Hericium erinaceus in Neurodegenerative Diseases: From Bench to Bedside and Beyond, How Far from the Shoreline?

Hericinosides A-M, Cyathane Diterpene Glycosides with α-Glucosidase Inhibitory Activity from the Medicinal Fungus Hericium erinaceus

Thirteen new cyathane diterpene glycosides, hericinosides A-M (1-13), and six known analogs, were isolated from the rice media fermentation of the medicinal fungus Hericium erinaceus. The sugar parts of 1 and 2 were highly modified, forming a unique 5/6/7/5/5/5 ring new skeleton system. All structures were elucidated based on spectroscopic data, and their relative configurations were determined according to the ROESY analysis. Possible biosynthetic pathways for compounds 1-13 were discussed. Compounds 6 and 19 showed significant α-glucosidase inhibitory activity with IC50 values of 82.7 and 199.5 μM, respectively. The results will facilitate further studies to expand the use of diterpene glycosides from this mushroom for actual and potential biological properties in metabolic regulation.

Investigating the Impact of Nutrition and Oxidative Stress on Attention Deficit Hyperactivity Disorder

Background/Objectives: Attention deficit hyperactivity disorder (ADHD) is the most common childhood-onset neurodevelopmental disorder, characterized by difficulty maintaining attention, impulsivity, and hyperactivity. While the cause of this disorder is still unclear, recent studies have stated that heredity is important in the development of ADHD. This is linked to a few comorbidities, including depression, criminal behavior, and anxiety. Although genetic factors influence ADHD symptoms, there are also non-genetic factors, one of which is oxidative stress (OS), which plays a role in the pathogenesis and symptoms of ADHD. This review aims to explore the role of OS in ADHD and its connection to antioxidant enzyme levels, as well as the gut-brain axis (GBA), focusing on diet and its influence on ADHD symptoms, particularly in adults with comorbid conditions. Methods: The literature search included the main available databases (e.g., Science Direct, PubMed, and Google Scholar). Articles in the English language were taken into consideration and our screening was conducted based on several words such as "ADHD", "oxidative stress", "diet", "gut-brain axis", and "gut microbiota." The review focused on studies examining the link between oxidative stress and ADHD, the role of the gut-brain axis, and the potential impact of dietary interventions. Results: Oxidative stress plays a critical role in the development and manifestation of ADHD symptoms. Studies have shown that individuals with ADHD exhibit reduced levels of key antioxidant enzymes, including glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), as well as a diminished total antioxidant status (TOS) compared to healthy controls. Additionally, there is evidence of a close bidirectional interaction between the nervous system and gut microbiota, mediated by the gut-brain axis. This relationship suggests that dietary interventions targeting gut health may influence ADHD symptoms and related comorbidities. Conclusions: Oxidative stress and the gut-brain axis are key factors in the pathogenesis of ADHD, particularly in adults with comorbid conditions. A better understanding of these mechanisms could lead to more targeted treatments, including dietary interventions, to mitigate ADHD symptoms. Further research is required to explore the therapeutic potential of modulating oxidative stress and gut microbiota in the management of ADHD.

Metabolic and Immune System Dysregulation: Unraveling the Connections between Alzheimer's Disease, Diabetes, Inflammatory Bowel Diseases, and Rheumatoid Arthritis

Alzheimer's disease (AD), diabetes mellitus (DM), inflammatory bowel diseases (IBD), and rheumatoid arthritis (RA) are chronic conditions affecting millions globally. Despite differing clinical symptoms, these diseases share pathophysiological mechanisms involving metabolic and immune system dysregulation. This paper examines the intricate connections between these disorders, focusing on shared pathways such as insulin resistance, lipid metabolism dysregulation, oxidative stress, and chronic inflammation. An important aspect is the role of amyloid-beta plaques and tau protein tangles, which are hallmark features of AD. These protein aggregates are influenced by metabolic dysfunction and inflammatory processes similar to those seen in DM, RA, and IBD. This manuscript explores how amyloid and tau pathologies may be exacerbated by shared metabolic and immune dysfunction. Additionally, this work discusses the gut-brain axis and the influence of gut microbiota in mediating disease interactions. Understanding these commonalities opens new avenues for multi-targeted therapeutic approaches that address the root causes rather than merely the symptoms of these conditions. This integrative perspective could lead to more effective interventions and improved patient outcomes, emphasizing the importance of a unified approach in managing these interconnected diseases.

The chemical structures, biosynthesis, and biological activities of secondary metabolites from the culinary-medicinal mushrooms of the genus Hericium: a review

Fungal phytochemicals derived from higher fungi, particularly those from the culinary-medicinal genus Hericium, have gained significant attention in drug discovery and healthcare. This review aims to provide a comprehensive analysis of the chemical structures, biosynthetic pathways, biological activities, and pharmacological properties of monomeric compounds isolated from Hericium species. Over the past 34 years, 253 metabolites have been identified from various Hericium species, including cyathane diterpenes, alkaloids, benzofurans, chromenes, phenols, pyrones, steroids, and other miscellaneous compounds. Detailed investigations into the biosynthesis of erinacines, a type of cyathane diterpene, have led to the discovery of novel cyathane diterpenes. Extensive research has highlighted the biological activities and pharmacological properties of Hericium-derived compounds, with particular emphasis on their neuroprotective and neurotrophic effects, immunomodulatory capabilities, anti-cancer activity, antioxidant properties, and antimicrobial actions. Erinacine A, in particular, has been extensively studied. Genomic, transcriptomic, and proteomic analyses of Hericium species have facilitated the discovery of new compounds and provided insights into enzymatic reactions through genome mining. The diverse chemical structures and biological activities of Hericium compounds underpin their potential applications in medicine and as dietary supplements. This review not only advances our understanding of Hericium compounds but also encourages further research into Hericium species within the realms of medicine, health, functional foods, and agricultural microbiology. The broad spectrum of compound types and their diverse biological activities present promising opportunities for the development of new pharmaceuticals and edible products.

Hericium erinaceus polysaccharides ameliorate nonalcoholic fatty liver disease via gut microbiota and tryptophan metabolism regulation in an aged laying hen model

Polysaccharides extracted from Hericium erinaceus (HEP) exhibit hepatoprotective activity in the alleviation of non-alcoholic fatty liver disease (NAFLD); however, the mechanisms underlying whether and how HEP regulation of the gut microbiota to alleviate liver-associated metabolic disorders are not well understood. This study used an aged laying hen model to explore the mechanisms through which HEP alleviates NAFLD, with a focus on regulatory function of HEP in the gut microbiome. The results showed that HEP ameliorated hepatic damage and metabolic disorders by improving intestinal barrier function and shaping the gut microbiota and tryptophan metabolic profiles. HEP increased the abundance of Lactobacillus and certain tryptophan metabolites, including indole-3-carboxylic acid, kynurenic acid, and tryptamine in the cecum. These metabolites upregulated the expression of ZO-1 and Occludin by activating the AhR and restoring the intestinal barrier integrity. The increased intestinal barrier functions decreased LPS transferring from the intestine to the liver, inhibited hepatic LPS/TLR4/MyD88/NF-κB pathway activation, and reduced hepatic inflammatory response and apoptosis. Fecal microbiota transplantation experiments further confirmed that the hepatoprotective effect is likely mediated by HEP-altered gut microbiota and their metabolites. Overall, dietary HEP could ameliorate the hepatic damage and metabolic disorders of NAFLD through regulating the "gut-liver" axis.

Combination Therapy for Sustainable Fish Oil Products: Improving Cognitive Function with n-3 PUFA and Natural Ingredients

Long-chain polyunsaturated omega-3 fatty acids (n-3 PUFAs), particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are recommended as beneficial dietary supplements for enhancing cognitive function. Although fish oil (FO) is renowned for its abundant n-3 PUFA content, combining FO with other natural products is considered as a viable option to support the sustainable development of FO products. This review aims to provide comprehensive insights into the advanced effects of combining FO or its components of DHA and EPA with natural products on protecting cognitive function. In two double-blind random control trials, no advanced effects were observed for adding curcumin to FO on cerebral function protection. However, 16 week's treatment of FO combined with vitamin E did not yield any advanced effects in cognitive factor scores. Several preclinical studies have demonstrated that combinations of FO with natural products can exhibit advanced effects in addressing pathological components in cognitive impairment, including neuroinflammation, oxidative stress, and neuronal survival. In conclusion, evidence from clinical trials for beneficial use of FO and natural ingredients combination is lacking. Greater cohesion is needed between preclinical and clinical data to substantiate the efficacy of FO and natural product combinations in preventing or slowing the progression of cognitive decline.

Unveiling the Chemical Composition and Biofunctionality of Hericium spp. Fungi: A Comprehensive Overview

In recent years, research on mushrooms belonging to the Hericium genus has attracted considerable attention due to their unique appearance and well-known medicinal properties. These mushrooms are abundant in bioactive chemicals like polysaccharides, hericenones, erinacines, hericerins, resorcinols, steroids, mono- and diterpenes, and corallocins, alongside essential nutrients. These compounds demonstrate beneficial bioactivities which are related to various physiological systems of the body, including the digestive, immune, and nervous systems. Extensive research has been conducted on the isolation and identification of numerous bioactive chemicals, and both in vitro and in vivo studies have confirmed their antimicrobial, antioxidant, immunomodulatory, antidiabetic, anticholesterolemic, anticancer, and neuroprotective properties. Therefore, this review aims to provide a comprehensive summary of the latest scientific literature on the chemical composition and secondary metabolites profile of Hericium spp. through an introduction to their chemical characteristics, speculated biosynthesis pathways for key chemical families, potential toxicological aspects, and a detailed description of the recent updates regarding the bioactivity of these metabolites.

Isolation and Evaluation of Erinacine A Contents in Mycelia of Hericium erinaceus Strains

Hericium erinaceus has long been favored for its remarkable nutritional and health-promoting benefits, and erinacine A is the key component responsible for the neuroprotective properties of H. erinaceus. Establishing an efficient method for separating erinacine A from H. erinaceus and screening the erinacine A-enriched strains is crucial to maximizing its benefits. Herein, we first reported that high-speed counter current chromatography (HSCCC) is an effective method for separating high-purity erinacine A. Using a two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (4.5:5:4.5:5, v/v/v/v), erinacine A with a purity of over 95% was separated. Then, we evaluated the content and yield of erinacine A in the liquid-fermented mycelia of Hericium germplasms. Both the content and yield of erinacine A varied greatly among the surveyed strains. The significant effect of the strain on the erinacine A content and yield was revealed by an analysis of variance. The highest erinacine A content and yield were observed in the mycelia of a wild strain HeG, reaching 42.16 mg/g and 358.78 mg/L, which is superior to the current highest outcomes achieved using submerged cultivation. The isolation method established and the strains screened in this study can be beneficial for the scaling up of erinacine A extraction and nutraceutical development to industrial levels.

Biological Activities of Ethanol Extracts of Hericium erinaceus Obtained as a Result of Optimization Analysis

Mushrooms are one of the indispensable elements of human diets. Edible mushrooms stand out with their aroma and nutritional properties. In this study, some biological activities of the wild edible mushroom Hericium erinaceus were determined. In this context, firstly, the most suitable extraction conditions of the fungus in terms of biological activity were determined. First, 64 different experiments were performed with the Soxhlet device under 40-70 °C extraction temperature, 3-9 h extraction time, and 0.5-2 mg/mL extraction conditions. As a result, a total antioxidant status (TAS) analysis was performed, and the extraction conditions were optimized so that the objective function was the maximum TAS value. The data obtained from the experimental study were modeled with artificial neural networks (ANNs), one of the artificial intelligence methods, and optimized with a genetic algorithm (GA). All subsequent tests were performed using the extract obtained under optimum extraction conditions. The antioxidant capacity of the mushroom was assessed using Rel assay kits and the DPPH and FRAP techniques. The agar dilution method was used to measure the antimicrobial activity. The anti-Alzheimer activity was assessed based on the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The antiproliferative activity was assessed against the A549 cancer cell line. The total phenolic content was measured using the Folin-Ciocalteu reagent. The measurement of total flavonoids was conducted using the aluminum chloride test. LC-MS/MS equipment was used to screen for the presence of standard chemicals. The optimum extraction conditions were found to be a 60.667 °C temperature, 7.833 h, and 1.98 mg/mL. It was determined that the mushroom has high antioxidant potential. It was determined that the substance was successful at combating common bacterial and fungal strains when used at dosages ranging from 25 to 200 µg/mL. The high antiproliferative effect of the substance was attributed to its heightened concentration. The anti-AChE value was found to be 13.85 μg/mL, while the anti-BChE value was confirmed to be 28.00 μg/mL. The phenolic analysis of the mushroom revealed the presence of 13 chemicals. This investigation found that H. erinaceus exhibits robust biological activity when extracted under appropriate circumstances.

Biologically active secondary metabolites from white-rot fungi

In recent years, there has been a considerable rise in the production of novel metabolites derived from fungi compared to the ones originating from bacteria. These organic substances are utilized in various sectors such as farming, healthcare, and pharmaceutical. Since all dividing living cells contain primary metabolites, secondary metabolites are synthesized by utilizing intermediate compounds or by-products generated from the primary metabolic pathways. Secondary metabolites are not critical for the growth and development of an organism; however, they exhibit a variety of distinct biological characteristics. White-rot fungi are the only microorganisms able to decompose all wood components. Hence, they play an important role in both the carbon and nitrogen cycles by decomposing non-living organic substrates. They are ubiquitous in nature, particularly in hardwood (e.g., birch and aspen) forests. White-rot fungi, besides ligninolytic enzymes, produce different bioactive substances during their secondary metabolism including some compounds with antimicrobial and anticancer properties. Such properties could be of potential interest for the pharmaceutical industries. Considering the importance of the untapped biologically active secondary metabolites from white-rot fungi, the present paper reviews the secondary metabolites produced by white-rot fungi with different interesting bioactivities.

The ethnopharmacology, phytochemistry and pharmacology of the genus Hericium

ETHNOPHARMACOLOGICAL RELEVANCE

Mushrooms in the genus Hericium are used as functional food and traditional medicines for a long history in East Asian countries such as China, India, Japan, and Korea. Some species of Hericium are called as monkey head mushroom (Houtougu) in China and Yamabushitake in Japan, which are traditionally considered as rare and precious health promoting food and medicinal materials for the treatment of dyspepsia, insomnia, chronic gastritis, and digestive tract tumors.

THE AIM OF THE REVIEW

This review aims to summarize the ethnopharmacology and structural diversity of secondary metabolites from Hericium species, as well as the pharmacological activities of the crude extracts and pure compounds from Hericium species in recent years.

MATERIALS AND METHODS

All the information was gathered by searching Scifinder, PubMed, Web of Science, ScienceDirect, Springer, Wiley, ACS, CNKI, Baidu Scholar, Google Scholar databases and other published materials (books and Ph.D. and M. Sc. Dissertations) using the keywords "Hericium", "Traditional uses", "Chemical composition", "Quality control" and "Pharmacological activity" (1971-May 2023). The species name was checked with https://www.mycobank.org/.

RESULTS

The traditional uses of Hericium species were summarized, and 230 secondary metabolites from Hericium species were summarized and classified into six classes, mainly focusing on their chemical diversity, biosynthesis, biological activities. The modern pharmacological experiments in vivo or in vitro on their crude and fractionated extracts showed that the chemical components from Hericium species have a broad range of bioactivities, including neuroprotective, antimicrobial, anticancer, α-glucosidase inhibitory, antioxidant, and anti-inflammatory activities.

CONCLUSIONS

The secondary metabolites discovered from Hericium species are highly structurally diverse, and they have the potential to be rich resources of bioactive fungal natural products. Moreover, the unveiled bioactivities of their crude extracts and pure compounds are closely related to critical human health concerns, and in-depth studies on the potential lead compounds, mechanism of pharmacological effects and pharmaceutical properties are clearly warranted.

Hericium erinaceus Extract Exerts Beneficial Effects on Gut-Neuroinflammaging-Cognitive Axis in Elderly Mice

Ageing is a biological phenomenon that determines the impairment of cognitive performances, in particular, affecting memory. Inflammation and cellular senescence are known to be involved in the pathogenesis of cognitive decline. The gut microbiota-brain axis could exert a critical role in influencing brain homeostasis during ageing, modulating neuroinflammation, and possibly leading to inflammaging. Due to their anti-ageing properties, medicinal mushrooms can be utilised as a resource for developing pharmaceuticals and functional foods. Specifically, Hericium erinaceus (He), thanks to its bioactive metabolites, exerts numerous healthy beneficial effects, such as reinforcing the immune system, counteracting ageing, and improving cognitive performance. Our previous works demonstrated the capabilities of two months of He1 standardised extract oral supplementation in preventing cognitive decline in elderly frail mice. Herein, we showed that this treatment did not change the overall gut microbiome composition but significantly modified the relative abundance of genera specifically involved in cognition and inflammation. Parallelly, a significant decrease in crucial markers of inflammation and cellular senescence, i.e., CD45, GFAP, IL6, p62, and γH2AX, was demonstrated in the dentate gyrus and Cornus Ammonis hippocampal areas through immunohistochemical experiments. In summary, we suggested beneficial and anti-inflammatory properties of He1 in mouse hippocampus through the gut microbiome-brain axis modulation.

Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance

The aim of this study was to assess the effects of guayusa extract and Nordic Lion's Mane (LM) on cognition. Using a randomized, double-blind, placebo-controlled, crossover design, we examined the effects of a single dose of 650 mg guayusa extract (AMT: AmaTea® Max) vs. 1 g Nordic-grown Lion's Mane (LM) vs. placebo (PL). Participants attended three testing visits consisting of neuropsychological tests (Go/No-go, N-Back, and Serial 7 s tasks) assessing performance, subjective assessments of cognitive perception, and vital signs. Each assessment was measured at baseline (pre-ingestion) and 1 and 2 h post ingestion. AMT significantly (p ≤ 0.05) improved the number of attempts during Serial 7s, total score, number of correct responses, total number of responses, and reaction time during N-Back and improved Go stimulus reaction time, but it reduced the percentage of correct responses in the No-go stimulus response during Go/No-go. LM significantly (p ≤ 0.05) improved the number of attempts during Serial 7s and reaction time during N-Back and improved Go stimulus reaction time in Go/No-go. AMT improved mental clarity, focus, concentration, mood, and productivity at 1 and 2 h (p < 0.05); the ability to tolerate stress at 1 h; and had greater ratings than LM and PL for mental clarity, focus, concentration, and productivity. PL improved focus and concentration at 1 h from baseline (p ≤ 0.05). AMT and LM improved subjective ratings of "happiness compared to peers" and "getting the most out of everything" (p < 0.05); however, this occurred earlier in LM (i.e., 1 h post ingestion). AMT uniquely elevated blood pressure from baseline. AMT significantly improved cognitive performance and self-perceived cognitive indices of affect over a 2 h period and perceptions of happiness 2 h post ingestion. In comparison, LM helped improve working memory, complex attention, and reaction time 2 h post ingestion and perceptions of happiness over a 2 h period.

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.

Deacylated Derivative of Hericenone C Treated by Lipase Shows Enhanced Neuroprotective Properties Compared to Its Parent Compound

Hericium erinaceus, a mushroom species commonly known as Yamabushitake in Japan, is known to have a stimulatory effect on neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Hericenone C, a meroterpenoid with palmitic acid as the fatty acid side chain, is reported to be one such stimulant. However, according to the structure of the compound, the fatty acid side chain seems highly susceptible to lipase decomposition, under in vivo metabolic conditions. To study this phenomenon, hericenone C from the ethanol extract of the fruiting body was subjected to lipase enzyme treatment and observed for changes in the chemical structure. The compound formed after the lipase enzyme digestion was isolated and identified using LC-QTOF-MS combined with ¹H-NMR analysis. It was found to be a derivative of hericenone C without its fatty acid side chain and was named deacylhericenone. Interestingly, a comparative investigation of the neuroprotective properties of hericenone C and deacylhericenone showed that the BDNF mRNA expression in human astrocytoma cells (1321N1) and the protection against H₂O_2-induced oxidative stress was considerably higher in the case of deacylhericenone. These findings suggest that the stronger bioactive form of the hericenone C compound is in fact deacylhericenone.