Dilinoleoyl-phosphatidylethanolamine from Hericium erinaceum protects against ER stress-dependent Neuro2a cell death via protein kinase C pathway

Uncovering Hericenones from the Fruiting Bodies of Hericium erinaceus through Interdisciplinary Collaboration

Hericium erinaceus is an edible and medicinal mushroom. Previously, we found hericenones C-H from the fruiting bodies and erinacines A-I from the mycelia of the fungus. These compounds stimulated nerve growth factor (NGF) synthesis both in vitro and in vivo; some have been suggested to be effective in the prevention and treatment of dementia. Recently, the total synthesis of hericenones C-H and their derivatives (1-4) was reported by one of the authors. We considered that the chemical synthetic route would also be reasonable as a biosynthetic pathway of the compounds. Based on the hypothesis, we investigated the endogenous existence of synthetic intermediates and products of the chemical synthesis in the fruiting bodies. The n-hexane-soluble part of the fruiting bodies of H. erinaceus was fractionated, and all the fractions were subjected to a product ion scan and multiple reaction monitoring (MRM) analysis by LC-MS/MS and compared to the authentic synthesized compounds. The analysis indicated the endogenous existence of 1-4 and the dehydrated form of 2 or 3. The dehydrated form was elucidated to be (Z)-5 by chemical synthesis, and a plausible biosynthetic pathway was proposed.

Neurotrophic and Neuroprotective Effects of Hericium erinaceus

Hericium erinaceus is a valuable mushroom known for its strong bioactive properties. It shows promising potential as an excellent neuroprotective agent, capable of stimulating nerve growth factor release, regulating inflammatory processes, reducing oxidative stress, and safeguarding nerve cells from apoptosis. The active compounds in the mushroom, such as erinacines and hericenones, have been the subject of research, providing evidence of their neuroprotective effects. Further research and standardization processes for dietary supplements focused on H. erinaceus are essential to ensuring effectiveness and safety in protecting the nervous system. Advancements in isolation and characterization techniques, along with improved access to pure analytical standards, will play a critical role in achieving standardized, high-quality dietary supplements based on H. erinaceus. The aim of this study is to analyze the protective and nourishing effects of H. erinaceus on the nervous system and present the most up-to-date research findings related to this topic.

Unveiling the Therapeutic Potentials of Mushroom Bioactive Compounds in Alzheimer's Disease

Alzheimer's disease (AD) stands as a prevailing neurodegenerative condition (NDs), leading to the gradual deterioration of brain cells and subsequent declines in memory, thinking, behavior, and emotion. Despite the intensive research efforts and advances, an effective curative treatment for the disease has not yet been found. Mushrooms, esteemed globally for their exquisite flavors and abundant nutritional benefits, also hold a wealth of health-promoting compounds that contribute to improving AD health. These compounds encompass polysaccharides, proteins, lipids, terpenoids, phenols, and various other bioactive substances. Particularly noteworthy are the potent neuroprotective small molecules found in mushrooms, such as ergothioneine, erinacine, flavonoids, alkaloids, ergosterol, and melanin, which warrant dedicated scrutiny for their therapeutic potential in combating AD. This review summarizes such positive effects of mushroom bioactive compounds on AD, with a hope to contribute to the development of functional foods as an early dietary intervention for this neurodegenerative disease.

Tracing the Path between Mushrooms and Alzheimer's Disease-A Literature Review

Alzheimer's disease (AD) is well-known among neurodegenerative diseases for the decline of cognitive functions, making overall daily tasks difficult or impossible. The disease prevails as the most common form of dementia and remains without a well-defined etiology. Being considered a disease of multifactorial origin, current targeted treatments have only managed to reduce or control symptoms, and to date, only two drugs are close to being able to halt its progression. For decades, natural compounds produced by living organisms have been at the forefront of research for new therapies. Mushrooms, which are well-known for their nutritional and medicinal properties, have also been studied for their potential use in the treatment of AD. Natural products derived from mushrooms have shown to be beneficial in several AD-related mechanisms, including the inhibition of acetylcholinesterase (AChE) and β-secretase (BACE 1); the prevention of amyloid beta (Aβ) aggregation and neurotoxicity; and the prevention of Tau expression and aggregation, as well as antioxidant and anti-inflammatory potential. Several studies in the literature relate mushrooms to neurodegenerative diseases. However, to the best of our knowledge, there is no publication that summarizes only AD data. In this context, this review aims to link the therapeutic potential of mushrooms to AD by compiling the anti-AD potential of different mushroom extracts or isolated compounds, targeting known AD-related mechanisms.

The Monkey Head Mushroom and Memory Enhancement in Alzheimer’s Disease

Alzheimer’s disease (AD) is a neurodegenerative disorder, and no effective treatments are available to treat this disorder. Therefore, researchers have been investigating Hericium erinaceus, or the monkey head mushroom, an edible medicinal mushroom, as a possible treatment for AD. In this narrative review, we evaluated six preclinical and three clinical studies of the therapeutic effects of Hericium erinaceus on AD. Preclinical trials have successfully demonstrated that extracts and bioactive compounds of Hericium erinaceus have potential beneficial effects in ameliorating cognitive functioning and behavioral deficits in animal models of AD. A limited number of clinical studies have been conducted and several clinical trials are ongoing, which have thus far shown analogous outcomes to the preclinical studies. Nonetheless, future research on Hericium erinaceus needs to focus on elucidating the specific neuroprotective mechanisms and the target sites in AD. Additionally, standardized treatment parameters and universal regulatory systems need to be established to further ensure treatment safety and efficacy. In conclusion, Hericium erinaceus has therapeutic potential and may facilitate memory enhancement in patients with AD.

Subchronic toxicity and genotoxicity studies of Hericium erinaceus β-glucan extract preparation

•

β-Glucan from Hericium erinaceus was investigated for subchronic toxicity and mutagenicity.

•

In the subchronic study, The No-Observed-Adverse-Effect Level (NOAEL) for Hericium erinaceus β-glucan was 2000 mg/kg bw/day.

•

In mutagenicity studies, Hericium erinaceus β-glucan did not reveal genotoxic effects.

The medicinal effects of Hericium erinaceus have been long documented in scientific studies of Eastern traditional medicine. It is widely consumed, because of its nutritional qualities and perceived health benefits. Also, it is rich in β-glucans, which has been shown to have immunomodulating and antitumor effects. The objective of the present study was to investigate adverse effects, if any, of β-glucan extract preparation from H. erinaceus in subchronic toxicity and genotoxicity studies. The conduct of these studies was in compliance with Good Laboratory Practice (GLP) and test guidelines established by the Organization for Economic Cooperation and Development (OECD). In the subchronic toxicity study, Sprague Dawley rats (12/sex/group) were administered (gavage) H. erinaceus β-glucan extract preparation at dose levels of 0, 500, 1000 and 2000 mg/kg body weight (bw)/day for 90 days. Treatment with H. erinaceus β-glucan extract preparation did not result in any toxicologically significant treatment-related changes in clinical observations, ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. Clinical pathology including hematology, serum chemistry, urinalysisand terminal necropsy (gross or histopathology findings) did not reveal any treatment-related adverse effects. The results of genotoxicity studies as evaluated by gene mutations in Salmonella typhimurium, in vitro chromosome aberrations and in vivo micronucleus test in mice did not reveal any genotoxicity of H. erinaceus β-glucan extract preparation. Based on the subchronic study, the no observed-adverse-effect level (NOAEL) for H. erinaceus β-glucan extract preparation was determined as 2000 mg/kg bw/day, the highest dose tested.

Total Synthesis, Structure Revision, and Neuroprotective Effect of Hericenones C-H and Their Derivatives

The first total syntheses of hericenones C-H and "putative 3-hydroxyhericenone F" were achieved. Highlights of the synthesis include the straightforward construction of the resorcinol core and geranyl side chain, assembly of the natural product skeleton by sequential O-geranylation and a clay/zeolite-mediated O → C rearrangement reaction, and a biomimetic cyclization to form a variety of bicyclic natural hericenones and their congeners. The structure of the "putative 3-hydroxyhericenone F" was revised as the 5-exo cyclization product (named: hericenone Z) of epoxyhericenone C through in-depth analyses of the cyclization modes in addition to NMR spectroscopic studies. To gain insights into the biological functions of geranyl-resorcinols in Hericium erinaceus, potential neuroprotective effects against endoplasmic reticulum (ER) stress-dependent cell death were evaluated systematically to clarify a fundamental structure-activity relationship. Among the compounds assayed, the linoleate-containing hericenone analogue, i.e., the regioisomer of hericene D, was found to possess the most potent neuroprotective effect against tunicamycin and thapsigargin-induced ER stress-dependent cell death.

A Fairy Chemical Suppresses Retinal Angiogenesis as a HIF Inhibitor

Neovascular retinal degeneration is a leading cause of blindness in advanced countries. Anti-vascular endothelial growth factor (VEGF) drugs have been used for neovascular retinal diseases; however, anti-VEGF drugs may cause the development of chorioretinal atrophy in chronic therapy as they affect the physiological amount of VEGF needed for retinal homeostasis. Hypoxia-inducible factor (HIF) is a transcription factor inducing VEGF expression under hypoxic and other stress conditions. Previously, we demonstrated that HIF was involved with pathological retinal angiogenesis in murine models of oxygen-induced retinopathy (OIR), and pharmacological HIF inhibition prevented retinal neovascularization by reducing an ectopic amount of VEGF. Along with this, we attempted to find novel effective HIF inhibitors. Compounds originally isolated from mushroom-forming fungi were screened for prospective HIF inhibitors utilizing cell lines of 3T3, ARPE-19 and 661W. A murine OIR model was used to examine the anti-angiogenic effects of the compounds. As a result, 2-azahypoxanthine (AHX) showed an inhibitory effect on HIF activation and suppressed Vegf mRNA upregulation under CoCl2-induced pseudo-hypoxic conditions. Oral administration of AHX significantly suppressed retinal neovascular tufts in the OIR model. These data suggest that AHX could be a promising anti-angiogenic agent in retinal neovascularization by inhibiting HIF activation.

Antia, a Natural Antioxidant Product, Attenuates Cognitive Dysfunction in Streptozotocin-Induced Mouse Model of Sporadic Alzheimer's Disease by Targeting the Amyloidogenic, Inflammatory, Autophagy, and Oxidative Stress Pathways

Background

Many neurodegenerative diseases such as Alzheimer's disease are associated with oxidative stress. Therefore, antioxidant therapy has been suggested for the prevention and treatment of neurodegenerative diseases.

Objective

We investigated the ability of the antioxidant Antia to exert a protective effect against sporadic Alzheimer's disease (SAD) induced in mice. Antia is a natural product that is extracted from the edible yamabushitake mushroom, the gotsukora and kothala himbutu plants, diosgenin (an extract from wild yam tubers), and amla (Indian gooseberry) after treatment with MRN-100.

Methods

Single intracerebroventricular (ICV) injection of streptozotocin (STZ) (3 mg/kg) was used for induction of SAD in mice. Antia was injected intraperitoneally (i.p.) in 3 doses (25, 50, and 100 mg/kg/day) for 21 days. Neurobehavioral tests were conducted within 24 h after the last day of injection. Afterwards, mice were sacrificed and their hippocampi were rapidly excised, weighed, and homogenized to be used for measuring biochemical parameters.

Results

Treatment with Antia significantly improved mice performance in the Morris water maze. In addition, biochemical analysis showed that Antia exerted a protective effect for several compounds, including GSH, MDA, NF-κB, IL-6, TNF-α, and amyloid β. Further studies with western blot showed the protective effect of Antia for the JAK2/STAT3 pathway.

Conclusions

Antia exerts a significant protection against cognitive dysfunction induced by ICV-STZ injection. This effect is achieved through targeting of the amyloidogenic, inflammatory, and oxidative stress pathways. The JAK2/STAT3 pathway plays a protective role for neuroinflammatory and neurodegenerative diseases such as SAD.

The Neuroprotective Effect of Hericium erinaceus Extracts in Mouse Hippocampus after Pilocarpine-Induced Status Epilepticus

Hericium erinaceus (HE), a culinary-medicinal mushroom, has shown therapeutic potential in many brain diseases. However, the role of HE in status epilepticus (SE)-mediated neuronal death and its underlying mechanisms remain unclear. We investigated the neuroprotective effects of HE using a pilocarpine-induced SE model. Male C57BL/6 mice received crude extracts of HE (60 mg/kg, 120 mg/kg, or 300 mg/kg, p.o.) for 21 d from 14 d before SE to 6 d after SE. At 7 d after SE, cresyl violet and immunohistochemistry of neuronal nuclei revealed improved hippocampal neuronal survival in animals treated with 60 mg/kg and 120 mg/kg of HE, whereas those treated with 300 mg/kg of HE showed similar neuronal death to that of vehicle-treated controls. While seizure-induced reactive gliosis, assessed by immunohistochemistry, was not altered by HE, the number of hippocampal cyclooxygenase 2 (COX2)-expressing cells was significantly reduced by 60 and 120 mg/kg of HE. Triple immunohistochemistry demonstrated no overlap of COX2 labeling with Ox42, in addition to a decrease in COX2/GFAP-co-immunoreactivity in the group treated with 60 mg/kg HE, suggesting that the reduction of COX2 by HE promotes neuroprotection after SE. Our findings highlight the potential application of HE for preventing neuronal death after seizures.

Biologically functional molecules from mushroom-forming fungi*

Fungi including mushrooms have been proved to be an important biosource of numerous metabolites having a huge variety of chemical structures and diverse bioactivities. Metabolites of mushrooms are of remarkable importance as new lead compounds for medicine and agrochemicals. This review presents some of our studies on biologically functional molecules purified from mushroom-forming fungi; (1) endoplasmic reticulum stress suppressor, (2) osteoclast-forming suppressing compounds, (3) plant growth regulators.

Specific Phospholipids Regulate the Acquisition of Neuronal and Astroglial Identities in Post-Mitotic Cells

Hitherto, the known mechanisms underpinning cell-fate specification act on neural progenitors, affecting their commitment to generate neuron or glial cells. Here, we show that particular phospholipids supplemented in the culture media modify the commitment of post-mitotic neural cells in vitro. Phosphatidylcholine (PtdCho)-enriched media enhances neuronal differentiation at the expense of astroglial and unspecified cells. Conversely, phosphatidylethanolamine (PtdEtn) enhances astroglial differentiation and accelerates astrocyte maturation. The ability of phospholipids to modify the fate of post-mitotic cells depends on its presence during a narrow time-window during cell differentiation and it is mediated by the selective activation of particular signaling pathways. While PtdCho-mediated effect on neuronal differentiation depends on cAMP-dependent kinase (PKA)/calcium responsive element binding protein (CREB), PtdEtn stimulates astrogliogenesis through the activation of the MEK/ERK signaling pathway. Collectively, our results provide an additional degree of plasticity in neural cell specification and further support the notion that cell differentiation is a reversible phenomenon. They also contribute to our understanding of neuronal and glial lineage specification in the central nervous system, opening up new avenues to retrieve neurogenic capacity in the brain.

Hericium erinaceus Extract Reduces Anxiety and Depressive Behaviors by Promoting Hippocampal Neurogenesis in the Adult Mouse Brain

Versatile biological activities of Hericium erinaceus (HE) have been reported in many brain diseases. However, roles of HE in major psychiatric disorders such as depression and anxiety remain to be investigated. Therefore, we evaluated whether HE could reduce anxiety and depressive behaviors in the adult mouse and its underlying mechanisms. Male C57BL/6 mice were administered HE (20 or 60 mg/kg, p.o.) or saline once a day for 4 weeks. Open field and tail suspension tests were performed 30 min after the last administration of HE, followed by forced swim test 2 days later. We found that chronic administration of HE showed anxiolytic and antidepressant-like effects. To elucidate possible mechanisms, proliferative activity of the hippocampal progenitor cells was assessed by immunohistochemistry of proliferating cell nuclear antigen (PCNA) and Ki67. Moreover, to evaluate neuronal survival in the dentate gyrus, 5-bromo-2'-deoxyuridine (BrdU) (120 mg/kg, i.p.) was given at the first day of HE administration, followed by isolation of the brains 4 weeks later. HE (60 mg/kg) increased the number of PCNA- and Ki67-positive cells in the subgranular zone of the hippocampus, indicating increased proliferation of hippocampal progenitors. In addition, BrdU- and BrdU/NeuN-positive cells in the dentate gyrus were significantly increased when treated with HE (60 mg/kg) compared with the saline-treated group, demonstrating enhanced neurogenesis by HE treatment. Taken together, the results indicate that chronic HE administration can exert anxiolytic and antidepressant-like effects, possibly by enhancing adult hippocampal neurogenesis.

Bioremediation of the neonicotinoid insecticide clothianidin by the white-rot fungus Phanerochaete sordida

Clothianidin (CLO) is a member of the neonicotinoid pesticides, which have been widely used worldwide over the last two decades. However, its toxicity for bees and neurological toxicity for humans are urgent problems. Here, the degradation of CLO by the white-rot fungus Phanerochaete sordida was examined in nitrogen-limited liquid medium. After incubation for 20days at 30°C, 37% of CLO was degraded in the cultures. High-resolution ESI-MS and NMR analyses of the culture supernatant identified N-(2-chlorothiazol-5-yl-methyl)-N'-methylurea (TZMU) as a metabolite of CLO degradation. The addition of cytochrome P450 inhibitors to the culture medium markedly reduced the degradation of CLO by P. sordida. And manganese peroxidase, a major ligninolytic enzyme secreted by this fungus, were not carried out CLO degradation. The effects of CLO and TZMU on the viability of the neuronal cell line Neuro2a demonstrated that P. sordida effectively degrades CLO into a metabolite that lacks neurotoxicity.

Therapeutic potential of culinary-medicinal mushrooms for the management of neurodegenerative diseases: diversity, metabolite, and mechanism

Mushrooms have long been used not only as food but also for the treatment of various ailments. Although at its infancy, accumulated evidence suggested that culinary-medicinal mushrooms may play an important role in the prevention of many age-associated neurological dysfunctions, including Alzheimer's and Parkinson's diseases. Therefore, efforts have been devoted to a search for more mushroom species that may improve memory and cognition functions. Such mushrooms include Hericium erinaceus, Ganoderma lucidum, Sarcodon spp., Antrodia camphorata, Pleurotus giganteus, Lignosus rhinocerotis, Grifola frondosa, and many more. Here, we review over 20 different brain-improving culinary-medicinal mushrooms and at least 80 different bioactive secondary metabolites isolated from them. The mushrooms (either extracts from basidiocarps/mycelia or isolated compounds) reduced beta amyloid-induced neurotoxicity and had anti-acetylcholinesterase, neurite outgrowth stimulation, nerve growth factor (NGF) synthesis, neuroprotective, antioxidant, and anti-(neuro)inflammatory effects. The in vitro and in vivo studies on the molecular mechanisms responsible for the bioactive effects of mushrooms are also discussed. Mushrooms can be considered as useful therapeutic agents in the management and/or treatment of neurodegeneration diseases. However, this review focuses on in vitro evidence and clinical trials with humans are needed.

Laxative effects of Liriope platyphylla are tightly correlated with suppression of endoplasmic reticulum stress in loperamide-induced constipation of SD rats

A dysfunction of endoplasmic reticulum (ER) stress response can result in various diseases, including cancer, inflammation, diabetes and neurodegenerative disorders. To investigate whether ER stress response can play an essential role in the induction and treatment of chronic constipation, alterations in the key parameters for ER stress were measured in loperamide (Lop) induced constipation Sprague Dawley (SD) rats treated with aqueous extracts of Liriope platyphylla (AEtLP), which has been shown to have a laxative effect. Symptoms of chronic constipation including alteration of stool parameters and the transverse colon's structure were successfully induced by Lop treatment. Laxative effects such as enhancement of stools parameters, recovery of the mucosa thickness, increased muscle thickness and recovery of flat luminal surface were also observed in the Lop+AEtLP treated group. Furthermore, enhancement of eukaryotic initiation factor 2 alpha (eIF2α) phosphorylation and inositol-requiring enzyme 1 beta (IRE1β) expression, key indicators for ER stress, that were observed in the Lop+vehicle treated group were significantly recovered in the Lop+AEtLP treated group, although the phosphorylation level of c-Jun N-terminal protein kinase (JNK) remained constant. Moreover, alterations in the transcription level of the marker genes X-box binding protein 1 (XBP-1) and growth arrest and DNA damage-inducible protein (GADD34) were similar to those of eIF2α and IRE1β. However, their level was slightly or completely recovered after AEtLP treatment. Overall, this study provides the first evidence that ER stress response may be tightly correlated with chronic constipation induced by Lop treatment, as well as the laxative effects of AEtLP.

Protective effects of Hericium erinaceus mycelium and its isolated erinacine A against ischemia-injury-induced neuronal cell death via the inhibition of iNOS/p38 MAPK and nitrotyrosine

Hericium erinaceus, an edible mushroom, has been demonstrated to potentiate the effects of numerous biological activities. The aim of this study was to investigate whether H. erinaceus mycelium could act as an anti-inflammatory agent to bring about neuroprotection using a model of global ischemic stroke and the mechanisms involved. Rats were treated with H. erinaceus mycelium and its isolated diterpenoid derivative, erinacine A, after ischemia reperfusion brain injuries caused by the occlusion of the two common carotid arteries. The production of inflammatory cytokines in serum and the infracted volume of the brain were measured. The proteins from the stroke animal model (SAM) were evaluated to determine the effect of H. erinaceus mycelium. H. erinaceus mycelium reduced the total infarcted volumes by 22% and 44% at a concentration of 50 and 300 mg/kg, respectively, compared to the SAM group. The levels of acute inflammatory cytokines, including interleukin-1β, interleukin-6 and tumor necrosis factor á, were all reduced by erinacine A. Levels of nitrotyrosine-containing proteins, phosphorylation of p38 MAPK and CCAAT enhancer-binding protein (C/EBP) and homologous protein (CHOP) expression were attenuated by erinacine A. Moreover, the modulation of ischemia injury factors present in the SAM model by erinacine A seemed to result in the suppression of reactive nitrogen species and the downregulation of inducible NO synthase (iNOS), p38 MAPK and CHOP. These findings confirm the nerve-growth properties of Hericium erinaceus mycelium, which include the prevention of ischemic injury to neurons; this protective effect seems to be involved in the in vivo activity of iNOS, p38 MAPK and CHOP.

Medicinal properties of Hericium erinaceus and its potential to formulate novel mushroom-based pharmaceuticals

Hericium erinaceus is an important mushroom with edible values and medicinal properties. Both the mycelium and the fruiting bodies contain many bioactive compounds with drug efficacy. Recent evidence demonstrates that it is helpful to various diseases, such as Alzheimer's disease, immunoregulatory, and many types of cancer. Furthermore, emerging pieces of evidence have shown that different active molecules in H. erinaceus have different functions on different organs in different diseases via the different mechanisms. Drawing on current research results, this review mainly focuses on the therapeutic effects of H. erinaceus on various diseases of multiple physiological systems, including the nervous system, digestive system, circulatory system, and immune system. This paper also discusses systematically the efficient protection of H. erinaceus against the diseases from the intricate experimental proofs by using the systematic viewpoints, which provides a framework for future research directions.

Receptor-interacting protein 140 attenuates endoplasmic reticulum stress in neurons and protects against cell death

Inositol 1, 4, 5-trisphosphate receptor (IP3R)-mediated Ca(2+) release from the endoplasmic reticulum (ER) triggers many physiological responses in neurons, and when uncontrolled can cause ER stress that contributes to neurological disease. Here we show that the unfolded protein response (UPR) in neurons induces rapid translocation of nuclear receptor-interacting protein 140 (RIP140) to the cytoplasm. In the cytoplasm, RIP140 localizes to the ER by binding to the IP3R. The carboxyl-terminal RD4 domain of RIP140 interacts with the carboxyl-terminal gate-keeping domain of the IP3R. This molecular interaction disrupts the IP3R's 'head-tail' interaction, thereby suppressing channel opening and attenuating IP3R-mediated Ca(2+) release. This contributes to a rapid suppression of the ER stress response and provides protection from apoptosis in both hippocampal neurons in vitro and in an animal model of ER stress. Thus, RIP140 translocation to the cytoplasm is an early response to ER stress and provides protection against neuronal death.

Endoplasmic reticulum stress suppressive compounds from the edible mushroom Mycoleptodonoides aitchisonii

Two novel compounds, 1 and 7, along with six known compounds (2-6 and 8), were isolated from the edible mushroom Mycoleptodonoides aitchisonii (bunaharitake in Japanese). The structures of the new compounds were determined by the interpretation of spectroscopic data. Compounds 1-4 and 6-8 showed protective activity against endoplasmic reticulum stress-dependent cell death.

Neuronal health - can culinary and medicinal mushrooms help?

Hericium erinaceus a culinary and medicinal mushroom is a well established candidate for brain and nerve health. Ganoderma lucidum, Grifola frondosa and Sarcodon scabrosus have been reported to have neurite outgrowth and neuronal health benefits. The number of mushrooms, however, studied for neurohealth activity are few compared to the more than 2 000 species of edible and / or medicinal mushrooms identified. In the on-going search for other potent culinary and / or medicinal mushrooms, indigenous mushrooms used in traditional medicines such as Lignosus rhinocerotis and Ganoderma neo-japonicum are also being investigated. Further, the edible mushroom, Pleurotus giganteus can be a potential candidate, too. Can these edible and medicinal mushrooms be tapped to tackle the health concerns of the aging population which is projected to be more than 80-90 million of people age 65 and above in 2050 who may be affected by age-related neurodegenerative disorders. Scientific validation is needed if these mushrooms are to be considered and this can be achieved by understanding the molecular and biochemical mechanisms involved in the stimulation of neurite outgrowth. Though it is difficult to extrapolate the in vitro studies to what may happen in the human brain, studies have shown that there can be improvement in cognitive abilities of the aged if the mushroom is incorporated in their daily diets.

Hericium erinaceus (Yamabushitake): a unique resource for developing functional foods and medicines

This article provides valuable scientific information for Hericium erinaceus and shows its potential for the development of new functional foods and drugs.

Antihyperglycemic and antihyperlipidemic activities of aqueous extract of Hericium erinaceus in experimental diabetic rats

Background

Hericium erinaceus, as a commonly used medicine or food, has attracted much attention due to its health effects when used as a home remedy for some diseases. The aim of this work was to investigate the hypoglycemic and hypolipidemic effects of aqueous extract of Hericium erinaceus (AEHE) in streptozotocin (STZ)-induced diabetic rats.

Methods

Diabetes was induced in Wistar rats by the administration of STZ (55 mg/kg BW.) intraperitoneally. AEHE (100 and 200 mg/kg BW.) was administered for a period of 28 days. The effects of AEHE on glucose, insulin, and lipid files in blood, and oxidative stress parameters in the liver were evaluated. The body weights of rats were recorded at day 0, 14 and 28th days.

Results

The administration of AEHE for 28 days in STZ diabetic rats resulted in a significant decrease in serum glucose level and a significant rise in serum insulin level. AEHE treatment attenuated lipid disorders. In addition, AEHE administration increased the activities of CAT, SOD, and GSH-Px, and GSH level, and reduced MDA level in the liver tissue significantly.

Conclusion

Our results suggest that AEHE possesses hypoglycemic, hypolipidemic, and antioxidant properties in STZ-induced diabetes rats.

Bovine milk phospholipid fraction protects Neuro2a cells from endoplasmic reticulum stress via PKC activation and autophagy

Endoplasmic reticulum stress commonly causes neuronal damage in a lot of neurodegenerative diseases. In this study, we examined neuroprotective effect of bovine milk phospholipid fraction (mPL) on mouse neuroblastoma Neuro2a cells from endoplasmic reticulum (ER) stress induced cell death. Neuro2a cells were induced cell death by ER stressor tunicamycin (TM) or thapsigargin (TG), and studied whether mPL could attenuate the toxicity. By preincubation with mPL, the cell viabilities were significantly increased in TM or TG treated cells, and caspase-12 activated cells induced by TM or TG treatment were significantly decreased. Protein kinase C inhibitor GF109203x significantly reduced the protective effect on TM induced cell death, and autophagy inhibitor 3-methyladenine reduced the protective effect on TM or TG induced cell death. Moreover, preincubation with mPL significantly stimulated autophagosomes formation observed by dansylcadaverine staining. Our data suggest that mPL will be applicable to prevent neurodegenerative diseases caused by ER stress.

Termitomycamides A to E, fatty acid amides isolated from the mushroom Termitomyces titanicus, suppress endoplasmic reticulum stress

Five fatty acid amides, termitomycamides A to E (1 to 5), were isolated from the giant edible mushroom Termitomyces titanicus. The structures of 1-5 were determined by the interpretation of spectral data and/or synthesis. Compounds 2 and 5 showed protective activity against endoplasmic reticulum stress-dependent cell death.

Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake

Hericium erinaceus, a well known edible mushroom, has numerous biological activities. Especially hericenones and erinacines isolated from its fruiting body stimulate nerve growth factor (NGF) synthesis, which expects H. erinaceus to have some effects on brain functions and autonomic nervous system. Herein, we investigated the clinical effects of H. erinaceus on menopause, depression, sleep quality and indefinite complaints, using the Kupperman Menopausal Index (KMI), the Center for Epidemiologic Studies Depression Scale (CES-D), the Pittsburgh Sleep Quality Index (PSQI), and the Indefinite Complaints Index (ICI). Thirty females were randomly assigned to either the H. erinaceus (HE) group or the placebo group and took HE cookies or placebo cookies for 4 weeks. Each of the CES-D and the ICI score after the HE intake was significantly lower than that before. In two terms of the ICI, "insentive" and "palpitatio", each of the mean score of the HE group was significantly lower than the placebo group. "Concentration", "irritating" and "anxious" tended to be lower than the placebo group. Our results show that HE intake has the possibility to reduce depression and anxiety and these results suggest a different mechanism from NGF-enhancing action of H. erinaceus.

Endoplasmic reticulum (ER) stress-suppressive compounds from scrap cultivation beds of the mushroom Hericium erinaceum

Four compounds were isolated from scrap cultivation beds of the mushroom, Hericium erinaceum. Compounds 1-4 were identified as methyl 4-hydroxy-3-(3-methylbutanoyl) benzoate, 2-chloro-1,3-dimethoxy-5-methylbenzene, methyl 4-chloro-3,5-dimethoxybenzoate, and 4-chloro-3,5-dimethoxybenzaldehyde by an interpretation of the NMR and MS data, respectively. This is the first reported isolation of 1 from a natural source. All the compounds showed protective activity against endoplasmic reticulum stress-dependent cell death.

Inhibition of alpha-mannosidase attenuates endoplasmic reticulum stress-induced neuronal cell death

N-glycosylation is crucial for proper folding of most of the proteins in the endoplasmic reticulum (ER). The N-glycans in the ER are mainly constructed of mannose. In this study, we examined whether inhibition of mannose trimming in the ER affects the susceptibility of PC-12 cells to ER stress. Pretreatment with 100 microM alpha-mannosidase inhibitor 1-deoxymannojirimycin (DMJ) in PC-12 cells significantly attenuated the cytotoxicity by ER stressors tunicamycin (TM), thapsigargin (TG), and amyloid beta1-42 (Abeta1-42), and reduced caspase-3 activation by TM and TG. Pretreatment with DMJ also protected primary cultured mouse cortical neurons from Abeta1-42 toxicity. With regard to the effect of DMJ pretreatment on ER stress signaling in PC-12 cells, DMJ attenuated TM- and TG-induced CHOP expression and TG stimulated JNK phosphorylation, which is associated with ER stress dependent cell death. Next, we examined the effect of mannose oligosaccharides, which have similar structures to N-glycans in the ER, on amyloidogenesis of Abeta1-42 that causes ER stress dependent neuronal cell death. Mannopentaose (M5) and Man9GlcNAc2 (M9) oligosaccharides significantly inhibited the amyloidogenesis of Abeta1-42. Our data suggests that inhibition of N-glycan processing in the ER attenuates ER stress-induced cell death by increasing high-mannose type oligosaccharides that reduce protein aggregation, such as amyloidogenesis.

An endoplasmic reticulum (ER) stress-suppressive compound and its analogues from the mushroom Hericium erinaceum

Three new compounds, 3-hydroxyhericenone F (1), hericenone I (2), and hericenone J (3), were isolated from the mushroom Hericium erinaceum. The structures of 1-3 were determined by the interpretation of spectral data. Compound 1 showed the protective activity against endoplasmic reticulum (ER) stress-dependent Neuro2a cell death, however, compounds 2 and 3 did not.

Protein kinase Ctheta is required for autophagy in response to stress in the endoplasmic reticulum

Autophagy is an evolutionally conserved process for the bulk degradation of cytoplasmic proteins and organelles. Recent observations indicate that autophagy is induced in response to cellular insults that result in the accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER). However, the signaling mechanisms that activate autophagy under these conditions are not understood. Here, we report that ER stress-induced autophagy requires the activation of protein kinase C (PKC), a member of the novel-type PKC family. Induction of ER stress by treatment with either thapsigargin or tunicamycin activated autophagy in immortalized hepatocytes as monitored by the conversion LC3-I to LC3-II, clustering of LC3 into dot-like cytoplasmic structures, and electron microscopic detection of autophagosomes. Pharmacological inhibition of PKC or small interfering RNA-mediated knockdown of PKC prevented the autophagic response to ER stress. Treatment with ER stressors induced PKC phosphorylation within the activation loop and localization of phospho-PKC to LC3-containing dot structures in the cytoplasm. However, signaling through the known unfolded protein response sensors was not required for PKC activation. PKC activation and stress-induced autophagy were blocked by chelation of intracellular Ca(2+) with BAPTA-AM. PKC was not activated or required for autophagy in response to amino acid starvation. These observations indicate that Ca(2+)-dependent PKC activation is specifically required for autophagy in response to ER stress but not in response to amino acid starvation.

Protein kinase C as a stress sensor

While there are many reviews which examine the group of proteins known as protein kinase C (PKC), the focus of this article is to examine the cellular roles of two PKCs that are important for stress responses in neurological tissues (PKC gamma and epsilon) and in cardiac tissues (PKC epsilon). These two kinases, in particular, seem to have overlapping functions and interact with an identical target, connexin 43 (Cx43), a gap junction protein which is central to proper control of signals in both tissues. While PKC gamma and PKC epsilon both help protect neural tissue from ischemia, PKC epsilon is the primary PKC isoform responsible for responding to decreased oxygen, or ischemia, in the heart. Both do this through Cx43. It is clear that both PKC gamma and PKC epsilon are necessary for protection from ischemia. However, the importance of these kinases has been inferred from preconditioning experiments which demonstrate that brief periods of hypoxia protect neurological and cardiac tissues from future insults, and that this depends on the activation, translocation, or ability for PKC gamma and/or PKC epsilon to interact with distinct cellular targets, especially Cx43. This review summarizes the recent findings which define the roles of PKC gamma and PKC epsilon in cardiac and neurological functions and their relationships to ischemia/reperfusion injury. In addition, a biochemical comparison of PKC gamma and PKC epsilon and a proposed argument for why both forms are present in neurological tissue while only PKC epsilon is present in heart, are discussed. Finally, the biochemistry of PKCs and future directions for the field are discussed, in light of this new information.