Oz Ginkgo Biloba

Overview

• Oz Ginkgo Biloba is a standardized botanical extract derived from the leaves of Ginkgo biloba L., a living fossil tree native to East Asia.
• The supplement is formulated to deliver a standardized concentration of flavonoid glycosides and terpene lactones.
• Its primary purpose is to support brain health and circulatory function in adults seeking to maintain cognitive performance and vascular tone.

Benefits

• Cognitive support: Randomized controlled trials (RCTs) show modest improvements in working memory and processing speed in healthy adults and patients with mild cognitive impairment when 120–240 mg/day of standardized extract is taken for 12–24 weeks (e.g., Ginkgo Evaluation of Memory Study).
• Cerebral blood flow: Ginkgo’s vasodilatory and anti-platelet effects increase cerebral perfusion, as demonstrated by transcranial Doppler and MRI perfusion studies, which may help mitigate age-related declines in oxygen delivery.
• Antioxidant protection: Flavonoids (quercetin, kaempferol) and terpenes (ginkgolides, bilobalide) neutralize reactive oxygen species, reducing lipid peroxidation in neuronal membranes.
• Auditory and visual function: Small-scale studies report better auditory processing and reduced visual-contrast sensitivity loss in older adults.
• Physical performance: In endurance-trained athletes, 160 mg/day has been linked to reduced perceived exertion and improved oxygen utilization, likely via enhanced microcirculation.

How It Works

• Process: Oz Ginkgo Biloba exerts its effects through several inter-related biochemical pathways.
• Flavonoid glycosides: Inhibit oxidative enzymes (NADPH-oxidase, xanthine oxidase) and up-regulate endogenous antioxidant enzymes (SOD, catalase).
• Terpene lactones: Antagonize platelet-activating factor (PAF) receptors, reducing platelet aggregation and improving microvascular flow.
• Bilobalide: Modulates GABA-A receptors, providing neuro-protective modulation of excitatory neurotransmission.
• Additional effects: Enhances nitric-oxide synthase (eNOS) activity, increasing NO-mediated vasodilation, and up-regulates cerebral blood-flow regulatory genes (e.g., VEGF, eNOS).
• Overall effect: The combined antioxidant, anti-inflammatory, and vasodilatory actions create a favorable environment for neuronal metabolism and synaptic plasticity.

Dosage

• Clinical research consistently uses a daily dose of 120–240 mg of standardized Ginkgo biloba extract (24 % flavonoid glycosides, 6 % terpene lactones).
• The most common regimen is 120 mg taken twice daily (morning and early afternoon) with meals to improve absorption and reduce gastrointestinal irritation.
• For acute cognitive tasks, a single 160 mg dose 30 minutes before a demanding mental activity has been studied without adverse events.
• Special populations:
  • Older adults (>65 y) often start at 80 mg/day and titrate upward.
  • Patients on anticoagulants should limit to ≤120 mg/day and monitor coagulation.
• For experimental neuro-vascular studies, a short-term loading dose of 300 mg for 7 days has been explored, but it is not recommended for routine supplementation.

Safety & Side Effects

• Ginkgo is generally well-tolerated, with mild adverse events reported in <5 % of users (headache, gastrointestinal upset, mild allergic skin reactions).
• Significant concerns:
  • Antiplatelet activity: concurrent use with warfarin, clopidogrel, aspirin, or novel oral anticoagulants can increase bleeding risk; dose reduction or discontinuation is advised 2 weeks before surgery.
• Contraindications: Pregnancy, lactation, and children <12 y due to limited safety data.
• Ginkgo may interact with cytochrome-P450 substrates (e.g., CYP2C19, CYP3A4) and reduce the efficacy of antiepileptic drugs by altering plasma levels.
• Persons with seizure disorders, severe liver disease, or scheduled for major surgery should avoid or consult a healthcare professional before use.

Chemistry

• The active fraction of Oz Ginkgo Biloba is a standardized extract containing:
  • Flavonoid glycosides (quercetin-3-O-glucoside, kaempferol-3-O-glucoside)
  • Terpene lactones (ginkgolide A, B, C, bilobalide)
• Ginkgolides are sesquiterpene lactones with a unique bicyclic ring system (C₁₉H₂₄O₅ for ginkgolide A, IUPAC: (2S,3R,4S,5R,6S)-5,6-dihydroxy-3-(2-hydroxymethyl-5-hydroxy-4-methoxy-1-oxo-2-pyrrolidinyl)-4-methyl-2-pyrrolidine).
• Bilobalide is a sesquiterpene lactone with formula C₁₅H₁₈O₈ (IUPAC: 4-(2-hydroxy-2-methylpropyl)-2-methyl-6-hydroxy-5-oxo-2-pyrrolidine).
• The standardized extract typically contains:
  • 24 % flavonoid glycosides (expressed as quercetin equivalents)
  • 6 % terpene lactones (ginkgolides A–C and bilobalide)
• The extract is water-ethanol-based, standardized to a minimum of 2.5 % ginkgolic acids (often reduced to <5 ppm) to minimize allergenic potential.

Sources & Quality

• Oz Ginkgo Biloba is sourced primarily from mature Ginkgo biloba trees cultivated in China (Shandong, Zhejiang provinces) and Korea.
• Leaves are harvested in late autumn when flavonoid concentrations peak.
• Leaves are dried at ≤40 °C to preserve thermolabile constituents.
• Extraction employs a 50 % ethanol-water mixture under controlled temperature (60 °C) and vacuum.
• The extract is purified by resin-based chromatography to achieve the 24 %/6 % standardization.
• The extract is tested for heavy metals, pesticide residues, and microbial load per USP <795> guidelines.
• High-quality manufacturers employ:
  • GMP-certified facilities
  • Batch-to-batch HPLC fingerprinting
  • Third-party certification (e.g., USP, NSF) to ensure consistency and safety.