Therapeutic effects of Lentinan in gastrointestinal inflammation and carcinogenesis – A scoping review of evidence from preclinical and clinical studies

Lentinan, a β-(1,3)-glucan derived from the mushroom Lentinus edodes, is known for its health-beneficial including anti-oxidant, anti-inflammatory, and anti-tumor effects particularly in the gastrointestinal tract, and even regarded as adjuvant in cancer treatment in Asia. There is, however, a knowledge gap regarding lentinan's clinical application and the underlying mechanisms of its pleiotropic effects. This prompted us to perform a scoping review summarizing current knowledge of lentinan's health-promoting and disease-alleviating properties in the gastrointestinal tract and beyond. Preclinical and clinical studies revealed protective and therapeutic effects of the compound in distinct gastrointestinal pathologies, including colitis, chemotherapy- and immunosuppression-induced intestinal injury, infection models as well as in colorectal carcinogenesis by modulating intestinal epithelial barrier integrity, immune signaling, and microbiota composition. Lentinan was reported to exert its anti-tumor effects by interfering with apoptosis, autophagy, stemness, and angiogenesis. Notably, lentinan enhanced the effectiveness of chemotherapy and chimeric antigen receptor T-cell (CAR-T) therapy, reduced treatment-related adverse events, improved survival and quality of life. The observed effects were dependent on lentinan's molecular weight, dose, and route of administration. In conclusion, lentinan application constitutes a promising intervention strategy in gastrointestinal and extra-intestinal including systemic morbidities that should be further investigated in preclinical and clinical studies.