Anti-Diabetic Activity of Polysaccharides from Auricularia cornea var. Li

Subcritical water extraction improves the ability of Auricularia cornea var. Li. Polysaccharides to stabilize hydrogels and emulsion gels

In this work, polysaccharides from Auricularia cornea var. Li. (ACP) were extracted by a novel subcritical water extraction (SWE) method. Their structural properties and ability to stabilize hydrogels and emulsion gels were investigated and compared with those obtained by the conventional hot water extraction (HWE) method. The results showed that the polysaccharide yield of SWE (45.11 ± 0.23 %) was higher than that of HWE (17.85 ± 0.51 %). The two polysaccharides had the same type of monosaccharides but different compositions, and the molecular weight of ACP-SWE was slightly lower. The molecular conformation of ACP-HWE exhibited a long-chain structure, whereas ACP-SWE was multi-branched with obvious entanglements between the molecular chains. Both polysaccharides were able to form gels at concentrations above 1.0 %, with the ACP-SWE hydrogel having a denser network structure with better rheological and textural properties. ACP-SWE also had a greater ability to stabilize emulsion gels. By adjusting the polysaccharide concentration (c, 0.2 %-1.0 %) and the oil phase volume fraction (φ, 0.4-0.8), ACP-SWE emulsion gels could be prepared in a single step of shear homogenization. This work revealed that the adsorption of ACP-SWE at the oil-water interface and cross-linking in the bulk phase, together with the filling effect of oil droplets, contributed to the stabilization of ACP-SWE emulsion gels.

Structural characterization and antioxidant activity evaluation of a polysaccharide from pink Auricularia cornea

An acidic polysaccharose (YL-D2N2) was isolated from crude polysaccharides of pink Auricularia cornea and characterized for its structural and antioxidant properties. YL-D2N2 consists of fucose, galactose, glucose, xylose, mannose and glucuronic acid in a molar ratio of 0.85: 1.50: 4.44: 27.52: 46.56: 19.13. It has a number-average molecular weight of about 52.811 kDa and a weight-average molecular weight of about 135.457 kDa. Structural characterization showed that YL-D2N2 consists of nine residues (Xylp-(1→, GlcpA-(1→, →2)-Xylp-(1→, →3)-Galp-(1→, →3)-Manp-(1→, →4)-GlcpA-(1→, →2,3)-Manp-(1→, →3,4)-Glcp-(1→, →3,6)-Manp-(1→), with a backbone of →3)-β-D-Manp-(1→, →2,3)-α-D-Manp-(1→, →3,6)-α-D-Manp-(1 → and side chains containing β-D-Xylp-(1 → and α-D-GlcpA-(1→. Notably, YL-D2N2 exhibits significant radical scavenging activity for superoxide anions, reaching 50.82 ± 0.64 % at a concentration of 3.2 mg/mL. Overall, YL-D2N2 exhibits a unique chemical structure and specialized applications for targeting superoxide anion radicals, providing valuable insights for further exploration of its structure-activity relationship.

Characterization of tea polysaccharides from Tieguanyin oolong tea and their hepatoprotective effects via AMP-activated protein kinase-mediated signaling pathways

In the present study, we succeeded in extracting tea polysaccharide (TPS) from Tieguanyin oolong tea, and the TPS was characterized. TPS is an acidic heteropolysaccharide containing rhamnose, arabinose, galactose, glucose (Glc), xylose, mannose, galacturonic acid, and guluronic acid. We found that TPS supplementation partially reversed the elevated levels of serum alanine aminotransferase, total cholesterol, and low-density lipoprotein cholesterol in high-fat diet (HD)-induced nonalcoholic fatty liver disease (NAFLD) mice (p < 0.05), and hepatic steatosis and impaired Glc tolerance were also ameliorated. After HD intervention, the activity of Adenosine 5'-monophosphate-activated protein kinase (AMPK) and its downstream genes, including Sirtuin 1 (SIRT1), sterol regulatory element-binding protein-1c (SREBP1c), acetyl-coenzyme A carboxylase 1 (ACC1), and adipose triglyceride lipase (ATGL), was significantly inhibited (p < 0.05). TPS can increase the expression of these genes. The hepatoprotective effects of TPS in AMPK-/- mice almost completely disappeared. Moreover, the expression levels of SIRT1, SREBP1c, ACC1, and ATGL did not significantly change after TPS supplementation (p > 0.05). Therefore, our findings suggest that TPS protects the liver from hepatic glucolipid metabolism disorders in HD-induced NAFLD mice by activating AMPK-mediated signaling pathways.

Macromolecules from mushrooms, venoms, microorganisms, and plants for diabetes treatment - Progress or setback?

Diabetes is a substantial public health issue, while its prevalence continues to rise worldwide, affecting millions of persons between the ages of 20 and 80, the development of new therapeutic classes improving glycemic control and consequently micro and macrovascular complications are needed. Today, diabetes treatment is daily for life, and should not be interrupted. However, insulin secretagogues medications, and exogenous self-administration of insulin provide efficient antidiabetic effects, but their misuse leads to hypoglycemic complications besides other risks, hence the need to look for other natural products not to use solely but in concert with others types of medications. In this review, we will highlight briefly the pathophysiology of diabetes and its complications, then we will report the main bioactive macromolecules derived from various sources of natural products providing anti-diabetic properties. However, further researches need to be carried out to face the limitations hampering the development of effective natural drugs for diabetes treatment.

Metabolic profiles and biomarkers of Auricularia cornea based on de-oiled camphor leaf substrate

This study investigates the metabolic responses of Auricularia cornea when cultured on de-oiled leaves of Cinnamomum longepaniculatum (DeCL), an underutilized waste product. The metabolic profiles of A. cornea cultured with four different quality ratios of DeCL substrate (0 %, 14 %, 28 % and 42 %) were analyzed by UHPLC-MS/MS-based metabolomics. A total of 516 metabolites were identified and classified into 78 categories, with phenols, alkaloids and flavonoids accounting for 26.7 % of the total. In addition, 32 metabolite biomarkers associated with eight major metabolic pathways were identified. This pioneering research provides valuable insights into the utilization of DeCL, and expands our knowledge of the metabolic dynamics underlying the growth of A. cornea on alternative substrates.

The function and application of edible fungal polysaccharides

Edible fungi, commonly known as mushrooms, are precious medicinal and edible homologous gifts from nature to us. Edible fungal polysaccharides (EFPs) are a variety of bioactive macromolecular which isolated from fruiting bodies, mycelia or fermentation broths of edible or medicinal fungus. Increasing researches have confirmed that EFPs possess multiple biological activities both in vitro and in vivo settings, including antioxidant, antiviral, anti-inflammatory, immunomodulatory, anti-tumor, hypoglycemic, hypolipidemic, and regulating intestinal flora activities. As a result, they have emerged as a prominent focus in the healthcare, pharmaceutical, and cosmetic industries. Fungal EFPs have safe, non-toxic, biodegradable, and biocompatible properties with low immunogenicity, bioadhesion ability, and antibacterial activities, presenting diverse potential applications in the food industries, cosmetic, biomedical, packaging, and new materials. Moreover, varying raw materials, extraction, purification, chemical modification methods, and culture conditions can result in variances in the structure and biological activities of EFPs. The purpose of this review is to provide comprehensively and systematically organized information on the structure, modification, biological activities, and potential applications of EFPs to support their therapeutic effects and health functions. This review provides new insights and a theoretical basis for prospective investigations and advancements in EFPs in fields such as medicine, food, and new materials.

The Protective Effect of Auricularia cornea var. Li. Polysaccharide on Alcoholic Liver Disease and Its Effect on Intestinal Microbiota

This study's objective was to examine the protective effect and mechanism of a novel polysaccharide (AYP) from Auricularia cornea var. Li. on alcoholic liver disease in mice. AYP was extracted from the fruiting bodies of Auricularia cornea var. Li. by enzymatic extraction and purified by DEAE-52 and Sephacryl S-400. Structural features were determined using high-performance liquid chromatography, ion exchange chromatography and Fourier-transform infrared analysis. Additionally, alcoholic liver disease (ALD) mice were established to explore the hepatoprotective activity of AYP (50, 100 and 200 mg/kg/d). Here, our results showed that AYP presented high purity with a molecular weight of 4.64 × 105 Da. AYP was composed of galacturonic acid, galactose, glucose, arabinose, mannose, xylose, rhamnose, ribos, glucuronic acid and fucose (molar ratio: 39.5:32.9:23.6:18.3:6.5:5.8:5.8:3.3:2:1.1). Notably, AYP remarkably reduced liver function impairment (alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (TC)), nitric oxide (NO) and malondialdehyde (MDA) of the liver and enhanced the activity of antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione (gGSH)) in mice with ALD. Meanwhile, the serum level of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were reduced in ALD mice treated by AYP. Furthermore, the AYPH group was the most effective and was therefore chosen to further investigate its effect on the intestinal microbiota (bacteria and fungi) of ALD mice. Based on 16s rRNA and ITS-1 sequencing data, AYP influenced the homeostasis of intestinal microbiota to mitigate the damage of ALD mice, possibly by raising the abundance of favorable microbiota (Muribaculaceae, Lachnospiraceae and Kazachstania) and diminishing the abundance of detrimental microbiota (Lactobacillus, Mortierella and Candida). This discovery opens new possibilities for investigating physiological activity in A. cornea var. Li. and provides theoretical references for natural liver-protecting medication research.

Comparative Analysis of Metabolic Compositions and Trace Elements of Ornithogalum caudatum with Different Growth Years

As a traditional medicine with extensive history, Ornithogalum caudatum has high nutritional and medicinal value. However, its quality evaluation criteria are insufficient because it is not included in the pharmacopeia. Simultaneously, it is a perennial plant, and the medicinal ingredients change with the growth years. Currently, studies on the synthesis and accumulation of metabolites and elements in O. caudatum during different growth years are unavailable. To address this issue, in this study, the 8 main active substances, metabolism profiles, and 12 trace elements of O. caudatum from different growth years (1, 3, and 5 years old) were analyzed. The main substances of O. caudatum changed significantly in different years of growth. Saponin and sterol contents increased with age; however, the polysaccharide content decreased. For metabolism profiling, ultrahigh-performance liquid chromatography tandem mass spectrometry was performed. Among the three groups, 156 differential metabolites with variable importance in projection values >1.0 and p < 0.05 were identified. Among the differential metabolites, 16 increased with increasing years of growth and have the potential to become age-identified markers. A trace element study showed that the contents of K, Ca, and Mg were higher, and the ratio of Zn/Cu was less than 0.1%. Heavy metal ions in O. caudatum did not increase with age. The results of this study provide a basis to evaluate the edible values of O. caudatum and facilitate further exploitation.

Antidiabetic activity of Armillaria mellea polysaccharides: Joint ultrasonic and enzyme assisted extraction

Armillaria mellea polysaccharides (AMPs) were obtained by ultrasonic assisted extraction (U), enzyme assisted extraction (E) and ultrasonic-enzyme assisted extraction (UE), respectively. The yield of UE-AMPs (6.32 ± 0.14%) was 1.64 times higher than that of U-AMPs (3.86 ± 0.11%) and 1.21 times higher than that of E-AMPs (5.21 ± 0.09%); meanwhile, the highest total sugar content and the lowest protein content were found in UE-AMPs. AMPs obtained from the three extraction methods had the same monosaccharide composition but in different proportions, allowing UE-AMPs to have the most potent antioxidant activity. The antidiabetic activity of UE-AMPs was investigated in streptozotocin (STZ)-induced diabetic mice. UE-AMPs, when given by gavage, greatly prevented weight loss, increased water intake, and considerably decreased blood glucose levels in diabetic mice, which were dose-dependent (P < 0.05). In addition, UE-AMPs also had a positive effect on the reduction of lipid levels in the blood, oxidative damage and liver function impairment. The pathological observation by hematoxylin-eosin staining (HE) revealed that UE-AMPs protected the organs of mice from diabetic complications (liver disease and nephropathy). Hence, our findings demonstrate that UE-AMPs are a suitable choice for improving diabetes and its complications and have great application prospects in the fields of natural medicine and functional food.