Extraction, purification, structural characteristics, biological activities, modifications, and applications from Hericium erinaceus polysaccharides: A review.

Hericium erinaceus (Bull.) Pers. is a respected medicinal and edible fungus known for its outstanding nutritional profile. In traditional Chinese medicine, it is viewed as a valuable medicinal resource offering various benefits, such as liver protection, spleen fortification, stomach nourishment, and improved digestion. The primary active ingredient, H. erinaceus polysaccharides (HEPs), exhibits diverse biological activities, including immunomodulatory, gastrointestinal protective, regulation of intestinal flora, anti-Alzheimer's, and antioxidant activities. These activities underscore the significant potential of HEPs for treating various diseases and developing HEPs-based pharmaceuticals. For instance, HEPs can exert immunomodulatory effects through the TLR4/NFκB/MyD88/MAPK/PI3K/Akt signaling pathways. Additionally, HEPs achieve immunomodulatory, gastrointestinal protection, and anti-inflammatory and anti-cancer effects by modulating intestinal microbiota. This review systematically summarizes the past five years' research on the extraction, purification, structural characteristics, pharmacological properties, structure-activity relationships, structural modifications, toxicological effects, and potential applications of HEPs. It highlights the diverse biological activities of HEPs in vivo and in vitro and discusses structural modification methods and their broad application prospects in food, medicine, industry, and other fields. These studies will enhance the understanding of HEPs and promote further exploration and innovation in the field of biological activity research and the development of potential applications.