Maitake (D-fraction) — The Immune-Modulating Mushroom Extract
Maitake D-fraction is a bioactive beta-glucan extract derived from the Maitake mushroom (Grifola frondosa), known for its potent immunomodulatory properties. In the context of longevity, it is investigated for its potential to enhance immune surveillance, support metabolic health, and exert anti-tumor effects.
Mechanism of Action
Maitake D-fraction is a protein-bound beta-1,6-glucan extracted from Grifola frondosa. It activates various effector cells such as macrophages, natural killer (NK) cells, and T cells. The beta-glucan activates macrophages via the Dectin-1/Syk/NF-κB signaling pathway. It also demonstrates antitumor activity by upregulating proapoptotic BAK-1, blocking tumor invasiveness, and reducing angiogenesis. Preclinical studies suggest antidiabetic effects via increased insulin sensitivity and decreased insulin resistance.
Human Trial Evidence
Data in humans are limited. In small trials, oral maitake extract appeared to have immunomodulatory effects in postmenopausal breast cancer patients and enhanced neutrophil and monocyte function in patients with myelodysplastic syndrome. No published human longevity trials. Animal/in-vitro evidence only.
Dosing Protocol
1-3 mg/kg per day of Maitake D-fraction extract is commonly used in clinical studies. Best taken orally, often in divided doses. Unestablished for human longevity.
Safety & Contraindications
Maitake is generally well tolerated. A case report suggests maitake can interact with warfarin, resulting in INR elevation. It may also increase the effects of hypoglycemic medications in type-2 diabetic patients, potentially leading to hypoglycemia. Caution is advised for individuals on blood thinners or antidiabetic drugs.