Oxidative stress, chronic disease, and muscle wasting

Aging-dependent mitochondrial bioenergetic impairment in the skeletal muscle of NNT-deficient mice

Overall health relies on features of skeletal muscle that generally decline with age, partly due to mechanisms associated with mitochondrial redox imbalance and bioenergetic dysfunction. Previously, aged mice genetically devoid of the mitochondrial NAD(P)+ transhydrogenase (NNT, encoded by the nicotinamide nucleotide transhydrogenase gene), an enzyme involved in mitochondrial NADPH supply, were shown to exhibit deficits in locomotor behavior. Here, by using young, middle-aged, and older NNT-deficient (Nnt-/-) mice and age-matched controls (Nnt+/+), we aimed to investigate how muscle bioenergetic function and motor performance are affected by NNT expression and aging. Mice were subjected to the wire-hang test to assess locomotor performance, while mitochondrial bioenergetics was evaluated in fiber bundles from the soleus, vastus lateralis and plantaris muscles. An age-related decrease in the average wire-hang score was observed in middle-aged and older Nnt-/- mice compared to age-matched controls. Although respiratory rates in the soleus, vastus lateralis and plantaris muscles did not significantly differ between the genotypes in young mice, the rates of oxygen consumption did decrease in the soleus and vastus lateralis muscles of middle-aged and older Nnt-/- mice. Notably, the soleus, which exhibited the highest NNT expression level, was the muscle most affected by aging, and NNT loss. Additionally, histology of the soleus fibers revealed increased numbers of centralized nuclei in older Nnt-/- mice, indicating abnormal morphology. In summary, our findings suggest that NNT expression deficiency causes locomotor impairments and muscle dysfunction during aging in mice.

The effect of pomegranate juice supplementation on C-reactive protein levels: GRADE-assessed systematic review and dose-response updated meta-analysis of data from randomized controlled trials

Pomegranate juice (PJ) has a possible anti-inflammatory effect because of its polyphenol content and antioxidants. However, the anti-inflammatory effect of PJ in randomized controlled trials (RCTs) has not been consistent. A previous meta-analysis conducted in 2016 reported a nonsignificant lowering effect of PJ on C-reactive protein (CRP) levels. This systematic review and meta-analysis aim to update the pooled effect size of PJ supplementation on CRP levels in RCT studies. PubMed, Scopus, and Web of Science databases were comprehensively searched until July 2023. Eligible studies were found by screening, their relevant data was extracted, and a risk of bias assessment was performed. The pooled effect size was calculated using a random effect model as the weighted mean difference (WMD) with a 95% confidence interval. This systematic review included 11 studies with 13 effect sizes and 696 participants. Meta-analysis showed that PJ supplementation led to a significant decrease in CRP levels compared to control groups (WMD: -2.55 mg/L; 95%CI: -3.44 to -1.66; p < 0.001). Subgroup analysis demonstrated the significant reduction effect of PJ on CRP levels in studies conducted on the both sexes or only females as well as Iranian population, individuals with 40 years≤, type 2 diabetes, polycystic ovary syndrome, or trials that intervened with PJ dosage of <250 ml/day. Meta-regression and dose-response analysis reported a nonsignificant linear and nonlinear relationship between intervention characteristics (duration and dose of PJ) and CRP changes. The current meta-analysis revealed that PJ supplemantation has a beneficial effect in improving CRP levels. It is recommended to understand this effect better, and find the optimal dose and duration of PJ supplementation to reduce CRP levels in the blood, and repeat meta-analysis after related RCTs are available. For the final proof of these effects, more detailed human studies are needed.

Antioxidant nanozymes as next-generation therapeutics to free radical-mediated inflammatory diseases: A comprehensive review

Recent developments in exploring the biological enzyme mimicking properties in nanozymes have opened a separate avenue, which provides a suitable alternative to the natural antioxidants and enzymes. Due to high and tunable catalytic activity, low cost of synthesis, easy surface modification, and good biocompatibility, nanozymes have garnered significant research interest globally. Several inorganic nanomaterials have been investigated to exhibit catalytic activities of some of the key natural enzymes, including superoxide dismutase (SOD), catalase, glutathione peroxidase, peroxidase, and oxidase, etc. These nanozymes are used for diverse biomedical applications including therapeutics, imaging, and biosensing in various cells/tissues and animal models. In particular, inflammation-related diseases are closely associated with reactive oxygen and reactive nitrogen species, and therefore effective antioxidants could be excellent therapeutics due to their free radical scavenging ability. Although biological enzymes and other artificial antioxidants could perform well in scavenging the reactive oxygen and nitrogen species, however, suffer from several drawbacks such as the requirement of strict physiological conditions for enzymatic activity, limited stability in the environment beyond their optimum pH and temperature, and high cost of synthesis, purification, and storage make then unattractive for broad-spectrum applications. Therefore, this review systematically and comprehensively presents the free radical-mediated evolution of various inflammatory diseases (inflammatory bowel disease, mammary gland fibrosis, and inflammation, acute injury of the liver and kidney, mammary fibrosis, and cerebral ischemic stroke reperfusion) and their mitigation by various antioxidant nanozymes in the biological system. The mechanism of free radical scavenging by antioxidant nanozymes under in vitro and in vivo experimental models and catalytic efficiency comparison with corresponding natural enzymes has also been presented.

Cinnamaldehyde attenuates TNF-α induced skeletal muscle loss in C2C12 myotubes via regulation of protein synthesis, proteolysis, oxidative stress and inflammation

Inflammation is the primary driver of skeletal muscle wasting, with oxidative stress serving as both a major consequence and a contributor to its deleterious effects. In this regard, regulation of both can efficiently prevent atrophy and thus will increase the rate of survival [1]. With this idea, we hypothesize that preincubation of Cinnamaldehyde (CNA), a known compound with anti-oxidative and anti-inflammatory properties, may be able to prevent skeletal muscle loss. To examine the same, C2C12 post-differentiated myotubes were treated with 25 ng/ml Tumor necrosis factor-alpha (TNF-α) in the presence or absence of 50 μM CNA. The data showed that TNF-α mediated myotube thinning and a lower fusion index were prevented by CNA supplementation 4 h before TNF-α treatment. Moreover, a lower level of ROS and thus maintained antioxidant defense system further underlines the antioxidative function of CNA in atrophic conditions. CNA preincubation also inhibited an increase in the level of inflammatory cytokines and thus led to a lower level of inflammation even in the presence of TNF-α. With decreased oxidative stress and inflammation by CNA, it was able to maintain the intracellular level of injury markers (CK, LDH) and SDH activity of mitochondria. In addition, CNA modulates all five proteolytic systems [cathepsin-L, UPS (atrogin-1), calpain, LC3, beclin] simultaneously with an upregulation of Akt/mTOR pathway, in turn, preserves the muscle-specific proteins (MHCf) from degradation by TNF-α. Altogether, our study exhibits attenuation of muscle loss and provides insight into the possible mechanism of action of CNA in curbing TNF-α induced muscle loss, specifically its effect on proteolysis and protein synthesis.

Protective Effect of Whole Wheat on Muscle Atrophy in C2C12 Cells via Akt/FoxO1 Signaling Pathways

Skeletal muscles are important for body movement, postural maintenance, and energy metabolism. Muscle atrophy is caused by various factors, including lack of exercise, age, genetics, and malnutrition, leading to the loss of muscle mass. The Akt/FoxO signaling pathway plays a key role in the regulation of muscle protein synthesis and degradation. Whole wheat contains functional ingredients that may indirectly contribute to muscle health and function and can help prevent or slow the progression of muscle atrophy. In this study, the protective effects of three wheat cultivars (Seodun, Ol, and Shinmichal 1) against hydrogen peroxide-induced muscle atrophy in C2C12 cells were investigated. We found that whole-wheat treatment reduced reactive oxygen species production, prevented glutathione depletion, and increased myotube diameter, thereby reducing muscle atrophy by activating myoblast differentiation. Generally, "Shinmichal 1" exhibited the highest activation of the Akt/FoxO signaling pathway. In contrast, "Seodun" showed similar or slightly higher activities than those of the H2O2-treated only group. In conclusion, whole wheat exerts a protective effect against muscle atrophy by activating the Akt/FoxO signaling pathway. This study indicates that whole wheat may help prevent muscle atrophy.

Sarcopenia Is Associated with Changes in Circulating Markers of Antioxidant/Oxidant Balance and Innate Immune Response

(1) Background: The involvement of redox balance alterations and innate immunity is suggested to play a key role in the pathogenesis of sarcopenia. This investigation aimed to define and relate modifications in circulating markers of redox homeostasis and the innate immune response in human sarcopenia. (2) Methods: A total of 32 subjects aged >65 years old and affected by sarcopenia according to the second "European Working Group on sarcopenia in older people" guidelines were compared with 40 non-sarcopenic age-matched controls. To assess systemic redox homeostasis, reduced (GSH) and oxidized (GSSG) blood glutathione and plasma malondialdehyde (MDA)- and 4-hydroxy-2,3-nonenal (HNE)-protein adducts were measured. Immune cells and circulating interleukins were determined to compare the innate immune response between both groups. (3) Results: Impaired redox balance in sarcopenic patients, characterized by a high blood GSSG/GSH ratio and plasma MDA/HNE-protein adducts, was sustained by reduced antioxidants in peripheral blood mononuclear cells. Furthermore, sarcopenic patients showed higher neutrophil-to-lymphocyte ratios and interleukin (IL)-4, IL-6, IL-10, and tumor necrosis factor (TNF) with respect to non-sarcopenic patients. Linear regression analysis resulted in a strong association between redox balance and immune response markers in the sarcopenic group. (4) Conclusions: These results support the interplay between redox homeostasis alteration and disruption of the innate immune response in the pathogenesis of sarcopenia.

Fish Oil Supplementation with Resistance Exercise Training Enhances Physical Function and Cardiometabolic Health in Postmenopausal Women

Menopause is a condition associated with an increased risk of dysregulation in cardiovascular and metabolic health among older women. While fish oil (FO) has garnered great attention for its health-enhancing properties, its potential for enhancing cardiometabolic health in this demographic remains to be established. The purpose of this study was to determine the clinical efficacy of an 8 wk administration of FO combined with programmed resistance exercise training (RET) on physical function and risk factors associated with cardiometabolic health in healthy older women. Twenty, healthy, older women were randomly assigned to one of the two experimental groups: resistance training with placebo (RET-PL) or RET with fish oil (RET-FO). Physical function, blood pressure (BP), triglyceride (TG), and systemic inflammation and oxidative stress biomarkers were assessed before and after the intervention. Statistical significance was set at p ≤ 0.05. Physical function was greatly enhanced in both RET and RET-FO. Handgrip strength substantially increased only in RET-FO. RET-FO exhibited significant decreases in BP, TG, inflammatory cytokines (TNF-α and IL-6), and oxidative stress (MDA and 8-OHdG) levels, while no detectable changes were found in RET-PL. Our findings indicate that FO administration during 8 wks of RET appears to enhance muscle function and lower risk factors linked to cardiometabolic disorders in postmenopausal women.

AAV1.NT-3 gene therapy in the SOD1KO mouse model of accelerated sarcopenia

BACKGROUND

Sarcopenia, an age-related loss of muscle mass, is a critical factor that affects the health of the older adults. The SOD1KO mouse is deficient of Cu/Zn superoxide dismutase, used as an accelerated aging model. We previously showed that NT-3 improves muscle fibre size by activating the mTOR pathway, suggesting a potential for attenuating age-related muscle loss. This study assessed the therapeutic efficacy of AAV1.NT-3 in this accelerated aging model.

METHODS

Twelve 6 months old SOD1KO mice were injected intramuscularly with a 1 × 1011 vg dose of AAV1.tMCK.NT-3, and 13 age-matched SOD1KO mice were used as controls. The treatment effect was evaluated using treadmill, rotarod and gait analyses as well as histological studies assessing changes in muscle fibre, and fibre type switch, in tibialis anterior, gastrocnemius, and triceps muscles, and myelin thickness by calculating G ratio in sciatic and tibial nerves. Molecular studies involved qPCR experiments to analyse the expression levels of mitochondrial and glycolysis markers and western blot experiments to assess the activity of mTORC1 pathway.

RESULTS

Treatment resulted in a 36% (154.9 vs. 114.1; P < 0.0001) and 76% increase (154.3 vs. 87.6; P < 0.0001) in meters ran, with treadmill test at 3 and 6 months post gene delivery. In addition, the treated cohort stayed on rotarod 30% (52.7 s vs. 40.4 s; P = 0.0095) and 54% (50.4 s vs. 32.7 s; P = 0.0007) longer, compared with untreated counterparts at 3 and 6 months post injection. Gait analysis, performed at endpoint, showed that stride width was normalized to wild type levels (29.3 mm) by an 11% decrease, compared with untreated cohort (28.6 mm vs. 32.1 mm; P = 0.0014). Compared with wild-type, SOD1KO mice showed 9.4% and 11.4% fibre size decrease in tibialis anterior and gastrocnemius muscles, respectively, which were normalized to wild type levels with treatment. Fibre diameter increase was observed prominently in FTG fibre type. G ratio analysis revealed hypomyelination in the tibial (0.721) and sciatic (0.676) nerves of SOD1KO model, which was reversed in the NT-3 cohort (0.646 and 0.634, respectively). Fibre size increase correlated with the increase in the p-S6 and p-4E-BP1 levels, and in the glycolysis markers in tibialis anterior. Alterations observed in the mitochondrial markers were not rescued with treatment. Overall, response to NT-3 was subdued in gastrocnemius muscle.

CONCLUSIONS

This study shows that AAV1.NT-3 gene therapy protected SOD1KO mouse from accelerated aging effects functionally and histologically. We further confirmed that NT-3 has potential to activate the mTOR and glycolytic pathways in muscle.

Biological principles of adult degenerative scoliosis

The global aging population has led to an increase in geriatric diseases, including adult degenerative scoliosis (ADS). ADS is a spinal deformity affecting adults, particularly females. It is characterized by asymmetric intervertebral disc and facet joint degeneration, leading to spinal imbalance that can result in severe pain and neurological deficits, thus significantly reducing the quality of life. Despite improved management, molecular mechanisms driving ADS remain unclear. Current literature primarily comprises epidemiological and clinical studies. Here, we investigate the molecular mechanisms underlying ADS, with a focus on angiogenesis, inflammation, extracellular matrix remodeling, osteoporosis, sarcopenia, and biomechanical stress. We discuss current limitations and challenges in the field and highlight potential translational applications that may arise with a better understanding of these mechanisms.

Skeletal muscle atrophy, regeneration, and dysfunction in heart failure: Impact of exercise training

This review highlights some established and some more contemporary mechanisms responsible for heart failure (HF)-induced skeletal muscle wasting and weakness. We first describe the effects of HF on the relationship between protein synthesis and degradation rates, which determine muscle mass, the involvement of the satellite cells for continual muscle regeneration, and changes in myofiber calcium homeostasis linked to contractile dysfunction. We then highlight key mechanistic effects of both aerobic and resistance exercise training on skeletal muscle in HF and outline its application as a beneficial treatment. Overall, HF causes multiple impairments related to autophagy, anabolic-catabolic signaling, satellite cell proliferation, and calcium homeostasis, which together promote fiber atrophy, contractile dysfunction, and impaired regeneration. Although both wasting and weakness are partly rescued by aerobic and resistance exercise training in HF, the effects of satellite cell dynamics remain poorly explored.

Sarcopenia and Anemia in Elderly Koreans: A Nationwide Population-Based Study

Sarcopenia and anemia are common diseases in the elderly and are caused by various factors. In this study, the association between sarcopenia and anemia in an elderly Korean population was examined. The Korea Centers for Disease Control and Prevention's cross-sectional, nationally representative Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2011) served as the source of the data for this study. Of the 2769 participants (1167 men and 1602 women) included in this study, a significant association was found between sarcopenia and anemia in the elderly in Korea. In Model 1, unadjusted for covariates, the prevalence of sarcopenia in all participants was 1.805 (95% CI 1.364-2.388) and 2.746 (95% CI 1.740-4.334) in men, and 1.494 (95% CI 1.045-2.138) in women. In Model 4, adjusted for all covariates, the prevalence of sarcopenia in all participants was 1.455 (95% CI 1.064-1.989) and 2.649 (95% CI 1.475-4.755) in men, but it was insignificant in women. While prior studies failed to consider variables such as exercise status and nutritional intake, this research incorporated these factors as covariates. Despite this comprehensive approach, this study still revealed an independent association between sarcopenia and anemia. Moreover, a significant association was uncovered among elderly men, with no corresponding association identified among women.

Effects of heat stress on markers of skeletal muscle proteolysis in dairy cattle

Heat stress (HS) markedly affects postabsorptive energetics and protein metabolism. Circulating urea nitrogen increases in multiple species during HS and it has been traditionally presumed to stem from increased skeletal muscle proteolysis; however, this has not been empirically established. We hypothesized HS would increase activation of the calpain and proteasome systems as well as increase degradation of autophagosomes in skeletal muscle. To test this hypothesis, lactating dairy cows (∼139 d in milk; parity ∼2.4) were exposed to thermal neutral (TN) or HS conditions for 7 d (8 cows/environment). To induce HS, cattle were fitted with electric blankets for the duration of the heating period and the semitendinosus was biopsied on d 7. Heat stress increased rectal temperature (1.3°C) and respiratory rate (38 breaths per minute) while it decreased dry matter intake (34%) and milk yield (32%). Plasma urea nitrogen (PUN) peaked following 3 d (46%) and milk urea nitrogen (MUN) peaked following 4 d of environmental treatment and while both decreased thereafter, PUN and MUN remained elevated compared with TN (PUN: 20%; MUN: 27%) on d 7 of HS. Contrary to expectations, calpain I and II abundance and activation and calpain activity were similar between groups. Likewise, relative protein abundance of E3 ligases, muscle atrophy F-box protein/atrogin-1 and muscle ring-finger protein-1, total ubiquitinated proteins, and proteasome activity were similar between environmental treatments. Finally, autophagosome degradation was also unaltered by HS. Counter to our hypothesis, these results suggest skeletal muscle proteolysis is not increased following 7 d of HS and call into question the presumed dogma that elevated skeletal muscle proteolysis, per se, drives increased AA mobilization.

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.

Redox Signaling in Chronic Kidney Disease-Associated Cachexia

Redox signaling alterations contribute to chronic kidney disease (CKD)-associated cachexia. This review aims to summarize studies about redox pathophysiology in CKD-associated cachexia and muscle wasting and to discuss potential therapeutic approaches based on antioxidant and anti-inflammatory molecules to restore redox homeostasis. Enzymatic and non-enzymatic systems of antioxidant molecules have been studied in experimental models of kidney diseases and patients with CKD. Oxidative stress is increased by several factors present in CKD, including uremic toxins, inflammation, and metabolic and hormone alterations, leading to muscle wasting. Rehabilitative nutritional and physical exercises have shown beneficial effects for CKD-associated cachexia. Anti-inflammatory molecules have also been tested in experimental models of CKD. The importance of oxidative stress has been shown by experimental studies in which antioxidant therapies ameliorated CKD and its associated complications in the 5/6 nephrectomy model. Treatment of CKD-associated cachexia is a challenge and further studies are necessary to investigate potential therapies involving antioxidant therapy.

Effects of Citrus kawachiensis Peel in Frailty-like Model Mice Induced by Low Protein Nutrition Disorders

"Frailty" caused by a decline in physiological reserve capacity, chronic inflammation, and oxidative stress in the elderly has recently become a major social issue. The present study examined the effects of the peel of Citrus kawachiensis (CK), which exhibits anti-inflammatory, antioxidant, and pro-neurogenesis activities in frailty-like model mice. Male C57BL/6 mice (15 weeks old) were fed an 18% protein diet (CON), a 2.5% protein diet (PM), and PM mixed with 1% dried CK peel powder for approximately 1 month. Mice were euthanized 2 or 8 days after a single intraperitoneal administration of lipopolysaccharide (LPS) and tissues were dissected. Among peripheral tissues, muscle weight, liver weight, and blood glucose levels were significantly higher in the PM-LPS-CK group than in the PM-LPS group. In the behavioral analysis, locomotive activity was significantly lower in the PM-LPS group than in the PM group. The reduction in locomotive activity in the PM-LPS-CK group was significantly smaller than that in the PM-LPS group. The quantification of microglia in the hippocampal stratum lacunosum-moleculare revealed that increases in the PM-LPS group were significantly suppressed by the dried CK peel powder. Furthermore, the quantification of synaptic vesicle membrane proteins in the hippocampal CA3 region showed down-regulated expression in the PM-LPS group, which was significantly ameliorated by the administration of the dried CK peel powder. Collectively, these results suggest that CK inhibits inflammation and oxidative stress induced by PM and LPS in the central nervous system and peripheral tissue. Therefore, C. kawachiensis is highly effective against "frailty".

Effects of Monoamino-Oxidase-A (MAO-A) Inhibition on Skeletal Muscle Inflammation and Wasting through Pancreatic Ductal Adenocarcinoma in Triple Transgenic Mice

Cancer cachexia describes a syndrome of muscle wasting and lipolysis that is still largely untreatable and negatively impacts prognosis, mobility, and healthcare costs. Since upregulation of skeletal muscle monoamine-oxidase-A (MAO-A), a source of reactive oxygen species, may contribute to cachexia, we investigated the effects of the MAO-inhibitor harmine-hydrochloride (HH, intraperitoneal, 8 weeks) on muscle wasting in a triple-transgenic mouse model of pancreatic ductal adenocarcinoma (PDAC) and wild type (WT) mice. Gastrocnemius and soleus muscle cryo-cross-sections were analyzed for fiber type-specific cross-sectional area (CSA), fraction and capillarization using ATPase- and lectin-stainings. Transcripts of pro-apoptotic, -atrophic, and -inflammatory signals were determined by RT-qPCR. Furthermore, we evaluated the integrity of neuromuscular junction (NMJ, pre-/post-synaptic co-staining) and mitochondrial ultrastructure (transmission electron microscopy). MAO-A expression in gastrocnemius muscle was increased with PDAC vs. WT (immunohistochemistry: p < 0.05; Western blot: by trend). PDAC expectedly reduced fiber CSA and upregulated IL-1β in both calf muscles, while MuRF1 expression increased in soleus muscle only. Although IL-1β decreased, HH caused an additional 38.65% (p < 0.001) decrease in gastrocnemius muscle (IIBX) fiber CSA. Moreover, soleus muscle CSA remained unchanged despite the downregulation of E3-ligases FBXO32 (p < 0.05) and MuRF1 (p < 0.01) through HH. Notably, HH significantly decreased the post-synaptic NMJ area (quadriceps muscle) and glutathione levels (gastrocnemius muscle), thereby increasing mitochondrial damage and centronucleation in soleus and gastrocnemius type IIBX fibers. Moreover, although pro-atrophic/-inflammatory signals are reversed, HH unfortunately fails to stop and rather promotes PDAC-related muscle wasting, possibly via denervation or mitochondrial damage. These differential adverse vs. therapeutic effects warrant studies regarding dose-dependent benefits and risks with consideration of other targets of HH, such as the dual-specificity tyrosine phosphorylation regulated kinases 1A and B (DYRK1A/B).

Effects of a lifestyle intervention on the biomarkers of oxidative stress in non-communicable diseases: A systematic review

Oxidative stress plays a critical role in the pathogenesis of chronic diseases. Therefore, improvement of oxidative stress status through lifestyle intervention can play a vital role in preventing and treating chronic diseases. This systematic review aims to provide an overview of articles published in the last decade examining the association between lifestyle intervention and oxidative stress biomarkers in the context of non-communicable diseases. The electronic databases PubMed and Web of Science were searched for relevant studies, following the PRISMA (Preferred Reporting of Systematic Reviews and Meta-Analyses) guidelines. This systematic review focused on the four important oxidative stress biomarkers; glutathione (GSH), superoxide dismutase (SOD), catalase, and malondialdehyde. 671 articles were identified, of which nine met the inclusion criteria. A trend emerged, showing that lifestyle modifications that focus on diet and physical health can improve oxidative stress in the form of an increase in superoxide dismutase and CAT levels and a decrease in Malondialdehyde levels in participants with non-communicable diseases (NCDs), GSH levels were not affected. However, the results are difficult to compare because of the heterogeneity of the methods of the biomarkers studied. Our review indicates that oxidative stress can be influenced by lifestyle modifications and may be an effective tool for the prevention and management of non-communicable diseases. This review also elucidated the importance of analyzing multiple oxidative stress biomarkers to evaluate oxidative stress, it further highlights the need to conduct long-term lifestyle intervention studies on oxidative stress biomarkers to understand the connection between oxidative stress biomarkers, NCDs and Lifestyle intervention.

Improving animal welfare status and meat quality through assessment of stress biomarkers: A critical review

Stress induces various physiological and biochemical alterations in the animal body, which are used to assess the stress status of animals. Blood profiles, serum hormones, enzymes, and physiological conditions such as body temperature, heart, and breathing rate of animals are the most commonly used stress biomarkers in the livestock sector. Previous exposure, genetics, stress adaptation, intensity, duration, and rearing practices result in wide intra- and inter-animal variations in the expression of various stress biomarkers. The use of meat proteomics by adequately analyzing the expression of various muscle proteins such as heat shock proteins (HSPs), acute phase proteins (APPs), texture, and tenderness biomarkers help predict meat quality and stress in animals before slaughter. Thus, there is a need to identify non-invasive, rapid, and accurate stress biomarkers that can objectively assess stress in animals. The present manuscript critically reviews various aspects of stress biomarkers in animals and their application in mitigating preslaughter stress in meat production.

Association between an oxidative balance score and mortality: a prospective analysis in the SUN cohort

PURPOSE

We aimed to prospectively investigate the association of an overall oxidative balance score (OBS) with all-cause death and cause-specific mortality among participants in the Seguimiento Universidad de Navarra (SUN) Study, a Mediterranean cohort of Spanish graduates.

METHODS

Using baseline information on 12 a priori selected dietary and non-dietary lifestyle pro- and antioxidants exposures-vitamins C and E, β-carotenes, selenium, zinc, heme iron, polyphenols, total antioxidant capacity, body mass index, alcohol, smoking, and physical activity-we constructed an equally weighted OBS categorized into quartiles, with higher scores representing greater antioxidant balance. Cox proportional hazards models were fitted to evaluate the association between the OBS and mortality.

RESULTS

A total of 18,561 participants (mean [SD] age, 38.5 [12.4] years; 40.8% males) were included in the analysis. During a median follow-up of 12.2 years (interquartile range 8.3-14.9), 421 deaths were identified, including 80 deaths from cardiovascular disease (CVD), 215 from cancer, and 126 from other causes. After adjustment for potential confounders, the hazard ratios and 95% confidence interval (CIs) between the highest quartile (predominance of antioxidants) vs. the lowest quartile (reference category) were 0.35 (95% CI 0.22-0.54, P-trend < 0.001) for all-cause mortality, 0.18 (95% CI 0.06-0.51, P-trend = 0.001) for CVD mortality, 0.35 (95% CI 0.19-0.65, P-trend = 0.002) for cancer mortality, and 0.45 (95% CI 0.20-1.02, P-trend = 0.054) for other-cause mortality.

CONCLUSION

Our findings suggest a strong inverse association between the OBS and all-cause, CVD, and cancer mortality. Individuals exposed to both antioxidant dietary and lifestyle factors may potentially experience the lowest mortality risk.

STUDY REGISTRY NUMBER

Dynamic Mediterranean Prospective Cohort: the SUN Project; NCT02669602. https://clinicaltrials.gov/ct2/show/NCT02669602 . https://proyectosun.es.

Are Skeletal Muscle Changes during Prolonged Space Flights Similar to Those Experienced by Frail and Sarcopenic Older Adults?

Microgravity exposure causes several physiological and psychosocial alterations that challenge astronauts' health during space flight. Notably, many of these changes are mostly related to physical inactivity influencing different functional systems and organ biology, in particular the musculoskeletal system, dramatically resulting in aging-like phenotypes, such as those occurring in older persons on Earth. In this sense, sarcopenia, a syndrome characterized by the loss in muscle mass and strength due to skeletal muscle unloading, is undoubtedly one of the most critical aging-like adverse effects of microgravity and a prevalent problem in the geriatric population, still awaiting effective countermeasures. Therefore, there is an urgent demand to identify clinically relevant biological markers and to underline molecular mechanisms behind these effects that are still poorly understood. From this perspective, a lesson from Geroscience may help tailor interventions to counteract the adverse effects of microgravity. For instance, decades of studies in the field have demonstrated that in the older people, the clinical picture of sarcopenia remarkably overlaps (from a clinical and biological point of view) with that of frailty, primarily when referred to the physical function domain. Based on this premise, here we provide a deeper understanding of the biological mechanisms of sarcopenia and frailty, which in aging are often considered together, and how these converge with those observed in astronauts after space flight.

Antioxidant, Antimicrobial, Cytotoxicity, and Larvicidal Activities of Selected Synthetic Bis-Chalcones

Plants are known to have numerous phytochemicals and other secondary metabolites with numerous pharmacological and biological properties. Among the various compounds, polyphenols, flavonoids, anthocyanins, alkaloids, and terpenoids are the predominant ones that have been explored for their biological potential. Among these, chalcones and bis-chalcones are less explored for their biological potential under in vitro experiments, cell culture models, and animal studies. In the present study, we evaluated six synthetic bis-chalcones that were different in terms of their aromatic cores, functional group substitution, and position of substitutions. The results indicated a strong antioxidant property in terms of DPPH and ABTS radical-scavenging potentials and ferric-reducing properties. In addition, compounds 1, 2, and 4 exhibited strong antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella enteritidis. The disc diffusion assay values were indicative of the antibacterial properties of these compounds. Overall, the study indicated the antioxidant and antimicrobial properties of the compounds. Our preliminary studies point to the potential of this class of compounds for further in vivo investigation.

Uremic Myopathy and Mitochondrial Dysfunction in Kidney Disease

Alterations in muscle structure and function in chronic kidney disease (CKD) patients are associated with poor outcomes. As key organelles in muscle cell homeostasis, mitochondrial metabolism has been studied in the context of muscle dysfunction in CKD. We conducted a study to determine the contribution of oxidative metabolism, glycolysis and fatty acid oxidation to the muscle metabolism in CKD. Mice developed CKD by exposure to adenine in the diet. Muscle of CKD mice showed significant weight loss compared to non-CKD mice, but only extensor digitorum longus (EDL) muscle showed a decreased number of fibers. There was no difference in the proportion of the various muscle fibers in CKD and non-CKD mice. Muscle of CKD mice had decreased expression of proteins associated with oxidative phosphorylation but increased expression of enzymes and transporters associated with glycolysis. In cell culture, myotubes exposed to uremic serum demonstrated decreased oxygen consumption rates (OCR) when glucose was used as substrate, conserved OCR when fatty acids were used and increased lactate production. In conclusion, mice with adenine-induced CKD developed sarcopenia and with increased glycolytic metabolism but without gross changes in fiber structure. In vitro models of uremic myopathy suggest fatty acid utilization is preserved compared to decreased glucose utilization.

Lipid-Encapsuled Grape Tannins Prevent Oxidative-Stress-Induced Neuronal Cell Death, Intracellular ROS Accumulation and Inflammation

The central nervous system (CNS) is particularly vulnerable to oxidative stress and inflammation, which affect neuronal function and survival. Nowadays, there is great interest in the development of antioxidant and anti-inflammatory compounds extracted from natural products, as potential strategies to reduce the oxidative/inflammatory environment within the CNS and then preserve neuronal integrity and brain function. However, an important limitation of natural antioxidant formulations (mainly polyphenols) is their reduced in vivo bioavailability. The biological compatible delivery system containing polyphenols may serve as a novel compound for these antioxidant formulations. Accordingly, in the present study, we used liposomes as carriers for grape tannins, and we tested their ability to prevent neuronal oxidative stress and inflammation. Cultured catecholaminergic neurons (CAD) were used to establish the potential of lipid-encapsulated grape tannins (TLS) to prevent neuronal oxidative stress and inflammation following an oxidative insult. TLS rescued cell survival after H2O2 treatment (59.4 ± 8.8% vs. 90.4 ± 5.6% H2O2 vs. TLS+ H2O2; p < 0.05) and reduced intracellular ROS levels by ~38% (p < 0.05), despite displaying negligible antioxidant activity in solution. Additionally, TLS treatment dramatically reduced proinflammatory cytokines’ mRNA expression after H2O2 treatment (TNF-α: 400.3 ± 1.7 vs. 7.9 ± 1.9-fold; IL-1β: 423.4 ± 1.3 vs. 12.7 ± 2.6-fold; p < 0.05; H2O2 vs. TLS+ H2O2, respectively), without affecting pro/antioxidant biomarker expression, suggesting that liposomes efficiently delivered tannins inside neurons and promoted cell survival. In conclusion, we propose that lipid-encapsulated grape tannins could be an efficient tool to promote antioxidant/inflammatory cell defense.

Green Extraction Process of Food Grade C-phycocyanin: Biological Effects and Metabolic Study in Mice

This study aimed to evaluate different parameters in the green process of organic Spirulina biomass (SB) C-phycocyanin (C-PC) extraction to understand the impact on weight and oral glucose tolerance of C-PC extract in Swiss mice fed with a high-fat diet (HFD). The proximate composition and antioxidant activity were analyzed in Spirulina by-products: SB, C-PC, and Remaining biomass (RB). The protein content on a dry basis was 52.05% in SB and 61.16% in RB and 118.97 μg/g in C-PC. The antioxidant activity was equal for SB and C-PC but higher than RB. However, RB can be considered a promising ingredient, promoting the sustainable use of the whole SB. Swiss mice were distributed in five groups: control diet (CD), HFD, HFD plus Spirulina biomass (HFDS), HFD plus C-PC (HFDC), and HFD plus remaining biomass (HFDR). HFDS increased the delta weight of the animals and showed glucose intolerance compared to the CD and HFDC groups. The results demonstrated that the supplementation of 500 mg/kg of body weight of SB in the HFDS group did not show antiobesogenic potential with an HFD, but it is essential to conduct further studies to bring other interesting responses regarding C-PC biological in vivo effects.

Redox Signaling and Stress in Inherited Myopathies

Significance: Reactive oxygen species (ROS) are highly reactive compounds that behave like a double-edged sword; they damage cellular structures and act as second messengers in signal transduction. Mitochondria and endoplasmic reticulum (ER) are interconnected organelles with a central role in ROS production, detoxification, and oxidative stress response. Skeletal muscle is the most abundant tissue in mammals and one of the most metabolically active ones and thus relies mainly on oxidative phosphorylation (OxPhos) to synthesize adenosine triphosphate. The impairment of OxPhos leads to myopathy and increased ROS production, thus affecting both redox poise and signaling. In addition, ROS enter the ER and trigger ER stress and its maladaptive response, which also lead to a myopathic phenotype with mitochondrial involvement. Here, we review the role of ROS signaling in myopathies due to either mitochondrial or ER dysfunction. Recent Advances: Relevant advances have been evolving over the last 10 years on the intricate ROS-dependent pathways that act as modifiers of the disease course in several myopathies. To this end, pathways related to mitochondrial biogenesis, satellite cell differentiation, and ER stress have been studied extensively in myopathies. Critical Issues: The analysis of the chemistry and the exact quantitation, as well as the localization of ROS, are still challenging due to the intrinsic labile nature of ROS and the technical limitations of their sensors. Future Directions: The mechanistic studies of the pathogenesis of mitochondrial and ER-related myopathies offer a unique possibility to discover novel ROS-dependent pathways. Antioxid. Redox Signal. 37, 301-323.

New Strains of Akkermansia muciniphila and Faecalibacterium prausnitzii are Effective for Improving the Muscle Strength of Mice with Immobilization-Induced Muscular Atrophy

Muscular atrophy is a muscle disease in which muscle mass and strength decrease due to aging, injury, metabolic disorders, or chronic conditions. Proteins in muscle tissue are degraded by the ubiquitin-proteasome pathway, and atrophy accelerates this pathway. Akkermansia muciniphila and Faecalibacterium prausnitzii strains are effective agents against metabolic and inflammatory diseases in next-generation probiotic research. In this study, we evaluated the efficacy of A. muciniphila strain EB-AMDK19 and F. prausnitzii strain EB-FPDK11 in a mouse model of muscular atrophy, since atrophy inhibits energy metabolism and immune activation. After oral administration of each strain for 4 weeks, the hind legs of the mice were fixed with a plaster cast to immobilize them for a week. As a result, the administration of EB-AMDK19 and EB-FPDK11 strains improved grip strength but did not increase muscle mass. At the molecular level, A. muciniphila and F. prausnitzii treatments decreased the expression levels of ubiquitin-proteasome genes, atrogin-1, MuRF, and cathepsin L. They increased the expression level of the mitochondrial biogenesis regulatory gene, PGC-1α. The effect of the strains was confirmed by a decrease in myostatin. Furthermore, A. muciniphila and F. prausnitzii modulated the immune function by enhancing ZO-1 and inhibiting IL-6. In particular, EB-AMDK19 promoted the expression of IL-10, an anti-inflammatory cytokine. These results suggest that A. muciniphila and F. prausnitzii may have beneficial effects on muscular atrophy, verified by newly isolated EB-AMDK19 and EB-FPDK11 as potential next-generation probiotics.

Sarcopenia definition: Does it really matter? Implications for resistance training

The loss of muscle mass, strength and function, known as sarcopenia, is common in older adults, and is associated with falls, fractures, cardiometabolic diseases, and lower quality of life. Sarcopenia can also occur secondarily to chronic diseases. Recently, sarcopenia was recognized as a disease with an International Classification of Disease (ICD) code, yet, at least five definitions for its clinical identification exist. Most definitions include three themes: low muscle mass, strength and physical performance. However, the definitions vary by the number of themes needed to diagnose sarcopenia and, within each theme various parameters and cut-off levels exist. The lack of consensus on what constitutes a diagnosis can create confusion and hesitation in sarcopenia diagnosis. Currently, no pharmacological treatment exists for sarcopenia. Resistance training (RT) is safe and effective to improve muscle mass, strength and physical performance in older adults and clinical populations. Based on current guidelines, whether an individual is defined as "sarcopenic", or not, does not change the way RT is prescribed. Here, we present evidence and the inconsistencies in sarcopenia definitions and recommend that focus should be on optimizing ways to prescribe RT and increase long-term adherence, rather than on slight modifications to sarcopenia definitions.

H2S Protects Against Immobilization-Induced Muscle Atrophy via Reducing Oxidative Stress and Inflammation

Chronic inflammation and oxidative stress are major triggers of the imbalance between protein synthesis and degradation during the pathogenesis of immobilization-induced muscle atrophy. This study aimed to elucidate the effects of hydrogen sulfide (H2S), a gas transmitter with potent anti-inflammatory and antioxidant properties, on immobilization-induced muscle atrophy. Mice were allocated to control and immobilization (IM) groups, which were treated with slow (GYY4137) or rapid (NaHS) H2S releasing donors for 14 days. The results showed that both GYY4137 and NaHS treatment reduced the IM-induced muscle loss, and increased muscle mass. The IM-induced expressions of Muscle RING finger 1 (MuRF1) and atrogin-1, two muscle-specific E3 ubiquitin ligases, were decreased by administration of GYY4137 or NaHS. Both GYY4137 and NaHS treatments alleviated the IM-induced muscle fibrosis, as evidenced by decreases in collagen deposition and levels of tissue fibrosis biomarkers. Moreover, administration of GYY4137 or NaHS alleviated the IM-induced infiltration of CD45 + leukocytes, meanwhile inhibited the expressions of the pro-inflammatory biomarkers in skeletal muscles. It was found that administration of either GYY4137 or NaHS significantly attenuated immobilization-induced oxidative stress as indicated by decreased H2O2 levels and 8-hydroxy-2′-deoxyguanosine (8-OHdG) immunoreactivity, as well as increased total antioxidant capacity (T-AOC), nuclear factor erythroid-2-related factor 2 (NRF2) and NRF2 downstream anti-oxidant targets levels in skeletal muscles. Collectively, the present study demonstrated that treatment with either slow or rapid H2S releasing donors protected mice against immobilization-induced muscle fibrosis and atrophy. The beneficial effects of H2S on immobilization-induced skeletal muscle atrophy might be due to both the anti-inflammatory and anti-oxidant properties of H2S.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

Cardiovasomobility: an integrative understanding of how disuse impacts cardiovascular and skeletal muscle health

Cardiovasomobility is a novel concept that encompasses the integration of cardiovascular and skeletal muscle function in health and disease with critical modification by physical activity, or lack thereof. Compelling evidence indicates that physical activity improves health while a sedentary, or inactive, lifestyle accelerates cardiovascular and skeletal muscle dysfunction and hastens disease progression. Identifying causative factors for vascular and skeletal muscle dysfunction, especially in humans, has proven difficult due to the limitations associated with cross-sectional investigations. Therefore, experimental models of physical inactivity and disuse, which mimic hospitalization, injury, and illness, provide important insight into the mechanisms and consequences of vascular and skeletal muscle dysfunction. This review provides an overview of the experimental models of disuse and inactivity and focuses on the integrated responses of the vasculature and skeletal muscle in response to disuse/inactivity. The time course and magnitude of dysfunction evoked by various models of disuse/inactivity are discussed in detail, and evidence in support of the critical roles of mitochondrial function and oxidative stress are presented. Lastly, strategies aimed at preserving vascular and skeletal muscle dysfunction during disuse/inactivity are reviewed. Within the context of cardiovasomobility, experimental manipulation of physical activity provides valuable insight into the mechanisms responsible for vascular and skeletal muscle dysfunction that limit mobility, degrade quality of life, and hasten the onset of disease.

Anti-Diabetes, Anti-Gout, and Anti-Leukemia Properties of Essential Oils from Natural Spices Clausena indica, Zanthoxylum rhetsa, and Michelia tonkinensis

Essential oils (EOs) of Clausena indica fruits, Zanthoxylum rhetsa fruits, and Michelia tonkinensis seeds were analyzed for their phytochemical profiles and biological activities, including anti-diabetes, anti-gout, and anti-leukemia properties. Sixty-six volatile compounds were identified by gas chromatography–mass spectrometry (GC–MS), in which, myristicin (68.3%), limonene (44.2%), and linalool (49.3%) were the most prominent components of EOs extracted from C. indica, Z. rhetsa, and M. tonkinensis, respectively. In addition, only EOs from C. indica inhibited the activities of all tested enzymes comprising α-amylase (IC₅₀ = 7.73 mg/mL), α-glucosidase (IC₅₀ = 0.84 mg/mL), and xanthine oxidase (IC₅₀ = 0.88 mg/mL), which are related to type 2 diabetes and gout. Remarkably, all EOs from C. indica, Z. rhetsa (IC₅₀ = 0.73 mg/mL), and M. tonkinensis (IC₅₀ = 1.46 mg/mL) showed a stronger anti-α-glucosidase ability than acarbose (IC₅₀ = 2.69 mg/mL), a known anti-diabetic agent. Moreover, the growth of leukemia cell Meg-01 was significantly suppressed by all EOs, of which, the IC₅₀ values were recorded as 0.32, 0.64, and 0.31 mg/mL for EOs from C. indica, Z. rhetsa, and M. tonkinensis, respectively. As it stands, this is the first report about the inhibitory effects of EOs from C. indica and Z. rhetsa fruits, and M. tonkinensis seeds on the human leukemia cell line Meg-01 and key enzymes linked to diabetes and gout. In conclusion, the present study suggests that EOs from these natural spices may be promising candidates for pharmaceutical industries to develop nature-based drugs to treat diabetes mellitus or gout, as well as malignant hematological diseases such as leukemia.

Effectiveness of maturity of Rubus occidentalis on hyperalgesia induced by acidic saline injection in rats

Background

Rubus occidentalis, also known as black raspberry, contains several bioactive components that vary depending on the maturity of the fruit. The goal of this study was to evaluate the efficacy of immature Rubus occidentalis extract(iROE) on acid-induced hyperalgesia, investigate the mechanism involved, and compare the antihyperalgesic effect of immature and mature ROEs.

Methods

In adult male Sprague-Dawley rats, chronic muscle pain was induced via two injections of acidic saline into one gastrocnemius muscle. To evaluate the dose response, the rats were injected intraperitoneally with 0.9% saline or iROE (10, 30, 100, or 300 mg/kg) following hyperalgesia development. To evaluate the mechanism underlying iROE-induced analgesia, the rats were injected intraperitoneally with saline, yohimbine 2 mg/kg, dexmedetomidine 50 μg/kg, prazosin 1 mg/kg, atropine 5 mg/kg, mecamylamine 1 mg/kg, or naloxone 5 mg/kg 24 h after hyperalgesia development, followed by iROE 300 mg/kg administration. To compare immature versus mature ROE, the rats were injected with mature ROE 300 mg/kg and immature ROE 300 mg/kg after hyperalgesia development. For all experiments, the mechanical withdrawal threshold(MWT) was evaluated using von Frey filaments before the first acidic saline injection, 24 h after the second injection, and at various time points after drug administration. Data were analysed using multivariate analysis of variance(MANOVA) and the linear mixed-effects model(LMEM). We compared the MWT at each time point using analysis of variance with the Bonferroni correction.

Results

The iROE 300 mg/kg injection resulted in a significant increase in MWT compared with the control, iROE 30 mg/kg, and iROE 100 mg/kg injections at ipsilateral and contralateral sites. The iROE injection together with yohimbine, mecamylamine, or naloxone significantly decreased the MWT compared with iROE alone, whereas ROE together with dexmedetomidine significantly increased the MWT. According to MANOVA, the effects of immature and mature ROEs were not significantly different; however, the LMEM presented a significant difference between the two groups.

Conclusions

Immature R. occidentalis showed antihyperalgesic activity against acid-induced chronic muscle pain, which may be mediated by the α2-adrenergic, nicotinic cholinergic, and opioid receptors. The iROE displayed superior tendency regarding analgesic effect compared to mature ROE.

Chemotherapy agents reduce protein synthesis and ribosomal capacity in myotubes independent of oxidative stress

Chemotherapeutic agents (CAs) are first-line antineoplastic treatments against a wide variety of cancers. Despite their effectiveness in halting tumor progression, side effects associated with CAs promote muscle loss by incompletely understood mechanisms. To address this problem, we first identified how oxidative stress impairs protein synthesis in C2C12 myotubes. Transient elevations in reactive oxygen species (ROS) resulted in protein synthesis deficits and reduced ribosomal (r)RNA levels. Oxidative stress did not reduce rRNA gene (rDNA) transcription, but it caused an increase in rRNA and protein oxidation. To determine whether CAs affect protein synthesis independent of oxidative stress, we exposed myotubes to Paclitaxel (PTX), Doxorubicin (DXR), or Marizomib (Mzb) at doses that did result in elevated ROS levels (sub-ROS). Exposure to CAs reduced protein synthesis and rRNA levels, but unlike oxidative stress, sub-ROS exposures impaired rDNA transcription. These results indicate that although oxidative stress disrupts protein synthesis by compromising ribosomal quantity and quality, CAs at sub-ROS doses compromise protein synthesis and ribosomal capacity, at least in part, by reducing rDNA transcription. Therefore, CAs negatively impact protein synthesis by causing oxidative stress in addition to directly reducing the ribosomal capacity of myotubes in a ROS-independent manner.

Effects of marine oligomeric polyphenols on body composition and physical ability of elderly individuals with sarcopenia: a pilot study

PURPOSE

We aimed to identify the effects of marine oligomeric polyphenol (MOP) intake in elderly individuals with sarcopenia.

METHODS

Older adults (aged 65 years or older) were recruited based on the diagnostic criterion for sarcopenia and were randomly assigned to the MOP intake group (n=10) or the placebo (PBO) intake group (n=10). To determine the effect of MOP intake received for four weeks, the pre- and post-intake body composition (weight, skeletal muscle mass, and bone density) and senior fitness tests were assessed.

RESULTS

Our results showed there were significant differences in the skeletal muscle mass (p=0.039), bone density (p=0.020), fat-free mass index (p=0.026), and 2.4 m up and go test (p=0.001) between pretest and post-test. There was a significant difference between the pre-test and post-test and an interaction effect for the one-leg stand test (p=0.010 and p=0.049, respectively). However, there were no significant differences in body fat percentage, calf circumference, grip strength, or the chair rise test.

CONCLUSION

Some variables exhibited significant differences in the pre- and post-assessments, and there was an interaction effect for the one-leg stand. However, this was insufficient to prove the effectiveness of MOP intake in improving sarcopenia. Therefore, additional studies are essential to examine the effects of MOP intake and exercise intervention on the body composition and fitness of patients over a longer period.

Effects of Betaine Supplementation on Markers of Metabolic Flexibility, Body Composition, and Anaerobic Performance in Active College-Age Females

Betaine (BET) has shown to be effective in improving body composition and performance, although research in women is lacking. This study investigated the effects of BET supplementation on markers of metabolic flexibility, body composition, and anaerobic performance in college females. Twenty-three active subjects with 21.8 ± 3.0 years of age, 66.6 ± 8.8 kg body mass, 1.6 ± 0.1 m height, and 23.2 ± 5.3% body fat performed a graded exercise test on a cycle ergometer consisting of 4 incremental, 3 min stages for collection of fat and carbohydrate oxidation rates. Three 10 s sprint tests were then completed against a resistance of 7.5% of body mass, separated by 2.5 min of recovery. The study comprised 3 phases: (a) pre-supplementation, (b) randomization to supplement for 2-weeks with either 2.4 g/day BET or placebo (parallel design), and (c) post-supplementation. Repeated-measures analysis of variance were conducted to determine interactions or main effects. There were no group differences for substrate oxidation rates (p > 0.05). Although body composition improved pre-post for both groups (p < 0.05), only the BET group experienced a significant increase in fat free mass (p < 0.01; ∼3%). Further, only the BET group experienced improvements to performance such as a higher mean power output during the final sprint (p = 0.02; ∼3%) and a lower RPE during the final stage of the graded exercise test (p = 0.02). Results from this study suggest BET supplementation may improve body composition and some markers of performance during exercise in collegiate women.

Prevalence of Hypovitaminosis C and its Relationship with Frailty in Older Hospitalised Patients: A Cross-Sectional Study

Frailty is common in older hospitalised patients and may be associated with micronutrient malnutrition. Only limited studies have explored the relationship between frailty and vitamin C deficiency. This study investigated the prevalence of vitamin C deficiency and its association with frailty severity in patients ≥75 years admitted under a geriatric unit. Patients (n = 160) with a mean age of 84.4 ± 6.4 years were recruited and underwent frailty assessment by use of the Edmonton Frail Scale (EFS). Patients with an EFS score <10 were classified as non-frail/vulnerable/mildly frail and those with ≥10 as moderate–severely frail. Patients with vitamin C levels between 11–28 μmol/L were classified as vitamin C depleted while those with levels <11 μmol/L were classified as vitamin C deficient. A multivariate logistic regression model determined the relationship between vitamin C deficiency and frailty severity after adjustment for various co-variates. Fifty-seven (35.6%) patients were vitamin C depleted, while 42 (26.3%) had vitamin C deficiency. Vitamin C levels were significantly lower among patients who were moderate–severely frail when compared to those who were non-frail/vulnerable/mildly frail (p < 0.05). After adjusted analysis, vitamin C deficiency was 4.3-fold more likely to be associated with moderate–severe frailty (aOR 4.30, 95% CI 1.33-13.86, p = 0.015). Vitamin C deficiency is common and is associated with a greater severity of frailty in older hospitalised patients.

Nutraceuticals in the Prevention and Treatment of the Muscle Atrophy

Imbalance of protein homeostasis, with excessive protein degradation compared with protein synthesis, leads to the development of muscle atrophy resulting in a decrease in muscle mass and consequent muscle weakness and disability. Potential triggers of muscle atrophy include inflammation, malnutrition, aging, cancer, and an unhealthy lifestyle such as sedentariness and high fat diet. Nutraceuticals with preventive and therapeutic effects against muscle atrophy have recently received increasing attention since they are potentially more suitable for long-term use. The implementation of nutraceutical intervention might aid in the development and design of precision medicine strategies to reduce the burden of muscle atrophy. In this review, we will summarize the current knowledge on the importance of nutraceuticals in the prevention of skeletal muscle mass loss and recovery of muscle function. We also highlight the cellular and molecular mechanisms of these nutraceuticals and their possible pharmacological use, which is of great importance for the prevention and treatment of muscle atrophy.

Attenuation of Oxidative Stress and Inflammatory Response by Chronic Cannabidiol Administration Is Associated with Improved n-6/n-3 PUFA Ratio in the White and Red Skeletal Muscle in a Rat Model of High-Fat Diet-Induced Obesity

The consumption of fatty acids has increased drastically, exceeding the nutritional requirements of an individual and leading to numerous metabolic disorders. Recent data indicate a growing interest in using cannabidiol (CBD) as an agent with beneficial effects in the treatment of obesity. Therefore, our aim was to investigate the influence of chronic CBD administration on the n-6/n-3 polyunsaturated fatty acids (PUFAs) ratio in different lipid fractions, inflammatory pathway and oxidative stress parameters in the white and red gastrocnemius muscle. All the designed experiments were performed on Wistar rats fed a high-fat diet (HFD) or a standard rodent diet for seven weeks and subsequently injected with CBD (10 mg/kg once daily for two weeks) or its vehicle. Lipid content and oxidative stress parameters were assessed using gas-liquid chromatography (GLC), colorimetric and/or immunoenzymatic methods, respectively. The total expression of proteins of an inflammatory pathway was measured by Western blotting. Our results revealed that fatty acids (FAs) oversupply is associated with an increasing oxidative stress and inflammatory response, which results in an excessive accumulation of FAs, especially of n-6 PUFAs, in skeletal muscles. We showed that CBD significantly improved the n-6/n-3 PUFA ratio and shifted the equilibrium towards anti-inflammatory n-3 PUFAs, particularly in the red gastrocnemius muscle. Additionally, CBD prevented generation of lipid peroxidation products and attenuated inflammatory response in both types of skeletal muscle. In summary, the results mentioned above indicate that CBD presents potential therapeutic properties with respect to the treatment of obesity and related disturbances.

Beneficial Role of Exercise in the Modulation of mdx Muscle Plastic Remodeling and Oxidative Stress

Duchenne muscular dystrophy (DMD) is an X-linked recessive progressive lethal disorder caused by the lack of dystrophin, which determines myofibers mechanical instability, oxidative stress, inflammation, and susceptibility to contraction-induced injuries. Unfortunately, at present, there is no efficient therapy for DMD. Beyond several promising gene- and stem cells-based strategies under investigation, physical activity may represent a valid noninvasive therapeutic approach to slow down the progression of the pathology. However, ethical issues, the limited number of studies in humans and the lack of consistency of the investigated training interventions generate loss of consensus regarding their efficacy, leaving exercise prescription still questionable. By an accurate analysis of data about the effects of different protocol of exercise on muscles of mdx mice, the most widely-used pre-clinical model for DMD research, we found that low intensity exercise, especially in the form of low speed treadmill running, likely represents the most suitable exercise modality associated to beneficial effects on mdx muscle. This protocol of training reduces muscle oxidative stress, inflammation, and fibrosis process, and enhances muscle functionality, muscle regeneration, and hypertrophy. These conclusions can guide the design of appropriate studies on human, thereby providing new insights to translational therapeutic application of exercise to DMD patients.

The Effects of Resveratrol on Oxidative Stress Markers: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

OBJECTIVE

Recent trial studies have found that resveratrol supplementation beneficially reduces oxidative stress marker, but, there is no definitive consensus on this context. The present systematic review and meta-analysis aimed to investigate the effect of resveratrol supplementation on oxidative stress parameters.

METHODS

We searched databases of Pubmed, Scopus and Cochrane Library up to December 2018 with no language restriction. Studies were reviewed according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) and Cochrane handbook. To compare the effects of resveratrol with placebo, weighted mean difference (WMD) with 95% confidence intervals (CI) were pooled based on the random-effects model.

RESULTS

Among sixteen clinical trials, we found that resveratrol supplementation increased GPx serum levels significantly (WMD: 18.61; 95% CI: 8.70 to 28.52; P<0.001) but had no significant effect on SOD concentrations (WMD: 1.01; 95% CI: -0.72 to 2.74; P= 0.25), MDA serum levels (WMD: -1.43; 95% CI: -3.46 to 0.61; P = 0.17) and TAC (WMD: -0.09; 95% CI: -0.29 to 0.11; P = 0.36) compared to placebo. Finally, we observed that resveratrol supplementation may not have a clinically significant effect on oxidative stress.

CONCLUSION

However, the number of human trials is limited in this context, and further large prospective clinical trials are needed to confirm the effect of resveratrol supplement on oxidative stress markers.

Beneficial effect of soy isoflavones and soy isoflavones plus soy protein on serum concentration of C-reactive protein among postmenopausal women: An updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Scientists suggest that soy isoflavones or the combination of soy isoflavones and soy protein may have beneficial effects on inflammation. Thus, the present study aims at conducting a systematic review and meta-analysis on randomized controlled trials (RCTs) in which the effect of soy isoflavones and the combination of soy isoflavones and soy protein on serum concentration of C-reactive protein (CRP) among postmenopausal women is assessed.

METHODS AND MATERIALS

A literature searching was done to identify a breadth of related references in PubMed, Scopus, ISI Web of Science, Cochrane Library, and Clinicaltrials.gov up to December 2020. The mean change from baseline in the CRP concentrations and its standard deviation (SD) for both intervention and comparison groups were used to calculate the effect size. The summary of the overall effects and heterogeneity was estimated by using the DerSimonian and Laird random effects model. The protocol was registered in PROSPERO (No. CRD42020166053).

RESULTS

This study considered 23 articles for systematic review and 19 articles for meta-analysis. The overall effect presented a non-significant effect of soy isoflavones on serum CRP concentrations (WMD = 0.08 mg/L, 95 % CI: -0.08, 0.24; p = 0.302) and the overall effect of the combination of soy isoflavones and soy protein indicated non-significant effect in serum levels of CRP (WMD= -0.02 mg/L 95 % CI: -0.12, 0.08; p = 0.715).

CONCLUSION

Published RCTs did not provide strong evidence regarding beneficial effect of soy isoflavones or the combination of soy isoflavones and soy protein on serum CRP concentration among postmenopausal women.

Impact of Low Hemoglobin on Body Composition, Strength, and Redox Status of Older Hemodialysis Patients Following Resistance Training

INTRODUCTION

The purpose of this study was to: (i) investigate the effect of six months of resistance training (RT) on body composition, muscle strength, hematological patterns, and redox profile in maintenance hemodialysis (HD) patients, and; (ii) evaluate the effects of baseline concentrations of hemoglobin on the RT response.

METHODS

One hundred fifty-seven subjects with chronic kidney disease (CKD) were randomly allocated into two groups: Control [CTL, (n = 76)] and RT (n = 81). A first visit was required for anamnesis and anthropometric measurements. Venous blood samples were collected at baseline and after twenty-four weeks of training in all patients for the analysis of clinical and redox balance markers. The RT program spanned six months and consisted of three sets of 8-12 repetitions with a rating of perceived exertion between 5 and 8 for three weekly sessions. Each exercise session was performed in twelve resistance exercises and it least for approximately 40 min.

RESULTS

The main results demonstrated that RT decreased waist circumference by 3%, and decreased thiobarbituric reactive species (TBARS) by 28%. Moreover, RT increased handgrip strength by 28.4%, fat-free mass by 4.1%, hemoglobin by 5%, iron by 33.4%, glutathione by 121%, and Trolox equivalent antioxidant capacity by 14.2% (p < 0.05). Low hemoglobin concentrations impaired the effect of RT on fat-free mass gain.

CONCLUSION

Six months of RT in HD patients improved clinical parameters, such as hemoglobin, iron, body composition, and redox balance, while low hemoglobin concentration impaired exercise-benefits on fat-free mass in patients with CKD. These findings can contribute to a better clinical application of RT in the maintenance of hemodialysis patients.

Gravity sensing in plant and animal cells

Gravity determines shape of body tissue and affects the functions of life, both in plants and animals. The cellular response to gravity is an active process of mechanotransduction. Although plants and animals share some common mechanisms of gravity sensing in spite of their distant phylogenetic origin, each species has its own mechanism to sense and respond to gravity. In this review, we discuss current understanding regarding the mechanisms of cellular gravity sensing in plants and animals. Understanding gravisensing also contributes to life on Earth, e.g., understanding osteoporosis and muscle atrophy. Furthermore, in the current age of Mars exploration, understanding cellular responses to gravity will form the foundation of living in space.

Protective effect of gamma-aminobutyric acid against oxidative stress by inducing phase II enzymes in C2C12 myoblast cells

In this study, the cytoprotective effect of gamma-aminobutyric acid (GABA) via inducing phase II enzymes in C2C12 myoblasts was evaluated. The highest concentration of GABA (100 μM) significantly increased the cell viability by approximately 90% in hydrogen peroxide-induced C2C12 cells. The treatment with GABA (100 μM) effectively decreased the glutathione (GSH) depletion and the activities of antioxidant enzymes such as catalase (CAT) and superoxide dismutase (SOD). And, reactive oxygen species (ROS) levels were effectively reduced by about 50% in GABA-treated cells. In addition, the protein expression of phase II enzymes, such as NADPH:quinone oxidoreductase 1 and heme oxygenase-1 was significantly increased by GABA treatment. Moreover, GABA treatment increased the nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression in the nucleus of C2C12 myoblasts. Altogether, the results in this study indicate that GABA possesses the cytoprotective effects against oxidative insults by regulating the GSH levels, CAT and SOD activities, ROS scavenging activities, and expression of phase II enzymes through the activation of Nrf2 in C2C12 cells. Hence, this study suggests that the GABA supplementation could be effective in alleviating oxidative stress-induced muscle damage. PRACTICAL APPLICATIONS: GABA exists in the germ and bran layers of rice and is well-known as the inhibitory neurotransmitter in the central nervous system. GABA also has various health beneficial effects, such as preventing chronic alcohol-related diseases and lowering blood pressure. The present study shows the cytoprotective effect of GABA against oxidative stress in C2C12 myoblasts, and suggests that GABA has great potential as a functional food ingredient for attenuating oxidative stress-induced muscle damage.

Exogenous Ketones as Therapeutic Signaling Molecules in High-Stress Occupations: Implications for Mitigating Oxidative Stress and Mitochondrial Dysfunction in Future Research

High-stress occupations (ie, firefighters, military personnel, police officers, etc.) are often plagued by cardiometabolic diseases induced by exposure to chronic stressors. Interrupted sleep cycles, poor dietary patterns, lack of physical activity, and smoke exposure along with simultaneous psychological stressors promote chronic low-grade inflammation and excessive oxidative stress. Collectively, these data suggest that practical interventions which might mitigate the underlying pathologies of these cardiometabolic diseases are warranted. Ketones, specifically R-βHB, modulates intracellular signaling cascades such as the cellular redox ratios of NAD+/NADH, the activity of NAD dependent deacetylases SIRT1 and SIRT3, and promotes a robust mitochondrial environment which favors reductions in oxidative stress and inflammation. To date, the literature examining R-βHB as a signaling metabolite has mostly been performed from endogenous R-βHB production achieved through nutritional ketosis or cell culture and mouse models using exogenous R-βHB. To the authors knowledge, only 1 study has attempted to report on the effects of exogenous ketones and the mitigation of oxidative stress/inflammation. Therefore, the scope of this review is to detail the mechanisms of R-βHB as a signaling metabolite and the role that exogenous ketones might play in mitigating diseases in individuals serving in high-stress occupations.

Antioxidant Supplementation Modulates Neutrophil Inflammatory Response to Exercise-Induced Stress

The aim of the present report was to evaluate the inflammatory response to a 2000-m running test considering neutrophil myeloperoxidase as an inflammatory marker, and to verify if supplements rich in antioxidants could modulate Post-test antioxidant and anti-inflammatory responses. To this end, a 21-day homogenization period was carried out with three groups: a control group, a supplemented group taking an almond beverage enriched with vitamins C and E and a third group consuming the same beverage but enriched with Lippia citriodora extract. At the end of this period, participants performed a 2000-m run, and blood samples were obtained the day before and immediately after the running test. Plasma and neutrophils were isolated. As a result, plasma creatine kinase and myoglobin increased, indicating Post-test muscle damage. Plasma oxidative markers were increased in all groups, except in the group supplemented with the almond beverage. Neutrophil antioxidant enzymes were significantly increased only in the control group, suggesting an antioxidant effect of the supplements provided in the other groups. Myeloperoxidase activity was significantly increased after the test in the control group, while increased enzyme levels were detected in plasma of the supplement groups. Therefore, antioxidant consumption seems to favour myeloperoxidase release. The connection of this observation with post-exercise recovery will require further investigation.