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.

Effects of Active Modified Atmosphere Packaging on Postharvest Quality of Shiitake Mushrooms (Lentinula edodes) Stored at Cold Storage

The effects of active modified atmosphere packaging （MAP） on the postharvest quality of shiitake mushrooms stored at cold temperature （4°C） were investigated.The gas components were 2% O2 ＋7% CO2 （MAP1）,2% O2 ＋10% CO2 （MAP2） and 2% O2 ＋13% CO2 （MAP3）,respectively.The results showed that active MAP could extend the shelf-life of shiitake mushrooms to 17 d and the concentration of carbon dioxide could influence the postharvest quality of shiitake mushrooms.MAP2 treatment inhibited the increase in respiration rate and malondinaldehyde （MDA） contents,delayed the decrease in firmness,soluble sugar and vitamin C,and obviously reduced the activity of polyphenol oxidase （PPO） and the degree of browning,therefore maintaining better quality.

Two cases of small bowel obstruction due to a shiitake mushroom

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.

Polysaccharides from Tricholoma matsutake and Lentinus edodes enhance 5-fluorouracil-mediated H22 cell growth inhibition

OBJECTIVE： Few studies have investigated the ef- fects produced by combinations of polysaccharides and chemotherapeutic drugs in cancer treatment. We hypothesized that a combination of polysaccha- rides （COP） from Lentinus edodes and Tricholoma matsutake would improve the efficacy of 5-fluoro- uracil （5-FU）-mediated inhibition of H22 cell growth. METHODS： Mice were injected H22 cells and then treated with either 5-FU, polysaccharides from Tri- choloma matsutake （PTM）, polysaccharides from Lentinus edodes （PL）, PTM ＋ PL, 5-FU ＋ PTM, 5-FU ＋ PL, or 5-FU ＋ COR The tumor weight and volume, and splenic CD4 ＋ and CD8 ＋ T cell frequencies, were determined. Additionally, splenic natural killer （NK） cell and cytotoxic T lymphocyte （CTL） activities were assessed and the serum levels of tumor necro- sis factor-a （TNF-a）, Interleukin-2 （IL-2）, and Interfer- on-y （IFN-y） were measured. RESULTS： Compared with mice from the control,5-FU, PL, PTM, PTM ＋ PL, 5-FU ＋ PL, and 5-FU ＋ PTM groups, mice treated with 5-FU ＋ COP showed： （a） significantly reduced tumor weight and volume （P〈 0.05）, （b） significantly higher serum levels of TNF-α, IL-2, and IFN-y （P〈0.05）, （c） significantly increased CD4＋ and CD8＋ 1 cell frequencies in the spleen （P〈 0.05）, and （d） significantly increased splenic NK cell and CTL activities （P〈0.05）. The tumor weight and volume in mice treated with 5-FU＋PL or 5-FU＋PTM were significantly reduced compared with mice treated with 5-FU alone （P〈0.05）. Serum levels of TNF-α, 11.-2, and IFN-y, frequencies of CD4 ＋ and CD8＋ T cells in the spleen, and splenic NK and CTL activities were also significantly increased in mice treated with 5-FU＋PL or 5-FU＋PTM compared with mice treated with 5-FU alone （P〈0.05）. CONCLUSION： Polysaccharides from Lentinus edodes and Tricholoma matsutake could enhance the efficacy of 5-FU-mediated H22 cell growth inhi- bition.