Investigation of the dose-dependent antivasospasmic effect of Ginkgo biloba extract (EGb 761) in experimental subarachnoid hemorrhage

Efficacy and safety of standardized Ginkgo biloba extract as adjuvant therapy for intracerebral hemorrhage in China: A systematic review and meta-analysis

Objective

The aim of this study was to systematically review the clinical efficacy and safety of standardized Ginkgo biloba extract (GBE) in the adjuvant treatment of intracerebral hemorrhage (ICH).

Methods

Relevant RCTs on GBE as adjuvant therapy for ICH were searched in seven Chinese and English databases. Data extraction of the included literature was performed after duplicate checking and screening, and Stata 15.1 software was applied for data analysis.

Results

With a total of 19 RCTs, the meta-analysis results showed that: Compared with conventional treatment alone, GBE combined with conventional treatment had a higher effective rate; NIHSS score and CSS score were lower; The residual hematoma was less. The volume of cerebral edema was smaller. ADL score was higher. MoCA score was higher. The serum levels of hs-CRP, TNF-α and IL-6 were lower; No significant difference was observed in the incidence of adverse reactions between conventional treatment alone and GBE combined with conventional treatment.

Conclusion

This study suggests that GBE as adjuvant therapy for ICH has better efficacy and is relatively safe compared with conventional treatment alone. However, due to the quality and quantity of included studies, further validation by more methodologically rigorous and multi-center studies with larger sample sizes is needed.

Standardized Ginkgo biloba extract EGb 761® attenuates early brain injury following subarachnoid hemorrhage via suppressing neuronal apoptosis through the activation of Akt signaling

BACKGROUND

Early brain injury (EBI) plays a critical role in determining the outcome of subarachnoid hemorrhage (SAH). The present study was designed to investigate the role of EGb 761, a standardized extract of Ginkgo biloba, in SAH-induced EBI and to explore its potential mechanism of action.

METHOD

A rat SAH model was established by the endovascular perforation process. Doses of 10, 50 and 100 mg/kg EGb 761 were injected intraperitoneally 2 h after SAH was induced. Mortality, SAH grade, neurological score and brain water content were measured 24 h after SAH was induced. A Western blot assay was performed to assess the expression of the apoptosis-related proteins Bax, Bcl-2, cleaved caspase-3, Akt and phosphorylated Akt (p-Akt). Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and neuronal nuclei (NeuN) double immunofluorescence staining were used to detect apoptotic neurons.

RESULTS

Animals suffered from serious neurological deficits and increased brain water content after induction of SAH. Rats treated with EGb 761 experienced dose-dependent attenuation of neurological dysfunction and decreased brain water content. In addition, EGb 761 significantly activated Akt signaling accompanied by increased Bcl-2 levels and decreased expression of Bax and cleaved caspase-3. Moreover, EGb 761 decreased the number of TUNEL/NeuN-positive cells in a dose-dependent manner. However, all the beneficial effects of EGb 761 for SAH were abolished by the Akt inhibitor MK2206.

CONCLUSION

Our results indicated that EGb 761 could ameliorate SAH-induced EBI and that the neuroprotective effects of EGb 761 against SAH were exerted via suppression of neuronal apoptosis through activation of the Akt pathway.

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

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.