Energy status regulated umami compound metabolism in harvested shiitake mushrooms(Lentinus edodes)with spores triggered to release

The molecular mechanisms of energy status related to the umami taste of postharvest shiitake mushrooms during spore release remain poorly understood.In this study,the variations of energy status and umami taste of mushrooms were measured at 25℃.At 24 h storage,slight spore prints of mushrooms were first pictured,respiration peaked.Significant ATP decrease and ADP increase were also observed as the initiation of postharvest senescence(P<0.05).Meanwhile,the activities of phosphohexose isomerase,succinate dehydrogenase,glucose-6-phosphate dehydrogenase and cytochrome c oxidase and the contents of umami nucleotides and amino acids were maintained at higher levels in mushrooms with spore release.Notably,the equivalent umami concentration(EUC)was strongly correlated with energy levels(R=0.80).Fifteen related gene expression levels in the energy metabolism pathway were downregulated.LecpdP1 and LeAK were significantly expressed in the conversion of ATP into AMP and played key roles in connecting the energy state and umami level.These results provided valuable insights on the umami taste associated with energy metabolism mechanism during postharvest mushroom spore release.

Protection of Allergic Asthma in Mice by Black Rice Bran Bioprocessed with Shiitake Mushroom Mycelia

We evaluated the potential of orally fed new food formulations to inhibit biomarkers reported to be involved in the causes of allergic asthma in mice. Asthma, a serious non-communicable disease, affects both adults and children and can be undertreated. New functional foods could provide therapeutic approaches. Here, the anti-asthma mechanism of a new functional food and three isolated fractions produced by bioprocessing black rice bran with shiitake mushroom mycelia was evaluated in mast cells, B cells, and orally fed mice and compared with non-bioprocessed black rice bran. In vitro, the treatments inhibited RBL-2H3 cell degranulation and immunoglobulin E (IgE) production. The in vitro anti-asthma effects were confirmed in orally fed mice following asthma induction by alumina and chicken egg ovalbumin (OVA). The suppression of asthma resulted from the inhibition of inflammation- and immune-related substances, including OVA-specific IgE, thymic stromal lymphopoietin, eotaxin, leukotriene C4, prostaglandin D2, and vascular cell adhesion molecule-1 in bronchoalveolar lavage fluid and serum. The treatment also reversed the thickening of the lung airway wall. The inflammation and asthma inhibition seems to be regulated by the balance of the T-helper cells’ Th1/Th2 immune response and the inhibition of multiple biomarkers associated with the cause of asthma. Future human clinical studies with adults and children should determine the potential therapeutic value of the anti-asthma effects of the new functional foods.

In vitro bone inducing effects of Lentinula edodes (shiitake) water extract on human osteoblastic cell cultures

The effect of Lentinula edodes water extract(LE)on two osteoblastic cell cultures(HOS 58 and Saos-2)was investigated to determine if this edible medicinal mushroom has osteoinductive properties.Activity of alkaline phosphatase and mineralization were used as indicators for the vitality and maturation of the bone cells.Cultivation of human osteosarcoma cells HOS 58 for five days in presence of a serial dilution of the aqueous extract of L.edodes(0.8μg/mL-125μg/mL)resulted in a significant elevation of alkaline phosphatase activity(ALP)of the cells in comparison to untreated cells.Saos-2 cells,incubated with LE(20μg/mL)andb-glycerol phosphate(2 mM)for 21 days,displayed a 2 fold level of mineralization than cells cultured soley with the positive control,b-glycerophosphate.The obtained results clearly indicate the activity of LE as a bone inducing agent in vitro.Therefore,the shiitake mushroom(L.edodes)deserves attention as a supportive dietary treatment or nutraceutical in the case of diseases accompanied with bone disorder,such as osteoporosis,osteopenia,and late complication of diabetes.

Shiitake dermatitis: a case report

Introduction Shiitake dermatitis (SD) is correlated with the ingestion of raw or undercooked shiitake mushrooms (SMs) and is more common in countries where SMs are habitually eaten.The condition was first reported in Japan by Nakamura in 1977[1] and has since been recorded worldwide.The associated reports are rare in the domestic.This disease is characterized by intensely pruritic isolated or grouped papules or papulovesicles with whiplash-striped,infiltrated erythema that arise in a pattern consistent with the K(o)bner phenomenon because of stripe-like scratching,thus differing the lesions from the immediate onset of dermographism[1].

Regulation of Respiratory and Ligninolytic Enzyme Activity of Lentinula edodes by Selenium

The production of mushrooms enriched with essential elements, e.g. selenium, for human health is an interesting strategy to improve the functional foods supply. The selenium is an essential mineral and makes part of structure of enzymes involved in the oxidative metabolism. However, the selenium effect on the activity of respiratory and lignocellulolytic enzymes has not been considered. The understanding of this effect is important to determine the selenium concentration that increases the mushroom productivity and the degradation rate of the substrate. In this study, it was observed reduction of the respiratory activity of Lentinula edodes (Berk.) Pegler, the shiitake mushroom, in function of the increasing of the sodium selenite concentration in the substrate (p < 0.05). Selenium did not inhibit the activity of the hydrolytic enzymes (cellulase and xylanase), but it increased the activity of the oxidative enzyme (laccase). Respiratory activity of L. edodes has a negative correlation with sodium selenite concentration added in substrate. Thus is important to define the ideal dose of selenium to be added to the substrate for increasing lignocellulosic residues degradation and, consequently, guarantee a higher production of Se-enriched mushrooms.

香菇引起的小肠梗阻两例报道

The shiitake mushroom(Lentinula edodes),known as Xiang-gu in China,has been an important component of Asian cuisine for hundreds of years.Although not easily digestible,there are few reports of them causing bowel obstruction.We present two cases of small bowel obstruction due to a shiitake mushroomrequiring surgical intervention.Two patients who did not have any teeth and did not use dentures presented with intestinal bowel obstruction and were referred to the Emergency Department of our hospital after eating a meal including shiitake mushrooms without cutting.The first patient underwent an emergency laparotomy and a semental small bowel resection and the other underwent laparoscopic small bowel incision for removal of a foreign body.The causes of the small bowel obstruction for the two patients were uncut shiitake mushrooms in the small bowel.The two patients recovered uneventfully post-operatively.