Ginkgo Biloba: Benefits, Uses, Safety and Dosing

Ginkgo biloba is a common memory-boosting herb also known as the maidenhair tree, fossil tree, baiu, icho, and silver apricot. It belongs to the family Ginkgoaceae and is native to south, central, and east China. It is currently cultivated in parts of France (Bordeaux), the United States (Carolina), Germany, and Japan (in the wild).

Ginkgo biloga is used in the following ways:

• Improve cognition and memory
• Improves physical mobility in peripheral artery disease.
• Aids in tinnitus and vertigo
• Used to support treatment of anxiety and schizophrenia
• Aids in stroke recovery

Medical Uses and ethnopharmacological profile of Ginkgo biloba

Traditional uses

The leaves and seeds were used in respiratory conditions like coughs, bronchitis, and expelling excess mucus. Roasted seeds were also used as a digestive aid. It was also used to alleviate symptoms of bladder/urinary issues. The plant was also used to boost blood circulation and support mental clarity. Topical preparations were used on the skin for abscesses, sores, and ulcers.

Clinical Uses and Research

Dementia: Leaf acetone/water dry extracts rich in flavones (kaempferol/quercetin) at a dose of 240 mg/kg in divided doses for 22-26 weeks were able to improve cognition. This was through the restoration of mitochondrial function by reducing its viscosity and allowing for enhanced microperfusion.

Vertigo and Tinnitus: Standard extracts in film-coated tablets rich in ginkgolides A, B, and C were able to alleviate neurosensory symptoms, restoring balance and promoting hearing. This was through the action of improving blood flow and reducing ischemic damage by inhibiting platelet activating factor with a dose of 120 mg twice daily for 12-24 weeks.

Cardiovascular health: patients with peripheral artery disease recorded an improvement in blood flow after taking standardized ginkgo extract. This was via reduction of blood viscosity and stimulation of nitric oxide leading to vasodilation and reduction in platelet formation. In turn, there was increased blood flow to peripheral organs like limbs. ( Saskia 2013).

Skin rejuvenation: Volunteers used topical standardized ginkgo cream over two weeks, and there was recorded improvement in skin texture and tautness. Ginkgo has a vasodilatory effect through nitric oxide stimulation, which increases microcapillary circulation of the skin vessels. This simple action boosts nutrient circulation to non-visible wounds and small tears as well as aging skin.

In vivo uses and Research

Obesity/type 2 diabetes: Ginkgo biloba extract was given orally to obese mice for 14 days, and there was a significant reduction in body fat as well as a reduction in food intake. It was noted that there was anti-inflammatory action in the fat cells that ultimately was linked to the reversal of insulin resistance. This also led to improved insulin signaling, thus pointing to applications in controlling hyperglycemia.

Hepatic protection: In a study involving uranium-induced organ toxicity in albino mice, biloba extract showed a dose-dependent reduction in elevated levels of markers like creatinine and AST levels. This is thought to be through the restoration of natural antioxidants like glutathione that scavenge for free radicals.

Wound healing: Rats given gingko extract at a dose of 50 mg/kg body weight showed faster healing and recovery. The compound hydrypyroline was isolated to act by promoting growth of new blood vessels and increasing collagen content in skin wounds. ( Bairy K. 2001)

In vitro uses and Research

Bone health: In a study of bone marrow stem cells, ginkgo biloba extract was able to promote osteogenesis via overexpressing osteogenic genes like BMP-2 and Runx2 that promote differentiation of stem cells into osteoblasts.

Antiviral: In studies against Zika and herpes 1 viruses in host cells, gingko extract rich in ginkgolic acid effectively inhibited viral fusion into the cells, thus inhibiting cell penetration and entry. ( Borenstein 2020).

Anti-cancer: Ginkgo bioflavonoids, when exposed to cervical cancer cell lines, induced programmed cell death by arresting the cell cycle at the G2/M phase via activation of a special protein (caspase-3) that oversees the dismantling of cancer cells.

Safety and Dosing Profile of ginkgo biloba

Forms and Dosing

• Standardized capsules and tablets–  80 to 240 mg daily in divided doses depending on indication.
• Tinctures- (1:5) is used 2- 5 mls thrice a day and 0.5-1 ml thrice a day for concentrated preparations (1:1)
• Teas/infusions: taken up to thrice a day.
• Intravenous infusions(clinical)– specific calculation for patients
• Dried powder– 1- 2 grams

Dementia/cognitive impairement- 120 mg twice or 240 mg once a day

Peripheral artery disease- 120-240 mg a day

Tinnitus- 120-240 mg a day

Anxiety disorders- 240-480 mg a day

Interactions

• Anticoagulants (enoxaparin/warfarin)—ginkgo may increase bleeding and bruising.
• Anticonvulsants (phenytoin)—gingko may reduce the action of anticonvulsants.
• Antidepressants (SSRIs, MAOIs) may put one at risk of developing serotonin syndrome.
• Antidiabetics (metformin) have the effect of fluctuating insulin secretion and metabolism.

Side effects

• Ginkgo headache
• Nausea, diarrhea and abdominal cramping
• Dizziness
• Heart palpitations
• Skin allergies (while handling whole products)
• Seizures (rare) caused by ginkgotoxins