Grape seed proanthocyanidin extract supplementation affects exhaustive exercise-induced fatigue in mice

Grape seed extract supplementation in non-alcoholic fatty liver disease

Background: Despite rising non-alcoholic fatty liver disease (NAFLD) prevalence and its impact on liver health, there's a lack of studies on grape seed extract's (GSE) effect on oxidative stress and quality of life (QoL) in NAFLD patients. This study aims to fill this gap by the potential benefits of GSE in reducing oxidative stress and improving QoL. Methods: In this randomized clinical trial study, fifty patients with NAFLD were randomly assigned to receive either 2 tablets of GSE containing 250 mg of proanthocyanidins or placebo (25 participants in each group) for two months. QoL was evaluated using the SF-36 questionnaire, and oxidative stress variables (TAC, MDA, SOD, GPx, CAT, and IL-6) were measured at the beginning and end of the study. Results: Compared with the control group, the group supplemented with GSE experienced greater reductions in IL-6 and MDA (3.14±1.43 pg/ml vs. 2.80±0.31 pg/ml; 4.16±2.09 μM vs. 4.59±1.19 μM, p for all <0.05), as well as greater increases in TAC, SOD, and GPx levels (0.18±0.08 mM vs. -0.03±0.09 mM; 10.5±6.69 U/ml vs. 8.93±1.63 U/ml; 14.7±13.4 U/ml vs. 8.24±3.03 U/ml, p for all <0.05). Furthermore, the QoL questionnaire showed that physical limitations, general health, and total physical health were significantly improved in the GSE group compared with the placebo (17.0±42.0 vs. -12.0±37.5; 3.80±14.8 vs. -3.92±9.55; 5.08 5.26 vs. -7.01±13.7, p for all <0.05). Conclusions: GSE can be effective in improving oxidative stress and QoL in patients with NAFLD. More studies are needed to confirm the results of this study.

Dietary Ferulic Acid Increases Endurance Capacity by Promoting Skeletal Muscle Oxidative Phenotype, Mitochondrial Function, and Antioxidant Capacity

SCOPE

Endurance capacity is essential for endurance athletes' achievement and individuals' health. Nutritional supplements are a proven way to enhance endurance capacity. Previous studies have shown that ferulic acid (FA) enhances endurance capacity, but the underlying mechanism is unclear. The study is aimed to investigate the mechanism by which FA increases endurance capacity.

METHODS AND RESULTS

Forty mice are divided into control and 0.5% FA-supplemented groups, and an exhaustive swimming test demonstrates increased endurance capacity with FA supplementation. This study investigates the underlying mechanism for this effect of FA. Firstly, RT-PCR and western blot analysis find that FA increases the transformation from fast to slow muscle fiber. Additionally, adenosine triphosphate concentration, metabolic enzyme activity, and mitochondrial DNA analysis find that FA increases mitochondrial biogenesis and activates nuclear factor erythroid 2-related factor (NRF)1 signaling pathway in muscle. Besides, through antioxidant capacity analysis, this study finds that FA activates NRF2 signaling pathway and improves the antioxidant capacity in muscle. Moreover, inhibiting NRF2 eliminates FA's effect on muscle fiber transformation in C2C12 cells.

CONCLUSION

Our results suggest that FA increases endurance capacity by promoting skeletal muscle oxidative phenotype, mitochondrial function, and antioxidant capacity, which may be related to the NRF1 and NRF2 signaling pathways.

Effect of Cucumis melo L. peel extract supplemented postbiotics on reprograming gut microbiota and sarcopenia in hindlimb-immobilized mice

Postbiotics made from lactic acid bacteria may ameliorate sarcopenia via the metabolic reprogramming of gut dysbiosis. This study investigated the anti-sarcopenic effect of postbiotics (WDK) produced from polyphenol-rich melon peel extract (Cucumis melo L. var. makuwa, KEE) and whey with Lentilactobacillus kefiri DH5 (DH5) in C2C12 skeletal muscle cells and hindlimb-immobilized mice. WDK significantly ameliorated palmitate-induced atrophy of C2C12 cells, restoring myotube length and diameter. It also upregulated the expression of myogenic genes including Atrogin-1, Igf-1, and MyoD. Hindlimb-immobilized C57BL/6J mice were randomly divided and orally administered 10 mL/kg body weight of saline (CON), Whey, Whey + DH5 (WD), DH5 + KEE, Whey + DH5 + KEE postbiotic (WDK) for three weeks (n = 10/group). Interestingly, WDK significantly improved muscle function in hindlimb-immobilized mice by restoring both the grip strength and the mass of the soleus muscle, which was closely related to the upregulation of the myoD gene. WDK increased microbial diversity and modulated the distribution of intestinal bacteria, particularly those involved in protein synthesis and the production of butyrate. There was a significant correlation between myogenic biomarkers and butyrate producing gut microbiota. Restoration of muscle mass and function following postbiotic WDK is strongly related to the regulation of myogenic genes by in part remodulating gut microbiota. In conclusion, these findings suggest that polyphenol- and whey-based postbiotics WDK may have potential as an effective manner to combat the progression of sarcopenia.

Molecular and biochemical investigations of the anti-fatigue effects of tea polyphenols and fruit extracts of Lycium ruthenicum Murr. on mice with exercise-induced fatigue

Background: The molecular mechanisms regulating the therapeutic effects of plant-based ingredients on the exercise-induced fatigue (EIF) remain unclear. The therapeutic effects of both tea polyphenols (TP) and fruit extracts of Lycium ruthenicum (LR) on mouse model of EIF were investigated. Methods: The variations in the fatigue-related biochemical factors, i.e., lactate dehydrogenase (LDH), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2 (IL-2), and interleukin-6 (IL-6), in mouse models of EIF treated with TP and LR were determined. The microRNAs involved in the therapeutic effects of TP and LR on the treatment of mice with EIF were identified using the next-generation sequencing technology. Results: Our results revealed that both TP and LR showed evident anti-inflammatory effect and reduced oxidative stress. In comparison with the control groups, the contents of LDH, TNF-α, IL-6, IL-1β, and IL-2 were significantly decreased and the contents of SOD were significantly increased in the experimental groups treated with either TP or LR. A total of 23 microRNAs (21 upregulated and 2 downregulated) identified for the first time by the high-throughput RNA sequencing were involved in the molecular response to EIF in mice treated with TP and LR. The regulatory functions of these microRNAs in the pathogenesis of EIF in mice were further explored based on Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses with a total of over 20,000-30,000 target genes annotated and 44 metabolic pathways enriched in the experimental groups based on GO and KEGG databases, respectively. Conclusion: Our study revealed the therapeutic effects of TP and LR and identified the microRNAs involved in the molecular mechanisms regulating the EIF in mice, providing strong experimental evidence to support further agricultural development of LR as well as the investigations and applications of TP and LR in the treatment of EIF in humans, including the professional athletes.

Oligomeric Proanthocyanidins: An Updated Review of Their Natural Sources, Synthesis, and Potentials

Oligomeric Proanthocyanidins (OPCs), as a class of compounds widely found in plants, are particularly abundant in grapes and blueberries. It is a polymer comprising many different monomers, such as catechins and epicatechins. The monomers are usually linked to each other by two types of links, A-linkages (C-O-C) and B-linkages (C-C), to form the polymers. Numerous studies have shown that compared to high polymeric procyanidins, OPCs exhibit antioxidant properties due to the presence of multiple hydroxyl groups. This review describes the molecular structure and natural source of OPCs, their general synthesis pathway in plants, their antioxidant capacity, and potential applications, especially the anti-inflammatory, anti-aging, cardiovascular disease prevention, and antineoplastic functions. Currently, OPCs have attracted much attention, being non-toxic and natural antioxidants of plant origin that scavenge free radicals from the human body. This review would provide some references for further research on the biological functions of OPCs and their application in various fields.

Anti-fatigue Effect of Traditional Chinese Medicines: A Review

A third of the world's population suffers from unexplained fatigue, hugely impacting work learning, efficiency, and health. The fatigue development may be a concomitant state of a disease or the side effect of a drug, or muscle fatigue induced by intense exercise. However, there are no authoritative guides or clinical medication recommendations for various fatigue classifications. Traditional Chinese medicines (TCM) are used as dietary supplements or healthcare products with specific anti-fatigue effects. Thus, TCM may be a potential treatment for fatigue. In this review, we outline the pathogenesis of fatigue, awareness of fatigue in Chinese and western medicine, pharmacodynamics mechanism, and substances. Additionally, we offer a comprehensive summary of fatigue and forecast the potential effect of novel herbal-based medicines against fatigue.

Cordyceps militaris acidic polysaccharides improve learning and memory impairment in mice with exercise fatigue through the PI3K/NRF2/HO-1 signalling pathway

Excessive exercise leads to body fatigue and destroys the balance of the oxidation/oxidation resistance system in the body, thus damaging the central nervous system and reducing learning and memory ability. Nrf2 is an important transcription factor that regulates the cell oxidative stress response. Therefore, the research and development of natural antioxidants with the effect of regulating Nrf2-related signalling pathways to improve central fatigue caused by body fatigue has application value. Methods and results: Cordyceps militaris polysaccharides were extracted, isolated and purified via DEAE-cellulose 52 and Sepharose CL-6B columns to obtain two saccharides, Cordyceps militaris acidic polysaccharides (CMPB) and CMPB-b. The results of behavioural tests showed that compared with the model group, the learning and memory abilities of the CMPB-H group (800 mg/kg) mice were remarkably improved in the dark avoidance and Morris water maze tasks (p < 0.01), and the levels of fatigue metabolites and oxidative stress in the body were obviously decreased (p < 0.01). The expression level of BDNF, PI3K, Nrf2 and HO-1 proteins in the hippocampus were significantly increased (p < 0.01). In vitro experiments, compared with the PC12 oxidative stress model group, CMPB-b high-dose group (100 μg/mL) had remarkably improved oxidative stress. CMPB-b also obviously promoted the phosphorylation of PI3K and AKT proteins (p < 0.01) and the nuclear translocation of Nrf2 (p < 0.01), and significantly increased the expression of HO-1 (p < 0.01). Conclusion: CMPB can alleviate the fatigue state of high-intensity swimming mice and improve the learning and memory impairment of exercise-fatigue mice by regulating the Nrf2-related signalling pathway. Its antioxidant active component CMPB-b exerts in vitro antioxidative neurological damage by the same mechanism. Our systematic studies provide strong supporting evidence for the future use of Cordyceps militaris acidic polysaccharides in health products to improve resistance to fatigue.

Garcinol Promotes the Formation of Slow-Twitch Muscle Fibers by Inhibiting p300-Dependent Acetylation of PGC-1α

The conversion of skeletal muscle fiber from fast-twitch to slow-twitch is crucial for sustained contractile and stretchable events, energy homeostasis, and anti-fatigue ability. The purpose of our study was to explore the mechanism and effects of garcinol on the regulation of skeletal muscle fiber type transformation. Forty 21-day-old male C57/BL6J mice (n = 10/diet) were fed a control diet or a control diet plus garcinol at 100 mg/kg (Low Gar), 300 mg/kg (Mid Gar), or 500 mg/kg (High Gar) for 12 weeks. The tibialis anterior (TA) and soleus muscles were collected for protein and immunoprecipitation analyses. Dietary garcinol significantly downregulated (p < 0.05) fast myosin heavy chain (MyHC) expression and upregulated (p < 0.05) slow MyHC expression in the TA and soleus muscles. Garcinol significantly increased (p < 0.05) the activity of peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) and markedly decreased (p < 0.05) the acetylation of PGC-1α. In vitro and in vivo experiments showed that garcinol decreased (p < 0.05) lactate dehydrogenase activity and increased (p < 0.05) the activities of malate dehydrogenase and succinic dehydrogenase. In addition, the results of C2C12 myotubes showed that garcinol treatment increased (p < 0.05) the transformation of glycolytic muscle fiber to oxidative muscle fiber by 45.9%. Garcinol treatment and p300 interference reduced (p < 0.05) the expression of fast MyHC but increased (p < 0.05) the expression of slow MyHC in vitro. Moreover, the acetylation of PGC-1α was significantly decreased (p < 0.05). Garcinol promotes the transformation of skeletal muscle fibers from the fast-glycolytic type to the slow-oxidative type through the p300/PGC-1α signaling pathway in C2C12 myotubes.

Potential Properties of Natural Nutraceuticals and Antioxidants in Age-Related Eye Disorders

Eye health is crucial, and the onset of diseases can reduce vision and affect the quality of life of patients. The main causes of progressive and irreversible vision loss include various pathologies, such as cataracts, ocular atrophy, corneal opacity, age-related macular degeneration, uncorrected refractive error, posterior capsular opacification, uveitis, glaucoma, diabetic retinopathy, retinal detachment, undetermined disease and other disorders involving oxidative stress and inflammation. The eyes are constantly exposed to the external environment and, for this reason, must be protected from damage from the outside. Many drugs, including cortisonics and antinflammatory drugs have widely been used to counteract eye disorders. However, recent advances have been obtained via supplementation with natural antioxidants and nutraceuticals for patients. In particular, evidence has accumulated that polyphenols (mostly deriving from Citrus Bergamia) represent a reliable source of antioxidants able to counteract oxidative stress accompanying early stages of eye diseases. Luteolin in particular has been found to protect photoreceptors, thereby improving vision in many disease states. Moreover, a consistent anti-inflammatory response was found to occur when curcumin is used alone or in combination with other nutraceuticals. Additionally, Coenzyme Q10 has been demonstrated to produce a consistent effect in reducing ocular pressure, thereby leading to protection in patients undergoing glaucoma. Finally, both grape seed extract, rich in anthocyanosides, and polynsatured fatty acids seem to contribute to the prevention of retinal disorders. Thus, a combination of nutraceuticals and antioxidants may represent the right solution for a multi-action activity in eye protection, in association with current drug therapies, and this will be of potential interest in early stages of eye disorders.

Red ginseng extract improves skeletal muscle energy metabolism and mitochondrial function in chronic fatigue mice

Background: Skeletal muscles are organs with high energy requirements, especially during vigorous exercise. Adequate mitochondrial function is essential to meet the high energy needs of skeletal muscle cells. Recent studies have reported that red ginseng can significantly improve chronic fatigue; however, the specific mechanism of action is still not clear. Methods: A chronic fatigue syndrome mouse model was developed using C57BL/6J mice through long-term compound stimulation of stress factors. Following this, the animals were orally administered 200, 400, or 600 mg/kg red ginseng extracts for 28 days. Skeletal muscle lactate acid, serum lactate dehydrogenase, urea concentrations, ATP level, mitochondrial membrane potential, activities of Na⁺-K⁺-ATPase and cytochrome c oxidase were determined using assay kits or an automatic biochemical analyser detection system. Skeletal muscle mitochondria morphology was observed using electron microscopy and the expression of p-AMPK, PGC-1α, ACO2 and complex I in skeletal muscle protein was determined by western blotting. Results: Oral administration of 400 or 600 mg/kg red ginseng extract in mice with chronic fatigue reduced lactic acid, lactate dehydrogenase and urea, rescued the density and morphology of skeletal muscle mitochondria, increased the activities of Na⁺-K⁺-ATPase and cytochrome c oxidase, and activated the AMPK/PGC-1α cascade pathway, resulting in improved skeletal muscle mitochondrial function by restoring ATP level, mitochondrial membrane potential, complex I and mitochondrial biogenesis. Conclusion: The anti-fatigue effects of red ginseng are partly related to its potent mitochondrial improving activity, including decreasing mitochondrial swelling and mitochondrial membrane permeability, increasing mitochondrial biogenesis, thus ameliorating mitochondrial dysfunction.

Ginseng Pectin WGPA Alleviates Exercise-Induced Fatigue by Enhancing Gluconeogenesis

With the development of medicine and sport science, growing attention has been paid to the recovery of exercise-induced fatigue. Ginseng pectin has been shown to be important for a variety of biological functions. Although many studies suggest that ginseng pectin plays an important role in the alleviation of exercise-induced fatigue, the underlying mechanism still remains unclear. In this study, C57BL/6J mice were subjected to a wheel apparatus for exhaustive exercise and fed with ginseng pectin WGPA (acidic fraction of water-soluble ginseng polysaccharides) afterwards. Subsequently, a series of physiological and biochemical indexes, such as blood lactic acid, blood glucose, muscle glycogen, insulin, and glucagon, is evaluated. Meanwhile, enzymatic activity and mRNA level of key enzymes involved in hepatic gluconeogenesis are analyzed. Our results demonstrate that the treatment of ginseng pectin WGPA can result in enhanced gluconeogenesis and decreased insulin and in turn facilitate the recovery of exercise-induced fatigue. In response to WGPA treatment, both phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6 phosphatase (G6Pase) activity were upregulated, indicating that these two enzymes play a critical role in WGPA-induced upregulation in gluconeogenesis. Moreover, mRNA level of G6Pase, but not PEPCK, was increased upon WGPA treatment, suggesting that G6Pase expression is regulated by WGPA. Importantly, the presence of WGPA downregulated insulin both in vivo and in vitro, suggesting the upregulation in gluconeogenesis may be due to alterations in insulin. Together, we provide evidence that ginseng pectin WGPA is able to alleviate exercise-induced fatigue by reducing insulin and enhancing gluconeogenesis.

Study on the Antifatigue Effect of Compound Amino Acid Capsules

Supplementing amino acids was proven to relieve fatigue caused by exercise. This study explored the antifatigue effects of compound amino acid capsules (CAAC) on rats undergoing the forced swimming test (FST). CAAC augmented the endurance of FST in rats and alleviated the damage of skeletal muscle tissue and reduced the content of biochemical indicators in the serum. Furthermore, CAAC prevented skeletal muscle dysfunction in FST rats by modulating inflammation and oxidation reactions. After the treatment with CAAC, apoptosis and apoptosis-related protein and p-p65 were weakened, while the levels of SIRT1 and SIRT1/PGC-1α/Nrf2 pathway-related proteins were enhanced. The antifatigue properties of CAAC were associated with its antioxidant and anti-inflammatory capabilities, which were realized by activating the SIRT1/PGC-1α/Nrf2 pathway.

Bioactive Compounds for Fibromyalgia-like Symptoms: A Narrative Review and Future Perspectives

Fibromyalgia (FM) is a prevalent, chronic condition without a cure or reliable therapy. The etiopathogenesis of this syndrome is ambiguous, which has heightened the challenge of discovering treatments to minimize patients’ painful symptoms. FM is characterized by diffuse musculoskeletal pain usually accompanied by functional pain syndromes, such as fatigue, sleep disturbances, cognitive difficulties, and mood issues. Currently available treatment options for FM are limited. Recent studies have suggested a potential role for dietary bioactive compounds in FM management. We performed a narrative review to evaluate the existing evidence regarding the dietary bioactive compounds for FM, and we proposed molecular mechanisms on this topic. The inclusion criteria were (i) human, in vivo, or in vitro studies, (ii) studies related to the effect of bioactive compounds on FM-like symptoms, (iii) peer-reviewed literature, and (iv) publications until February 2022 in PubMed and Google Scholar. Exclusion criteria were (i) study designs using CCI, SNI, or SNL models because they are more NP models rather than FM models, and (ii) studies published in a language other than English. Keywords were dietary bioactive compounds, fibromyalgia, cell, animals, humans. Here, we report the effects of commonly consumed bioactive compounds (capsaicin, ginger, curcumin, n-3 PUFA, grape seed extract, naringin, and genistein) on FM-like symptoms in cellular, animal, and human studies. Cellular studies demonstrated that these bioactive compounds reduce pro-inflammatory production and increase antioxidant capacity of neurons or myoblasts that regulate apoptosis/cell survival. Animal studies showed that these regularly consumed bioactive compounds have an effect on FM-like symptoms, as evidenced by decreased pain hypersensitivity and fatigue as well as improved social behaviors. Further studies are warranted to allow meaningful comparison and quantification of the efficacy of these bioactive compounds on FM-like symptoms across studies, in terms of actual changes in antioxidant capacity, pain hypersensitivity, fatigue, and social behaviors. To date, human studies regarding the efficacy of these bioactive compounds on FM-like symptoms are limited and inconclusive. Our review identifies this important knowledge gap and proposes that the development and use of improved preclinical FM models are needed, particularly concerning the usage of female animals to better mimic FM pathophysiology and symptomatology.

The Effect of Hot Water Extract of Tilapia on Exercise Capacity in Mice

Tilapia (Oreochromis mossambicus) has become one of the main aquatic products of Taiwan. The aim of this study was to evaluate the efficacy of a hot water extract of tilapia (HWET) in relieving fatigue and enhancing exercise performance in mice in a swimming endurance test. Male ICR mice were randomly divided into four groups (n = 10 per group) and treated with either a vehicle (control group) or different doses of HWET, which were designated as HWET-L (800 mg/kg/day), HWET-M (1600 mg/kg/day), and HWET-H (4000 mg/kg/day). The results of the swimming endurance test showed that HWET treatment significantly improved exercise-induced fatigue as the swimming time of the mice increased (p < 0.05). One hour after the test, blood samples were collected from each mouse and serum biochemical parameters were measured. The serum levels of lactate, creatine kinase (CK), and blood urea nitrogen (BUN) were lower in mice treated with HWET compared to the control group. Moreover, HWET treatment increased serum glucose levels and glycogen content in the liver. Enhanced glutathione (GSH) content in the liver and muscle was also found in the HWET-M and HWET-H groups. Western blot results showed that the expression of tumor necrosis factor-α (TNF-α) in the liver tissue was downregulated by HWET treatment. Taken together, our results demonstrate that HWET supplementation could enhance exercise performance and alleviate fatigue via biochemical profile improvements. This suggests that HWET has the potential for future development into functional foods or nutritional supplements to relieve fatigue.

Effects of dietary grape seed proanthocyanidin extract supplementation on meat quality, muscle fiber characteristics and antioxidant capacity of finishing pigs

The aim of this study was to investigate effects of dietary grape seed proanthocyanidin extract (GSPE) supplementation on meat quality, muscle fiber characteristics and antioxidant capacity of finishing pigs. The data showed GSPE increased pH24 h, redness, crude protein content and decreased shear force, drip loss48 h, lactate content and glycolytic potential in longissimus dorsi (LD) muscle, accompanied by increased contents of total polyunsaturated fatty acid (PUFA), n-3 PUFA, and the ratio of PUFA to saturated fatty acid. GSPE promoted MyHC I mRNA and slow MyHC protein expression, and increased slow-twitch fiber percentage. The activities of total antioxidant capacity, total superoxide dismutase, catalase and glutathione peroxidase in LD muscle were increased by GSPE while malondialdehyde content was decreased. Together, this study demonstrated that dietary GSPE supplementation can effectively improve the color, water-holding capacity, tenderness and nutritional value of pork, and increase slow-twitch fiber percentage and antioxidant capacity of finishing pigs.

Impact of dietary polyphenols on neuroinflammation-associated disorders

Neurodegenerative disorders like Alzheimer's, Parkinson's, and associated dementia typically originate with altered protein folding and aggregation of their β structures in the neurons. This self-aggregation leads to glial activation in the brain, causing neuroinflammation and leads to neuronal death. According to statistics provided by WHO, there are around 50 million people with dementia worldwide and every year, 10 million more cases are projected to increase. Also, around 5-8 percentage of people who are aged above 60 globally has dementia or associated disorders. Over 82 million in 2030 and 152 in 2050 are expected to have dementia. Most of these patients fall into low-middle-income countries which makes it even more essential to find an affordable and effective treatment method. Polyphenols of different origin are studied for their potential role as anti-neuro-inflammatory molecules. This review would summarize recent advances in three widely researched dietary polyphenols projected as potential therapeutic agents for disorders like Alzheimer's, Parkinson's, etc. They are Resveratrol, Catechins, and Tannins. The review would discuss the recent advances and challenges in using these polyphenols using specific examples as potential therapeutic agents against neuroinflammation associated disorders. An abstract of neuroinflammation-associated events and the effects by selected polyphenols.

Recent Advances in Panax ginseng C.A. Meyer as a Herb for Anti-Fatigue: An Effects and Mechanisms Review

As an ancient Chinese herbal medicine, Panax ginseng C.A. Meyer (P. ginseng) has been used both as food and medicine for nutrient supplements and treatment of human diseases in China for years. Fatigue, as a complex and multi-cause symptom, harms life from all sides. Millions worldwide suffer from fatigue, mainly caused by physical labor, mental stress, and chronic diseases. Multiple medicines, especially P. ginseng, were used for many patients or sub-healthy people who suffer from fatigue as a treatment or healthcare product. This review covers the extract and major components of P. ginseng with the function of anti-fatigue and summarizes the anti-fatigue effect of P. ginseng for different types of fatigue in animal models and clinical studies. In addition, the anti-fatigue mechanism of P. ginseng associated with enhancing energy metabolism, antioxidant and anti-inflammatory activity is discussed.

A single dose of purple grape juice improves physical performance and antioxidant activity in runners: a randomized, crossover, double-blind, placebo study

PURPOSE

To investigate the effects of a single dose of juice on physical performance, oxidative stress, inflammation and muscle damage in runners.

METHODS

Fourteen recreational male runners (39 ± 9 years, VO2peak = 55.9 ± 6.5 ml/kg/min) performed two running tests to exhaustion at 80% of VO2max after ingesting grape juice or a placebo drink (10 ml/kg/day) randomly. Blood samples were taken before and 2 h after supplementation and immediately after running to analyze total antioxidant capacity (TAC), malondialdehyde (MDA), alpha-1 acid glycoprotein (A1GPA), high-sensitivity C-reactive protein (hs-CRP), creatine kinase (CK) and lactate dehydrogenase (LDH).

RESULTS

The participants ran for an average of 59.2 ± 27.8 min until exhaustion in the placebo group and for 68.4 ± 29.7 min until exhaustion in the grape juice intake group, which was a significantly longer time (p = 0.008). This improvement in physical performance was accompanied by a 43.6% increase in TAC (p = 0.000) at the post-exercise timepoint compared to the level at baseline. MDA, A1GPA, hs-CRP, CK, and LDH did not exhibit changes. In contrast, no significant change in any variable was observed after consuming the placebo drink.

CONCLUSION

The single-dose intake of purple grape juice demonstrated an ergogenic effect in recreational runners by increasing run time to exhaustion and increasing antioxidant activity.

Anti-fatigue effect of anwulignan via the NRF2 and PGC-1α signaling pathway in mice

OBJECTIVE

To examine the anti-fatigue function of anwulignan from Schisandra and its underlying mechanism.

METHODS

After an excessive fatigue mouse model was created, anwulignan was administered to the mice, and its effect on exercise tolerance was studied by the weight-bearing swimming test, rotarod test, grip strength test, and tail suspension test. The biochemical indicators closely related to fatigue, including blood urea nitrogen (BUN), lactic acid (LD), lactate dehydrogenase (LDH), and creatine kinase (CK) in the serum; liver glycogen (LG) in the liver tissue; muscle glycogen (MG); inorganic phosphate (Pi) and Annexin V in the gastrocnemius; superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities; malondialdehyde (MDA), catalase (CAT), and thiobarbituric acid reactive substances (TBARS); and the 8-hydroxy-2-deoxyguanosine (8-OHdG) and reactive oxygen species (ROS) content in both serum and the gastrocnemius were detected. Morphological changes were also observed. The anti-fatigue-related proteins of the NRF2/ARE, Bcl2, and PGC-1α pathways in the gastrocnemius of the mice were detected by western blot.

RESULTS

Anwulignan significantly increased the exercise tolerance by decreasing BUN, LD, LDH, CK, Pi, MDA, TBARS, 8-OHdG, ROS, and Annexin V levels and increasing LG, MG, SOD, CAT, and GSH-Px levels, significantly upregulated the expression of NRF2 and Bcl2 proteins, which are anti-oxidation and anti-apoptosis regulators, and also activated the p38MAPK-PGC-1α pathway.

CONCLUSION

Anwulignan can increase exercise tolerance and relieve fatigue in an excessive fatigue mouse model. The underlying mechanism may be through its regulatory effect on the NRF2 and PGC-1α signaling pathway. This study will provide scientific data for anwulignan to be developed as a novel and efficient component in anti-oxidant or anti-fatigue health food.

Effects of Grape Seed Proanthocyanidin Extract on Obesity

Obesity is a chronic metabolic disease resulting from excessive fat accumulation and/or abnormal distribution caused by multiple factors. As a major component of metabolic syndrome, obesity is closely related to many diseases such as type 2 diabetes mellitus, hyperlipidemia, hypertension, coronary heart disease, stroke and cancer. Hence, the problem of obesity cannot be ignored, and recent studies have shown that grape seed proanthocyanidin extract (GSPE) has an antiobesity effect. This paper systematically reviews the research progress and potential mechanism of GSPE emphasizing on obesity prevention and treatment.

Procyanidin B2 Promotes Skeletal Slow-Twitch Myofiber Gene Expression through the AMPK Signaling Pathway in C2C12 Myotubes

Dimer procyanidin B2 [epicatechin-(4β-8)-epicatechin] (PB2) has attracted a lot of interest in nutrition and medicine because of its significant health-promoting abilities. However, the function of PB2 on different types of skeletal myofiber is still unclear. Here, we have found that PB2 significantly increased protein expression of the slow myosin heavy chain (MyHC) and decreased fast MyHC protein in C2C12 myotubes, accompanied by upregulation of mRNA expression of MyHC I, MyHC IIa, and Tnni1 and downregulation of MyHC IIx and MyHC IIb. We have also found that PB2 enhanced the activities of malate dehydrogenase and succinic dehydrogenase and reduced lactate dehydrogenase activity. PB2 promoted phosphorylation of AMPK and significantly increased mRNA expression of AMPKα1. The upstream factors of AMPK, such as phospho-LKB1, NRF1, and CaMKKβ, and the downstream factors of AMPK, including Sirt1 and PGC-1α, were also increased by PB2. Specific suppression of AMPK signaling by AMPKα1 siRNA or by AMPK inhibitor compound C significantly attenuated the PB2-induced upregulation of phospho-AMPK, PGC-1α, and slow MyHC and downregulation of fast MyHC. Our findings suggested that PB2 promotes skeletal slow-twitch myofiber gene expression through the AMPK signaling pathway in C2C12 myotubes.

Grape Seeds Proanthocyanidins: An Overview of In Vivo Bioactivity in Animal Models

Over the last decade, proanthocyanidins (PACs) are attracting attention not only from the food industry but also from public health organizations due to their health benefits. It is well-known that grapes are a good source of PACs and for that reason, the industry is also focused on grape by-products identification and bioactivity evaluation. Grape seeds extract (GSPE) is a rich source of PACs, mainly composed of monomeric catechin and epicatechin, gallic acid and polymeric and oligomeric proanthocyanidins. Thus, this review encompasses the state-of-art structure and the most recent evidence about the impact of GSPE on chronic diseases, with a focus on oxidative stress, inflammation and metabolic syndrome (MeS)-related disorders such as obesity, diabetes and cardiovascular risk disease in vivo to offer new perspectives in the field that allow further research. Despite the controversial results, is undeniable that PACs from grape seeds are highly antioxidants, thus, the capacity of GSPE to improve oxidative stress might mediate the inflammation process and the progress of MeS-related pathologies. However, further well-design animal studies with standardized dosages and GSPE composition are necessary to shed light into the cause-effect relationship in a more accurate way to later allow a deeper study of the effect of GSPE in humans.