- Lentinan is a biologically active β-glucan polysaccharide extracted from the fruiting body of the shiitake mushroom (Lentinula edodes).
- Structurally, it is a β-(1→3)-glucan with β-(1→6)-linked side chains, a configuration common among fungal polysaccharides that exhibit immunomodulatory activity.
- Lentinan is water-soluble and forms helical structures in solution, a property closely linked to its bioactivity. Unlike small-molecule drugs, lentinan does not directly kill pathogens or cancer cells; instead, it enhances the body’s immune responses, making it an important immunotherapeutic agent.
- The biological activity of lentinan is centered on its ability to modulate the immune system. It activates macrophages, dendritic cells, T lymphocytes, and natural killer (NK) cells by interacting with β-glucan receptors such as Dectin-1 and complement receptor 3 (CR3). This stimulation leads to increased production of cytokines, including interleukins, interferons, and tumor necrosis factors, which collectively strengthen host defense mechanisms. Because of this immunostimulatory role, lentinan has been widely investigated as an anticancer adjuvant. Clinical studies, particularly in Japan and China, have shown that lentinan can improve survival rates and quality of life in patients with gastric cancer, colorectal cancer, and other malignancies when used alongside chemotherapy.
- Beyond oncology, lentinan exhibits a range of additional biological activities. It has been reported to show antiviral, antibacterial, and antioxidant effects, supporting its potential role in combating infections and reducing oxidative stress. In traditional medicine, shiitake mushrooms have long been valued for their health benefits, and lentinan is considered one of the primary compounds responsible for these therapeutic properties. Its ability to regulate immune function also makes it a candidate for use in managing chronic diseases and supporting overall immune health.
- From a pharmacological perspective, lentinan is regarded as safe and well-tolerated, with minimal toxicity compared to conventional chemotherapeutic agents. However, because it is a high-molecular-weight polysaccharide, its absorption is limited when taken orally. For clinical applications, lentinan is typically administered through injection, ensuring direct bioavailability. Research is ongoing to develop modified forms or delivery systems—such as nanoparticles or conjugates—that could improve its effectiveness when taken orally.
- In addition to its medical uses, lentinan has attracted attention in the fields of functional foods and nutraceuticals. With growing global interest in mushroom-derived health products, lentinan is marketed as a natural immune booster and dietary supplement. Its dual identity as both a traditional medicinal compound and a scientifically validated immunomodulator bridges ancient practices with modern biotechnology.
