Spatial structure and anti-fatigue of polysaccharide from Inonotus obliquus

Resveratrol Alleviated Intensive Exercise-Induced Fatigue Involving in Inhibiting Gut Inflammation and Regulating Gut Microbiota

Resveratrol (trans-3,4',5-trihydroxystilbene, RES) is a stilbenoid naturally present in a variety of plants. Although there are several reports about its anti-fatigue activity, its impact on intensive exercise-induced fatigue and the underlying mechanisms are yet not well understood. In the present study, we established a swimming exercise protocol in mice that is similar to the fatigue condition induced by a long period of intensive exercise and explored the effect of RES on fatigue and the mechanisms from the perspective of intestinal injury and gut microbiota. The results revealed that RES significantly prolonged exhaustive swimming time in fatigued mice and improved the serum indexes associated with fatigue, including serum glucose, lactic acid (LA), urea nitrogen (BUN), lactate dehydrogenase (LDH), creatine kinase (CK), catalase (CAT), glutathione peroxidase (GSH-Px), and glycogen storage in liver and muscle. Meanwhile, RES increased the expressions of ZO-1, Occludin, and Claudin-1, thereby enhancing intestinal barrier integrity and inhibiting mRNA expressions of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the colon, thereby improving the pathological injury in the colon. Importantly, RES modified gut microbiota dysbiosis by increasing the diversity of gut microbiota, regulating microbiota associated with inflammation and fatty acid metabolism at the phylum (Bacteroidetes and Firmicutes), family (Erysipelotrichaceae, Enterobacteriaceae, and Prevotellaceae), and genus (Brevundimonas diminuta, Coprobacillus, Megasphaera, and Lactobacillus) levels, respectively. The results supplemented the anti-fatigue mechanism for RES from the perspective of intestinal injury and gut microbiota. The detailed mechanisms and associated metabonomics analysis remain for further study.

Plant polysaccharides and antioxidant benefits for exercise performance and gut health: from molecular pathways to clinic

In the last three decades, our understanding of how exercise induces oxidative stress has significantly advanced. Plant polysaccharides, such as dietary fibers and resistant starches, have been shown to enhance exercise performance by improving energy metabolism, reducing fatigue, increasing strength and stamina, mitigating oxidative stress post-exercise, facilitating muscle recovery, and aiding in detoxification. Moreover, antioxidants found in plant-based foods play a crucial role in protecting the body against oxidative stress induced by intense physical activity. By scavenging free radicals and reducing oxidative damage, antioxidants can improve exercise endurance, enhance recovery, and support immune function. Furthermore, the interaction between plant polysaccharides and antioxidants in the gut microbiota can lead to synergistic effects on overall health and performance. This review provides a comprehensive overview of the current research on plant polysaccharides and antioxidants in relation to exercise performance and gut health.

Extraction methods, structural diversity and potential biological activities of Artemisia L. polysaccharides (APs): A review

The extraction and structural characterization of polysaccharides are challenging in plants with overlapping distributions such as Artemisia, the plant genus producing antimalarial drug artemisinin discovered by the Nobel Prize 2015 winning Professor Tu You-you. The diversity in Artemisia polysaccharides (APs) is due to difference in extraction methods leading to different bioactivities. In spite of that, APs utilization is decelerated due to lack of a review portraying current advancements. This review delivers data on extraction, structural characterization and bioactivities of APs with emphasis on mechanisms of action and structure-function relationships. Outcomes indicated that various polysaccharides in 16 Artemisia species were reported and comprehensively described. The common methods for preparing APs were hot water and microwave assisted extractions with maximum yield. Maximum plant parts used to extract APs include leaves, aerial part, whole plant and seeds. The APs presented varying molecular weight, monosaccharide composition, carbohydrates, proteins, uronic acids and phenolic content with around 20 bioactivities. Data on structure-function relationships indicated that the bioactivities of APs are highly correlated with the differences in Mw and monosaccharide's type. While Artemisia species discussed here are the most studied species for their polysaccharides, other Artemisia species may offer unique polysaccharides with distinct biological properties; hence, the future research could focus on expanding the scope of species studied. Broader investigations are also needed specifically on the structure-function relationships of APs with the elucidation of impact of unknown factors on their efficacy.

An acid polysaccharide from Mentha haplocalyx exerts the antifatigue effect via activating AMPK

Fatigue is a pathological state that can impair physical and cognitive performance, making the development of effective therapeutic strategies crucial. In this study, an acid polysaccharide (MHa) was isolated from Mentha haplocalyx. Structural analysis showed that MHa (40.7 kDa) has a backbone consisting of 4-α-GalAp, 6-α-Galp, and 4,6-α-Galp, with branches at the C6 of 4,6-α-Galp linked to four distinct side chains, including 4-α-Galp, 3,6-β-Manp, t-α-Araf, t-α-Rhap, t-α-Glcp, and t-β-Rhap. MHa possesses a triple-helix conformation with a sheet-like appearance, which may contribute to its biological stability and activity. Functionally, MHa exhibited significant antifatigue effects, with the 400 mg/kg dose showing the most potent activity. Compared to the model group, treatment with 400 mg/kg of MHa increased the exhaustive swimming time by 1.89-fold in fatigued mice, reduced blood lactate and urea nitrogen levels by 24.21 % and 35.57 %, respectively, and enhanced liver glycogen, muscle glycogen, and ATP levels by 20.08 %, 46.52 %, and 50.43 %, respectively. MHa improved the activities of Ca2+-Mg2+-ATPase and Na+-K+-ATPase, while also enhancing antioxidant defense. Mechanistically, MHa promotes mitochondrial biogenesis and enhances oxidative defense via activating AMPK. These findings highlight the potential of MHa as a promising candidate for developing antifatigue supplements, offering a novel strategy to mitigate fatigue.

Exploring the anti-fatigue properties of ginseng stem and leaf saponins: Using UHPLC-MS metabolomics and neurotransmitter analysis

BACKGROUND

Chronic fatigue syndrome (CFS) is a crippling illness with limited effective treatment options. Recent findings have suggested that ginseng stem and leaf saponins (GSLS) possess anti-fatigue effects. However, the detailed mechanisms by which GSLS impact CFS have yet to be fully elucidated.

PURPOSE

This study aimed to explore the efficacy and underlying mechanisms of GSLS in the treatment of peripheral and central fatigue in mice with CFS.

METHODS

A CFS model was established in male C57BL/6 mice, which were then subjected to prolonged swimming tests. The validity of this model and the efficacy of GSLS were verified using the forced exhaustion swimming test and the Morris water maze test. The anti-fatigue mechanism of GSLS was verified using pathological section observations, biochemical index tests, neurotransmitter analysis, and Ultra-high performance liquid chromatography-high-resolution mass spectrometry (UHPLC-MS) metabolomics analysis.

RESULTS

GSLS prolonged the swim time-to-exhaustion in CFS mice and reduced escape latency in the water maze, revealing their anti-fatigue and memory-improving effects. GSLS significantly protected both peripheral (liver) and central (hippocampus) tissues, as shown in pathological sections. Biochemical indices suggested that GSLS mitigate peripheral fatigue by reducing energy expenditure and oxidative damage and inhibiting the production of harmful metabolites. Furthermore, GSLS altered the abnormal levels of 14 neurotransmitters in the brains of CFS mice, including seven upregulated and seven downregulated neurotransmitters, highlighting their role in mitigating central fatigue through neurotransmitter regulation. Serum metabolomics analysis identified alterations in 19 metabolites across 11 metabolic pathways, thereby elucidating the potential mechanisms by which GSLS treat CFS.

CONCLUSION

GSLS ameliorate damage caused by both peripheral and central fatigue. They also act on multiple pathogenic mechanisms by modulating neurotransmitters and serum biomarkers, making them a potential therapeutic agent for CFS.

Shenling Baizhu San alleviates central fatigue through SIRT1-PGC-1α-Mediated mitochondrial biogenesis

ETHNOPHARMACOLOGICAL RELEVANCE

Shenling Baizhu San (SLBZS) is a Traditional Chinese Medicine (TCM) formula composed of 10 medicinal herbs, historically used to strengthen the spleen, replenish qi, and alleviate fatigue-related symptoms. SLBZS originates from the 'Taiping Huimin Heji Ju Fang' of the Song Dynasty. Central fatigue (CF), a subtype of fatigue, is considered in TCM to be closely associated with spleen deficiency. However, there is currently a lack of research on SLBZS's therapeutic effects on CF and the pharmacological mechanisms underlying its potential benefits.

AIM OF THE STUDY

This study aims to assess the effects of SLBZS on CF in rats induced by the Modified Multiple Platform Method (MMPM) and to elucidate the underlying mechanisms, focusing on mitochondrial biogenesis and SIRT1/PGC-1α pathway regulation.

MATERIALS AND METHODS

CF was induced in male Wistar rats using MMPM, involving intermittent sleep deprivation over 21 days. SLBZS was administered at low(LSLBZS), medium(MSLBZS), and high doses(HSLBZS). Chemical components of SLBZS were identified and quantified using Liquid Chromatography-Tandem Mass Spectrometry(LC-MS/MS). Behavioral tests evaluated physical performance, emotional state, and cognitive function, while serum biochemical markers, mitochondrial morphology, and the protein and gene expression levels of the SIRT1/PGC-1α pathway were analyzed to explore underlying mechanisms.

RESULTS

A total of 141 main compounds in SLBZS were identified, comprising various components such as flavonoids, phenylpropanoids, terpenoids, among others. SLBZS significantly improved physical performance, alleviated negative emotions, and enhanced cognitive function in CF rats. Biochemically, SLBZS increased serum ATP levels and reduced fatigue-related markers. Mitochondrial analysis demonstrated that SLBZS reversed mitochondrial degeneration, increased mitochondrial number, and increased mtDNA copy number in the hippocampus. Furthermore, SLBZS upregulated SIRT1/PGC-1α pathway expression at both the protein and gene levels in the hippocampus. Notably, the HSLBZS group demonstrated particularly pronounced effects.

CONCLUSION

SLBZS significantly alleviates CF symptoms enhances mitochondrial function via upregulating the SIRT1/PGC-1α pathway, positioning it as a promising alternative for CF management by addressing both its physiological and symptomatic aspects.

Physical radiation induced the yield of triterpenoids in hypha of Inonotus obliquus to increase

HSD-IO01, a new pure strain of I. obliquus, was isolated and purified from the sclerotium of I. obliquus of Daxing'an Mountains. Physical radiation-assisted liquid fermentation technology was explored to increase the triterpenoids yield of HSD-IO01. In the 100 mL optimized liquid fermentation system, the hypha dry weight of HSD-IO01 was 1.7734 g, and the triterpenoids yield was 43.43 mg. Yields of triterpenoids increased after induction with ultrasound, microwave, or UV light, respectively. Among them, ultrasonic treatment had the most remarkable induction effect. The yield of triterpenoids would be increased to 68.35 mg (57.38 %) when the HSD-IO01 was treated by 100 W ultrasonic for 45 min. Establishing ultrasonic-assisted liquid fermentation technology could further promote the detailed development and comprehensive utilization of I. obliquus resources.

Dual-factor model of sleep and diet: a new approach to understanding central fatigue

Background

Numerous studies have recently examined the impact of dietary factors such as high-fat diets on fatigue. Our study aims to investigate whether high-fat diet (HFD) alone or combined with alternate-day fasting (ADF) can lead to the central fatigue symptoms and to investigate the potential integration of dietary and sleep variables in the development of central fatigue models.

Methods

Seventy-five male Wistar rats were divided into five groups: control, HFD, HFD + ADF, modified multiple platform method (MMPM), and MMPM+HFD + ADF. Each group underwent a 21-day modeling period according to their respective protocol. Their behavioral characteristics, fatigue biochemical markers, hippocampal pathological changes, mitochondrial ultrastructure, and oxidative stress damage were analyzed.

Results

Our findings demonstrate that using only HFD did not cause central fatigue, but combining it with ADF did. This combination led to reduced exercise endurance, decreased locomotor activity, impaired learning and memory abilities, along with alterations in serum levels of alanine aminotransferase (ALT), creatine kinase (CK), and lactate (LAC), as well as hippocampal pathological damage and other central fatigue symptoms. Moreover, the MMPM+HFD + ADF method led to the most obvious central fatigue symptoms in rats, including a variety of behavioral changes, alterations in fatigue-related biochemical metabolic markers, prominent pathological changes in hippocampal tissue, severe damage to the ultrastructure of mitochondria in hippocampal regions, changes in neurotransmitters, and evident oxidative stress damage. Additionally, it was observed that rats subjected to HFD + ADF, MMPM, and MMPM+HFD + ADF modeling method exhibited significant brain oxidative stress damage.

Conclusion

We have demonstrated the promotive role of dietary factors in the development of central fatigue and have successfully established a more stable and clinically relevant animal model of central fatigue by integrating dietary and sleep factors.

Ginkgo Biloba Bioactive Phytochemicals against Age-Related Diseases: Evidence from a Stepwise, High-Throughput Research Platform

The seeds of ginkgo biloba L (GB) have been widely used worldwide. This study investigated the bioefficacies of whole GB seed powder (WGP) retaining the full nutrients of ginkgo against aging, atherosclerosis, and fatigue. The experimental results indicated that WGP lowered brain monoamine oxidase and serum malondialdehyde levels, enhanced thymus/spleen indexes, and improved learning ability, and delayed aging in senescent mice. WGP regulated lipid levels and prevented atherosclerosis by reducing triglycerides, lowering low-density lipoprotein cholesterol, increasing high-density lipoprotein cholesterol, and decreasing the atherosclerosis index. WGP improved exercise performance by reducing blood lactate accumulation and extending exhaustive swimming and climbing times, improved energy storage by increasing muscle/liver glycogen levels, and relieved physical fatigue. Network pharmacology analysis revealed 270 potential targets of WGP that play roles in cellular pathways related to inflammation inhibition, metabolism regulation, and anti-cellular senescence, etc. Protein-protein interaction analysis identified 10 hub genes, including FOS, ESR1, MAPK8, and SP1 targets. Molecular docking and molecular dynamics simulations showed that the bioactive compounds of WGP bound well to the targets. This study suggests that WGP exerts prominent health-promoting effects through multiple components, targets, and pathways.

Effects of Chemical Modification on the Structure and Biological Activities of Polysaccharides Extracted from Inonotus Obliquus by Microwave

A novel polysaccharide, Inonotus obliquus polysaccharide (IOP), was extracted using a microwave extraction method and subsequently subjected to modifications through sulfation, carboxymethylation, phosphorylation, and acetylation. Its physical and chemical properties were analyzed using various chemical techniques, including high-pressure liquid chromatography, ultraviolet light, Fourier-transform infrared spectroscopy, X-ray diffraction, Congo red test, and scanning electron microscopy. The antioxidant capacity was assessed using DPPH, ABTS, and hydroxyl radical assays, as well as by measuring the reducing power. Additionally, hypoglycemic activity was evaluated through α-glucosidase and α-amylase assays. The results indicated that the chemical modifications effectively altered the physical and chemical properties, as well as the biological activities of IOP. Compared to the unmodified IOP, the derivatives exhibited reduced sugar content, uronic acid content, and molecular weight, while demonstrating varying levels of antioxidant and hypoglycemic capabilities. Notably, the carboxymethylated IOP (IOP-C) displayed lower molecular weight, higher ABTS free radical scavenging rate, greater reducing ability, and increased α-amylase inhibition rate. Therefore, IOP-C shows promise as a potential edible antioxidant and hypoglycemic agent.

A review of the polysaccharides against fatigue and the underlying mechanism

Fatigue is a common physiological state that affects normal human activities. Prolonged fatigue induces a variety of diseases and seriously affects human health, so it is imperative to discover nutritional dietary supplements and treatments without side effects, among which natural anti-fatigue polysaccharides have shown great potential. Polysaccharides, a class of biomolecules produced by a variety of organisms such as plants, animals, bacteria and algae, have attracted much attention in recent years due to their anti-fatigue activity and fewer side effects. This review summarizes the classification, dosage and experimental models of polysaccharides with anti-fatigue activity obtained from different natural sources. We also review the fatigue-relieving effects of these polysaccharides through mechanisms such as modulating oxidative damage, regulating energy metabolism and influencing intestinal flora, as well as the effects of molecular weights, monosaccharide compositions, structural features and chemical modifications of the polysaccharides on their anti-fatigue activities to support their potential application value in functional foods and pharmaceuticals. New valuable insights for future research on natural polysaccharides are also presented in the field of natural production of bio-based functional materials, functional foods and therapeutic agents.

Selection and Genetic Analysis of High Polysaccharide-Producing Mutants in Inonotus obliquus

Inonotus obliquus, a medicinal fungus, has garnered significant attention in scientific research and medical applications. In this study, protoplasts of the I. obliquus HS819 strain were prepared using an enzymatic method and achieved a regeneration rate of 5.83%. To enhance polysaccharide production of I. obliquus HS819, atmospheric and room temperature plasma (ARTP) technology was employed for mutagenesis of the protoplasts. Through liquid fermentation, 32 mutant strains exhibiting diverse characteristics in morphology, color of the fermentation broth, mycelial pellet size, and biomass were screened. Secondary screening identified mutant strain A27, which showed a significant increase in polysaccharide production up to 1.67 g/L and a mycelial dry weight of 17.6 g/L, representing 137.67% and 15% increases compared to the HS819 strain, respectively. Furthermore, the fermentation period was reduced by 2 days, and subsequent subculture cultivation demonstrated stable polysaccharide production and mycelial dry weight. The genome resequencing analysis of the HS819 strain and mutant strain A27 revealed 3790 InDel sites and mutations affecting 612 functional genes associated with polysaccharide synthesis. We predict that our findings will be helpful for high polysaccharide production through genetic engineering of I. obliquus.

Replicating human characteristics: A promising animal model of central fatigue

Central fatigue is a common pathological state characterized by psychological loss of drive, lack of appetite, drowsiness, and decreased psychic alertness. The mechanism underlying central fatigue is still unclear, and there is no widely accepted successful animal model that fully represents human characteristics. We aimed to construct a more clinically relevant and comprehensive animal model of central fatigue. In this study, we utilized the Modified Multiple Platform Method (MMPM) combined with alternate-day fasting (ADF) to create the animal model. The model group rats are placed on a stationary water environment platform for sleep deprivation at a fixed time each day, and they were subjected to ADF treatment. On non-fasting days, the rats were allowed unrestricted access to food. This process was sustained over a period of 21 days. We evaluated the model using behavioral assessments such as open field test, elevated plus maze test, tail suspension test, Morris water maze test, grip strength test, and forced swimming test, as well as serum biochemical laboratory indices. Additionally, we conducted pathological observations of the hippocampus and quadriceps muscle tissues, transmission electron microscope observation of mitochondrial ultrastructure, and assessment of mitochondrial energy metabolism and oxidative stress-related markers. The results revealed that the model rats displayed emotional anomalies resembling symptoms of depression and anxiety, decreased exploratory behavior, decline in learning and memory function, and signs of skeletal muscle fatigue, successfully replicating human features of negative emotions, cognitive decline, and physical fatigue. Pathological damage and mitochondrial ultrastructural alterations were observed in the hippocampus and quadriceps muscle tissues, accompanied by abnormal mitochondrial energy metabolism and oxidative stress in the form of decreased ATP and increased ROS levels. In conclusion, our ADF+MMPM model comprehensively replicated the features of human central fatigue and is a promising platform for preclinical research. Furthermore, the pivotal role of mitochondrial energy metabolism and oxidative stress damage in the occurrence of central fatigue in the hippocampus and skeletal muscle tissues was corroborated.

Polysaccharides derived from natural edible and medicinal sources as agents targeting exercise-induced fatigue: A review

Exercise-induced fatigue (EF) is a common occurrence during prolonged endurance and excessive exercise and is mainly caused by energy depletion, harmful metabolite accumulation, oxidative stress, and inflammation. EF usually leads to a reduction in initiating or maintaining spontaneous activities and muscle performance and ultimately results in a decrease in the quality of life of people who engage in physical work. Therefore, the interest in investigating EF-targeting agents with minimal side effects and good long-term efficacy has substantially increased. Natural edible and medicinal polysaccharides have shown positive anti-EF effects, but the relevant reviews are rare. This review comprehensively summarizes studies on natural polysaccharides from edible and medicinal sources that can relieve EF and improve physical performance from the past decade, focusing on their sources, monosaccharide compositions, anti-EF effects, and possible molecular mechanisms. Most of these anti-EF polysaccharides are heteropolysaccharides and are mainly composed of glucose, arabinose, galactose, rhamnose, xylose, and mannose. In EF animal models, the polysaccharides exert positive EF-alleviating effects through energy supply, metabolic regulation, antioxidation, anti-inflammation, and gut microbiota remodeling. However, further studies are still needed to clarify the anti-EF effects of these polysaccharides on human beings. In summary, the present review expects to provide scientific data for the future research and development of natural polysaccharide-based anti-EF drugs, dietary supplements, and health-care products for specific fatigue groups.

Therapeutic properties of Inonotus obliquus (Chaga mushroom): A review

Inonotus obliquus, also known as Chaga, is a medicinal mushroom that has been used for therapeutic purposes since the sixteenth century. Collections of folk medicine record the application of Chaga for the treatment of diseases such as gastrointestinal cancer, diabetes, bacterial infection, and liver diseases. Modern research provides scientific evidence of the therapeutic properties of I. obliquus extracts, including anti-inflammatory, antioxidant, anticancer, anti-diabetic, anti-obesity, hepatoprotective, renoprotective, anti-fatigue, antibacterial, and antiviral activities. Various bioactive compounds, including polysaccharides, triterpenoids, polyphenols, and lignin metabolites have been found to be responsible for the health-benefiting properties of I. obliquus. Furthermore, some studies have elucidated the underlying mechanisms of the mushroom's medicinal effects, revealing the compounds' interactions with enzymes or proteins of important pathways. Thus, this review aims to explore available information on the therapeutic potentials of Inonotus obliquus for the development of an effective naturally sourced treatment option.

Dietary Polysaccharides Exert Anti-Fatigue Functions via the Gut-Muscle Axis: Advances and Prospectives

Due to today's fast-paced lifestyle, most people are in a state of sub-health and face "unexplained fatigue", which can seriously affect their health, work efficiency, and quality of life. Fatigue is also a common symptom of several serious diseases such as Parkinson's, Alzheimer's, cancer, etc. However, the contributing mechanisms are not clear, and there are currently no official recommendations for the treatment of fatigue. Some dietary polysaccharides are often used as health care supplements; these have been reported to have specific anti-fatigue effects, with minor side effects and rich pharmacological activities. Dietary polysaccharides can be activated during food processing or during gastrointestinal transit, exerting unique effects. This review aims to comprehensively summarize and evaluate the latest advances in the biological processes of exercise-induced fatigue, to understand dietary polysaccharides and their possible molecular mechanisms in alleviating exercise-induced fatigue, and to systematically elaborate the roles of gut microbiota and the gut-muscle axis in this process. From the perspective of the gut-muscle axis, investigating the relationship between polysaccharides and fatigue will enhance our understanding of fatigue and may lead to a significant breakthrough regarding the molecular mechanism of fatigue. This paper will provide new perspectives for further research into the use of polysaccharides in food science and food nutrition, which could help develop potential anti-fatigue agents and open up novel therapies for sub-health conditions.

Polygonatum cyrtonema Hua Polysaccharide Alleviates Fatigue by Modulating Osteocalcin-Mediated Crosstalk between Bones and Muscles

Osteocalcin was reported to regulate muscle energy metabolism, thus fighting fatigue during exercise. The current work aimed to investigate the anti-fatigue effect and the underlying mechanism of a homogeneous polysaccharide (PCPY-1) from Polgonatum cyrtonema after structure characterization. In the exhaustive swimming mouse model and the co-culture system of BMSCs/C2C12 cells, PCPY-1 significantly stimulated BMSC differentiation into osteoblasts as determined by ALP activity, matrix mineralization, and the protein expressions of osteogenic markers BMP-2, phosphor-Smad1, RUNX2, and osteocalcin. Meanwhile, PCPY-1 remarkably enhanced myoblast energy metabolism by upregulating osteocalcin release and GPRC6A protein expression; the phosphorylation levels of CREB and HSL; the mRNA levels of GLUT4, CD36, FATP1, and CPT1B; and ATP production in vitro and in vivo. Accordingly, PCPY-1 exhibited good anti-fatigue capacity in mice as confirmed by fatigue-related indicators. Our findings indicated PCPY-1 could enhance osteocalcin-mediated communication between bones and muscles, which was conducive to muscle energy metabolism and ATP generation, thus alleviating fatigue in exhausted swimming mice.

New Inonotus Polysaccharides: Characterization and Anticomplementary Activity of Inonotus rheades Mycelium Polymers

Inonotus is a small genus of xylotrophic basidiomycetes and a source of bioactive fungochemicals among which a special place is occupied by polymeric compounds. In this study, polysaccharides that are widespread in Europe, Asia, and North America and a poorly understood fungal species, I. rheades (Pers.) Karst. (fox polypore), were investigated. Water-soluble polysaccharides of I. rheades mycelium were extracted, purified, and studied using chemical reactions, elemental and monosaccharide analysis, UV-Vis and FTIR spectroscopy, gel permeation chromatography, and linkage analysis. Five homogenic polymers (IRP-1-IRP-5) with molecular weights of 110-1520 kDa were heteropolysaccharides that consist mainly of galactose, glucose, and mannose. The dominant component, IRP-4, was preliminary concluded to be a branched (1→3,6)-linked galactan. Polysaccharides of I. rheades inhibited the hemolysis of sensitized sheep erythrocytes by complement from human serum, signifying anticomplementary activity with the greatest effects for the IRP-4 polymer. These findings suggest that I. rheades mycelium is a new source of fungal polysaccharides with potential immunomodulatory and anti-inflammatory properties.

Structure characterization and anti-fatigue activity of an acidic polysaccharide from Panax ginseng C. A. Meyer

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng C. A. Meyer is a traditional Chinese herbal medicine, which has been used in China for more than 2000 years. Its traditional effect of "invigorating vitality" is mainly reflected in anti-fatigue. However, due to the difficulty of identification of polysaccharide structure, there are few reports on homogeneous ginseng polysaccharide, and the molecular mechanism of its anti-fatigue effect remains to be further explored.

AIM OF THE STUDY

In order to find the homogenous ginseng polysaccharide with the most anti-fatigue effect, this study is for the first time extracted, isolated and structurally identified polysaccharide monomer from Mountain Cultivated Ginseng (MCG). Then the anti-fatigue activity and molecular mechanism were studied.

MATERIALS AND METHODS

The structure of ginseng acidic polysaccharide APS-1 prepared by high performance gel permeation chromatography (HPGPC) was determined by acid hydrolysis/HPLC, methylation/GC-MS and NMR analysis. Anti-fatigue effect was evaluated by exhaustive swimming model, and AMPK axis-related proteins were detected by Western blot.

RESULTS

APS-1 significantly prolonged fatigue tolerance time, alleviated accumulation of BLA, LDH and BUN, increased activities of SOD and CAT, alleviated oxidative damage caused by MDA, increased activity of CK, regulated glycolysis, and alleviated muscle fiber contraction. The expressions of LKB1, p-AMPK, PGC-1α and Glut4 in muscle were significantly up-regulated.

CONCLUSIONS

The anti-fatigue effect of APS-1 was significantly, and the molecular mechanism may be related to the activation of AMPK axis signaling pathway to improve glucose uptake and mitochondrial function.

Effect of Inonotus obliquus Extract Supplementation on Endurance Exercise and Energy-Consuming Processes through Lipid Transport in Mice

Inonotus obliquus (IO) is used as functional food to treat diabetes. This study investigated the effect of IO supplementation on body composition in relation to changes in energy expenditure and exercise performance. Male Institute of Cancer Research mice were divided into four groups (n = 8 per group) and orally administered IO once daily for 6 wk at 0 (vehicle), 824 (IO-1×), 1648 (IO-2×), and 2472 mg/kg (IO-3×). IO supplementation increased muscle volume, exhaustive treadmill time, and glycogen storage in mice. Serum free fatty acid levels after acute exercise improved in the IO supplementation group, which exhibited changes in energy expenditure through the peroxisome proliferator-activated receptor (PPAR) pathway. RNA sequencing revealed significantly increased PPAR signaling; phenylalanine, ascorbate, aldarate, and cholesterol metabolism; chemical carcinogenesis; and ergosterol biosynthesis in the IO group compared with the vehicle group. Thus, IO supplements as nutraceuticals have a positive effect on lipid transport and exercise performance. In addition, this study was only IO supplementation without training-related procedures.

Herb Polysaccharide-Based Drug Delivery System: Fabrication, Properties, and Applications for Immunotherapy

Herb polysaccharides (HPS) have been studied extensively for their healthcare applications. Though the toxicity was not fully clarified, HPS were widely accepted for their biodegradability and biocompatibility. In addition, as carbohydrate polymers with a unique chemical composition, molecular weight, and functional group profile, HPS can be conjugated, cross-linked, and functionally modified. Thus, they are great candidates for the fabrication of drug delivery systems (DDS). HPS-based DDS (HPS-DDS) can bypass phagocytosis by the reticuloendothelial system, prevent the degradation of biomolecules, and increase the bioavailability of small molecules, thus exerting therapeutic effects. In this review, we focus on the application of HPS as components of immunoregulatory DDS. We summarize the principles governing the fabrication of HPS-DDS, including nanoparticles, micelles, liposomes, microemulsions, hydrogels, and microneedles. In addition, we discuss the role of HPS in DDS for immunotherapy. This comprehensive review provides valuable insights that could guide the design of effective HPS-DDS.

Structure Characterization, Immunological Activity, and Mechanism of a Polysaccharide From the Rhizome of Menispermum dauricum DC

The purpose of this study was to investigate the structural characterization and immunological activity in vitro and in vivo of a polysaccharide from the rhizome of Menispermum dauricum. A new polysaccharide named MDP was isolated from the rhizome of Menispermum dauricum by hot water extraction, ethanol precipitation, anion-exchange, and gel-filtration chromatography. MDP was homogeneous and had a molecular weight of 6.16 ×103 Da, and it was an α-D-glucan containing a (1 → 6)-linked backbone, with a glucosyl residue at the C-3 position along the main chain. MDP exhibited immunological activity in vitro, which could significantly promote the proliferation and phagocytosis of RAW264.7 cells and the release of TNF-α and IL-6 factors. For immunological activity in vivo. MDP could significantly increase the thymus and spleen indices, enhance the macrophage function, increase the level of cytokine (IL-6 and TNF-α) and immunoglobulin IgM in the serum and regulate T lymphocyte subsets. Furthermore, MDP elevated the expression of the critical nodes in the TLR4-MyD88 signaling pathways in vivo. These results support the concept that MDP may exhibit immunological activity through TLR4-MyD88 signaling pathway in vivo.

The anti-fatigue activity of corn peptides and their effect on gut bacteria

BACKGROUND

Corn peptides (CPs) are rich in branched-chain amino acids such as leucine and have a variety of biological activities such as antioxidant and improved lipid distribution. In this article, we prepared CPs by enzymatic digestion of corn proteins and evaluated their anti-fatigue activity.

RESULTS

We evaluated the anti-fatigue effect of CPs through an exhaustive swimming experiment. The results showed that CPs were able to significantly reduce the rate of body weight gain and prolong the duration of exhaustive swimming. Besides, CPs reduced blood urea nitrogen (BUN) levels after exercise, while they significantly increased muscle glycogen and liver glycogen stores. They reduced muscle cell damage from exercise. In addition, CPs were effective in increasing AMPK, PGC-1α and PI3K protein expression levels and promoting Akt phosphorylation. Correlation analysis showed that CPs increased the abundance of probiotics such as Lactobacillus and Akkermansia in the gut microflora.

CONCLUSION

CPs, which enhanced exercise performance in mice and could modulate gut microbial composition, had significant anti-fatigue activity. © 2021 Society of Chemical Industry.

Anti-fatigue effect of phlorizin on exhaustive exercise-induced oxidative injury mediated by Nrf2/ARE signaling pathway in mice

Oxidative stress plays a crucial role in fatigue, thus it is of significance to develop safe and efficient antioxidant to prevent fatigue. Phlorizin (PHZ) is a major active ingredient of dihydrochalcone from Lithocarpus polystachyus Rehd., which has already been approved as a new food material in China since 2017. The current study was designed to investigate the effect of PHZ on fatigue, and further to elucidate its possible underlying mechanism. Our results revealed that PHZ exerted beneficial effect on exhaustive exercise-induced fatigue in mice, as reflected by rotarod test and exhaustive swimming test. Moreover, PHZ also effectively decreased the levels of blood urea nitrogen, creatine kinase and plasma lactic acid, increased the liver glycogen and skeletal muscle glycogen of fatigued mice, as evidenced by enzyme linked immunosorbent assay. PHZ balanced the redox status through reducing generation of reactive oxygen species, enhancing the activities of antioxidative enzymes. Furthermore, PHZ not only increased the ratio of Bcl2/Bax, but also decreased the level of cleaved-caspase 3. Notably, PHZ facilitated nuclear factor erythroid 2-related factor 2 (Nrf2) translocated from cytoplasm to nucleus, and up-regulated its downstream antioxidant response element including heme oxygenase-1 and NADPH quinone oxidoreductase-1. Intriguingly, PHZ directly bound to Nrf2, as evidenced by molecular docking, and the anti-fatigue effects of PHZ were almost abolished in Nrf2 deficient mice. In summary, our findings suggest that PHZ might be a natural occurring antioxidant with safety profile to relieve fatigue via targeting Nrf2 to inhibit apoptosis.

Lipid-Lowering Effects of Inonotus obliquus Polysaccharide In Vivo and In Vitro

Excessive lipid intake will cause hyperlipidemia, fatty liver metabolism disease, and endanger people’s health. Edible fungus polysaccharide is a natural active substance for lipid lowering. In this study, the HepG2 cell model induced by oleic acid and mice model induced by a high-fat diet was established. The lipid-lowering effects of Inonotus obliquus polysaccharide (IOP) was investigated in vivo and in vitro. Glucose (251.33 mg/g), rhamnose (11.53 mg/g), ribose (5.10 mg/g), glucuronic acid (6.30 mg/g), and galacturonic acid (2.95 mg/g) are present in IOP, at a ratio of 85.2:3.91:1.73:2.14:1. The molecular weight of IOP is 42.28 kDa. Treatment with 60 mg/L of IOP showed a significant lipid-lowering effect in HepG2 cells compared with the oleic acid-treated group. In the oil red O-stained images, the red fat droplets in the IOP-treated groups were significantly reduced. TC and TG levels of IOP-treated groups decreased. IOP can alleviate the lipid deposition in the mice liver due to high-fat diet, and significantly reduce their serum TC, TG, and LDL-C contents. IOP could activate AMPK but decrease the SREBP-1C, FAS, and ACC protein expression related to adipose synthesis in mice. IOP has a certain potential for lipid-lowering effects both in vivo and in vitro.

Chemical properties and anti-fatigue effect of polysaccharide from Pholiota nameko

The aim of this study was to explore the primary chemical properties and anti-fatigue effect in vivo of Pholiota nameko polysaccharide (PNP). Through UV-visible spectrum, the absorption peaks of proteins, nucleic acids and pigments were not found. The organic functional groups of polysaccharides (3,289.97, 1,584.72, and 1,045.23 cm^-1 so on) were measured by IR spectroscopy. The PNP was a semi-crystalline or non-crystalline substance, possessed a three-dimensional lump structure with a smooth, dense surface and amorphous structure according to the scanning electron microscopy and XRD images. Moreover, the PNP was chain or bright-spot structures formed by the entanglement of multiple polysaccharide fibers on the basis of atomic force microscopy. The results of anti-fatigue suggested the PNP could significantly extend the forced swim time from 121.58 ± 18.48 and 101.91 ± 14.27 min to 154.95 ± 24.26 and 134.13 ± 25.71 min in male and female mice respectively. The LDH activity was up to 31.68 ± 4.60 U/ml in male mice and 29.49 ± 5.12 U/ml in female mice. Meanwhile, the Ca²⁺ -Mg²⁺ -ATPase activity was reached to 2.49 ± 0.41 μmol/(mg·h) in male mice and 2.44 ± 0.29 μmol/(mg·h) in female mice. The SOD activity was increased to 5.92 ± 1.19 U/ml in male mice and 5.89 ± 0.98 U/ml in female mice, while the MDA content was decreased to 2.24 ± 0.34 nmol/mg in male mice and 2.02 ± 0.41 nmol/mg in female mice. These results showed a theoretical basis for application of the PNP in food and pharmacy as a natural physical strengthening substance. PRACTICAL APPLICATIONS: Fatigue affects physical and mental health in vivo, which resulted in negative effects on everyday tasks, leisure activities, cognitive and behavioral performances and is very common in modern life. Therefore, this study was designed to explore the primary chemical properties and research the anti-fatigue effects of Pholiota nameko polysaccharide (PNP) in mice. And then, it would be a reference for the development and utilization of PNP as a kind of healthy food on sub-health.

Characteristics and antifatigue activity of graded polysaccharides from Ganoderma lucidum separated by cascade membrane technology

In this paper, cascade membrane technology was utilized to classify polysaccharides from Ganoderma lucidum (GLPs). The properties and antifatigue activity of graded polysaccharides were identified and compared. GLPs were separated using cascade ultrafiltration membranes of 100 kDa, 10 kDa and 1 kDa in sequence. The molecular weights of polysaccharides in these GLP fractions were approximately 322.0 kDa, 18.8 kDa and 6.4 kDa, and all polysaccharides were in active β-configurations. This showed that all graded GLPs could elongate swimming time, improve endurance and promote fatigue recovery, especially polysaccharides with molecular weights above 10 kDa. This demonstrated that GLPs could decrease the activities of SUN and CK and the levels of MDA and BLA. They also increased the level of Gly, accelerated fat transformation, and improved the activities of GPx, SOD and LDH in all treated mice. Accordingly, GLPs above 10 kDa might be potential agents with antifatigue activity.

Effect of molecular weight on the antibacterial activity of polysaccharides produced by Chaetomium globosum CGMCC 6882

This study investigated the effect of molecular weight on antibacterial activity of polysaccharides. Results showed that low molecular weight (3.105 × 10⁴ Da) polysaccharide (GCP-2) had higher inhibitory effects against Escherichia coli and Staphylococcus aureus than high molecular weight (5.340 × 10⁴ Da) polysaccharide (GCP-1). Meanwhile, antibacterial activities of GCP-2 and GCP-1 against S. aureus were higher than those of E. coli. Minimum inhibitory concentrations (MICs) of GCP-1 against E. coli and S. aureus were 2.0 mg/mL and 1.2 mg/mL, and MICs of GCP-2 against E. coli and S. aureus were 1.75 mg/mL and 0.85 mg/mL, respectively. Antibacterial mechanisms investigation revealed that GCP-2 and GCP-1 influenced cell membrane integrity, Ca²⁺-Mg²⁺-ATPase activity on cell membrane and calcium ions in cytoplasm of E. coli and S. aureus, but not cell wall. Present work provided important implications for future studies on development of antibacterial polysaccharides based on molecular weight feature.

Carbon Source Affects Synthesis, Structures, and Activities of Mycelial Polysaccharides from Medicinal Fungus Inonotus obliquus

The effects of various carbon sources on mycelial growth and polysaccharide synthesis of the medicinal fungus Inonotus obliquus in liquid fermentation were investigated. After 12-d fermentation, mycelial biomass, polysaccharide yield, and polysaccharide content were significantly higher in Glc+Lac group (glucose and lactose used as combined carbon source) than in other groups. Crude polysaccharides (CIOPs) and the derivative neutral polysaccharides (NIOPs) were obtained from mycelia fermented using Glc, fructose (Fru), Lac, or Glc+Lac as carbon source. Molecular weights of four NIOPs (termed as NIOPG, NIOPF, NIOPL, and NIOPGL) were respectively 780.90, 1105.00, 25.32, and 10.28 kDa. Monosaccharide composition analyses revealed that NIOPs were composed of Glc, Man, and Gal at different molar ratios. The NIOPs were classified as α-type heteropolysaccharides with 1→2, 1→3, 1→4, 1→6 linkages in differing proportions. In in vitro cell proliferation assays, viability of RAW264.7 macrophages was more strongly enhanced by NIOPL or NIOPGL than by NIOPG or NIOPF, and proliferation of HeLa or S180 tumor cells was more strongly inhibited by NIOPG or NIOPGL than by NIOPF or NIOPL, indicating that immune-enhancing and anti-tumor activities of NIOPs were substantially affected by carbon source. qRT-PCR analysis revealed that expression levels of phosphoglucose isomerase (PGI) and UDP-Glc 4-epimerase (UGE), two key genes involved in polysaccharide synthesis, varied depending on carbon source. Our findings, taken together, clearly demonstrate that carbon source plays an essential role in determining structure and activities of I. obliquus polysaccharides by regulating expression of key genes in polysaccharide biosynthetic pathway.

Recent Developments in Inonotus obliquus (Chaga mushroom) Polysaccharides: Isolation, Structural Characteristics, Biological Activities and Application

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.

Deciphering the antitumoral potential of the bioactive metabolites from medicinal mushroom Inonotus obliquus

ETHNOPHARMACOLOGICAL RELEVANCE

The crude extracts of the medicinal mushroom Inonotus obliquus have been used as an effective traditional medicine to treat malicious tumors, gastritis, gastric ulcers, and other inflammatory conditions in Russia and most Baltic countries.

AIM OF THIS REVIEW

Deciphering the antitumoral potential of the bioactive metabolites from I. obliquus and addressing its possibility to be used as effective agents for tumor treatment, restoration of compromised immunity and protection of gastrointestinal damage caused by chemotherapy.

MATERIALS AND METHODS

We analysed the current achievements and dilemma in tumor chemo- or immunotherapy. In this context, we searched the published literatures on I. obliquus covering from 1990 to 2020, and summarized the activities of antitumor, antioxidation, and immunomodulation by the polysaccharides, triterpenoids, small phenolic compounds, and hispidin polyphenols. By comparing the merits and shortcomings of current and traditional methodology for tumor treatment, we further addressed feasibility for the use of I. obliquus as an effective natural drug for tumor treatment and prevention.

RESULTS

The diverse bioactive metabolites confer I. obliquus great potential to inhibit tumor growth and metastasis. Its antitumor activities are achieved either through suppressing multiple oncogenic signals including but not limited to the activation of NF-κB and FAK, and the expression of RhoA/MMP-9 via ERK1/2 and PI3K/Akt signaling pathway. The antitumor activities can also be achieved by inhibiting tyrosinase activity via PAK1-dependent signaling pathway or altering lysosomal membrane permeabilization through blocking tubulin polymerization and/or disturbing energy metabolism through LKB1/AMPK pathway. In addition, the metabolites from I. obliquus also harbour the potentials to reverse MDR either through selective inhibition on P-gp/ABCB1 or MRP1/ABCC1 proteins or the induction of G2/M checkpoint arrest in tumor cells of chemoresistant phenotypes mediated by Nox/ROS/NF-kB/STAT3 signaling pathway. In addition to the eminent effects in tumor inhibition, the metabolites in I. obliquus also exhibit immunomodulatory potential to restore the compromised immunity and protect against ulcerative damage of GI tract caused by chemotherapy.

CONCLUSIONS

I. obliquus possesses the potential to reduce incidence of tumorigenesis in healthy people. For those whose complete remission has been achieved by chemotherapy, administration of the fungus will inhibit the activation of upstream oncogenic signals and thereby prevent metastasis; for those who are in the process of chemotherapy administration of the fungus will not only chemosensitize the tumor cells and thereby increasing the chemotherapeutic effects, but also help to restore the compromised immunity and protect against ulcerative GI tract damage and other side-effects induced by chemotherapy.

Hydrolyzed peptides from purple perilla (Perilla frutescens L. Britt.) seeds improve muscle synthesis and exercise performance in mice

The purple perilla (Perilla frutescens L. Britt.) seed peptides (PPSP) were obtained and their improvement of muscle synthesis and exercise performance was investigated in this work. Results showed that the weight-average molecular weight of the PPSP was 869 Dalton. The PPSP were rich in branched-chain amino acids (18.82 g/100 g) and anti-fatigue amino acids, including glutamate (Glu), aspartic acid (Asp), and arginine (Arg). After the administration of PPSP at 1.2 g kg^-1  day^-1 for 4 weeks, the muscle coefficient and muscle fiber thickness in mice displayed a distinct (p < .05) increase via the upregulation of myogenic differentiation (MyoD) and myogenin (MyoG). The improved muscle strength and exercise tolerance were also observed. Simultaneously, the levels of the biochemical blood markers associated with fatigue and the glycogen degradation in liver and muscle were significantly (p < .05) suppressed. These results suggested that PPSP could effectively promote muscle synthesis and ameliorate exercise fatigue. PRACTICAL APPLICATIONS: Purple perilla is an annual herbal plant and widely grown in Asian countries as an important crop and food. It is believed that the protein content of purple perilla seeds can reach 23.7%, and the protein is rich in essential amino acids. However, the information about the beneficial effects of their proteins or peptides on muscle synthesis and anti-exercise fatigue were still limited. The present results discovered that the PPSP can effectively promote the growth of muscle tissue and improve exercise tolerance. It is indicated that PPSP may have a potential application value in partly or completely replacing animal proteins such as whey protein.

Inonotus obliquus - from folk medicine to clinical use

The Inonotus obliquus (I. obliquus) mushroom was traditionally used to treat various gastrointestinal diseases. For many years, mounting evidence has indicated the potential of I. obliquus extracts for treatment of viral and parasitic infections. Furthermore, substances from I. obiquus have been shown to stimulate the immune system. The most promising finding was the demonstration that I. obliquus has hypoglycemic and insulin sensitivity potential. This review summarizes the therapeutic potential of I. obliquus extracts in counteracting the progression of cancers and diabetes mellitus as well as their antiviral and antiparasitic activities and antioxidant role. As shown by literature data, various authors have tried to determine the molecular mechanism of action of I. obliquus extracts. Two mechanisms of action of I. obliquus extracts are currently emerging. The first is associated with the broad-sense impact on antioxidant enzymes and the level of reactive oxygen species (ROS). The other is related to peroxisome proliferator-activated receptor gamma (PPARγ) effects. This receptor may be a key factor in the anti-inflammatory, antioxidant, and anti-cancer activity of I. obliquus extracts. It can be concluded that I. obliquus fits the definition of functional food and has a potentially positive effect on health beyond basic nutrition; however, studies that meet the evidence-based medicine (EBM) criteria are needed.

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Extracts or polysaccharides from I. obliquus exhibit an anti-cancer potential in vitro.

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Extracts or polysaccharides from I. obliquus exhibit anti-inflammation potential.

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Extracts or polysaccharides from I. obliquus exhibit hypoglycemic and insulin sensitivity potential.