Gastrodia elata (Tian Ma) | Supplementopedia

Overview

Gastrodia elata (commonly called Tian Ma) is a leaf‑less, myco‑heterotrophic orchid native to East Asia. Its tuberous rhizome has been used for centuries in Traditional Chinese Medicine (TCM) chiefly as a neuro‑protective and “calming” herb, and modern supplements market it for cognitive, neurological, and metabolic support.

Benefits

Neuro‑protection & cognition: Randomized trials and animal studies show Gastrodia elata extracts improve memory, attenuate oxidative stress, and protect against ischemic and neurodegenerative injury (e.g., reduced infarct size in rodent stroke models).
Seizure & migraine relief: Controlled trials in patients with epilepsy and migraine report reduced frequency and intensity when gastrodin (the primary active) is added to standard therapy.
Anxiety & sleep: Double‑blind studies demonstrate reduced scores on anxiety and insomnia scales, likely via GABA‑ergic modulation.
Anti‑inflammatory & analgesic: Meta‑analyses of pre‑clinical data reveal inhibition of NF‑κB and COX‑2, lowering inflammatory cytokines (IL‑1β, TNF‑α).
Metabolic modulation: Small human trials suggest modest improvements in glucose tolerance and lipid profiles, linked to enhanced insulin signaling and reduced hepatic steatosis in animal models.

How It Works

Gastrodia elata’s pharmacology centers on the phenolic glucoside gastrodin (C₁₃H₁₈O₇) and its metabolite p‑hydroxybenzyl alcohol. Gastrodin crosses the blood–brain barrier, where it:

Enhances GABAergic transmission: by up‑regulating GABA‑A receptor subunits and inhibiting GABA‑transaminase, increasing synaptic GABA.
Scavenges reactive oxygen species (ROS): via direct antioxidant activity and up‑regulation of Nrf2‑dependent antioxidant enzymes (HO‑1, NQO1).
Modulates neuroinflammation: by suppressing NF‑κB and MAPK pathways, lowering cytokine release.
Regulates calcium homeostasis: through inhibition of voltage‑gated Ca²⁺ channels, reducing excitotoxicity.
Activates PI3K/Akt and AMPK pathways: improving neuronal survival and improving insulin signaling in peripheral tissues.

These combined actions underpin its neuro‑protective, anxiolytic, and metabolic benefits.

Dosage

Clinical trials have used gastrodin doses ranging 25–100 mg/day (equivalent to 0.5–2 g of dried G. elata rhizome) divided into 2–3 doses.

Cognitive/neurological applications: 30 mg of standardized gastrodin extract taken twice daily with meals is typical.
Seizure or migraine prophylaxis: 50–100 mg/day divided into 2 doses has shown efficacy.
Metabolic or anti‑inflammatory protocols: 40–60 mg daily for 8‑12 weeks is common.

Timing is flexible, but consistency (morning and evening) enhances steady plasma levels. For elderly or low‑body‑weight individuals, start at 25 mg/day and titrate up. Use of a standardized extract (≥5 % gastrodin) ensures dose reliability.

Safety & Side Effects

Gastrodia elata is generally well‑tolerated. Reported side‑effects are mild: gastro‑intestinal upset, dizziness, or mild drowsiness (≤5 % of users).

Contraindications: include pregnancy, lactation, and severe liver disease because hepatic metabolism of gastrodin may be altered.
Drug interactions: gastrodin may potentiate benzodiazepines, barbiturates, and antiepileptic drugs (additive CNS depression) and may affect warfarin by modestly inhibiting CYP2C9, increasing INR.
Caution: in renal impairment (dose reduction 50 %).
Children <12 yr and individuals with hypotension should avoid high doses.
Discontinue if severe dizziness or allergic rash occurs.

Chemistry

The principal bioactive, gastrodin, is a β‑D‑glucoside of 4‑hydroxy‑3‑methoxybenzyl alcohol.

IUPAC name: 4-(hydroxymethyl)-2-methoxyphenyl β‑D‑glucopyranoside;
Molecular formula C₁₃H₁₈O₇;
Molecular weight 286.27 g mol⁻¹.

It is a hydrophilic phenolic glucoside with a glucose moiety linked via an O‑glycosidic bond to a phenyl‑based aglycone. The molecule is highly soluble in water (≈1 g/10 mL) and stable at pH 5–7, but hydrolyzes to p‑hydroxybenzyl alcohol under acidic conditions. Other constituents include vanillin, p‑hydroxybenzaldehyde, and several polysaccharides, which contribute to anti‑oxidant activity. The glycosidic bond is cleaved by intestinal β‑glucosidases, releasing the active aglycone, which is then metabolized to p‑hydroxybenzyl alcohol in the liver.

Sources & Quality

Gastrodia elata is cultivated primarily in China (Sichuan, Yunnan, Zhejiang provinces), Japan, and Korea, where it grows in symbiosis with forest fungi (mycorrhiza) on decaying wood. Commercial supplements use root‑tuber extracts harvested in late autumn when gastrodin content peaks (~5 % w/w). Extraction commonly employs water‑ethanol (70 % ethanol) maceration, followed by spray‑drying to produce a standardized powdered extract.

Good Agricultural and Collection Practices (GACP) and Good Manufacturing Practices (GMP) ensure low heavy‑metal and pesticide levels.
Authenticity is verified by HPLC‑UV or LC‑MS quantifying gastrodin; DNA barcoding confirms species identity.
High‑quality products are labeled “standardized to ≥5 % gastrodin” and undergo microbial, heavy‑metal, and pesticide testing to ensure safety and potency.