Polyphenol supplementation: benefits for exercise performance or oxidative stress?

Effects of acai supplementation (Euterpe precatoria Mart) on muscle recovery markers after jump protocol

The objective was to evaluate the effects of acai supplementation (AS) on markers of muscle damage. Twelve men participated in the 21-day study. All performed the damage protocol (DP) in two moments, separated by 7 days. The DP consisted of 10 sets of 10 CMJs, with a recovery of 1 min between sets. The AS was performed for 7 days with 40 g/day of dehydrated acai (GA) or placebo (GP). Blood parameters (CK, LDH and Trolox-equivalent antioxidant capacity - TEAC) were evaluated at 0 h and 24 h. Ultrasound images (VL, RF and GM), DOMS in lower limbs and isometric peak torque (IPT) of knee extensors and flexors were evaluated at 0 h, 24 h, 48 h and 72 h after DP. A time-treatment interaction was observed for TEAC (p = 0.01), in which the GA presented increases of 11% after 24 h. Similarly, time-treatment interaction was observed for knee flexors IPT (p = 0.02), where GA showed superior recovery after 24 h (GA = 108 ± 23 vs. GP = 92 ± 24 N∙m) and 72 h (GA = 113 ± 31 vs. GP = 98 ± 26 N∙m). No significance was observed in the fatigue index for knee extensors (p = 0.75) and flexors (p = 0.89), indicating similar fatigue in both situations. We concluded that AS increased the TEAC and promoted faster recovery of the knee flexors IPT when compared to GP.

Polyphenol supplementation boosts aerobic endurance in athletes: systematic review

In recent years, an increasing trend has been observed in the consumption of specific polyphenols, such as flavonoids and phenolic acids, derived from green tea, berries, and other similar sources. These compounds are believed to alleviate oxidative stress and inflammation resulting from exercise, potentially enhancing athletic performance. This systematic review critically examines the role of polyphenol supplementation in improving aerobic endurance among athletes and individuals with regular exercise habits. The review involved a thorough search of major literature databases, including PubMed, Web of Science, SCOPUS, SPORTDiscus, and Embase, covering re-search up to the year 2023. Out of 491 initially identified articles, 11 met the strict inclusion criteria for this review. These studies specifically focused on the incorporation of polyphenols or polyphenol-containing complexes in their experimental design, assessing their impact on aerobic endurance. The methodology adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the risk of bias was evaluated using the Cochrane bias risk assessment tool. While this review suggests that polyphenol supplementation might enhance certain aspects of aerobic endurance and promote fat oxidation, it is important to interpret these findings with caution, considering the limited number of studies available. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023453321.

Effects of a Singular Dose of Mangiferin-Quercetin Supplementation on Basketball Performance: A Double-Blind Crossover Study of High-Level Male Players

Pre-exercise mangiferin-quercetin may enhance athletic performance. This study investigated the effect of mangiferin-quercetin supplementation on high-level male basketball players during a basketball exercise simulation test (BEST) comprising 24 circuits of 30 s activities with various movement distances. The participants were divided into two groups (EXP = 19 and CON = 19) and given a placebo one hour before the BEST (PRE-condition). The following week, the EXP group received mangiferin-quercetin (84 mg/140 mg), while the CON group received a placebo (POST-condition) before the BEST in a double-blind, cross-over design. The mean heart rate (HR) and circuit and sprint times (CT and ST) during the BEST were measured, along with the capillary blood lactate levels (La-), the subjective rating of muscle soreness (RPMS), and the perceived exertion (RPE) during a resting state prior to and following the BEST. The results showed significant interactions for the mean CT (p = 0.013) and RPE (p = 0.004); a marginal interaction for La- (p = 0.054); and non-significant interactions for the mean HR, mean ST, and RPMS. Moreover, the EXP group had significantly lower values in the POST condition for the mean CT (18.17 ± 2.08 s) and RPE (12.42 ± 1.02) compared to the PRE condition (20.33 ± 1.96 s and 13.47 ± 1.22, respectively) and the POST condition of the CON group (20.31 ± 2.10 s and 13.32 ± 1.16, respectively) (p < 0.05). These findings highlight the potential of pre-game mangiferin-quercetin supplementation to enhance intermittent high-intensity efforts in sports such as basketball.

Concomitant dual-site tDCS and dark chocolate improve cognitive and endurance performance following cognitive effort under hypoxia: a randomized controlled trial

Ten male cyclists were randomized into four experimental conditions in this randomized, cross-over, double-blind, and sham-controlled study to test the combined effect of acute dark chocolate (DC) ingestion and anodal concurrent dual-site transcranial direct current stimulation (a-tDCS) targeting M1 and left DLPFC on cognitive and whole-body endurance performance in hypoxia after performing a cognitive task. Two hours before the sessions, chocolate was consumed. After arriving at the lab, participants completed an incongruent Stroop task for 30 min in hypoxia (O2 = 13%) to induce mental fatigue, followed by 20 min of tDCS (2 mA) in hypoxia. Then, in hypoxia, they performed a time-to-exhaustion task (TTE) while measuring physiological and psychophysiological responses. Cognitive performance was measured at baseline, after the Stroop task, and during and after TTE. TTE in 'DC + a-tDCS' was significantly longer than in 'white chocolate (WC) + a-tDCS' and WC + sham-tDCS'. The vastus medialis muscle electromyography amplitude was significantly higher in 'DC + a-tDCS' and 'DC + sham-tDCS' than in 'WC + sh-tDCS'. During and after the TTE, choice reaction time was significantly lower in 'DC + a-tDCS' compared to 'WC + sh-tDCS'. Other physiological or psychophysiological variables showed no significant differences. The concurrent use of acute DC consumption and dual-site a-tDCS might improve cognitive and endurance performance in hypoxia.

Antioxidants and Sports Performance

The role of reactive oxygen species and antioxidant response in training adaptations and sports performance has been a large issue investigated in the last few years. The present review aims to analyze the role of reactive oxygen species and antioxidant response in sports performance. For this aim, the production of reactive oxygen species in physical activities, the effect of reactive oxygen species on sports performance, the relationship between reactive oxygen species and training adaptations, inflammation, and the microbiota, the effect of antioxidants on recovery and sports performance, and strategies to use antioxidants supplementations will be discussed. Finally, practical applications derived from this information are discussed. The reactive oxygen species (ROS) production during physical activity greatly influences sports performance. This review concludes that ROS play a critical role in the processes of training adaptation induced by resistance training through a reduction in inflammatory mediators and oxidative stress, as well as appropriate molecular signaling. Additionally, it has been established that micronutrients play an important role in counteracting free radicals, such as reactive oxygen species, which cause oxidative stress, and the effects of antioxidants on recovery, sports performance, and strategies for using antioxidant supplements, such as vitamin C, vitamin E, resveratrol, coenzyme Q10, selenium, and curcumin to enhance physical and mental well-being.

Possible Side Effects of Polyphenols and Their Interactions with Medicines

Polyphenols are an important component of plant-derived food with a wide spectrum of beneficial effects on human health. For many years, they have aroused great interest, especially due to their antioxidant properties, which are used in the prevention and treatment of many diseases. Unfortunately, as with any chemical substance, depending on the conditions, dose, and interactions with the environment, it is possible for polyphenols to also exert harmful effects. This review presents a comprehensive current state of the knowledge on the negative impact of polyphenols on human health, describing the possible side effects of polyphenol intake, especially in the form of supplements. The review begins with a brief overview of the physiological role of polyphenols and their potential use in disease prevention, followed by the harmful effects of polyphenols which are exerted in particular situations. The individual chapters discuss the consequences of polyphenols’ ability to block iron uptake, which in some subpopulations can be harmful, as well as the possible inhibition of digestive enzymes, inhibition of intestinal microbiota, interactions of polyphenolic compounds with drugs, and impact on hormonal balance. Finally, the prooxidative activity of polyphenols as well as their mutagenic, carcinogenic, and genotoxic effects are presented. According to the authors, there is a need to raise public awareness about the possible side effects of polyphenols supplementation, especially in the case of vulnerable subpopulations.

The Effect of a Hydroxytyrosol-Rich, Olive-Derived Phytocomplex on Aerobic Exercise and Acute Recovery

There is current scientific interest in naturally sourced phenolic compounds and their potential benefits to health, as well as the effective role polyphenols may provide in an exercise setting. This study investigated the chronic effects of supplementation with a biodynamic and organic olive fruit water phytocomplex (OliPhenolia® [OliP]), rich in hydroxytyrosol (HT), on submaximal and exhaustive exercise performance and respiratory markers of recovery. Twenty-nine recreationally active participants (42 ± 2 yrs; 71.1 ± 2.1 kg; 1.76 ± 0.02 m) consumed 2 × 28 mL∙d−1 of OliP or a taste- and appearance-matched placebo (PL) over 16 consecutive days. Participants completed a demanding, aerobic exercise protocol at ~75% maximal oxygen uptake (V˙O2max) for 65 min 24 h before sub- and maximal performance exercise tests prior to and following the 16-day consumption period. OliP reduced the time constant (τ) (p = 0.005) at the onset of exercise, running economy (p = 0.015) at lactate threshold 1 (LT1), as well as the rating of perceived exertion (p = 0.003) at lactate turnpoint (LT2). Additionally, OliP led to modest improvements in acute recovery based upon a shorter time to achieve 50% of the end of exercise V˙O2 value (p = 0.02). Whilst OliP increased time to exhaustion (+4.1 ± 1.8%), this was not significantly different to PL (p > 0.05). Phenolic compounds present in OliP, including HT and related metabolites, may provide benefits for aerobic exercise and acute recovery in recreationally active individuals. Further research is needed to determine whether dose-response or adjunct use of OliP alongside longer-term training programs can further modulate exercise-associated adaptations in recreationally active individuals, or indeed support athletic performance.

Polyphenol Supplementation and Antioxidant Status in Athletes: A Narrative Review

Antioxidants in sports exercise training remain a debated research topic. Plant-derived polyphenol supplements are frequently used by athletes to reduce the negative effects of exercise-induced oxidative stress, accelerate the recovery of muscular function, and enhance performance. These processes can be efficiently modulated by antioxidant supplementation. The existing literature has failed to provide unequivocal evidence that dietary polyphenols should be promoted specifically among athletes. This narrative review summarizes the current knowledge regarding polyphenols' bioavailability, their role in exercise-induced oxidative stress, antioxidant status, and supplementation strategies in athletes. Overall, we draw attention to the paucity of available evidence suggesting that most antioxidant substances are beneficial to athletes. Additional research is necessary to reveal more fully their impact on exercise-induced oxidative stress and athletes' antioxidant status, as well as optimal dosing methods.

Phytochemical Profiling, Antioxidant and Anti-Inflammatory Activity of Plants Belonging to the Lavandula Genus

Lavender is a valuable medicinal plant belonging to the Lamiaceae family. Currently 39 species are known, but only Lavandula angustifolia is a pharmacopoeial raw material. Lavender has a long history of medicinal use and mainly exhibits antioxidant, anti-inflammatory, sedative, antidepressant, spasmolytic, anticholinesterases, antifungal and antibacterial properties. Used internally, it relieves symptoms of mental stress and insomnia and supports digestion. Topical use of lavender in aromatherapy, neuralgia and antiseptics is also known. The constant interest in lavender, and in particular in Lavandula angustifolia, in the field of medicine and pharmacy is evidenced by the growing number of publications. In view of so many studies, it seems important to review traditional and modern extraction techniques that determine the chemical composition responsible for the antioxidant and anti-inflammatory effects of various extracts from the species of the Lavandula genus.

Nutritional Compounds to Improve Post-Exercise Recovery

The metabolic and mechanical stresses associated with muscle-fatiguing exercise result in perturbations to bodily tissues that lead to exercise-induced muscle damage (EIMD), a state of fatigue involving oxidative stress and inflammation that is accompanied by muscle weakness, pain and a reduced ability to perform subsequent training sessions or competitions. This review collates evidence from previous research on a wide range of nutritional compounds that have the potential to speed up post-exercise recovery. We show that of the numerous compounds investigated thus far, only two-tart cherry and omega-3 fatty acids-are supported by substantial research evidence. Further studies are required to clarify the potential effects of other compounds presented here, many of which have been used since ancient times to treat conditions associated with inflammation and disease.

Does Opuntia ficus-indica Juice Supplementation Improve Biochemical and Cardiovascular Response to a 6-Minute Walk Test in Type 2 Diabetic Patients?

Background and objectives: The purpose of this study was to evaluate the effect of Opuntia ficus-indica juice (OFIJ) on performance and biochemical and physiological responses to a 6 min walking test (6MWT) in diabetic patients. Materials and Methods: Twenty diabetic patients performed a 6MWT at 07:00 h. During each test session, they were asked to drink 70 mL/day of natural OFIJ or placebo (PLA) for 4 days. Results: the results showed that cardiovascular parameters increased significantly after the 6MWT under both conditions. While, cortisol, HbA1c, cholesterol total (CT), triglycerides (TG), as well as low-density lipoprotein (LDL) were not modified between without and with supplementation. Likewise, no significant variation in performance was observed for PLA and OFIJ (p > 0.05). The cardiovascular parameters (heart rate max (HRmax), diastolic blood pressure (DBP), and systolic blood pressure (SBP)), lipid profile (CT, TG, LDL, and high-density lipoprotein HDL), hormonal parameters (insulin and glucagon), HbA1c and lactate ([La]) did not present any significant modification either between PLA or OFIJ (p > 0.05). Muscle-damage markers (creatine kinase (CK) and lactate dehydrogenase (LDH)], cortisol, and liver parameters (i.e., oxidative stress marker, γGT, and total bilirubin) as well as glucose (GLC) were affected by supplementation (p < 0.05) before and after the 6MWT, but this change was significant only for OFIJ (p < 0.05). Conclusion: OFIJ had an antioxidant capacity, improved performance of the 6MWT, and reduced muscle-damage markers and glucose level in type 2 diabetic patients.

Efficacy and safety of dietary polyphenol supplementation in the treatment of non-alcoholic fatty liver disease: A systematic review and meta-analysis

Background

Dietary polyphenol treatment of non-alcoholic fatty liver disease (NAFLD) is a novel direction, and the existing clinical studies have little effective evidence for its therapeutic effect, and some studies have inconsistent results. The effectiveness of dietary polyphenols in the treatment of NAFLD is still controversial. The aim of this study was to evaluate the therapeutic efficacy of oral dietary polyphenols in patients with NAFLD.

Methods

The literature (both Chinese and English) published before 30 April 2022 in PubMed, Cochrane, Medline, CNKI, and other databases on the treatment of NAFLD with dietary polyphenols was searched. Manual screening, quality assessment, and data extraction of search results were conducted strictly according to the inclusion and exclusion criteria. RevMan 5.3 software was used to perform the meta-analysis.

Results

The RCTs included in this study involved dietary supplementation with eight polyphenols (curcumin, resveratrol, naringenin, anthocyanin, hesperidin, catechin, silymarin, and genistein) and 2,173 participants. This systematic review and meta-analysis found that 1) curcumin may decrease body mass index (BMI), Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Triglycerides (TG) total cholesterol (TC), and Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) compared to placebo; and curcumin does not increase the occurrence of adverse events. 2) Although the meta-analysis results of all randomized controlled trials (RCTs) did not reveal significant positive changes, individual RCTs showed meaningful results. 3) Naringenin significantly decreased the percentage of NAFLD grade, TG, TC, and low-density lipoprotein cholesterol (LDL-C) and increased high-density lipoprotein cholesterol (HDL-C) but had no significant effect on AST and ALT, and it is a safe supplementation. 4) Only one team presents a protocol about anthocyanin (from Cornus mas L. fruit extract) in the treatment of NAFLD. 5) Hesperidin may decrease BMI, AST, ALT, TG, TC, HOMA-IR, and so on. 6) Catechin may decrease BMI, HOMA-IR, and TG level, and it was well tolerated by the patients. 7) Silymarin was effective in improving ALT and AST and reducing hepatic fat accumulation and liver stiffness in NAFLD patients.

Conclusion

Based on current evidence, curcumin can reduce BMI, TG, TC, liver enzymes, and insulin resistance; catechin can reduce BMI, insulin resistance, and TG effectively; silymarin can reduce liver enzymes. For resveratrol, naringenin, anthocyanin, hesperidin, and catechin, more RCTs are needed to further evaluate their efficacy and safety.

Role of Nuclear Factor Erythroid 2 (Nrf2) in the Recovery of Long COVID-19 Using Natural Antioxidants: A Systematic Review

Coronavirus disease 2019 (COVID-19) is an infectious disease with approximately 517 million confirmed cases, with the average number of cases revealing that patients recover immediately without hospitalization. However, several other cases found that patients still experience various symptoms after 3–12 weeks, which is known as a long COVID syndrome. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can activate nuclear factor kappa beta (NF-κβ) and unbind the nuclear factor erythroid 2-related factor 2 (Nrf2) with Kelch-like ECH-associated protein 1 (Keap1), causing inhibition of Nrf2, which has an important role in antioxidant response and redox homeostasis. Disrupting the Keap1–Nrf2 pathway enhances Nrf2 activity, and has been identified as a vital approach for the prevention of oxidative stress and inflammation. Hence, natural antioxidants from various sources have been identified as a promising strategy to prevent oxidative stress, which plays a role in reducing the long COVID-19 symptoms. Oxygen-rich natural antioxidant compounds provide an effective Nrf2 activation effect that interact with the conserved amino acid residues in the Keap1-binding pocket, such as Ser602, Ser363, Ser508, and Ser555. In this review, the benefits of various natural antioxidant compounds that can modulate the Nrf2 signaling pathway, which is critical in reducing and curing long COVID-19, are highlighted and discussed.

Antioxidative properties of phenolic compounds and their effect on oxidative stress induced by severe physical exercise

Extensive research has found strongly increased generation of reactive oxygen species, free radicals, and reactive nitrogen species during acute physical exercise that can lead to oxidative stress (OS) and impair muscle function. Polyphenols (PCs), the most abundant antioxidants in the human diet, are of increasing interest to athletes as antioxidants. Current literature suggests that antioxidants supplementation can effectively modulate these processes. This overview summarizes the actual knowledge of chemical and biomechanical properties of PCs and their impact as supplements on acute exercise-induced OS, inflammation control, and exercise performance. Evidence maintains that PC supplements have high potency to positively impact redox homeostasis and improve skeletal muscle's physiological and physical functions. However, many studies have failed to present improvement in physical performance. Eleven of 15 representative experimental studies reported a reduction of severe exercise-induced OS and inflammation markers or enhancement of total antioxidant capacity; four of eight studies found improvement in exercise performance outcomes. Further studies should be continued to address a safe, optimal PC dosage, supplementation timing during a severe training program in different sports disciplines, and effects on performance response and adaptations of skeletal muscle to exercise.

Effect of Methyl Gallate on 1-Nitropyrene-Induced Keratinocyte Toxicity in a Human and Canine Skin Model

The skin, which is the largest organ of the human body, is in direct contact with pollutants in the surrounding atmosphere. Meanwhile, 1-nitropyrene (1-NP), the most abundant nitro-polycyclic aromatic hydrocarbon found in particulate matter, is known to have carcinogenic effects; however, studies on its toxicity in human and canine skin are still needed. In this study, we investigated 1-NP-induced apoptosis and inflammatory pathways in HaCaT cells. In addition, we also measured the cytoprotective effect of methyl gallate (MG), which is widely distributed in medicinal and edible plants and is well known for its anti-inflammatory and antioxidant properties. MG inhibited 1-NP-induced cell death and apoptosis pathways, including the cleavage of PARP and activation of caspase-3, -7, and -9. MG also suppressed 1-NP-induced COX-2 expression and phosphorylation of mitogen-activated protein kinases (MAPKs) and MAPK kinases (MAPKKs). Our findings suggest that 1-NP induces skin toxicity in human and canine through apoptosis and inflammatory responses, and moreover, that this can be prevented by treatment with MG.

Recovery of Natural Polyphenols from Spinach and Orange By-Products by Pressure-Driven Membrane Processes

Spinach and orange by-products are well recognized for their health benefits due to the presence of natural polyphenols with antioxidant activity. Therefore, the demand to produce functional products containing polyphenols recovered from vegetables and fruits has increased in the last decade. This work aims to use the integrated membrane process for the recovery of polyphenols from spinach and orange wastes, implemented on a laboratory scale. The clarification (microfiltration and ultrafiltration, i.e., MF and UF), pre-concentration (nanofiltration, NF), and concentration (reverse osmosis, RO) of the spinach and orange extracts were performed using membrane technology. Membrane experiments were carried out by collecting 1 mL of the permeate stream after increasing the flow rate in 1 mL/min steps. The separation and concentration factors were determined by HPLC-DAD in terms of total polyphenol content and by polyphenol families: hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids. The results show that the transmembrane flux depended on the feed flow rate for MF, UF, NF, and RO techniques. For the spinach and orange matrices, MF (0.22 µm) could be used to remove suspended solids; UF membranes (30 kDa) for clarification; NF membranes (TFCS) to pre-concentrate; and RO membranes (XLE for spinach and BW30 for orange) to concentrate. A treatment sequence is proposed for the two extracts using a selective membrane train (UF, NF, and RO) to obtain polyphenol-rich streams for food, pharmaceutical, and cosmetic applications, and also to recover clean water streams.

The Effect of a Citrus and Pomegranate Complex on Physical Fitness and Mental Well-Being in Healthy Elderly: A Randomized Placebo-Controlled Trial

OBJECTIVES

This study investigates whether a citrus and pomegranate complex (CPC) improves physical fitness, mental well-being, and blood biomarkers for oxidative stress and endothelial function in healthy elderly.

DESIGN

A randomized placebo-controlled cross-over trial.

PARTICIPANTS

The study included 36 healthy elderly aged 60-75 years old.

INTERVENTION AND MEASUREMENTS

Participants received four weeks of CPC supplementation and performed the handgrip strength and senior fitness test. Quality of life (QOL) was assessed and blood samples were analyzed for oxidative stress and endothelial function markers.

RESULTS

After four weeks of CPC supplementation, handgrip strength significantly improved (p=0.019), compared to placebo. Moreover, the thinking, memory, learning, and concentration facets were improved (p=0.042), compared to placebo, and plasma malondialdehyde decreased, compared to placebo (p=0.033). The intervention did not affect senior fitness and the other QOL domains and blood parameters.

CONCLUSION

Four weeks of daily CPC supplementation significantly improves handgrip strength and self-evaluated measures of psychological function in healthy older adults. Further research should focus on mechanisms associated with physical performance.

Neuroprotective Role of Nutritional Supplementation in Athletes

BACKGROUND

Neurodegenerative disorders belong to different classes of progressive/chronic conditions that affect the peripheral/central nervous system. It has been shown through studies that athletes who play sports involving repeated head trauma and sub-concussive impacts are more likely to experience neurological impairments and neurodegenerative disorders in the long run.

AIMS

The aim of the current narrative review article is to provide a summary of various nutraceuticals that offer promise in the prevention or management of sports-related injuries, especially concussions and mild traumatic brain injuries.

METHODS

This article reviews the various potential nutraceutical agents and their possible mechanisms in providing a beneficial effect in the injury recovery process. A thorough survey of the literature was carried out in the relevant databases to identify studies published in recent years. In the present article, we have also highlighted the major neurological disorders along with the associated nutraceutical(s) therapy in the management of disorders.

RESULTS

The exact pathological mechanism behind neurodegenerative conditions is complex as well as idiopathic. However, mitochondrial dysfunction, oxidative stress as well as intracellular calcium overload are some common reasons responsible for the progression of these neurodegenerative disorders. Owing to the multifaceted effects of nutraceuticals (complementary medicine), these supplements have gained importance as neuroprotective. These diet-based approaches inhibit different pathways in a physiological manner without eliciting adverse effects. Food habits and lifestyle of an individual also affect neurodegeneration.

CONCLUSION

Studies have shown nutraceuticals (such as resveratrol, omega-3-fatty acids) to be efficacious in terms of their neuroprotection against several neurodegenerative disorders and to be used as supplements in the management of traumatic brain injuries. Protection prior to injuries is needed since concussions or sub-concussive impacts may trigger several pathophysiological responses or cascades that can lead to long-term complications associated with CNS. Thus, the use of nutraceuticals as prophylactic treatment for neurological interventions has been proposed.

Oxidative Stress, Mitochondrial Function and Adaptation to Exercise: New Perspectives in Nutrition

Cells have the ability to adapt to stressful environments as a part of their evolution. Physical exercise induces an increase of a demand for energy that must be met by mitochondria as the main (ATP) provider. However, this process leads to the increase of free radicals and the so-called reactive oxygen species (ROS), which are necessary for the maintenance of cell signaling and homeostasis. In addition, mitochondrial biogenesis is influenced by exercise in continuous crosstalk between the mitochondria and the nuclear genome. Excessive workloads may induce severe mitochondrial stress, resulting in oxidative damage. In this regard, the objective of this work was to provide a general overview of the molecular mechanisms involved in mitochondrial adaptation during exercise and to understand if some nutrients such as antioxidants may be implicated in blunt adaptation and/or an impact on the performance of exercise by different means.

Physical Activity and Nutritional Influence on Immune Function: An Important Strategy to Improve Immunity and Health Status

Physical activity (PA) and nutrition are the essential components of a healthy lifestyle, as they can influence energy balance, promote functional ability of various systems and improve immunity. Infections and their associated symptoms are the common and frequent challenges to human health that are causing severe economic and social consequences around the world. During aging, human immune system undergoes dramatic aging-related changes/dysfunctions known as immunosenescence. Clinically, immunosenescence refers to the gradual deterioration of immune system that increases exposure to infections, and reduces vaccine efficacy. Such phenomenon is linked to impaired immune responses that lead to dysfunction of multiple organs, while lack of physical activity, progressive loss of muscle mass, and concomitant decline in muscle strength facilitate immunosenescence and inflammation. In the present review, we have discussed the role of nutrition and PA, which can boost the immune system alone and synergistically. Evidence suggests that long-term PA is beneficial in improving immune system and preventing various infections. We have further discussed several nutritional strategies for improving the immune system. Unfortunately, the available evidence shows conflicting results. In terms of interaction with food intake, PA does not tend to increase energy intake during a short time course. However, overcoming nutritional deficiencies appears to be the most practical recommendation. Through the balanced nutritious diet intake one can fulfill the bodily requirement of optimal nutrition that significantly impacts the immune system. Supplementation of a single nutrient as food is generally not advisable. Rather incorporating various fruits and vegetables, whole grains, proteins and probiotics may ensure adequate nutrient intake. Therefore, multi-nutrient supplements may benefit people having deficiency in spite of sufficient diet. Along with PA, supplementation of probiotics, bovine colostrum, plant-derived products and functional foods may provide additional benefits in improving the immune system.

The effects of cocoa flavanols on indices of muscle recovery and exercise performance: a narrative review

Exercise-induced muscle damage (EIMD) is associated with oxidative stress and inflammation, muscle soreness, and reductions in muscle function. Cocoa flavanols (CF) are (poly)phenols with antioxidant and anti-inflammatory effects and thus may attenuate symptoms of EIMD. The purpose of this narrative review was to collate and evaluate the current literature investigating the effect of CF supplementation on markers of exercise-induced oxidative stress and inflammation, as well as changes in muscle function, perceived soreness, and exercise performance. Acute and sub-chronic intake of CF reduces oxidative stress resulting from exercise. Evidence for the effect of CF on exercise-induced inflammation is lacking and the impact on muscle function, perceived soreness and exercise performance is inconsistent across studies. Supplementation of CF may reduce exercise-induced oxidative stress, with potential for delaying fatigue, but more evidence is required for any definitive conclusions on the impact of CF on markers of EIMD.

Got Beer? A Systematic Review of Beer and Exercise

Beer is used to socialize postexercise, celebrate sport victory, and commiserate postdefeat. Rich in polyphenols, beer has antioxidant effects when consumed in moderation, but its alcohol content may confer some negative effects. Despite beer's popularity, no review has explored its effects on exercise performance, recovery, and adaptation. Thus, a systematic literature search of three databases (PubMed, SPORTDiscus, and Web of Science) was conducted by two reviewers. The search resulted in 16 studies that were appraised and reviewed. The mean PEDro score was 5.1. When individuals are looking to rehydrate postexercise, a low-alcohol beer (<4%) may be more effective. If choosing a beer higher in alcoholic content (>4%), it is advised to pair this with a nonalcoholic option to limit diuresis, particularly when relatively large volumes of fluid (>700 ml) are consumed. Adding Na+ to alcoholic beer may improve rehydration by decreasing fluid losses, but palatability may decrease. These conclusions are largely based on studies that standardized beverage volume, and the results may not apply equally to situations where people ingest fluids and food ad libitum. Ingesting nonalcoholic, polyphenol-rich beer could be an effective strategy for preventing respiratory infections during heavy training. If consumed in moderation, body composition and strength qualities seem largely unaffected by beer. Mixed results that limit sweeping conclusions are owed to variations in study design (i.e., hydration and exercise protocols). Future research should incorporate exercise protocols with higher ecological validity, recruit more women, prioritize chronic study designs, and use ad libitum fluid replacement protocols for more robust conclusions.

Four Days of Blueberry Powder Supplementation Lowers the Blood Lactate Response to Running But Has No Effect on Time-Trial Performance

Blueberries are abundant with anthocyanins possessing antioxidant and anti-inflammatory properties. As these properties combat fatigue and promote recovery, blueberry supplementation may enhance performance and recovery. Thus, the objectives were to examine the effects of two blueberry supplementation protocols on running performance, physiological responses, and short-term recovery. Using a randomized, double-blind, placebo (PLA)-controlled crossover design, 14 runners completed an 8-km time trial (TT) after supplementation with 4 days of blueberries (4DAY), 4 days of a PLA, or 2 days of placebo followed by 2 days of blueberries (2DAY). Heart rate and ratings of perceived exertion were monitored during the TT. Blood lactate, vertical jump, reactive strength index, and salivary markers were assessed before and after. No significant differences were observed for time to complete the TT (PLA: 3,010 ± 459 s; 2DAY: 3,014 ± 488 s; 4DAY: 3,011 ± 423 s), heart rate, ratings of perceived exertion, or any of the salivary markers. An interaction effect (p = .027) was observed for blood lactate, with lower post-TT concentrations in 4DAY (5.4 ± 2.0 mmol/L) than PLA (6.6 ± 2.5 mmol/L; p = .038) and 2DAY (7.4 ± 3.4 mmol/L; p = .034). Post-TT decreases in vertical jump height were not different, whereas the decline in reactive strength index was less following 4DAY (-6.1% ± 13.5%) than the other conditions (PLA: -12.6% ± 10.1%; 2DAY: -11.6% ± 11.5%; p = .038). Two days of supplementation did not influence performance or physiological stress. Although 4 days of supplementation did not alter performance, it blunted the increase in blood lactate, perhaps reflecting altered lactate production and/or clearance, and offset the decrease in dynamic muscle function post-TT, as indicated by the reactive strength index differences.

The Potential Role of Korean Mistletoe Extract as an Anti-Inflammatory Supplementation

Korean mistletoe has anti-inflammatory and antioxidant functions and may be a useful training supplement. We investigated the effect of Korean mistletoe extract (KME) on inflammatory markers after high-intensity exercise by 20 university male rowers (KME group vs. CON group) consuming 110 mL KME/dose (2 times a day over 8 weeks). Blood samples were collected for measurement of serum cytokine levels at baseline, immediately after exercise, and following 30 minutes of recovery. Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) were used as markers for inflammation. After supplementation, IL-6 and TNF-α levels were significantly lowered in the KME group than in the CON group at baseline, immediately after exercise, and following 30 minutes of recovery. KME can reduce high-strength exercise-induced increases in the levels of serum inflammatory cytokines in active individuals and improve anti-inflammatory functions.

Role of Polyphenols as Antioxidant Supplementation in Ischemic Stroke

Stroke is the second most common cause of death globally and the leading cause of death in China. The pathogenesis of cerebral ischemia injury is complex, and oxidative stress plays an important role in the fundamental pathologic progression of cerebral damage in ischemic stroke. Previous studies have preliminarily confirmed that oxidative stress should be a potential therapeutic target and antioxidant as a treatment strategy for ischemic stroke. Emerging experimental studies have demonstrated that polyphenols exert the antioxidant potential to play the neuroprotection role after ischemic stroke. This comprehensive review summarizes antioxidant effects of some polyphenols, which have the most inhibition effects on reactive oxygen species generation and oxidative stress after ischemic stroke.

Dietary Antiplatelets: A New Perspective on the Health Benefits of the Water-Soluble Tomato Concentrate Fruitflow®

Our understanding of platelet functionality has undergone a sea change in the last decade. No longer are platelets viewed simply as regulators of haemostasis; they are now acknowledged to be pivotal in coordinating the inflammatory and immune responses. This expanded role for platelets brings new opportunities for controlling a range of health conditions, targeting platelet activation and their interactions with other vascular cells. Antiplatelet drugs may be of wider utility than ever expected but often cause platelet suppression too strong to be used out of clinical settings. Dietary antiplatelets represent a nutritional approach that can be efficacious while safe for general use. In this review, we discuss potential new uses for dietary antiplatelets outside the field of cardiovascular health, with specific reference to the water-soluble tomato extract Fruitflow^®. Its uses in different aspects of inflammation and immune function are discussed, highlighting exercise-induced inflammation, mediating the effects of air pollution, and controlling thrombotic aspects of the immune response. Potential future developments in women’s health, erectile dysfunction, and the allergic response indicate how broad the utility of dietary antiplatelets can be.

Improvement of Fatigue Symptoms and Endurance Capacity by the Combined Administration of Cervus elaphus L., Angelica gigas Nakai, and Astragalus membranaceus Bunge

Fatigue is a common phenomenon usually observed in healthy, as well as in nonhealthy, individuals that affects their performance and quality of life. Efficient supplementation to relieve fatigue is of significant importance. This study was designed to investigate the efficacy of three prescreened natural resources (Cervus elaphus L. [CEL], Angelica gigas Nakai [AGN], and Astragalus membranaceus Bunge [AMB]) against fatigue symptoms induced by heavy exercise. Effects on muscle fatigue and endurance capacity during exercise were investigated in C2C12 myoblasts and exercised mice. A combination of CEL, AGN, and AMB (CEL:AGN:AMB, 1:2:1) treatment in myoblasts reduced intracellular reactive oxygen species levels induced by hydrogen peroxide by ∼20 times (P < .001). The optimal mixture extract combination was determined as CEL:AGN:AMB, 1:2:1 (CAA), which was recombined by applying the extraction yield of individual substance for in vivo study. Compared to the exercise control (EC) group, the serum lactate dehydrogenase level decreased by ∼40% due to CAA administration. The proliferator-activated receptor gamma coactivator 1-alpha protein expression increased significantly (P < .05) after CAA administration compared to that observed in the normal control group. In parallel, CAA treatment significantly (P < .05) enhanced the maximum running time compared to the EC group. Overall, combinatorial administration exhibited greater efficacy compared to each individual treatment, indicating that CAA could be used as an efficient ergogenic and antifatigue supplement.

An Antioxidant Nanoparticle Enhances Exercise Performance in Rat High-intensity Running Models

Although the adverse effects of excessively generated reactive oxygen species (ROS) on the body during aerobic exercise have been debated, there are few reports on the remarkable effects of the application of conventional antioxidants on exercise performance. The conventional antioxidants could not enhance exercise performance due to their rapid excretion from the body and serious adverse effects on the cellular respiratory system. In this study, impact of the original antioxidant self-assembling nanoparticle, redox-active nanoparticle (RNP), is investigated on the exercise performance of rats during running experiments. With an increase in the dose of the administered RNP, the all-out time of the rat running extends in a dose-dependent manner. In contrast, with an increase in the dose of the low-molecular-weight (LMW) antioxidant, the all-out running time of the rats decreases. The control group and LMW antioxidant treated group decrease in the number of red blood cells (RBCs) and increase oxidative stress after running. However, the RNP group maintains a similar RBC level and oxidative stress as that of the sedentary group. The results suggest that RNP, which shows long-blood circulation without disturbance of mitohormesis, effectively removes ROS from the bloodstream to suppresses RBC oxidative stress and damage, thus improving exercise performance.

Impact of Olive Oil Supplement Intake on Dendritic Cell Maturation after Strenuous Physical Exercise: A Preliminary Study

Physical exercise is known to have a dose-dependent effect on the immune system and can result in an inflammatory process in athletes that is proportional to the intensity and duration of exertion. This inflammatory process can be measured by cell markers such as dendritic cells (DCs), which, in humans, consist of the myeloid DC (mDCs) and plasmacytoid DC (pDCs) subpopulations. The aim of this study was to measure DC differentiation to determine the possible anti-inflammatory effects, after intense aerobic effort, of the intake of a 25 mL extra-virgin olive oil supplement. Three healthy sports-trained subjects went through resistance exercise loads on two days separated by a week: on one day after active supplement intake and on the other day after placebo supplement intake. The results show that the highest increase (77%) in the percentage of mDCs as a proportion of pDCs was immediately after testing. Independently of the supplement taken, mature mDCs showed a decreasing trend between the test one hour after and 24 h after testing ended. Nevertheless, measured in terms of the coefficient of variation, only the decrease (46%) for extra-virgin olive oil supplementation was statistically significant (95% CI: 30–62%; p = 0.05). In conclusion, an extra-virgin olive oil supplement could reduce the inflammatory impact of intense aerobic effort and improve recovery at 24 h.

Blueberry supplementation reduces the blood lactate response to running in normobaric hypoxia but has no effect on performance in recreational runners

Background

Blueberries are concentrated with anthocyanins possessing antioxidant properties. As these properties counter fatigue, blueberry supplementation may improve performance and recovery, particularly in hypoxia, where oxidative stress is elevated.

Methods

This study examined the effects of blueberry supplementation on running performance, physiological responses, and recovery in normobaric hypoxia. Eleven experienced runners completed a 30-minute time-trial (TT) in normobaric hypoxia (%O₂ = 15.5 %) on separate days after supplementation with four days of blueberries (BLU) or four days of placebo (PLA). Heart rate (HR), oxygen saturation (SaO₂) and ratings of perceived exertion (RPE) were monitored during the TT. Blood lactate and fraction of exhaled nitric oxide (F_ENO) were assessed pre-TT, post-TT, and during recovery.

Results

No significant differences were observed in the distance run during the TT, HR, SaO₂, and RPE. The post-TT increase in blood lactate was significantly lower in BLU than PLA (p = 0.036). Pre-TT and post-TT F_ENO did not differ between conditions. Blood lactate recovery following the TT was similar between conditions.

Conclusions

Four days of blueberry supplementation did not alter running performance or cardiovascular and perceptual responses in normobaric hypoxia. Supplementation lowered the blood lactate response to running, however, the significance of this finding is uncertain given the absence of an ergogenic effect.

Flavonoid Containing Polyphenol Consumption and Recovery from Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis

BACKGROUND

Flavonoid polyphenols are bioactive phytochemicals found in fruits and teas among other sources. It has been postulated that foods and supplements containing flavonoid polyphenols may enhance recovery from exercise-induced muscle damage (EIMD) through upregulation of cell signalling stress response pathways, particularly the nuclear factor erythroid 2-related factor 2 (NRF2) pathway.

OBJECTIVES

This study aims to investigate the ability of polyphenol treatments containing flavonoids to enhance recovery of skeletal muscle strength, soreness and creatine kinase post EIMD.

METHODS

Medline (Pubmed), Embase and SPORTdiscus were searched from inception to August 2020 for randomised placebo-controlled trials which assessed the impact of 6 or more days of flavonoid containing polyphenol ingestion on skeletal muscle recovery in the 96-h period following a single bout of EIMD. A total of 2983 studies were screened in duplicate resulting in 26 studies included for analysis. All meta-analyses were undertaken using a random-effects model.

RESULTS

The pooled results of these meta-analyses show flavonoid polyphenol treatments can enhance recovery of muscle strength by 7.14% (95% CI [5.50-8.78], P < 0.00001) and reduce muscle soreness by 4.12% (95% CI [- 5.82 to - 2.41] P = 0.00001), no change in the recovery of creatine kinase concentrations was observed.

CONCLUSION

These results indicate that ingestion of polyphenol treatments which contain flavonoids has significant potential to improve recovery of muscular strength and reduce muscle soreness in the 4-day period post EIMD. However, the characterisation of polyphenol dosage and composition of study treatments should be prioritised in future research to facilitate the development of specific guidelines for the inclusion of flavonoid-rich foods in the diet of athletes and active individuals.

Onosma bracteata Wall. induces G0/G1 arrest and apoptosis in MG-63 human osteosarcoma cells via ROS generation and AKT/GSK3β/cyclin E pathway

Onosma bracteata Wall. (Boraginaceae), commonly known as "gaozaban" is a highly valuable medicinal herb, useful in the treatment of body swellings, abdominal pain, eye-related problems, fever, and urinary calculi. The present study was performed to investigate the antioxidant properties of extract/fractions, viz. ethanol (Obeth) extract, hexane (Obhex) fraction, chloroform (Obcl) fraction, ethyl acetate (Obea) fraction, butanol (Obbu) fraction, and aqueous (Obaq) fraction isolated from O. bracteata. Obea fraction showed stronger free radical quenching ability in various antioxidant assays, as compared to the other fractions. Obea fraction with effective free radical-scavenging properties was further evaluated for the antiproliferative activity against human osteosarcoma MG-63, human neuroblastoma IMR-32, and human lung cancer A549 cell lines using MTT assay. Obea fraction showed strong cytotoxicity with GI₅₀ value of 88.56, 101.61, and 112.7 μg/ml towards MG-63, IMR-32, and A549 cells respectively. Mechanistic studies revealed that Obea fraction in osteosarcoma MG-63 cells increased reactive oxygen species (ROS) level and reduced mitochondrial membrane potential. In the presence of Obea, the cells were found to be arrested in the G₀/G₁ phase in a dose-dependent manner which is also confirmed by the enhancement in the early apoptotic cell population in flow cytometer analysis. Western blotting demonstrated the decrease in expression of p-NFκB, COX-2, p-Akt, and Bcl-xL, whereas upregulation was observed in the expression of GSK-3β, p53, caspase-3, and caspase-9 proteins. RT-qPCR studies revealed downregulation of Bcl-2, cyclin E, CDK2, and mortalin gene expression and upregulation in the expression of p53 genes. The antioxidant and cytotoxic potential of Obea was attributed to the presence of catechin, kaempferol, onosmin A, and epicatechin, as revealed by HPLC analysis. This is the first report regarding the antiproliferative potential of O. bracteata against osteosarcoma.

The 4R's Framework of Nutritional Strategies for Post-Exercise Recovery: A Review with Emphasis on New Generation of Carbohydrates

Post-exercise recovery is a broad term that refers to the restoration of training capacity. After training or competition, there is fatigue accumulation and a reduction in sports performance. In the hours and days following training, the body recovers and performance is expected to return to normal or improve. ScienceDirect, PubMed/MEDLINE, and Google Scholar databases were reviewed to identify studies and position declarations examining the relationship between nutrition and sports recovery. As an evidence-based framework, a 4R’s approach to optimizing post-exercise recovery was identified: (i) Rehydration—a fundamental process that will depend on the athlete, environment and sports event; (ii) Refuel—the consumption of carbohydrates is not only important to replenish the glycogen reserves but also to contribute to the energy requirements for the immune system and tissue reparation. Several bioengineered carbohydrates were discussed but further research is needed; (iii) Repair—post-exercise ingestion of high-quality protein and creatine monohydrate benefit the tissue growth and repair; and (iv) Rest—pre-sleep nutrition has a restorative effect that facilitates the recovery of the musculoskeletal, endocrine, immune, and nervous systems. Nutritional consultancy based on the 4R’s is important for the wise stewardship of the hydration, feeding, and supplementation strategies to achieve a timely recovery.

The effect of dietary (poly)phenols on exercise-induced physiological adaptations: A systematic review and meta-analysis of human intervention trials

We performed a systematic review and meta-analysis to determine whether (poly)phenol supplementation augments the physiological adaptations to exercise training. Eligible studies administered a (poly)phenol supplement alongside ≥2 weeks of supervised exercise in adult humans. After screening, 22 studies were included in the analysis. Isoflavones and green tea (poly)phenols were administered most frequently. Quality assessments suggested most studies were free from bias. (Poly)phenols had no effect on training-induced adaptations in muscle strength, peak power output, and V̇O_2max, but enhanced exercise capacity (SMD: 0.67, 95% CI: 0.25 to 1.09, p < 0.01). (Poly)phenols had no overall effect on fat loss (SMD: 0.10, 95% CI: -0.10 to 0.29; p = 0.97) or lean mass gains (SMD: 0.06, 95% CI: -0.18 to 0.30, p = 0.62) but sub-analysis suggested that isoflavones increased lean mass (SMD: 0.25, 95 CI%: -0.00 to 0.50, p = 0.05). Resveratrol impaired adaptations in two studies, although this was a non-statistically significant finding (SMD: -0.54, 95% CI: -1.15 to 0.07, p = 0.08). Our results suggest that isoflavones may augment aspects of the adaptive response to exercise training, while resveratrol may compromise training adaptations. More high-quality research is needed to resolve the effects of (poly)phenols on exercise training adaptations.

Does red orange juice supplementation has a protective effect on performance, cardiovascular parameters, muscle damage and oxidative stress markers following the Yo-Yo Intermittent Recovery Test Level-1 under polluted air?

This study aimed to investigate the effect of red orange juice supplementation (ROJS) on performance, cardiovascular parameters, muscle damage and oxidative stress markers of athletes following exercise under polluted air. Eleven soccer players performed a Yo-Yo Intermittent Recovery Test Level-1 in polluted area (PA) and non-polluted area (NPA). Participants are invited to drink 500 ml of red orange or placebo (PLA) juice 2.5 h before the test. Blood samples were collected at rest and 3 min after each session to assess creatine kinase (CK), lactate dehydrogenase, malondialdehyde (MDA) and total antioxidant status. Our results showed that, VO_2max, heart rate and systolic blood pressure post-exercise were significantly altered by pollution with both supplements, but the damage was lowered more with ROJS than PLA. Concerning muscle damage and oxidative stress markers, orange juice supplementation blunted the effect of pollution on CK levels post-exercise (p > 0.05) and decreases significantly (p < 0.05) the MDA levels post-exercise in PA and NPA compared to PLA supplementation. In conclusion, ROJS seemed to be an appropriate strategy to reduce the risk of exposure to pollution especially on muscle damage and oxidative stress markers.

Screening of Antibacterial Activity, Antioxidant Activity, and Anticancer Activity of Euphorbia hirta Linn. Extracts

This study aimed to screen the anticancer and antioxidant potential and antimicrobial activity of methanol, petroleum ether, chloroform, ethyl acetate, butanol of Euphorbia hirta Linn. extracts (EH-Me, EH-PE, EH-Ch, EH-EA and EH-Bu, respectively). The results of 2,2-diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging assay and lipid peroxidation inhibition assay showed that EH-EA was the strongest antioxidant (IC50 = 10.33 ± 0.01 µg/mL; IC50 = 1.48 ± 0.12 µg/mL, respectively) compared to all other extracts. In the antimicrobial activity of the extracts against eight strains of Gram-positive and Gram-negative bacteria using the agar disc diffusion method, we found the EH-EA to be the best antimicrobial agent. Anticancer activities of those extracts were examined by sulforhodamine B (SRB) in vitro cytotoxicity assay on two cancer cell lines, including lung cancer cells NCI-H460 and liver cancer cells Hep G2. EH-EA at concentration of 100 μg/mL has significant inhibitory activity the growth of lung cancer cells NCI-H460 and liver cancer cells Hep G2 compared to all other extracts. Our results suggest that E. hirta Linn. extracts possess significant biological activities, including antimicrobial, antioxidant, and moderate anticancer properties. Our results show that this plant could be a good source for natural antioxidants and a possible pharmaceutical supplement. Among five analyzed extracts, EH-EA extract has the strongest activities, and should be used to determine phytochemicals and mechanisms of these activities.

The role of polyphenols in poultry nutrition

In the last two decades, poultry and animal industries became increasingly interested in using plant-based feed supplements, herbs and their derivatives to retain or enhance their health and productivity. These health benefits for the host mainly attributed to the secondary plant metabolites, namely polyphenols. Polyphenols are renowned for their antioxidant, immunomodulatory, anti-mutagenic and anti-inflammatory properties. However, despite these advantages of polyphenols, they have been characterized by poor absorption in the gut and low concentration in target cells that compromise their role as effective antioxidants. The low bioavailability of polyphenols necessitates the need for further investigations to harness their full potential in poultry farms. This review is existing evidence about the bioavailability of polyphenols and their antioxidant, immunomodulatory, antimicrobial, detoxification properties and their impacts on poultry performance.

Antioxidants in Sport Sarcopenia

The decline of skeletal muscle mass and strength that leads to sarcopenia is a pathology that might represent an emergency healthcare issue in future years. Decreased muscle mass is also a condition that mainly affects master athletes involved in endurance physical activities. Skeletal muscles respond to exercise by reshaping the biochemical, morphological, and physiological state of myofibrils. Adaptive responses involve the activation of intracellular signaling pathways and genetic reprogramming, causing alterations in contractile properties, metabolic status, and muscle mass. One of the mechanisms leading to sarcopenia is an increase in reactive oxygen and nitrogen species levels and a reduction in enzymatic antioxidant protection. The present review shows the recent experimental models of sarcopenia that explore molecular mechanisms. Furthermore, the clinical aspect of sport sarcopenia will be highlighted, and new strategies based on nutritional supplements, which may contribute to reducing indices of oxidative stress by reinforcing natural endogenous protection, will be suggested.

Açaí (Euterpe oleracea Mart.) seed extract improves aerobic exercise performance in rats

The purpose of this study was to examine whether the supplementation with an açai (Euterpe oleracea Mart.) seed extract (ASE) would affect the aerobic exercise performance in rats and correlate with the vascular function, muscle oxidative stress and mitochondrial biogenesis. Male Wistar rats were divided into five groups: Sedentary, Sedentary with chronic supplementation of ASE, Training, Training with chronic (200 mg/Kg/day intragastric gavage for 5 weeks) or acute (30 min before the maximal treadmill stress test (MST) supplementation with ASE. The exercise training was performed on a treadmill (30 min/day; 5 days/week) for 4 weeks. The chronic supplementation with ASE increased the exercise time (58%) and the running distance (129%) in relation to the MST, while the Training group increased 40% and 78% and the Training with acute ASE group increased 30% and 63%, respectively. The training-induced increase of ACh vasodilation was not changed by ASE, but the norepinephrine-induced vasoconstriction was reduced by chronic and acute supplementation with ASE. The increased levels of malondialdehyde in soleus muscle homogenates from the Training group was reduced only by chronic supplementation with ASE. The muscle antioxidant defense, NO₂ levels, and expression of the mitochondrial biogenesis-related proteins (PGC1α, SIRT-1, p-AMPK/AMPK, Nrf-2) were not different between Training and Sedentary groups, but all these parameters were increased in the Training with Chronic ASE compared with the Sedentary groups. In conclusion, chronic supplementation with ASE improves aerobic physical performance by increasing the vascular function, reducing the oxidative stress, and up-regulating the mitochondrial biogenesis key proteins.

Potential health benefits of (poly)phenols derived from fruit and 100% fruit juice

(Poly)phenol-rich diets have been associated with reduced risk of various diseases. Coffee and tea are typically identified as dietary sources of chlorogenic acid and flavan-3-ols; however, 100% fruit juice greatly contributes to anthocyanin, flavonol, flavan-3-ols, and flavanone intake, making them complementary sources of dietary (poly)phenols. Thus, the aim of this narrative review was to provide an overview of fruit (poly)phenols and their potential health benefits. Fruit (poly)phenols have been associated with several health benefits (eg, reduced risk of cardiovascular disease and neurocognitive benefits). Although perspectives on 100% fruit juice consumption are controversial due to the perception of sugar content, growing evidence supports the role of fruit in whole and 100% juice forms to provide consumer benefits in alignment with dietary guidance. However, differences in (poly)phenol profiles and bioavailability likely exist between whole fruit and 100% fruit juice due to processing and the presence/absence of fiber. Ongoing studies are better defining similarities and differences between whole fruit and 100% fruit juice to elucidate protective mechanisms and align with processing and consumer products.

Fruit supplementation reduces indices of exercise-induced muscle damage: a systematic review and meta-analysis

This systematic review and meta-analysis examined the effects of fruit supplements on indices of muscle damage and physical performance measures following muscle-damaging exercise protocols. The PEDro scale and Cochrane's risk of bias tool was used to critically appraise each study, whilst forest plots were generated to report on standardised mean differences (SMD) and p-values. The studies employed a crossover-randomised design, or a randomised controlled placebo design, with measures compared between the supplement (SUPP) and placebo (PLA) conditions at 24 and 48 h following the muscle-damaging exercise protocols. Compared to the PLA condition, the SUPP condition exhibited significantly lower levels of indirect muscle damage markers (p = 0.02; I² = 44%), inflammatory markers (p = 0.03; I² = 45%) and oxidative stress (p < 0.001; I² = 58%), whilst antioxidant capacity was significantly increased (p = 0.04; I² = 82%) at 24 h post-exercise. The maximal isometric voluntary contraction was significantly greater for the SUPP condition than the PLA at 24 h (p < 0.001; I² = 81%) and 48 h (p < 0.001; 84%) post-exercise. Only a few studies reported on functional outcome measures (i.e. countermovement jump, cycling, sprint and running maximal oxygen uptake), and the findings appeared conflicting according to qualitative analyses. Fruit supplementation minimised the level of several biomarkers of muscle damage, inflammation and oxidative stress, whilst improved muscular contractility during periods of EIMD. These findings demonstrate that fruit supplements could be used as recovery strategies from strenuous exercise sessions.

Nutritional interventions for reducing the signs and symptoms of exercise-induced muscle damage and accelerate recovery in athletes: current knowledge, practical application and future perspectives

PURPOSE

This review provides an overview of the current knowledge of the nutritional strategies to treat the signs and symptoms related to EIMD. These strategies have been organized into the following sections based upon the quality and quantity of the scientific support available: (1) interventions with a good level of evidence; (2) interventions with some evidence and require more research; and (3) potential nutritional interventions with little to-no-evidence to support efficacy.

METHOD

Pubmed, EMBASE, Scopus and Web of Science were used. The search terms 'EIMD' and 'exercise-induced muscle damage' were individually concatenated with 'supplementation', 'athletes', 'recovery', 'adaptation', 'nutritional strategies', hormesis'.

RESULT

Supplementation with tart cherries, beetroot, pomegranate, creatine monohydrate and vitamin D appear to provide a prophylactic effect in reducing EIMD. β-hydroxy β-methylbutyrate, and the ingestion of protein, BCAA and milk could represent promising strategies to manage EIMD. Other nutritional interventions were identified but offered limited effect in the treatment of EIMD; however, inconsistencies in the dose and frequency of interventions might account for the lack of consensus regarding their efficacy.

CONCLUSION

There are clearly varying levels of evidence and practitioners should be mindful to refer to this evidence-base when prescribing to clients and athletes. One concern is the potential for these interventions to interfere with the exercise-recovery-adaptation continuum. Whilst there is no evidence that these interventions will blunt adaptation, it seems pragmatic to use a periodised approach to administering these strategies until data are in place to provide and evidence base on any interference effect on adaptation.

Modulation of Endothelial Glycocalyx and Microcirculation in Healthy Young Men during High-Intensity Sprint Interval Cycling-Exercise by Supplementation with Pomegranate Extract. A Randomized Controlled Trial

The natural components of the pomegranate fruit may provide additional benefits for endothelial function and microcirculation. It was hypothesized that supplementation with pomegranate extract might improve glycocalyx properties and microcirculation during acute high-intensity sprint interval cycling exercise. Eighteen healthy and recreationally active male volunteers 22-28 years of age were recruited randomly to the experimental and control groups. The experimental group was supplemented with pomegranate extract 20 mL (720 mg phenolic compounds) for two weeks. At the beginning and end of the study, the participants completed a high-intensity sprint interval cycling-exercise protocol. The microcirculation flow and density parameters, glycocalyx markers, systemic hemodynamics, lactate, and glucose concentration were evaluated before and after the initial and repeated (after 2 weeks supplementation) exercise bouts. There were no significant differences in the microcirculation or glycocalyx over the course of the study (p < 0.05). The lactate concentration was significantly higher in both groups after the initial and repeated exercise bouts, and were significantly higher in the experimental group compared to the control group after the repeated bout: 13.2 (11.9-14.8) vs. 10.3 (9.3-12.7) mmol/L, p = 0.017. Two weeks of supplementation with pomegranate extract does not influence changes in the microcirculation and glycocalyx during acute high-intensity sprint interval cycling-exercise. Although an unexplained rise in blood lactate concentration was observed.

Spirulina platensis prevents oxidative stress and inflammation promoted by strength training in rats: dose-response relation study

The purpose of this study was to evaluate the effects of Spirulina Platensis supplementation on selected blood markers of oxidative stress, muscle damage, inflammation, and performance in trained rats. Rats (250 g - 300 g) were submitted to a strength training program (eight weeks), divided into four groups: control (GT) (trained without supplementation), trained with daily-supplementation of 50 mg/kg (GT50), 150 mg/kg (GT150) and 500 mg/kg (GT500). Training consisted of a jump protocol in PVC-cylinder containing water, with increasing load over experimental weeks. We evaluated the markers of oxidative stress (malondialdehyde - MDA and antioxidant capacity) and inflammation (C-reactive protein) at the end of the training. Among groups submitted to strength training, concentration of C-reactive protein decreased after 8 weeks of intervention in the trained group and GT500. Strength training enhanced plasma MDA concentration of malondialdehyde with supplementation of S. platensis in GT150 and GT500. In plasma analysis, strength training enhanced the percentage of oxidation inhibition, with spirulina supplementation in rates of 150 and 500 mg/kg. Spirulina supplementation for 8 weeks (in a dose-effect manner) improved antioxidant capacity as well as attenuated exercise-induced increases in ROS and inflammation. As a practical application, the use as high doses did not cause a reduction in positive physiological adaptations to exercise training. Additional studies are necessary to test the application of Spirulina Platensis in other contexts, as collective sports (basketball, football, soccer).

Phytochemicals for Improving Aspects of Cognitive Function and Psychological State Potentially Relevant to Sports Performance

Subjective alertness and optimal cognitive function, including in terms of attention, spatial/working memory and executive function, are intrinsic to peak performance in many sports. Consumption of a number of plant-derived ‘secondary metabolite’ phytochemicals can modulate these psychological parameters, although there is a paucity of evidence collected in a sporting context. The structural groups into which these phytochemicals fall—phenolics, terpenes and alkaloids—vary in terms of the ecological roles they play for the plant, their toxicity and the extent to which they exert direct effects on brain function. The phenolics, including polyphenols, play protective roles in the plant, and represent a natural, benign component of the human diet. Increased consumption has been shown to improve cardiovascular function and is associated with long-term brain health. However, whilst short-term supplementation with polyphenols has been shown to consistently modulate cerebral blood-flow parameters, evidence of direct effects on cognitive function and alertness/arousal is currently comparatively weak. Terpenes play both attractant and deterrent roles in the plant, and typically occur less frequently in the diet. Single doses of volatile monoterpenes derived from edible herbs such as sage (Salvia officinalis/lavandulaefolia) and peppermint (Mentha piperita), diterpene-rich Ginkgo biloba extracts and triterpene-containing extracts from plants such as ginseng (Panax ginseng/quinquefolius) and Bacopa monnieri have all been shown to enhance relevant aspects of cognitive function and alertness. The alkaloids play toxic defensive roles in the plant, including via interference with herbivore brain function. Whilst most alkaloids are inappropriate in a sporting context due to toxicity and legal status, evidence suggests that single doses of nicotine and caffeine may be able to enhance relevant aspects of cognitive function and/or alertness. However, their benefits may be confounded by habituation and withdrawal effects in the longer term. The efficacy of volatile terpenes, triterpene-rich extracts and products combining low doses of caffeine with other phytochemicals deserves more research attention.

Daily Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants for 5 Weeks Supports Exercise Recovery Through the Management of Oxidative Stress and Inflammation: A Randomized Placebo Controlled Pilot Study

Background: Regular exercise is essential to a healthy lifestyle but evokes an oxidative and inflammatory stress. Depending upon its intensity and duration this can result in either beneficial adaptive changes or underlying tissue damage that impacts upon long-term health and individual sporting training schedules. Functional foods containing plant bioactives have potential to support exercise through management of the detrimental aspects of exercise and complement ergonomic adaptive benefits. Aim: Previously we reported that a single consumption of a 3.2 mg/kg New Zealand blackcurrant anthocyanin-rich extract (BAE) 1 h before a 30 min rowing exercise attenuated moderate exercise-mediated oxidative stress and supported innate immunity. Here we evaluate whether the efficacy of a single consumption of BAE 1 h prior to exercise is changed after extended daily BAE consumption for 5 weeks. Results: On week 1, a single consumption of BAE 1 h before a 30 min row mediated a significant (p < 0.05) 46% reduction in post-exercise-induced malondialdehyde (MDA) by 2 h compared to a 30% reduction in the placebo group. Similar efficacy was observed 5 weeks later after daily consumption of BAE. In addition, daily BAE consumption for 5 weeks improved the efficacy to (a) resolve acute inflammation, and (b) increased plasma IL-10, salivary beta-defensin 2 (BD2) and secretory IgA. Although no change in plasma antioxidant capacity was detected, a significant (p < 0.009) positive correlation between plasma IL-10 and plasma antioxidant capacity (R 2 = 0.35) was observed on week 6 after 5 week BAE consumption suggesting IL-10 influences antioxidant properties. Using a differentiated myotubule cell-line revealed that whilst IL-10 had no direct antioxidant neutralizing action, longer-term exposure (24 h) attenuated 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH)-induced myotubule oxidative stress, supporting a putative role for IL-10 in the modulation of cellular antioxidant systems. Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effectiveness of a single consumption of BAE and promotes beneficial/protective antioxidant/anti-inflammatory cellular events that facilitate exercise recovery.

Tricarboxylic acid cycle dehydrogenases inhibition by naringenin: experimental and molecular modelling evidence

The study of polyphenols’ effects on health has been gaining attention lately. In addition to reacting with important enzymes, altering the cell metabolism, these substances can present either positive or negative metabolic alterations depending on their consumption levels. Naringenin, a citrus flavonoid, already presents diverse metabolic effects. The objective of this work was to evaluate the effect of maternal naringenin supplementation during pregnancy on the tricarboxylic acid cycle activity in offspring’s cerebellum. Adult female Wistar rats were divided into two groups: (1) vehicle (1 ml/kg by oral administration (p.o.)) or (2) naringenin (50 mg/kg p.o.). The offspring were euthanised at 7th day of life, and the cerebellum was dissected to analyse citrate synthase, isocitrate dehydrogenase (IDH), α-ketoglutarate dehydrogenase (α-KGDH) and malate dehydrogenase (MDH) activities. Molecular docking used SwissDock web server and FORECASTER Suite, and the proposed binding pose image was created on UCSF Chimera. Data were analysed by Student’s t test. Naringenin supplementation during pregnancy significantly inhibited IDH, α-KGDH and MDH activities in offspring’s cerebellum. A similar reduction was observed in vitro, using purified α-KGDH and MDH, subjected to pre-incubation with naringenin. Docking simulations demonstrated that naringenin possibly interacts with dehydrogenases in the substrate and cofactor binding sites, inhibiting their function. Naringenin administration during pregnancy may affect cerebellar development and must be evaluated with caution by pregnant women and their physicians.