Ginkgo Biloba Extract Improves Stroke Consequences

by | Feb 5, 2018 | 2017, Brain Health, Ginkgo Biloba, Stroke

Written by Joyce Smith, BS. Participants who supplemented with Ginkgo biloba extract for six months had significant improvements in cognitive and neurological functioning after acute ischemic stroke.

gingko biloba - botanicalsStroke is one of the leading causes of disability and mortality worldwide. Thrombolysis and intra-artery therapy are the only two effective interventions for stroke and, because of a limited time window, are available to only a minority of stroke patients1. Thirty percent of post-stroke victims suffer from cognitive decline and Alzheimer’s, thus reinforcing the need for safe and inexpensive treatment alternatives.

Ginkgo biloba extract (GEB), commercially available as a non-prescription food supplement, contains ingredients that can vary by age, species and gender of the Ginkgo tree 2. While most studies use the standardized EGb761 from Schwabe Pharmaceuticals, researchers, in this study used tablets from Jiangsu Shenlong Pharmaceutical Co., which they believe have more protective chemicals, less harmful constituents and an expected better therapeutic effect. GBE protects against ischemic stroke by scavenging free radicals. It also suppresses the activity of angiotensin converting enzyme (ACE) by inhibiting contraction of small arteries, dilating cerebral blood vessels, and increasing cerebral blood flow 3.

The researchers’ objective 4 was to evaluate the effectiveness and safety of (GBE) in acute ischemic stroke and whether it can protect against reoccurring future strokes. This multicenter, prospective, randomized, open label, blinded, controlled clinical trial began enrolling patients within 7 days of suffering a stroke, from five hospitals in China Jiangsu Province. Participants were assigned to the GBE group (n=177) which took 450 mg GBE with 100 mg aspirin daily or the control group (n=179) which took 100 mg aspirin daily for 6 months. The primary outcome was the decline in the Montreal Cognitive Assessment score at 6 months. Secondary outcomes were other neuropsychological tests of cognitive and neurological function, the incidence of adverse events and additional stroke.

Compared to control, the GBE group test results for cognitive and neurological function revealed the following:

  • Significant cognitive improvements as indicated by a marked slow down in the decline in the Montreal Cognitive Assessment scores (−2.77±0.21 vs −1.99±0.23, P=0.0116 (30 days); −3.34±0.24 vs −2.48±0.26, P=0.0165 (90 days); −4.00±0.26 vs −2.71±0.26, P=0.0004 (180 days) compared to controls.
  • Significant cognitive improvements as indicated by improvements in the National Institutes of Health Stroke Scale scores at 12 and 30 days, modified Rankin Scale scores, the Barthel Index scores, and the Mini-Mental State Examination scores at 30, 90 and 180 days. (P<0.05) compared to controls.
  • Webster’s digit symbol test scores at 30 days and Executive Dysfunction Index scores at 30 and 180 days were also improved compared to controls. (P<0.05)
  • No significant differences were seen in adverse or vascular events.

The researchers suggest that bias may have existed due to no double-blinding (there was single-blinding only), and in assessing the cognitive status of participating subjects. Longer intervention periods and larger trials are needed to allow for sub-group analysis of stroke severity and cognitive decline. Nonetheless, in this study, GBE, in combination with aspirin treatment, alleviated cognitive and neurological deficits after acute ischemic stroke without increasing the incidence of vascular events.

Source: Li S, Zhang X, Fang Q, et al. Ginkgo biloba extract improved cognitive and neurological functions of acute ischemic stroke: a randomized controlled trial. Stroke and Vascular Neurology 2017;2: e000104. doi:10.1136/svn- 2017-000104

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Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

  1. Bluhmki E, Chamorro Á, Dávalos A, et al. Stroke treatment with alteplase given 3· 0–4· 5 h after onset of acute ischaemic stroke (ECASS III): additional outcomes and subgroup analysis of a randomised controlled trial. The Lancet Neurology. 2009;8(12):1095-1102.
  2. Yao X, Shang E, Zhou G, et al. Comparative characterization of total flavonol glycosides and terpene lactones at different ages, from different cultivation sources and genders of Ginkgo biloba leaves. International journal of molecular sciences. 2012;13(8):10305-10315.
  3. Mansour SM, Bahgat AK, El-Khatib AS, Khayyal MT. Ginkgo biloba extract (EGb 761) normalizes hypertension in 2K, 1C hypertensive rats: role of antioxidant mechanisms, ACE inhibiting activity and improvement of endothelial dysfunction. Phytomedicine. 2011;18(8-9):641-647.
  4. Li S, Zhang X, Fang Q, et al. Ginkgo biloba extract improved cognitive and neurological functions of acute ischaemic stroke: a randomised controlled trial. Stroke and Vascular Neurology. 2017;2(4):189-197.