Inhibition of Mitochondrial Oxidative Stress and Apoptosis in the Protection of Ginkgo biloba extract 50 Against Cognitive Impairment.

Abstract

Ethnopharmacological relevance: Ginkgo biloba L., a traditional medicinal plant with a long history of use in China, has been widely employed to promote blood circulation, relieve asthma, and enhance memory. It is also used in the management of cardiovascular and cerebrovascular conditions in various traditional practices. Although Ginkgo biloba shows promise in improving cognitive function and vascular health, its specific efficacy and underlying mechanism in cerebral small vessel disease remain unclear.

Aim of the study: Cerebral small vessel disease (CSVD), a leading cause of cognitive decline and dementia, currently lacks effective treatment options. As a new generation extract of Ginkgo biloba L., Ginkgo biloba extract 50 (GBE50) was developed to investigate its potential therapeutic effects on CSVD and the underlying mechanisms.

Materials and methods: The bilateral carotid artery stenosis (BCAS) model was established in mice using microcoils, followed by therapeutic intervention. Cognitive function was assessed via the Morris water maze and Y-maze tests, while motor activity was evaluated using the open-field test. White matter and neuronal damage were analyzed through MRI, Luxol Fast Blue staining, and Nissl staining. The blood-active ingredients of GBE50 were identified using UPLC-Q-TOF-MS. Network pharmacology was applied to predict potential therapeutic targets of GBE50 against CSVD, and molecular docking was conducted to evaluate the binding interactions between key compounds and related proteins. The predicted targets and pathways were further validated through reverse transcription quantitative PCR (RT-qPCR, Western blot, and biochemical assays).

Results: GBE50 significantly improved cognitive impairment in BCAS mice. MRI and histological analyses confirmed that GBE50 alleviated white matter lesions and hippocampal neuronal loss. Twenty ingredients, including quercetin, kaempferol, and isorhamnetin, were identified in GBE50, with 80 potential therapeutic targets. Molecular docking revealed strong binding affinities between key GBE50 compounds and apoptosis-related proteins such as CASP3, CASP9, BAX, BCL-2, and Cytochrome c. Twenty key genes were also validated by RT-qPCR. BCAS induced oxidative stress, inflammation, and mitochondrial apoptosis-related gene expression, which were mitigated by GBE50. BCAS increased malondialdehyde (MDA) levels and the NADP⁺/NADPH ratio while decreasing superoxide dismutase (SOD), and these imbalances were reversed by GBE50. Expression of Cytochrome c, BAX, and CASP3 was elevated, whereas BCL-2 was reduced in BCAS mice, effects counteracted by GBE50.

Conclusions: GBE50 alleviates cognitive impairment, white matter lesions, and neuronal loss in CSVD, potentially by inhibiting mitochondrial oxidative stress and apoptosis.