β-Glucans from Shiitake mushrooms: LENTINAN

Mushrooms are very rich foods from a nutritional point of view and characterized by the presence of numerous bioactive compounds useful for our body. Among these compounds, β-glucans are of particular interest due to their beneficial properties for our health.

β-glucans are a class of polysaccharides made up of repeating D-glucose units, joined together by glycosidic bonds which can be of three types β-1,3, β-1,4 or β-1,6 . In addition to fungi, we can find β-glucans in other food products such as plant foods and algae but also in yeasts and bacteria where, however, we find them in different forms depending on the type of glycosidic bond established between the individual units.

The main physicochemical properties of β-glucans include antioxidant activity, which is responsible for the elimination of reactive oxygen species, and the role of dietary fiber useful for reducing the absorption of cholesterol, promoting intestinal transit and for the prebiotic action on the intestinal microbiota.

Furthermore, as demonstrated by the scientific literature, we cannot fail to mention the anti-tumor and immunostimulatory effects that β-glucans taken in the diet can have on the cells of the immune system following the binding with their receptors present on these cells.

For thousands of years, natural compounds containing β-glucans of fungal origin have been used in China and Japan for their effects on general health. LENTINAN has been identified in shiitake mushrooms ( Lentinula edodes ), a β-glucan specifically involved in strengthening the immune system. Lentinan is made up of glucose units joined by β-1,3 bonds which every 5 residues have two side chains joined by β-1,6 bonds.

In macrophages, T lymphocytes and NK cells we find a specific receptor for Lentitane, the binding of which stimulates the activity of these cells responsible for defending our body from potentially pathogenic organisms. Furthermore, the stimulation of macrophages determines the production of cytokines , i.e. local immunomodulators, which in turn activate adaptive immunity against foreign antigens. We can therefore say that Lentinan can act in two ways on our immune system: directly by promoting the activity of the immune cells responsible for the most immediate but non-specific innate response, and indirectly through the activation of macrophages which in turn determine a stimulation of the response slower and more specific adaptive immunity.

Opening a current topic, we can say that very recent studies are demonstrating the action of Lentinan extracted from shiitake mushrooms also on the immune system of patients affected by COVID-19 . In fact, in these patients characterized by a strong pulmonary inflammatory state due to the infection, following the administration of Lentinan, a reduction in the production of molecules with pro-inflammatory activity at the pulmonary level and also a reduction in oxidative stress was observed, again demonstrating once the involvement of Lentinan in the modulation of the immune system in response to infection by the pathogenic microorganism.

To conclude, we can say that once again we have demonstrated how Shiitake Mushrooms can truly be effective allies in supporting and keeping our immune system in balance! Discover IoBoscoVivo Shiitake Mushrooms in our shop! https://shop.ioboscovivo.it/collections/all

Bibliography

• Nakashima, A., Yamada, K., Iwata, O., Sugimoto, R., Atsuji, K., Ogawa, T., Ishibashi-Ohgo, N., & Suzuki, K. (2018). β-Glucan in Foods and Its Physiological Functions. Journal of nutritional science and vitaminology, 64(1), 8–17. Available at https://doi.org/10.3177/jnsv.64.8
• HAZAMA, S., WATANABE, S. et al., (2009) Efficacy of Orally Administered Superfine Dispersed Lentinan (β-1,3-Glucan) for the Treatment of Advanced Colorectal Cancer. Anticancer Research , vol. 29 no. 7 2611-2617. Available at http://ar.iiarjournals.org/content/29/7/2611.long
• Murphy, Emma J et al. (2020). β-Glucan extracts from the same edible shiitake mushroom Lentinus edodes produce differential in-vitro immunomodulatory and pulmonary cytoprotective effects - Implications for coronavirus disease (COVID-19) immunotherapies.” The Science of the total environment vol. 732: 139330. Available at https://doi.org/10.1016/j.scitotenv.2020.139330