Ginkgo Biloba Extract

Ginkgo Biloba leaf consists of 24% flavonoids and 6% terpene trilactones, and also contains proanthocyanidins, polyprenols, organic acids, and polysaccharides. Seeds are lignan-rich, but also contain toxic alkylphenols and ginkgotoxin. In addition to classical antioxidant mechanisms and neuro-protective activities, EGb 761 and some individual components act as multitarget agents with anti-inflammatory (NF-κB, PAF, MAPK down-regulation), broad spectrum antibacterial, anti-viral, anti-obesity, anti-atherogenic and anti-cancer activities tested in over 22 tumor cell lines and rodent models of metabolic dysfunction or neurodegeneration. Ginkgolic acids, biflavones, and 4-methoxypyridoxin are responsible for dose-dependent cytotoxic, genotoxic and allergenic effects; some dietary supplements contain ginkgolic acids at levels over 1600 times the pharmacopoeial limit of 5 ppm.

Fig. 1 Ginkgo Biloba leaf. (Biernacka P.; et al. 2023)

Reviewing 1,038 preclinical studies and 98 clinical trials for evidence if standardized Ginkgo biloba extract (GBE) could treat Alzheimer's disease (AD), authors selected 17 rodent studies and 20 double-blind placebo-controlled trials. In animal models of AD, GBE robustly enhanced performance in the Morris water-maze task (reduced escape latency and increased platform-crossing) and decreased Aβ deposition, tau hyper-phosphorylation, oxidative stress, apoptosis and neuro-inflammation. Clinical studies showed daily doses of 240 mg GBE taken for ≥24 weeks provided modest benefits on SKT and ADAS-Cog scores among people with early stage AD (benefits were most pronounced for those between the ages of 60 and 70 years old) and no benefit for those over 75 years old or with more advanced pathology.

Fig. 2 Ginkgo biloba extract in Alzheimer's disease treatment. (Xie L.; et al. 2022)