How Extraction Methods Program the Healing Power of Mushroom Polysaccharides

Mushrooms have long occupied a curious space between the kitchen and the pharmacy, but a sweeping new analysis argues that scientists have been reading their medicinal potential the wrong way. According to a comprehensive review published in the Journal of Advanced Research, the health benefits of polysaccharides from edible and medicinal mushrooms are not fixed properties of the fungi themselves. Instead, they are programmed by the way the compounds are extracted, with every choice of solvent, temperature, time, and purification step reshaping the molecular architecture that determines whether a polysaccharide fights tumors, tames inflammation, or simply scavenges free radicals.

The review, led by Cunchao Zhao and colleagues, introduces a framework the authors call ESAR, short for Extraction–Structure–Activity Relationship. The central idea is deceptively simple: extraction conditions determine molecular structure, and molecular structure determines biological function. Yet the authors contend that decades of mushroom polysaccharide research have treated these three dimensions separately, with extraction specialists optimizing yields, chemists cataloging compositions, and pharmacologists screening activities, all without cross-linking the data needed to reveal causal, predictive relationships. The result, they argue, is a field that has remained largely descriptive rather than mechanistic.

To build the framework, the team searched Web of Science and Google Scholar for English-language studies published between 2020 and 2025, retrieving roughly 1,800 records. After screening and deduplication, about 206 studies were retained for qualitative synthesis, with inclusion contingent on analytical validation by at least two orthogonal techniques such as nuclear magnetic resonance spectroscopy, FTIR, gas chromatography–mass spectrometry, or size-exclusion chromatography coupled with multi-angle light scattering. The synthesis maps how processing variables, including pH, temperature, ionic strength, solvent type, and extraction time, feed into structural outputs such as monosaccharide composition, glycosidic linkages, molecular weight, and higher-order conformation, and how those outputs in turn govern biological effects.

The structural stakes are considerable. Most mushroom polysaccharides are dominated by glucose, mannose, and galactose, with rarer sugars such as fucose, rhamnose, arabinose, and xylose modulating heterogeneity. Mild hot-water extraction tends to enrich glucose-heavy beta-glucans, which primarily drive immune activation through the Dectin-1 receptor, whereas alkaline or enzyme-assisted routes recover more mannans and other heteropolymers that often correlate with antioxidant activity. Excess heat or acid can selectively strip away deoxy sugars or depolymerize the chains entirely. In one cited example, monosaccharide composition remained stable at 79 degrees Celsius for three hours, but extraction above 100 degrees Celsius produced clear compositional shifts and a marked loss of beta-glucan branching.

Molecular weight emerges as another dialable quality attribute, and the review is emphatic that the popular assumption that smaller is always better does not hold. Low-molecular-weight fragments penetrate cells more efficiently and can trigger reactive-oxygen-dependent apoptosis in cancer cells, while high-molecular-weight polymers achieve multivalent receptor clustering that supercharges immune signaling. Lentinan from shiitake, extracted with hot water, retains a triple-helical beta-glucan structure in the 4 to 60 kilodalton range that engages Dectin-1 and complement receptor 3 to stimulate cytokine release. Yet alkaline extraction of Phellinus linteus mycelia yielded a polysaccharide of roughly 343 kilodaltons with potent anti-proliferative and hepatoprotective effects, and a 336-kilodalton polysaccharide from Lentinus velutinus killed HeLa and HepG2 cancer cells while sparing normal cells. Mid-range polymers between roughly 20 and 40 kilodaltons, such as fractions from Helvella leucopus and Hypsizygus ulmarius, consistently combine solubility with receptor accessibility.

To make such comparisons meaningful across methods as different as hot water, deep eutectic solvents, ultrasound, microwave, and subcritical water, the authors introduce a standardized hardness index that quantifies extraction severity. Thermal treatments are scored in degree-hours, chemical treatments in molarity-hours, and physical intensification in watt-hours or megapascal-hours. The index reveals, for example, that subcritical water at 140 to 180 degrees Celsius drives auto-hydrolysis that slashes molecular weight to around 2 kilodaltons, while ionic liquids disrupt hydrogen bonding and swell cell walls to release intact 500-kilodalton beta-glucans. A table mapping dozens of species, from Ganoderma lucidum to Poria cocos, links each extraction condition to the resulting structure and activity, providing what amounts to a recipe book for tailoring polysaccharides to specific applications.

Conformation adds a further layer of control. Triple-helical conformations, generally preserved by hot-water or enzyme-assisted extraction, strengthen multivalent binding to immune receptors and are consistently associated with potent immunomodulation, activating signaling cascades through NF-kappaB and MAPK pathways. Ultrasound and microwave treatment can uncoil those helices, exposing side chains that sometimes strengthen radical scavenging but weaken Dectin-1 recognition. Chemical modification tells the same story in reverse: DMSO and alkali transform lentinan’s triple helix into single chains and reduce its activity, but incorporating selenium nanoparticles restores helicity and enhances antitumor efficacy, while sulfonation partially recovers function through charged-group interactions with immune receptors.

The framework’s predictive power is most striking in the immunology and metabolism chapters. Beta-(1,3)-glucans with beta-(1,6) branches from shiitake, reishi, and Dictyophora indusiata show the strongest macrophage and cytokine activation, whereas linear alpha-(1,4) or beta-(1,4) polysaccharides from some Pleurotus and Auricularia species yield milder antioxidant or prebiotic effects. In diabetes models, branched beta-glucans of moderate molecular weight enhance glucose uptake through GLUT4 translocation and PI3K/Akt activation, while gut microbiota studies show Morchella polysaccharides promoting beneficial Lactobacillus populations and Auricularia hydrolysates improving GLP-1 secretion. In obesity models, Pleurotus eryngii polysaccharides reduced fat deposition by upregulating LDL receptors, and Tremella fuciformis polysaccharides suppressed adipogenic transcription factors including PPAR-gamma and C/EBP-alpha.

Notably, the review challenges the assumption that purification always improves performance. Crude polysaccharides from Lepista nuda outperformed purified isolates in antioxidant assays, and complete deproteinization of lentinan extracts reduced interleukin-2 induction, pointing to synergistic contributions from co-extracted proteins and phenolics. The authors also flag persistent weaknesses in the literature: receptor activation is usually inferred rather than measured directly, helix preservation is rarely confirmed by circular dichroism or SAXS, and inconsistent calibration and assay protocols make cross-study comparison unreliable. Conflicting trends in antioxidant activity, with some studies favoring low-molecular-weight fractions and others high-molecular-weight ones, likely reflect these methodological inconsistencies rather than genuine biology.

The translational outlook is nonetheless substantial. Lentinan, schizophyllan, and the polysaccharopeptides PSK and PSP have already advanced to clinical use or evaluation as cancer adjuvants in Japan and China, and a meta-analysis of 52 randomized trials found lentinan combined with cisplatin improved outcomes in malignant pleural effusion. Beyond medicine, extraction-tailored polysaccharides are stabilizing emulsions, fortifying gluten-free baked goods, extending the shelf life of biodegradable curcumin-doped packaging films, and boosting probiotic viability in yogurt. The authors close with a playbook for the field: report processing parameters precisely, pair orthogonal structural analytics with mechanism-anchored bioassays on matched fractions, deliberately target molecular-weight sweet spots, and validate through adequately powered human studies. If adopted, they argue, ESAR could transform scattered correlations into predictive design rules, turning mushroom polysaccharide development from a search for active extracts into the engineering of process-defined polymer architectures for targeted therapeutic and nutritional ends.

Subject of Research: Process-programmed relationships between extraction methods, molecular structure, and bioactivity of edible and medicinal mushroom polysaccharides.

Article Title: Process-Programmed Extraction–Structure–Activity Relationships (ESAR) in edible and medicinal mushroom polysaccharides: a mechanistic and application-oriented framework

Article References: Zhao, C., Aaqil, M., He, R., Kamil, M., Zheng, J., Guo, Y., Zhang, Z., Nawaz, T., Zhang, F., You, L., & Tian, Y. (2026). Process-Programmed Extraction–Structure–Activity Relationships (ESAR) in edible and medicinal mushroom polysaccharides: a mechanistic and application-oriented framework. Journal of Advanced Research, 87, 1045-1077. https://doi.org/10.1016/j.jare.2025.12.040

Image Credits: AI Generated

DOI: 10.1016/j.jare.2025.12.040

Keywords: mushroom polysaccharides, extraction methods, structure–activity relationships, beta-glucans, immunomodulation, antitumor activity, antioxidant, molecular weight, triple helix, gut microbiota, antidiabetic, functional foods