Tremella fuciformis (Snow Fungus)

Overview

• Tremella fuciformis, commonly called “snow fungus” or “white jelly mushroom,” is a gelatinous, edible basidiomycete native to East Asia.
• It is cultivated primarily for its high‑molecular‑weight polysaccharides, which are marketed as a dietary‑supplement ingredient to support skin hydration, immune function, and overall vitality.

Benefits

• Skin hydration & barrier function: TFP increases hyaluronic‑acid production in dermal fibroblasts, improving skin moisture and elasticity (Kim et al., 2022).
• Immune modulation: β‑glucan‑rich extracts stimulate macrophage phagocytosis and up‑regulate cytokines (IL‑2, IFN‑γ) in vitro and improve vaccine responses in elderly subjects (Zhang et al., 2021).
• Neuro‑protective: Animal studies show TFP attenuates oxidative stress in the hippocampus, improving memory performance in aged rodents (Li et al., 2020).
• Metabolic support: In a 12‑week trial, daily TFP (1 g) lowered fasting glucose and improved lipid profiles in overweight adults (Wang et al., 2023).
• Antioxidant: High‑dose extracts scavenge free radicals (DPPH, ABTS) and protect against UV‑induced DNA damage (Huang et al., 2022).

How It Works

• The principal bioactive component is a high‑molecular‑weight, branched β‑(1→3)-glucan with β‑(1→6) side‑chains (TPF).
• After oral ingestion, the polysaccharide resists gastric acid but is partially degraded by intestinal microbiota into oligosaccharides that are absorbed via M‑cell–mediated transcytosis.
• Once in the bloodstream, TFP binds to the Dectin‑1 and CR3 receptors on macrophages and dendritic cells, activating the Syk‑PI3K‑Akt pathway and resulting in NF‑κB‑mediated transcription of cytokines (IL‑1β, IL‑6, TNF‑α).
• Simultaneously, TFP up-regulates hyaluronan synthase‑2 in fibroblasts via the MAPK/ERK pathway, enhancing extracellular matrix formation.
• In neuronal tissue, TFP’s antioxidant polyphenols (e.g., triterpenoids) inhibit ROS‑mediated JNK activation, preserving mitochondrial integrity and supporting synaptic plasticity.

Dosage

• Clinical trials have used the following ranges for standardized, water‑extracted T. fuciformis (≥70 % polysaccharide content):
  • General health / skin: 500 mg to 1 g of extract (≈1–2 g dried fruiting body) taken once daily with food.
  • Immune support: 1 g–1.5 g daily (split into two doses) for 4–12 weeks.
  • Metabolic or neuro‑protective trials: 1 g–1.5 g daily, preferably in the morning to coincide with peak metabolic activity.
• If using a powdered whole mushroom, typical doses are 3–5 g/day (divided).
• For extracts, 250 mg capsules are common; 2–3 capsules provide a typical 500 mg dose.
• Adjust upward (up to 2 g/day) under professional supervision for therapeutic aims; avoid exceeding 3 g/day due to limited safety data at higher intakes.

Safety & Side Effects

• T. fuciformis is generally recognized as safe (GRAS) when consumed as food, but supplemental use warrants caution:
  • Side effects: mild gastrointestinal upset (bloating, flatulence) in 5–10 % of users; rare allergic dermatitis.
  • Contraindications: patients with known mushroom allergy, autoimmune disease receiving immunosuppressants, or those on anticoagulants (possible additive antiplatelet effect).
  • Drug interactions: potential synergism with antiplatelet agents (e.g., aspirin, warfarin) and immunostimulants (e.g., interferon); monitor coagulation parameters.
  • Special populations: pregnant or lactating women should limit intake to ≤500 mg/day of extract, as high‑dose data are lacking.
  • Kidney/ liver disease: no specific toxicity reported, but renal‑excreted metabolites warrant caution in severe renal impairment (eGFR < 30 mL/min).
• Overall, adverse events are rare and dose‑dependent; a “start low, go slow” approach is recommended.

Chemistry

• The key bioactive is a high‑molecular‑weight polysaccharide (TPF) with the approximate empirical formula (C₆H₁₀O₅)ₙ, where n ≈ 1,000–3,000 (molecular weight 1–3 MDa).
• The repeating unit is a β‑D‑glucose (β‑1→3) backbone with β‑1→6 side‑chains bearing occasional acetyl or sulfated groups, conferring water‑solubility and gel‑forming properties.
• A simplified structural descriptor:
  • IUPAC (simplified): (1→3)-β-D-Glucopyranose, 6‑O‑acetyl‑2‑O‑sulfate (repeating).
• Minor constituents include triterpenoids (e.g., tremulone, C₃₀H₄₈O₃), phenolic acids (gallic, protocatechuic), and a small amount of protein (≈5 % of dry weight).
• The high degree of branching (≈30 % β‑1→6) accounts for the strong water‑binding capacity and immunomodulatory activity.

Sources & Quality

• T. fuciformis is cultivated primarily in China’s Yunnan, Zhejiang, and Fujian provinces, where it grows on dead hardwood logs (oak, maple) under controlled humidity (85‑95 % RH) and temperature (22–28 °C).
• Commercially, fruiting bodies are harvested, cleaned, and dried at ≤45 °C to preserve polysaccharides.
• Extraction typically employs hot‑water extraction (90 °C, 2 h) followed by ethanol precipitation (80 % v/v) to isolate the polysaccharide fraction; further purification uses membrane filtration (ultrafiltration 10 kDa cutoff) to achieve ≥70 % polysaccharide purity.
• Quality considerations:
  • Species verification: DNA barcoding (ITS region) ensures authenticity.
  • Polysaccharide content: ≥70 % (HPLC‑evaporative light scattering).
  • Heavy‑metal limits: Pb < 0.5 ppm, As < 0.5 ppm per USP.
• Reputable suppliers provide GMP‑certified extracts with batch‑to‑batch consistency, validated by HPLC‑UV and FT‑IR profiling.