or EGb 761 (100 mg/kg) prior to middle cerebral artery occlusion (MCAO) and cerebral cortex tissues were collected 24 h after MCAO. A proteomic approach revealed a reduction in parvalbumin expression in the vehicle-treated animals, whereas EGb 761 pretreatment attenuates the ischemic injury-induced decrease in parvalbumin expression. RT-PCR and Western blot analyses clearly confirmed the fact that EGb 761 prevents the injury-induced decrease in parvalbumin. Moreover, the results of immunohistochemical staining showed that the number of parvalbumin-positive cells was lower in vehicle-treated animals than in sham-operated animals, and EGb 761 averted this decrease. Thus, these results suggest that the maintenance of parvalbumin expression is associated with the neuroprotective function of EGb 761 against neuronal damage induced by ischemia.

Keyword

EGb 761; neuroprotection; parvalbumin

MeSH Terms

Adult
Animals
Blotting, Western
Brain
Brain Injuries
Calcium
Cell Death
Cerebral Cortex
Ginkgo biloba
Humans
Infarction, Middle Cerebral Artery
Ischemia
Male
Neurons
Neuroprotective Agents
Plant Extracts
Rats, Sprague-Dawley
Calcium
Neuroprotective Agents
Plant Extracts

Figure

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  Figure 1 TTC staining of brain slices in vehicle-treated, EGb 761-treated, and sham-operated animals. The ischemic area remained white, while the intact area was stained red. The percentage of ischemic lesion area was calculated as lesion area/whole brain section area. Data (n=4) are represented as mean±S.E.M. *P<0.05.

• 

  Figure 2 Parvalbumin protein spots identified by MALDI-TOF in the cerebral cortices of vehicle-treated, EGb 761-treated, and sham-operated animals. Circles indicate the protein spots. The intensity of the spots was measured using PDQuest software. The intensity ratio is defined as the spot intensity of vehicle- or EGb 761-treated animals to the spot intensity of the sham group. Data (n=4) are mean±S.E.M. *P<0.05. Mw and IP indicate molecular weight and isoelectric point, respectively.

• 

  Figure 3 RT-PCR analysis of parvalbumin in the cerebral cortices of vehicle-treated, EGb 761-treated, and sham-operated animals. Each lane represents an individual experimental animal. The results of densitometric analysis are presented as the ratio of the intensity of parvalbumin to the intensity of actin. Data (n=4) are mean±S.E.M. *P<0.05.

• 

  Figure 4 Western blot analysis of parvalbumin in the cerebral cortices of vehicle-treated, EGb 761-treated, and sham-operated animals. Each lane represents an individual experimental animal. The results of densitometric analysis are presented as the ratio of the intensity of parvalbumin to the intensity of actin. Molecular weight markers (kDa) are depicted on the left. Data (n=4) are mean±S.E.M. *P<0.05.

• 

  Figure 5 Immunostaining of parvalbumin in the cerebral cortices of vehicle-treated, EGb 761-treated, and sham-operated animals. Arrows indicate positive cells. The index of positive cells indicates the percentage of the number of parvalbumin-positive cells to the total number of cells. Scale bar=100 µm. Data (n=4) are represented as mean±S.E.M. *P<0.05.

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