A Review of Development and Utilization for Edible Fungal Polysaccharides: Extraction, Chemical Characteristics, and Bioactivities.

Edible fungi, commonly known as mushrooms, are precious medicinal and edible homologous gifts from nature to us. Because of their distinctive flavor and exceptional nutritional and medicinal value, they have been a frequent visitor to people's dining tables and have become a hot star in the healthcare, pharmaceutical, and cosmetics industries. Edible fungal polysaccharides (EFPs) are an essential nutrient for edible fungi to exert bioactivity. They have attracted much attention because of their antioxidant, immunomodulatory, antitumor, hypoglycemic, and hypolipidemic bioactivities. As a result, EFPs have demonstrated outstanding potential over the past few decades in various disciplines, including molecular biology, immunology, biotechnology, and pharmaceutical chemistry. However, the complexity of EFPs and the significant impact of mushroom variety and extraction techniques on their bioactivities prevents a complete investigation of their biological features. Therefore, the authors of this paper thoroughly reviewed the comparison of different extraction methods of EFPs and their advantages and disadvantages. In addition, the molecular weight, monosaccharide composition, and glycosidic bond type and backbone structure of EFPs are described in detail. Moreover, the in vitro and in vivo bioactivities of EFPs extracted by different methods and their potential regulatory mechanisms are summarized. These provide a valuable reference for improving the extraction process of EFPs and their production and development in the pharmaceutical field.

Effects of Extraction Conditions on Crude Polysaccharides and Antioxidant Activities of the Lion's Mane Medicinal Mushroom, Hericium erinaceus (Agaricomycetes).

Dietary supplements are important to sustain an adequate level of antioxidants to balance reactive oxygen species (ROS) in vivo. Hericium erinaceus is one of the rare wood-rotting mushrooms with polysaccharides, which play antioxidant roles in multiple physiological systems of the organism. Can higher polysaccharide content yield higher antioxidant activity? The research on this is scarce. Therefore, the influence of extraction conditions on contents and antioxidant activities of polysaccharide from H. erinaceus was investigated by response surface methodology. Three main independent variables (extraction temperature, time, solid-liquid ratio) were taken into consideration. The extraction and the antioxidant activities were optimized using a Box-Behnken design. Interestingly, the effects of each factor were personalized. Extraction temperature was the dominant factor influencing the polysaccharide contents and antioxidant activities. In addition, the optimal condition to obtain the highest yield of polysaccharide was not in accord with the optimal condition to maximize the antioxidant activities. The effects of every extraction factor on antioxidant activities were various, probably because different components obtained under different extraction conditions had diverse antioxidant mechanisms. This study will help researchers to focus more on the effective components and their antioxidant abilities, rather than blindly pursue the yields of total polysaccharides.

One-pot conversion of biomass-derived xylose and furfural into levulinate esters via acid catalysis.

Direct conversion of biomass-derived xylose and furfural into levulinic acid, a platform molecule, via acid-catalysis has been accomplished for the first time in dimethoxymethane/methanol. Dimethoxymethane acted as an electrophile to transform furfural into 5-hydroxymethylfurfural (HMF). Methanol suppressed both the polymerisation of the sugars/furans and the Aldol condensation of levulinic acid/ester.

Comparative studies on extracts from Hericium erinaceus by different polarity reagents to gain higher antioxidant activities.

Hericium erinaceus (H. erinaceus) is a source of exogenous antioxidants that has been traditionally used in China for the prevention and treatment of oxidative stress-associated disease. In the present study, the bioactive compounds of H. erinaceus were extracted with the following eight representative reagents: n-Hexane, xylene, chloroform, anhydrous ether, ethyl acetate, acetone, anhydrous ethanol and distilled water. The in vitro antioxidant activities were also evaluated. All of the extracted compounds exhibited reducing power and scavenging activity against 1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion free radicals. In addition, the antioxidant capacities varied with the used chemical reagents and exhibited dose-dependent effects. Extracts from anhydrous ethanol, chloroform and acetone were capable of inhibiting lipid peroxidation. The anhydrous ethanol extracts were observed to have significant levels of antioxidant compounds since they had a strong reducing power, high scavenging rates against DPPH and superoxide anion-free radicals (>90%), and high inhibition rates on lipid peroxidation (>60%). The present study will provide reference data for the antioxidant applications of H. erinaceus in pharmaceutical use and disease prevention.

Antioxidant and antimicrobial properties of water soluble polysaccharide from Arachis hypogaea seeds.

The water soluble crude polysaccharide (AHP) was obtained from the aqueous extracts of the Arachis hypogaea seeds through hot water extraction followed by ethanol precipitation. Antioxidant activities and inhibitory activities against the bacteria of AHP were investigated. AHP at 2 mg/mL was found to inhibit the formation of superoxide anion (55.33 %) and hydroxyl radicals (30.85 %), to scavenge the DPPH radical (57.43 %) and to chelate iron ion (27.83 %) in in vitro systems. AHP also exhibited the antibacterial activities. AHP at 12.5 mg/mL could inhibit the growth of the Gram-positive bacteria, implying that the Gram-positive bacteria were more sensitive to AHP than the Gram-negative bacteria. Polysaccharide with antioxidant and antibacterial activities in the "Chang Sheng Guo" further increased the nutritive values of peanuts as well as the natural health product potential.

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.

Gecko CD59 is implicated in proximodistal identity during tail regeneration.

Several adult reptiles, such as Gekko japonicus, have the ability to precisely re-create a missing tail after amputation. To ascertain the associated acquisition of positional information from blastemal cells and the underlying molecular mechanism of tail regeneration, a candidate molecule CD59 was isolated from gecko. CD59 transcripts displayed a graded expression in the adult gecko spinal cord with the highest level in the anterior segment, with a stable expression along the normal tail. After tail amputation, CD59 transcripts in the spinal cord proximal to the injury sites increased markedly at 1 day and 2 weeks; whereas in the regenerating blastema, strong CD59 positive signals were detected in the blastemal cells anterior to the blastema, with a gradual decrease along the proximodistal (PD) axis. When treated with RA following amputation, CD59 transcripts in the blastema were up-regulated. PD confrontation assays revealed that the proximal blastema engulfed the distal one after in vitro culture, and rabbit-anti human CD59 antibody was able to block this PD engulfment. Overexpression of the CD59 during tail regeneration causes distal blastemal cells to translocate to a more proximal location. Our results suggest that position identity is not restricted to amphibian limb regeneration, but has already been established in tail blastema of reptiles. The CD59, a cell surface molecule, acted as a determinant of proximal-distal cell identity.

Molecular characterization of major allergens Ara h 1, 2, 3 in peanut seed.

Peanut is among the most commonly used dietary seeds, but peanut allergens, especially Ara h 1 (Arachis hypogaea allergy 1), 2 and 3, can cause severe IgE-mediated reactions. In this study, the molecular characterization and expression pattern of three allergens in peanut LUHUA 8, the representative of the cultivated lines in China, are reported. In situ hybridization and real time PCR analysis revealed high expression levels and different tissue expression patterns of the three allergens, which might be connected with many aspects, such as the strong conservation of intron phase of the allergen genes, the low energy of the mRNA's regions, and the complicated post-translational modifications. Furthermore, the different sequences between the cloned allergens and the reported sequences previously involved the charged amino acids especially in IgE epitopes, which might alter specific physicochemical and physiological properties, and thus influence the immunity of the allergens. The identification of the specific features of the allergen genes would be of considerable importance to the basic understanding of the specific characteristics of peanut seed allergens.

[Progress of researches on the allergens Ara h 1, Ara h 2 and Ara h 3 from peanut].

Peanut is one of the most popular foods in the world due to its high nutrition; however, it contains multiple seed storage proteins which are identified as allergens and hence are the most common cause of life-threatening, IgE-mediated anaphylaxis among the hypersensitive individuals. Three peanut proteins, Arachis hypogaea allergy 1, 2, 3 (Ara h 1, Ara h 2 and Ara h 3), which have the common biochemical characteristics like resistance to proteases and heat, are considered as the major allergens because they are recognized by serum IgE from a peanut-allergic patient population. The linear IgE-binding epitopes in the allergens lay the foundation of the anaphylaxis in the peanut-allergic individuals. Peanut allergy is often a life-long problem, so many investigators are focusing on decreasing clinical reactivity. In this review, the latest advances in the researches on biochemical characteristics, structure and function of the three major allergens were described and particular attention was given to the immunity properties of the three allergens. The future research directions were also discussed.

The ycaC-related protein from the amphioxus Branchiostoma belcheri (BbycaCR) interacts with creatine kinase.

The ycaC-related gene, ycaCR, is uncharacterized, and has no assigned function to date. Here we clearly showed that the ycaC-related gene from the amphioxus Branchiostoma belcheri, BbycaCR, coded for a novel member of the isochorismatase superfamily, which is mainly localized in the mitochondrial fraction. Both pull-down and reverse pull-down analyses revealed that BbycaCR was able to interact with creatine kinase, an enzyme involved in energy transduction, in addition to binding to native ycaCR, forming a homopolymer. Surprisingly, neither isochorismatase, nicotinamidase nor N-carbamoylsarcosine amidohydrolase activity was detected for BbycaCR, although it possessed the putative catalytic triad of Asp19, Arg(Lys)84 and Cys118 that is found in ycaC proteins. Both tissue section in situ hybridization and immunohistochemistry showed that BbycaCR was ubiquitously expressed in amphioxus, although at different expression levels, suggesting that BbycaCR plays a conserved fundamental cellular role in amphioxus. It is proposed that BbycaCR may be indirectly involved in energy transduction.

Tissue- and stage-specific expression of a fatty acid binding protein-like gene from amphioxus Branchiostoma belcheri.

A cDNA clone encoding an amphioxus fatty acid binding protein-like (AmphiFABPL) protein was isolated from a gut cDNA library of Branchiostoma belcheri. It contained a 423 bp open reading frame corresponding to a deduced protein of 140 amino acids with a predicted molecular mass of approximately 15.9 kDa. Phylogenetic analysis showed that AmphiFABPL fell outside the vertebrate clade of fatty acid binding proteins (FABPs), being positioned at the base of the chordate lineage, and was almost equally homologous to various vertebrate FABPs, suggesting that it may be the archetype of vertebrate FABPs. Both northern blotting and in situ hybridization analyses demonstrated that AmphiFABPL was expressed in the hepatic caecum and hind-gut, and although at a much lower level, it was also present in the endostyle, ovary and testis. In addition, whole-mount in situ hybridization revealed that AmphiFABPL was initially expressed in the posterior two thirds of the primitive gut, including the mid-gut where the hepatic caecum will form later, in 2-day larvae. The expression pattern is closely similar to that of the L-FABP and I-FABP genes in vertebrates, supporting the hypothesis that the hepatic caecum in the amphioxus is homologous to the vertebrate liver.

Characterization and tissue-specific expression of phosphatidylcholine transfer protein gene from amphioxus Branchiostoma belcheri.

An amphioxus cDNA, encoding phosphatidylcholine transfer protein (AmphiPCTP), was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It contains a 660-bp open reading frame corresponding to a deduced protein of 219 amino acids. Phylogenetic tree analysis showed that AmphiPCTP clustered with PCTP subgroup of PCTP subfamily containing steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domains. AmphiPCTP had an exon-intron organization similar to that of human and rat PCTP genes in terms of both exon number and sequence homology of each exon, suggesting that PCTP has probably maintained a similar function in both amphioxus and mammalian species. Both in situ hybridization histochemistry and whole-mount in situ hybridization revealed a tissue-specific expression pattern of AmphiPCTP with the high levels in the hepatic caecum and primitive gut, including the region where the hepatic caecum will form later during development. This apparently agrees with the hypothesis that amphioxus hepatic caecum is equivalent to vertebrate liver. These results suggest a conserved role of PCTPs in amphioxus as well as mammalian species.

Human TRP14 gene homologue from amphioxus Branchiostoma belcheri: identification, evolution, expression and functional characterization.

Thioredoxin-related protein of 14 kDa, TRP14, has previously been identified only in humans. Here we report the identification and expression of an amphioxus TRP14 gene, named AmphiTRP14, the first such data in a non-mammalian organism. AmphiTRP14 consists of a 372-bp open reading frame coding for a 123-amino-acid protein with a calculated molecular weight of 14 kDa. It shares 56% identity with human TRP14 and possesses a highly conserved motif CPDC. Sequence comparison suggests the evolutionary appearance of the four-exon-three-intron organization of TRP14 genes after the split of protostome/deuterostome, which is highly conserved since then. AmphiTRP14 has been successfully expressed in Escherichia coli and purified. The recombinant protein exhibited features characteristic of human TRP14, including a reductase activity towards insulin. Both in situ hybridization histochemistry and immunohistochemistry revealed that AmphiTRP14 was expressed in a tissue-specific manner, with the most abundant expression in the hepatic caecum, ovary and hind-gut. This suggests that AmphiTRP14 plays a fundamental but tissue-specific role, or alternatively reflects differences in the tissue susceptibility to oxidative damage.

Characterization and expression of amphioxus ApoD gene encoding an archetype of vertebrate ApoD proteins.

Here we report a homologue of the apolipoprotein D gene (AmphiApoD) in amphioxus, Branchiostoma belcheri tsingtauense, the first such finding in a basal chordate cephalochordate. The main features of the protein predicted from AmphiApoD are characteristic of the apolipoprotein D. Phylogenetic analysis places AmphiApoD at the base of the phylogenetic tree, suggesting that AmphiApoD is the archetype of the vertebrate ApoD genes. Both whole mount in situ hybridization and Northern blotting and RT-PCR as well as in situ hybridization histochemistry reveal that AmphiApoD is expressed in tissues derived from mesoderm and endoderm including notochord and hind-gut, which contrasts with the strong expression patterns of ApoD genes in the ectodermal derivatives in mammals and birds. The expression profiles of the ApoD gene may have been changed to be expressed in the endo-mesodermal derivatives in amphioxus after the vertebrate and cephalochordate lineages diverged; alternatively, the ApoD gene may first have been expressed in the endo-mesoderm during embryogenesis in the last common ancestor of all chordates, and subsequently came to be expressed in the ectodermal derivatives of vertebrates including mammals and birds.