New Ginkgo Extract Can Aid Stroke Recovery

An ischemic stroke is a common type of brain injury caused by impaired blood flow to the brain. Currently, the only FDA-approved treatment for strokes is the drug Tissue Plasminogen Activator (TPA), composed of the human TPA protein that breaks down blood clots. However, its effectiveness is limited by the time frame of administration and associated complications. While studying the effect of plant extracts from the species Ginkgo biloba L. (GBE) on strokes in mice, researchers discovered a new ginkgo extract (nGBE) containing pinitol, a compound with known anti-inflammatory effects, that reduced stroke severity 24 hours after a stroke [1]. Now, in a new publication in the journal Neuroscience, scientists show that nGBE also improves long-term function and promotes recovery after a stroke in mice [2].

Previous research on GBE shows that it can prevent brain cell death, improve cognitive function, and promote the formation of new neurons (neurogenesis) in animal models after a stroke [3]. GBE contains over 230 compounds that target multiple stroke mechanisms and provide longer-term protection against repeated strokes by acting in cells such as microglia [3]. Microglia are the brain’s resident immune cells and the first responders to an ischemic injury [4]. During and after a stroke, they can generate both pro-inflammatory reactions, which can contribute to long-term pathological damage as well as anti-inflammatory reactions, which can promote recovery [4]. Damage to white matter in particular, or clusters of neuron cell bodies inside the brain whose axons are covered by myelin sheath, correlates with later cognitive deficits [5].

Figure 1: This figure shows the difference in brain blood flow between mice treated with nGBE and the vehicle or control group. In the reperfusion 24h row, we can see that blood flow is significantly greater in the nGBE group, which demonstrates its effectiveness in stroke recovery. [2]

In this new study, researchers found the administration of nGBE to male mice can reduce this damage or infarct volume after stroke [3]. 14 days after a stroke, mice that received nGBE showed less brain tissue loss compared to a control group. Moreover, the brains of mice receiving nGBE have reduced inflammation a week after a stroke, increased white matter structural integrity after 28 days, and less reactive microglia signals. These changes in the brains of mice receiving nGBE after stroke resulted in significantly improved sensorimotor and cognitive functions in mice compared to those receiving a placebo, suggesting nGBE as a potential new therapeutic for stroke [3].

These results provide insight into the impact of nGBE on long-term functional recovery and white matter integrity protection after ischemic stroke. By enhancing sensorimotor and cognitive functions post-stroke, nGBE promises to fill the critical gaps left by current stroke treatments, which are often limited in efficacy and timing for such a time-sensitive and life-threatening condition. Though more research is needed to determine nGBE’s clinical use dosage and procedure for humans, this study is a stepping stone in furthering possible stroke treatments.

References

[1] Ji H, Zhou X, Wei W, Wu W, Yao S. Ginkgol Biloba extract as an adjunctive treatment for ischemic stroke: A systematic review and meta-analysis of randomized clinical trials. Medicine (Baltimore). 2020 Jan;99(2):e18568. doi: 10.1097/MD.0000000000018568. PMID: 31914035; PMCID: PMC6959928.

[2] Dong, W., Gong, T., Zhao, S., Wen, S., Chen, Q., Jiang, M., Ye, W., Huang, Q., Wang, C., Yang, C., Liu, X., & Wang, Y. (2023). A novel extract from ginkgo biloba inhibits neuroinflammation and maintains white matter integrity in experimental stroke. Neuroscience, 523, 7–19. https://doi.org/10.1016/j.neuroscience.2023.05.015

[3] Zou X, Liu S, Zou H, Zhou W, Fu H, Wei J, Zhang J, Zeng H, Tan T, Zhou W, Wu H, Chen X, Zhou X. Inflammatory mechanisms of Ginkgo Biloba extract in improving memory functions through lncRNA-COX2/NF-κB pathway in mice with status epilepticus. CNS Neurosci Ther. 2023 Jan;29(1):471-482. doi: 10.1111/cns.14019. Epub 2022 Nov 23. PMID: 36419341; PMCID: PMC9804085.

[4] Li, Q., & Barres, B. A. (2018). Microglia and macrophages in brain homeostasis and disease. Nature reviews. Immunology, 18(4), 225–242. https://doi.org/10.1038/nri.2017.125

[5] Filley C. M. (2021). Cognitive Dysfunction in White Matter Disorders: New Perspectives in Treatment and Recovery. The Journal of neuropsychiatry and clinical neurosciences, 33(4), 349–355. https://doi.org/10.1176/appi.neuropsych.21030080