A novel Hericium erinaceus polysaccharide: Structural characterization and prevention of H2O2-induced oxidative damage in GES-1 cells

Structural Analysis and Antioxidant Activity of Alkaline-Extracted Glucans from Hericium erinaceus

An alkali-soluble β-glucan (AHEP-A-b, 20 kDa) purified from Hericium erinaceus fruiting bodies, was structurally characterized and examined for antioxidant activity. Methylation analysis and NMR spectroscopy show that the backbone of AHEP-A-b is composed of (1→6)-linked-D-β-glucopyran residues, branched at O-3 of glucopyranose (Glcp) residues with [→3)-β-D-Glcp-(1→] oligosaccharides or single unit of β-Glcp. Periodate oxidation analysis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) indicate that the degree of polymerization (DP) of [→3)-β-D-Glcp-(1→] side chains is 2 to 8. Functionally, AHEP-A-b is a relatively strong antioxidant as demonstrated by using 2, 2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical (ABTS·+), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and hydroxyl radicals scavenging assays. The present study lays the foundation for further studies into structure-activity relationships of polysaccharides from H. erinaceus.

Experimental Models in Unraveling the Biological Mechanisms of Mushroom-Derived Bioactives against Aging- and Lifestyle-Related Diseases: A Review

Mushrooms have garnered considerable interest among researchers due to their immense nutritional and therapeutic properties. The presence of biologically active primary and secondary metabolites, which includes several micronutrients, including vitamins, essential minerals, and other dietary fibers, makes them an excellent functional food. Moreover, the dietary inclusion of mushrooms has been reported to reduce the incidence of aging- and lifestyle-related diseases, such as cancer, obesity, and stroke, as well as to provide overall health benefits by promoting immunomodulation, antioxidant activity, and enhancement of gut microbial flora. The multifunctional activities of several mushroom extracts have been evaluated by both in vitro and in vivo studies using cell lines along with invertebrate and vertebrate model systems to address human diseases and disorders at functional and molecular levels. Although each model has its own strengths as well as lacunas, various studies have generated a plethora of data regarding the regulating players that are modulated in order to provide various protective activities; hence, this review intends to compile and provide an overview of the plausible mechanism of action of mushroom-derived bioactives, which will be helpful in future medicinal explorations.

Preventive and therapeutic effects of an exopolysaccharide produced by Lacticaseibacillus rhamnosus on alcoholic gastric ulcers

Crude exopolysaccharides produced by Lacticaseibacillus rhamnosus SHA113 were previously found to exhibit anti-alcoholic gastric ulcer activity in mice, but their major active fraction, structural characteristics, and underlying mechanisms remain unknown. Here, LRSE1 was identified as the active exopolysaccharide fraction produced by L. rhamnosus SHA113 responsible for the above effects. Purified LRSE1 had a molecular weight of 4.9 × 10⁴ Da and was comprised of L-fucose, D-mannose, D-glucuronic acid, d-glucose, D-galactose, and L-arabinose in the molar ratio of 2.4:6.5:1.2:1.00:0.3:0.6, respectively. The oral administration of LRSE1 resulted in a significant protective and therapeutic effect on alcoholic gastric ulcers in mice. These effects were identified to involve a reduction in reactive oxygen species, apoptosis, and the inflammatory response, increases in antioxidant enzyme activities, and increases in the phylum Firmicutes and decreases in the genera Enterococcus, Enterobacter, and Bacteroides in the gastric mucosa of mice. In vitro experiments showed that the administration of LRSE1 both inhibited apoptosis in GEC-1 cells via the TRPV1-P65-Bcl-2 pathway and inhibited the inflammatory response in RAW264.7 cells via the TRPV1-PI3K pathway. For the first time, we have identified the active exopolysaccharide fraction produced by Lacticaseibacillus that protects against alcoholic gastric ulcers and determined that its effect involves TRPV1-mediated pathways.

Gastroprotective activity of polysaccharide from the fruiting body of Hericium erinaceus against acetic acid-induced gastric ulcer in rats and structure of one bioactive fraction

This study aimed at investigating gastroprotective activity of Hericium erinaceus polysaccharide (HEP) and characterizing one of its bioactive fractions. Acetic acid-induced gastric ulcer (GU) rat model was used to evaluate the gastroprotective activity of HEP, while H₂O₂-induced injury GES-1 cell model was conducted to screen the bioactive fractions from HEP. Moreover, one of the bioactive fractions was characterized using methylation and 1D/2D NMR analysis. Results indicated HEP treatment could ameliorate acetic acid-induced GU in rats. HEP supplement decreased levels of interleukin-6, tumor necrosis factor-α and malondialdehyde and myeloperoxidase activity, and increased releases of nitric oxide, prostaglandin E2, epidermal growth factor, vascular endothelial growth factor and basic fibroblast growth factor and superoxide dismutase activity in gastric tissues of ulcerated rats. Five purified polysaccharides from HEP were screened to be bioactive fractions with cytoprotection on H₂O₂-induced injury in GES-1 cells. Among them, RP-S was characterized to be a (1 → 6)-β-D-glucan, whose backbone was composed of →6)-β-D-Glcp-(1 → residue and branched with T-β-D-Glcp-(1 → residue at O-3 position. In conclusion, HEP possessed gastroprotection against acetic acid-induced GU in rats and one of its bioactive fractions was a β-D-glucan. This study supports the utilization of HEP in anti-GU and provides evidences for the structure of gastroprotective HEP.

Isolation, Characterization and Antioxidant Activity of Yam Polysaccharides

This study aimed to characterize the structure of Chinese yam (Dioscoreae Rhizoma) polysaccharide (CYP) and to investigate its protective effect against H₂O₂-induced oxidative damage in IEC-6 cells. The chemical composition and structural characteristics of the samples were analyzed by chemical and instrumental methods, including high-performance gel permeation chromatography, high-performance anion-exchange chromatography (HPAEC), Fourier transformed infrared (FT-IR), ultraviolet (UV), and scanning electron microscopy (SEM). Antioxidant activity was evaluated by establishing a cellular model of oxidative damage. The molecular weight of CYP was 20.89 kDa. Analysis of the monosaccharide composition revealed that CYP was primarily comprised of galactose (Gal), glucose (Glu), and galacturonic acid (GalA), and the ratio between them was 28.57:11.28:37.59. Pretreatment with CYP was able to improve cell viability, superoxide dismutase (SOD) activity, and reduce intracellular reactive oxygen species (ROS) production and malondialdehyde (MDA) content after H₂O₂ injury. CYP also attenuated oxidative damage in cells through the mitogen-activated protein kinase (MAPK) signaling pathway. This study showed that CYP was an acidic heteropolysaccharide with a good protective effect against oxidative damage, and it thus has good prospects in food and biopharmaceutical industries.

Protective effect of sterols extracted from Lotus plumule on ethanol-induced injury in GES-1 cells in vitro

In this study, sterols were isolated from Lotus plumule by Soxhlet extraction and saponification and were further characterized by GC-MS analysis. The results showed that the sterols extracted from Lotus plumule mainly contained β-sitosterol, fucosterol, and campesterol. Models were established in vitro to investigate the protective effects of Lotus plumule sterols (LPSs) on ethanol-induced injury in human gastric epithelium (GES-1) cells. The results showed that appropriate concentrations of LPSs and β-sitosterol could protect GES-1 cells from ethanol-induced injury by reducing ROS levels, reducing calcium ion release, increasing antioxidant enzyme activity and maintaining mitochondrial membrane potential. Western blot experiment results also showed that appropriate concentrations of LPSs and β-sitosterol could up-regulate the expression of the anti-apoptotic protein Bcl-2 and down-regulate the pro-apoptotic proteins Bax and caspase-3 in GES-1 cells. Meanwhile, sterol pretreatment groups down-regulated the protein expression levels of p-P38 and p-JNK in ethanol-damaged GES-1 cells and up-regulated the expression level of p-ERK, suggesting that sterols protect GES-1 cells from ethanol-induced damage by regulating the MAPK signaling pathway. Taken together, Lotus plumule sterols could effectively prevent gastric cell damage in vitro and suggest the potential application of LPSs as bioactive ingredients for healthy foods.

Macrofungi as a Nutraceutical Source: Promising Bioactive Compounds and Market Value

Macrofungi production and economic value have been increasing globally. The demand for macrofungi has expanded rapidly owing to their popularity among consumers, pleasant taste, and unique flavors. The presence of high quality proteins, polysaccharides, unsaturated fatty acids, minerals, triterpene sterols, and secondary metabolites makes macrofungi an important commodity. Macrofungi are well known for their ability to protect from or cure various health problems, such as immunodeficiency, cancer, inflammation, hypertension, hyperlipidemia, hypercholesterolemia, and obesity. Many studies have demonstrated their medicinal properties, supported by both in vivo and in vitro experimental studies, as well as clinical trials. Numerous bioactive compounds isolated from mushrooms, such as polysaccharides, proteins, fats, phenolic compounds, and vitamins, possess strong bioactivities. Consequently, they can be considered as an important source of nutraceuticals. Numerous edible mushrooms have been studied for their bioactivities, but only a few species have made it to the market. Many species remain to be explored. The converging trends and popularity of eastern herbal medicines, natural/organic food product preference, gut-healthy products, and positive outlook towards sports nutrition are supporting the growth in the medicinal mushroom market. The consumption of medicinal mushrooms as functional food or dietary supplement is expected to markedly increase in the future. The global medicinal mushroom market size is projected to increase by USD 13.88 billion from 2018 to 2022. The global market values of promising bioactive compounds, such as lentinan and lovastatin, are also expected to rise. With such a market growth, mushroom nutraceuticals hold to be very promising in the years to come.

Enzymatic-fingerprinting workflow of polysaccharides in Hericium erinaceus fruiting bodies: From HILIC-ESI--MS screening to targeted MIM profiling

In this study, an uncommon enzymatic-fingerprinting workflow, was proposed for characterization and discrimination of mushroom polysaccharides (MPs) by hydrophilic interaction liquid chromatography-negative electrospray mass spectrometry (HILIC-ESI^--MS). Firstly, the HILIC-ESI^--MS was used to screen and identify the enzymatic digestion products of MPs using HILIC-Orbitrap based on full scan and MS/MS modes. Secondly, a targeted structural-fingerprinting of polysaccharides (SFP) was built in a multiple-ion monitoring (MIM) mode using the same HILIC separation with a triple quadrupole MS. Thirdly, a case study of polysaccharides in Hericium erinaceus fruiting bodies (HEP) was performed to obtain the expected SFP based on dextranase digestion that allows for visual discrimination of polysaccharides from other five edible mushrooms attributed to Agrocybe cylindracea, Arimillaria mellea, Flammulina velutipes, Pleurotus eryngii, and Lentinula edodes. Furthermore, a major structural backbone of HEP was unveiled by occurrence of → ⁶(Hex)¹ → along with multiple possible substitutions including of terminal GalA, Fuc, acetyl, → ⁴Hex¹ →, and → ³Hex¹ →. Finally, the similarity analysis, hierarchical cluster analysis (HCA), and partial least squares discriminant analysis (PLS-DA) were performed to visualize various MPs. As a result, the enzymatic-fingerprinting workflow presents an effective example for quality evaluation of fungi polysaccharides using a SFP strategy.

Hericium Erinaceus Prevents DEHP-Induced Mitochondrial Dysfunction and Apoptosis in PC12 Cells

Hericium Erinaceus (HE) is a medicinal plant known to possess anticarcinogenic, antibiotic, and antioxidant activities. It has been shown to have a protective effect against ischemia-injury-induced neuronal cell death in rats. As an extending study, here we examined in pheochromocytoma 12 (PC12) cells, whether HE could exert a protective effect against oxidative stress and apoptosis induced by di(2-ethylhexyl)phthalate (DEHP), a plasticizer known to cause neurotoxicity. We demonstrated that pretreatment with HE significantly attenuated DEHP induced cell death. This protective effect may be attributed to its ability to reduce intracellular reactive oxygen species levels, preserving the activity of respiratory complexes and stabilizing the mitochondrial membrane potential. Additionally, HE pretreatment significantly modulated Nrf2 and Nrf2-dependent vitagenes expression, preventing the increase of pro-apoptotic and the decrease of anti-apoptotic markers. Collectively, our data provide evidence of new preventive nutritional strategy using HE against DEHP-induced apoptosis in PC12 cells.