Shiitake Mushrooms (Lentinula Edodes)
Polysaccharide and extracts from Lentinula edodes: structural features and antiviral activity
Lentinula edodes, known as shiitake, has been utilized as food, as well as, in popular medicine, moreover, compounds isolated from its mycelium and fruiting body have shown several therapeutic properties. The aim of this study was to determine the antiviral activity of aqueous (AqE) and ethanol (EtOHE) extracts and polysaccharide (LeP) from Lentinula edodes in the replication of poliovirus type 1 (PV-1) and bovine herpes virus type 1 (BoHV-1).
In conclusion, we suggest that AqE, EtOHE and LeP act on the initial processes of PV-1 and BoHV-1 replication. The extracts and the polysaccharide could be considered as a source of potential antiviral substances. However, further study is necessary to better understanding of the step(s) of viral replication where inhibition occurs.
In Vitro Assessment of Shiitake Mushroom (Lentinula edodes) Extract for Its Antigingivitis Activity
Gingivitis is a preventable disease characterised by inflammation of the gums due to the buildup of a microbial biofilm at the gingival margin. It is implicated as a precursor to periodontitis, a much more serious problem which includes associated bone loss. Unfortunately, due to poor oral hygiene among the general population, gingivitis is prevalent and results in high treatment costs. Consequently, the option of treating gingivitis using functional foods, which promote oral health, is an attractive one. Medicinal mushrooms, including shiitake, have long been known for their immune system boosting as well as antimicrobial effects; however, they have not been employed in the treatment of oral disease. In the current study, the effectiveness of shiitake mushroom extract was compared to that of the active component in the leading gingivitis mouthwash, containing chlorhexidine, in an artificial mouth model (constant depth film fermenter). The total bacterial numbers as well as numbers of eight key taxa in the oral community were investigated over time using multiplex qPCR. The results indicated that shiitake mushroom extract lowered the numbers of some pathogenic taxa without affecting the taxa associated with health, unlike chlorhexidine which has a limited effect on all taxa.
In conclusion, the comparison of the different treatments using the CDFF has given a valuable insight into the community dynamics of dental plaque as well as an indication of the efficacy of the treatments. Chlorhexidine was found to be effective at lowering a number of taxa, associated with both health and disease; however, shiitake mushroom extract was shown to be effective at reducing the numbers of the oral pathogen F. nucleatum, while having little effect on some of the taxa associated with health. The results imply that the action of shiitake mushroom extract should be investigated further for its beneficial effects on oral health.
Lentinula edodes β-glucan enriched diet induces pro- and anti-inflammatory macrophages in rabbit
β-glucans exhibited in cell walls of several pathogens as bacteria or fungi are sensed by pathogen recognition receptors such as scavenger receptors present in antigen presenting cells, i.e., macrophages. β-glucans obtained from Shiitake mushrooms were chemically characterized. A β-glucan supplemented diet was assayed for 30 days in rabbits aiming to characterize the immune response elicited in blood-derived macrophages. M1 and M2 profiles of macrophage differentiation were confirmed in rabbits by in vitro stimulation with IFN-γ and IL-4 and marker quantification of each differentiation pathway. Blood derived macrophages from rabbits administered in vivo with the β-glucan supplemented diet showed higher IL-4, IFN-γ and RAGE together with lower IL-10 relative expression, indicative of an ongoing immune response. Differences in IL-1β, IL-13 and IL-4 expression were also found in rabbit sera by ELISA suggesting further stimulation of the adaptive response. Recent challenges in the rabbit industry include the search of diet supplements able to elicit an immune stimulation with particular interest in facing pathogens such as viruses or bacteria. β–glucans from fungi may contribute to maintain an immune steady state favouring protection and thus reducing antibiotic treatment.
Supplementation of rabbits’ diet with Shiitake-derived β-glucans for 30 days induced a lower IL-10 expression and higher levels of IL-4 and IFN-γ all of which indicates an ongoing immune response. Further comparisons with the control group also revealed IL1-β and RAGE as significantly induced by the supplemented diet (Figure 2(c,d)). Increased IL-1β, IL-4 or IL-13 cytokine production was observed in the supernatant of ConA-stimulated lymphocytes confirming RNA relative expression results. β-glucans orally consumed were able to modify significantly the macrophage maturation profile suggesting that protective roles could be based on macrophage differentiation upon recognition of branched β-glucans.