Systematical Investigation on Anti-Fatigue Function and Underlying Mechanism of High Fischer Ratio Oligopeptides from Antarctic Krill on Exercise-Induced Fatigue in Mice.

High Fischer ratio oligopeptides (HFOs) have a variety of biological activities, but their mechanisms of action for anti-fatigue are less systematically studied at present. This study aimed to systematically evaluate the anti-fatigue efficacy of HFOs from Antarctic krill (HFOs-AK) and explore its mechanism of action through establishing the fatigue model of endurance swimming in mice. Therefore, according to the comparison with the endurance swimming model group, HFOs-AK were able to dose-dependently prolong the endurance swimming time, reduce the levels of the metabolites (lactic acid, blood urea nitrogen, and blood ammonia), increase the content of blood glucose, muscle glycogen, and liver glycogen, reduce lactate dehydrogenase and creatine kinase extravasation, and protect muscle tissue from damage in the endurance swimming mice. HFOs-AK were shown to enhance Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities and increase ATP content in muscle tissue. Meanwhile, HFOs-AK also showed significantly antioxidant ability by increasing the activities of superoxide dismutase and glutathione peroxidase in the liver and decreasing the level of malondialdehyde. Further studies showed that HFOs-AK could regulate the body's energy metabolism and thus exert its anti-fatigue effects by activating the AMPK signaling pathway and up-regulating the expression of p-AMPK and PGC-α proteins. Therefore, HFOs-AK can be used as an auxiliary functional dietary molecules to exert its good anti-fatigue activity and be applied to anti-fatigue functional foods.

The Antioxidant and Anti-Fatigue Effects of Rare Ginsenosides and γ-Aminobutyric Acid in Fermented Ginseng and Germinated Brown Rice Puree.

γ-aminobutyric acid (GABA) and rare ginsenosides are good antioxidant and anti-fatigue active components that can be enriched via probiotic fermentation. In this study, ginseng and germinated brown rice were used as raw materials to produce six fermented purees using fermentation and non-fermentation technology. We tested the chemical composition of the purees and found that the content of GABA and rare ginsenoside (Rh4, Rg3, and CK) in the puree made of ginseng and germinated brown rice (FGB) increased significantly after fermentation. The antioxidant activity of the six purees was determined using cell-free experiments, and it was found that FGB had better ferric-ion-reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging rates, exhibiting better antioxidant effects. We then evaluated the antioxidant effect of FGB in HepG2 cells induced by H2O2 and found that FGB can reduce the generation of reactive oxygen species (ROS) in HepG2 cells and increase the membrane potential level, thereby improving oxidative damage in these cells. In vivo experiments also showed that FGB has good antioxidant and anti-fatigue activities, which can prolong the exhaustive swimming time of mice and reduce the accumulation of metabolites, and is accompanied by a corresponding increase in liver glycogen and muscle glycogen levels as well as superoxide dismutase and lactate dehydrogenase activities. Finally, we believe that the substances with good antioxidant and anti-fatigue activity found in FGB are derived from co-fermented enriched GABA and rare ginsenosides.

Effect of HY7602 Fermented Deer Antler on Physical Fatigue and Antioxidant Activity in Mice.

Lactobacillus curvatus HY7602 fermented antler (FA) ameliorates sarcopenia and improves exercise performance by increasing muscle mass, muscle fiber regeneration, and mitochondrial biogenesis; however, its anti-fatigue and antioxidant effects have not been studied. Therefore, this study aimed to investigate the anti-fatigue and antioxidant effects and mechanisms of FA. C2C12 and HepG2 cells were stimulated with 1 mM of hydrogen peroxide (H2O2) to induce oxidative stress, followed by treatment with FA. Additionally, 44-week-old C57BL/6J mice were orally administered FA for 4 weeks. FA treatment (5-100 µg/mL) significantly attenuated H2O2-induced cytotoxicity and reactive oxygen species (ROS) production in both cell lines in a dose-dependent manner. In vivo experiments showed that FA treatment significantly increased the mobility time of mice in the forced swimming test and significantly downregulated the serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatine kinase (CK), and lactate. Notably, FA treatment significantly upregulated the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione/oxidized glutathione ratio (GSH/GSSG) and increased the mRNA expression of antioxidant genes (SOD1, SOD2, CAT, GPx1, GPx2, and GSR) in the liver. Conclusively, FA is a potentially useful functional food ingredient for improving fatigue through its antioxidant effects.

Study on Anti-fatigue Effects and Mechanisms of Polysaccharide from Paris polyphylla.

The objectives of this study were to investigate the anti-fatigue effects of Paris polyphylla polysaccharide component 1 (PPPm-1) and explore its mechanisms. A mouse model of exercise-induced fatigue was established by weight-bearing swimming to observe the effects of different concentrations of PPPm-1 on weight-bearing swimming time. The anti-fatigue effect of PPPm-1 was determined by the effects of contraction amplitude, contraction rate, and diastolic rate of the frog gastrocnemius muscle in vivo before and after infiltration with 5 mg/mL PPPm-1. The effects of PPPm-1 on the contents of blood lactate, serum urea nitrogen, hepatic glycogen, muscle glycogen in the exercise fatigue model of mice, and acetylcholine (ACh) content and acetylcholinesterase (AChE) activity at the junction of the frog sciatic nerve-gastrocnemius under normal physiological, and Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities of the frog gastrocnemius were determined by enzyme-linked immunosorbent assay (ELISA), to investigate the anti-fatigue mechanisms of PPPm-1. The results showed that PPPm-1 could significantly prolong the weight-bearing swimming time in mice (P < 0.01), decrease the contents of blood lactate and serum urea nitrogen, increase the contents of the hepatic glycogen and muscle glycogen of mice after exercise fatigue compared with those of the control group, and there was extremely significant difference in most indicators (P < 0.01). The 5 mg/mL of PPPm-1 could significantly promote the contraction amplitude, contraction rate, and relaxation rate of the gastrocnemius muscle in the frogs, and the content of ACh at the junction of the frog sciatic nerve-gastrocnemius (P < 0.01), but it had obvious inhibitory effetc on the activity of AChE at the junction of the frog sciatic nerve-gastrocnemius (P < 0.01). PPPm-1 could increase the Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities of gastrocnemius in the frogs (for Ca2+-Mg2+-ATPase, P < 0.01). The above results suggested that the PPPm-1 had a good anti-fatigue effect, and its main mechanisms were related to improving endurance and glycogen reserve, reducing glycogen consumption, lactate and serum urea nitrogen accumulation, and promoting Ca2+ influx.

Dietary Supplementation with Lauric Acid Improves Aerobic Endurance in Sedentary Mice via Enhancing Fat Mobilization and Glyconeogenesis.

BACKGROUND: Lauric acid (LA), a major, natural, medium-chain fatty acid, is considered an efficient energy substrate for intense exercise and in patients with long-chain fatty acid ß-oxidation disorders. However, few studies have focused on the role of LA in exercise performance and related glucolipid metabolism in vivo. OBJECTIVES: We aimed to investigate the effect of dietary supplementation with LA on exercise performance and related metabolic mechanisms. METHODS: Male C57BL/6N mice (14 wk old) were fed a basal diet or a diet containing 1% LA, and a series of exercise tests, including a high-speed treadmill test, aerobic endurance exercises, a 4-limb hanging test, and acute aerobic exercises, were performed. RESULTS: Dietary supplementation with 1.0% LA accelerated the recovery from fatigue after explosive exercise (P < 0.05) and improved aerobic endurance and muscle strength in sedentary mice (P = 0.039). Lauric acid intake not only changed muscle fatty acid profiles, including increases in C12:0 and n-6/n-3 PUFAs (P < 0.001) and reductions in C18:0, C20:4n-6, C22:6n-3, and n-3 PUFAs (P < 0.05) but also enhanced fat mobilization from adipose tissue and fatty acid oxidation in the liver, at least partly via the AMP-activated protein kinase-acetyl CoA carboxylase pathway (P < 0.05). Likewise, LA supplementation promoted liver glyconeogenesis and conserved muscular glycogen during acute aerobic exercise (P < 0.05), which was accompanied by an increase in the mitochondrial DNA copy number and Krebs cycle activity in skeletal muscle (P < 0.05). CONCLUSIONS: Dietary supplemental LA serves as an efficient energy substrate for sedentary mice to improve aerobic exercise endurance and muscle strength through regulation of glucolipid metabolism. These findings imply that LA supplementation might be a promising nutritional strategy to improve aerobic exercise performance in sedentary people.

Gut microbiota as a potential target for developing anti-fatigue foods.

Fatigue has many negative effects on human health. As such, it is desirable to develop anti-fatigue foods and understand the mechanisms of their action. Based on a comprehensive review of the literature, this article discusses the important roles of gut microbiota in fatigue and anti-fatigue. Studies have shown that an increase in pathogenic bacteria and a decrease in beneficial bacteria co-exist when fatigue is present in both rodents and humans, whereas changes in gut microbiota were reported after intervention with anti-fatigue foods. The roles of gut microbiota in the activities of anti-fatigue foods can also be explained in the causes and the effects of fatigue. Among the causes of fatigue, the accumulation of lactic acid, decrease of energy, and reduction of central nervous system function were related to gut microbiota metabolism. Among the harmful effects of fatigue, oxidative stress, inflammation, and intestinal barrier dysfunction were related to gut microbiota dysbiosis. Furthermore, gut microbiota, together with anti-fatigue foods, can inhibit pathogen growth, convert foods into highly anti-oxidative or anti-inflammatory products, produce short-chain fatty acids, maintain intestinal barrier integrity, inhibit intestinal inflammation, and stimulate the production of neurotransmitters that regulate the central nervous system. Therefore, it is believed that gut microbiota play important roles in the activities of anti-fatigue foods and may provide new insights on the development of anti-fatigue foods.

Peptides obtained by enzymatic decomposition of mackerel induce recovery from physical fatigue by enhancing the SIRT1-mediated antioxidant effect in the soleus muscle of mice.

Fatigue is a serious health problem, and long-term fatigue can lead to mental illnesses and accelerated aging. Oxidative stress, which causes excessive production of reactive oxygen species, is generally thought to increase during exercise and is an indicator of fatigue. Peptides obtained by enzymatic decomposition of mackerel (EMP) contain selenoneine, a strong antioxidant. Although antioxidants increase endurance, the effects of EMP on physical fatigue are unknown. The present study aimed to clarify this aspect. We investigated the effects of EMP on changes in locomotor activity, expression levels of silent mating type information regulation 2 homolog peroxisome 1 (SIRT1), proliferator-activated receptor-γ coactivator-1α (PGC1α), and antioxidative-related proteins including superoxide dismutase 1 (SOD1), SOD2, glutathione peroxidase 1, and catalase in the soleus muscle following EMP treatment before and/or after forced walking. Treatment with EMP before and after forced walking, and not only at one or another time point, improved the subsequent decrease in the locomotor activity and enhanced the levels of SIRT1, PGC1α, SOD1, and catalase expression in the soleus muscle of mice. Moreover, EX-527, a SIRT1 inhibitor, abolished these effects of EMP. Thus, we suggest that EMP combats fatigue by modulating the SIRT1/PGC1α/SOD1-catalase pathway.

Effect of Globin Digests on Physical Fatigue in Mice.

Globin digest (GD) inhibits dietary hypertriglyceridemia; however, its effects on physical fatigue remain unknown. Therefore, this study aimed to investigate the potential anti-fatigue effects of GD. Repeated administration of GD and valine (Val)-Val-tyrosine (Tyr)-proline (Pro), a component of GD, for five days prevented the forced walking-induced decrease in locomotion. Furthermore, GD treatment reversed the forced walking-induced increase in blood lactate levels in mice and increased phosphorylated AMP-activated protein kinase (p-AMPK) in the soleus muscle, suggesting that the anti-fatigue effect of GD involves AMPK activation in the soleus muscle through reduced blood lactate.

The Efficient Synthesis and Anti-Fatigue Activity Evaluation of Macamides: The Unique Bioactive Compounds in Maca.

Macamides are a class of amide alkaloids that are only found in maca and are widely considered to be its bioactive marker compounds. More than thirty macamide monomers have been identified in recent years; however, it is difficult to obtain a single macamide monomer from the maca plant because of their similar structures and characteristics. We used the carbodiimide condensation method (CCM) to efficiently synthesize five typical macamides, including N-benzyl-hexadecanamide (NBH), N-benzyl-9Z,12Z,15Z-octadecenamide, N-(3-methoxybenzyl)-9Z,12Z-octadecenamide, N-benzyl-9Z,12Z-octadecenamide, and N-(3-methoxybenzyl)-9Z,12Z,15Z-octadecadienamide. All the synthesized macamides were purified by a one-step HPLC with a purity of more than 95%. NBH is the most abundant macamide monomer in natural maca, and it was selected to evaluate the anti-fatigue effects of macamides. The results indicated that NBH could enhance the endurance capacity of mice by increasing liver glycogen levels and decreasing blood urea nitrogen, lactate dehydrogenase, blood ammonia, and blood lactic acid levels. Macamides might be the active substances that give maca its anti-fatigue active function.

Optimization of Supercritical Fluid CO2 Extraction from Yellow Horn Seed and Its Anti-Fatigue and Antioxidant Activity.

A supercritical fluid carbon dioxide (SF-CO2) extraction method was used to obtain the optimum process for extracting yellow horn seed oil. The anti-fatigue and antioxidant properties of the extracted oil were investigated through animal experiments. The optimum process conditions for SF-CO2 extraction of the yellow horn oil were 40 MPa, 50 °C and 120 min, with an extraction yield of 31.61%. The high-dose group of yellow horn oil could significantly increase the weight-bearing swimming time, the hepatic glycogen (HG) content and decrease the lactic acid (LA) content and blood urea nitrogen (BUN) content (p < 0.05) in mice. Moreover, it improved the antioxidant ability by reducing the malondialdehyde (MDA) content (p < 0.01) and raising the glutathione reductase (GR) content and superoxide dismutase (SOD) content (p < 0.05) in mice. Yellow horn oil has the effects of being an anti-fatigue and antioxidant substance, which provides a basis for its further utilization and development.

Anti-fatigue properties of the ethanol extract of Moringa oleifera leaves in mice.

BACKGROUND: Moringa oleifera (M. oleifera) leaves are rich in nutrients and bioactive ingredients. This study was aimed at evaluating the anti-fatigue effect of the ethanol extract of M. oleifera leaves (MLEE) on mice and its primary mechanism of action using a weight-loaded forced swimming test. In the present study, MLEE was prepared by ultrasound-assisted extraction, and its anti-fatigue effect and antioxidant capacity were evaluated in mice. Mice were administrated MLEE (320 mg kg-1 body weight) for 15 days. RESULTS: MLEE supplementation significantly increased levels of glucose and non-esterified fatty acids (NEFA), while decreasing levels of lactate and blood urea nitrogen in serum (P < 0.05); the levels of glycogen in the liver and muscle were also increased, as was the activity of glycogen synthase and the level of NEFA in muscle (P < 0.05). According to a Western blot analysis, MLEE increased the expression of AMPKα1, JNK, AKT and STAT3 in the muscle of mice. CONCLUSION: Our findings indicate that MLEE has an anti-fatigue effect via the AMPK-linked route, which enables it to control energy metabolism and enhance antioxidant enzyme activity. © 2023 Society of Chemical Industry.

[Anti-fatigue effect of Lubian on kidney Yin deficiency and kidney Yang deficiency mice and mechanism based on PI3K-Akt pathway].

This study aimed to investigate the anti-fatigue effect and mechanism of Lubian(Cervi Penis et Testis) on kidney Yin deficiency and kidney Yang deficiency mice. After one week of adaptive feeding, 88 healthy male Kunming mice were randomly divided into a blank group, a kidney Yin deficiency model group, a kidney Yin deficiency-Panacis Quinquefolii Radix(PQR) group, kidney Yin deficiency-Lubian treatment groups, a kidney Yang deficiency model group, a kidney Yang deficiency-Ginseng Radix et Rhizoma(GR) group, and kidney Yang deficiency-Lubian treatment groups, with eight mice in each group. The kidney Yin deficiency model and kidney Yang deficiency model were prepared by daily regular oral administration of dexamethasone acetate and hydrocortisone, respectively, and meanwhile, corresponding drugs were provided. The mice in the blank group received blank reagent. The treatment lasted 14 days. The exhaustive swimming time was measured 30 min after drug administration on the 14th day. On the 15th day, blood was collected from eyeballs and the serum was separated to determine the content of lactic acid(LD), blood urea nitrogen(BUN), lactate dehydrogenase(LDH), cyclic adenosine monophosphate(cAMP), and cyclic guanosine monophosphate(cGMP). The liver was dissected to determine the content of liver glycogen and the protein expression of phosphoinositide 3-kinase(PI3K) and protein kinase B(Akt). Compared with the kidney Yang deficiency model group, the kidney Yang deficiency-Lubian treatment groups showed increased body weight(P<0.05), relieved symptoms of Yang deficiency, decreased cGMP content(P<0.01), increased cAMP/cGMP(P<0.01), prolonged exhausted swimming time(P<0.01), reduced LD(P<0.01), elevated BUN content(P<0.01), increased liver glycogen content(P<0.01), and increased protein expression of PI3K and Akt in the liver(P<0.05). Compared with the kidney Yin deficiency model group, the kidney Yin deficiency-Lubian treatment groups showed increased body weight(P<0.01), relieved symptoms of Yin deficiency, increased content of cGMP(P<0.01), decreased cAMP/cGMP(P<0.01), prolonged exhausted swimming time(P<0.01), decreased LD(P<0.01), decreased BUN content(P<0.01), increased liver glycogen content(P<0.01), and increased protein expression of PI3K(P<0.05) and Akt in the liver(P<0.05). To sum up, Lubian can regulate Yin deficiency and Yang deficiency and increase glycogen synthesis by affecting the PI3K-Akt pathway, thereby exerting an anti-fatigue role.

Polysaccharides from apple pomace exhibit anti-fatigue activity through increasing glycogen content.

The polysaccharides were isolated from apple pomace by hot-water extraction, and their anti-fatigue activity was evaluated in C2C12 muscle myoblasts and male Kunming mice. The purified polysaccharides from apple pomace (PAP) have a molecular weight of 1.74 × 105 Da and were composed of mannose, rhamnose, glucose, galactose and arabinose. In C2C12 myoblasts, PAP showed no cytotoxicity in the concentrations of 0-300 µg/ml. PAP treatment increased the glycogen content, while the ATP content was not affected in C2C12 myoblasts. Further investigation found that the activity and gene expression of glycogen synthase, rather than glycogen phosphorylase, were upregulated by PAP treatment. The studies in vivo showed that PAP treatment did not affect the food intake and weight again in mice. Importantly, PAP prolonged the exhaustive swimming time, increased hepatic and skeletal muscle glycogen levels, and effectively inhibited the accumulation of blood lactic and blood urea nitrogen in mice. Taken together, the results suggested that PAP exhibit anti-fatigue activity in vitro and in vivo through increasing glycogen content.

Stretchable Hydrogels with Low Hysteresis and High Fracture Toughness for Flexible Electronics.

Stretchable materials, especially hydrogels, are emerging in various fields recently. Many applications demand low hysteresis and high fracture toughness of the materials to be used under dynamic mechanical loads. Herein, the authors report a hydrogel with high fracture toughness and low hysteresis through using a strong metal coordination bond and relatively high crosslinking density. This design allows the sacrificial bond to remain intact under normal operation, while fracturing to dissipate mechanical energy in the fracture zone to prevent propagation of the cracks. The obtained hydrogel exhibits a low hysteresis (≈1.5%) and a high fracture toughness (≈2,164 J m-2 ). Moreover, the hydrogel possesses a high fatigue threshold of ≈141 J m-2 and a reasonable conductivity. This study provides a worth-adopted approach to synthesize hydrogels with low hysteresis and high fracture toughness.

Muscle-like fatigue-resistant hydrogels by mechanical training.

Skeletal muscles possess the combinational properties of high fatigue resistance (1,000 J/m2), high strength (1 MPa), low Young's modulus (100 kPa), and high water content (70 to 80 wt %), which have not been achieved in synthetic hydrogels. The muscle-like properties are highly desirable for hydrogels' nascent applications in load-bearing artificial tissues and soft devices. Here, we propose a strategy of mechanical training to achieve the aligned nanofibrillar architectures of skeletal muscles in synthetic hydrogels, resulting in the combinational muscle-like properties. These properties are obtained through the training-induced alignment of nanofibrils, without additional chemical modifications or additives. In situ confocal microscopy of the hydrogels' fracturing processes reveals that the fatigue resistance results from the crack pinning by the aligned nanofibrils, which require much higher energy to fracture than the corresponding amorphous polymer chains. This strategy is particularly applicable for 3D-printed microstructures of hydrogels, in which we can achieve isotropically fatigue-resistant, strong yet compliant properties.

Anti-Fatigue Glasses Based on Microprisms for Preventing Eyestrain.

Although microprisms have become an important medical means of strabismus treatment, related research concerning the design, fabrication, and testing of microprismatic glasses for preventing eyestrain has rarely been reported. In this study, the structure of microprismatic glasses for preventing eyestrain related to using electronic monitors, including computers and mobile phones, is introduced. A designing theory of anti-fatigue glasses with microprisms is developed. The fabrication technique and the process are described, and the performances of the fabricated microprisms are characterized. Finally, a compact testing system for the measurement of prismatic diopter is designed and constructed. This measuring system can be used not only for Fresnel microprisms, but also for other types of prisms. The measured results agree with our calculations. Although this study is focused on optimizing the objective prismatic diopter for anti-fatigue microprismatic glasses, 2.0-3.0 prismatic diopters (Δ) for each eye in the anti-fatigue glasses are suggested according to our experience on strabismus treatments. The clinical research for patients using the developed anti-fatigue glasses will be fully implemented in our further research to confirm the optimal subjective prismatic value.

Effects of Paradigm Color and Screen Brightness on Visual Fatigue in Light Environment of Night Based on Eye Tracker and EEG Acquisition Equipment.

Nowadays, more people tend to go to bed late and spend their sleep time with various electronic devices. At the same time, the BCI (brain−computer interface) rehabilitation equipment uses a visual display, thus it is necessary to evaluate the problem of visual fatigue to avoid the impact on the training effect. Therefore, it is very important to understand the impact of using electronic devices in a dark environment at night on human visual fatigue. This paper uses Matlab to write different color paradigm stimulations, uses a 4K display with an adjustable screen brightness to jointly design the experiment, uses eye tracker and g.tec Electroencephalogram (EEG) equipment to collect the signal, and then carries out data processing and analysis, finally obtaining the influence of the combination of different colors and different screen brightness on human visual fatigue in a dark environment. In this study, subjects were asked to evaluate their subjective (Likert scale) perception, and objective signals (pupil diameter, θ + α frequency band data) were collected in a dark environment (<3 lx). The Likert scale showed that a low screen brightness in the dark environment could reduce the visual fatigue of the subjects, and participants preferred blue to red. The pupil data revealed that visual perception sensitivity was more vulnerable to stimulation at a medium and high screen brightness, which is easier to deepen visual fatigue. EEG frequency band data concluded that there was no significant difference between paradigm colors and screen brightness on visual fatigue. On this basis, this paper puts forward a new index­the visual anti-fatigue index, which provides a valuable reference for the optimization of the indoor living environment, the improvement of satisfaction with the use of electronic equipment and BCI rehabilitation equipment, and the protection of human eyes.

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 effects of fermented soybean protein peptides in mice.

BACKGROUND: Bioactive protein hydrolysates and peptides are believed to help counteract and ameliorate physical fatigue. Fermented soybean protein peptides (FSPPs) were prepared by protease hydrolysis and microbial fermentation. The present study aimed to evaluate the anti-fatigue properties of FSPPs. RESULTS: The forced swimming time in the FSPP group was 35.78% longer than the control group, the oxygen-resistant survival time of the FSPP group was significantly prolonged and the prolongation rate was 31.00%. In addition, FSPPs decreased the lactic acid (LD), blood urea nitrogen (BUN) and creatine kinase (CK) concentration by 27.47%, 25.93% and 21.70%, respectively, after treatment, while increasing the levels of liver glycogen and muscle glycogen by 93.35% and 67.31%, respectively. FSPPs can significantly increase gut microbiota diversity and regulate the species richness of gut microbiota. The results of real-time polymerase chain reaction (RT-PCR) and western blotting showed that FSPPs activate p-AMPK/PGC1-α and PI3K/Akt/mTOR signaling pathways. CONCLUSION: These results indicate that treatment with FSPPs induces anti-fatigue effects, which may be due to the mediating muscle protein synthesis and participation in skeletal muscle hypertrophy, providing energy for muscle cells. FSPPs may have potential applications in the food industry as functional material additives. © 2021 Society of Chemical Industry.

Effects of salidroside on exercise tolerance of mice under high altitude hypoxia environment.

OBJECTIVE: To investigate the effect of salidroside on the exercise tolerance of mice under high altitude hypoxia environment. METHODS: C57BL/6J healthy male mice were randomly divided into normoxia control group, model control group, Rhodiola rosea capsule group and salidroside low-dose (5 mg/kg), medium-dose (10 mg/kg) and high-dose (20 mg/kg) groups, with 15 mice in each group. After 3 days, all groups (except the normoxia control group) entered a plateau with an altitude of 4010 m. After 1 day of hypoxia exposure, the exhausted swimming test was performed to determine the exhaustive time of mice; the pathological changes of liver and muscle tissue were observed with hematoxylin and eosin staining. The levels of malondialdehyde (MDA), hydrogen peroxide (H 2O 2), glutathione (GSH), total superoxide dismutase (T-SOD), glycogen, lactate and ATPase were measured and compared among groups. RESULTS: Compared with the normoxia control group, the exhaustive swimming time of the model control group was shortened ( P<0.05), the liver tissue and muscle tissue were pathologically damaged, the level of oxidative stress was significantly increased, the levels of sodium potassium ATPase and calcium magnesium ATPase were significantly increased. Compared with the model control group, the exhaustive swimming time of the mice in the Rhodiola rosea capsule group and salidroside groups was significantly prolonged ( P<0.05). The oxidative stress injury was alleviated, the contents of MDA, H 2O 2 and lactic acid in liver and muscle tissues decreased, the contents of GSH, liver glycogen and muscle glycogen increased, and the activities of T-SOD and ATPase increased (all P<0.05). CONCLUSION: Salidroside has significant anti-fatigue activity, and its anti-fatigue effect is related to the reduction of oxidative stress damage, the reduction of the accumulation of undesirable metabolites and the increase in the reserve of energy substances.