Supplementation with vitamins C and E inhibits the release of interleukin-6 from contracting human skeletal muscle

The effect of vitamin C on the recovery of activity and survival of autografted ovaries through inhibition of oxidation and inflammation

Ovarian tissue autografting is a valuable clinical option to help restore fertility in women with cancer. However, many follicles are lost due to ischemia-reperfusion (IR) injury, which depletes follicles after grafting. We aimed to investigate the effect of vitamin C, an antioxidant with anti-apoptotic and anti-inflammatory properties, on improving the structure and function of autografted ovaries in mice. Thirty-six female NMRI mice (4-5 weeks old) were divided into three groups of 12: control (no grafting), autograft + vitamin C (50 mg/kg/day intraperitoneally), and autograft + saline (100 µl/day/animal, intraperitoneally). After the ovarian autografting and before the start of the experiment, each group was further divided into 7-day and 28-day subgroups. Seven days after ovary autografting, serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), and inflammatory factors were measured. On day 28, ovarian histology, DNA fragmentation, and estradiol and progesterone levels were assessed. Results were analyzed using one-way ANOVA and Tukey's test, with significance set at p<0.05. In the autograft + vitamin C group, there were significant increases in the mean total volume of the ovary, cortex (p<0.05), medulla, number of follicles, and levels of IL-10, progesterone, estradiol, and TAC (p<0.001), compared to the autograft group. Conversely, the rate of apoptosis and serum levels of MDA, IL-6, and TNF-α were notably reduced in the autograft + vitamin C group (p<0.001). These results suggest that vitamin C can significantly enhance the recovery of autografted ovaries through its antioxidant, anti-inflammatory, and anti-apoptotic effects.

Preconditioning Exercise Inhibits Neuron Ferroptosis and Ameliorates Brain Ischemia Damage by Skeletal Muscle-Derived Exosomes via Regulating miR-484/ACSL4 Axis

Aims: Although there is evidence that patients with stroke who exercise regularly before stroke have a better prognosis than those who do not exercise, the detailed mechanism remains unclear. Moreover, neuronal death plays a central role in neurological dysfunction caused by ischemic stroke. Thus, we investigated whether exercise could reduce stroke-induced neuronal death and its associated mediators in the current study. Results: Ferroptosis was the most dominant form of programmed cell death in neurons. Preconditioning exercise before stroke improved the neurological function and decreased the infarct area in rats with ischemic stroke. Preconditioning exercise attenuated stroke-induced ferroptosis by reducing lipid peroxidation (LPO) production, upregulating glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), and downregulating acyl-CoA synthetase long-chain family member 4 (ACSL4). High-throughput sequencing and dual luciferase reporter assays revealed that exercise-induced exosomal miR-484 inhibits Acsl4 expression. Moreover, we showed that exercise-induced exosomal miR-484 is mainly derived from skeletal muscle, and the neuroprotective effect of preconditioning exercise is suppressed by inhibiting miR-484 production in skeletal muscle. Innovation: This study suggested that neuronal ferroptosis is the most dominant form of programmed cell death in a hypoxic environment. Moreover, we showed that the ferroptosis pathway is a potential therapeutic target in ischemic stroke and that preconditioning exercise could be an effective antioxidant intervention for cerebral ischemia. Conclusion: Our work revealed that preconditioning exercise before stroke exerts neuroprotective effects against brain ischemia by skeletal muscle-derived exosomal miR-484 via inhibiting ferroptosis. Antioxid. Redox Signal. 41, 769-792.

Molecular Dissection of the Arsenic-Induced Leukocyte Incursion into the Inflamed Thymus and Spleen and Its Amelioration by Co-supplementation of L-Ascorbic Acid and α-Tocopherol

Arsenic, a surreptitious presence in our environment, perpetuates a persistent global menace with its deleterious impacts. It possesses the capability to trigger substantial immunosuppression by instigating inflammation in critical organs like the thymus and spleen. L-Ascorbic acid (L-AA) exhibits robust immunoregulatory prowess by orchestrating the epigenetic terrain through TET and JHDM pathways. Conversely, α-tocopherol (α-T) demonstrates the capacity to dampen the production of pro-inflammatory cytokines by modulating the PI3K-Akt axis. Given these insights, this inquiry embarks on exploring the mitigative potential of L-AA and α-T co-supplementation at the transcriptome level within leukocytes under arsenic exposure. Concurrently, the research endeavours to unravel the potent anti-inflammatory effects of administering α-T and L-AA, alleviating inflammation within the spleen and thymus amidst arsenic-induced insult and delving deeply into their immunomodulatory mechanisms. The rats were randomly allocated into eight distinct groups for subsequent experimentation: (I) the control group was administered solely with distilled water as the vehicle (control); (II) NaAsO2-treated group (As); (III) NaAsO2 treated along with L-ascorbic acid and α-tocopherol supplemented group (As + L-AA + α-T); (IV) L-ascorbic acid and α-tocopherol supplemented group (L-AA + α-T); (V) NaAsO2 treated along with L-ascorbic acid supplemented group (As + L-AA); (VI) only L-ascorbic acid supplemented group (L-AA); (VII) NaAsO2 treated along with α-tocopherol supplemented group (As + α-T); (VIII) only α-tocopherol supplemented group (α-T). Rats treated with NaAsO2 exhibited an increased neutrophil count in their bloodstream, as revealed by a comprehensive transcriptomic analysis showcasing heightened expressions of ItgaM, MMP9, and Itga4 within circulating leukocytes under arsenic exposure. Concurrently, arsenic heightened the expression of pro-inflammatory cytokines within the thymus and spleen. This elevated cytokine activity promoted the upregulation of ICAM-1 on vascular endothelial cells, facilitating the infiltration of Ly6g + leukocytes into the afflicted thymus and spleen. Remarkably, the combination of L-AA acid and α-T demonstrated substantial therapeutic efficacy, adeptly reducing the influx of Ly6g + leukocytes into these immune sites and subsequent reduction of excessive collagen deposition. The dynamic duo of L-AA and α-T achieved this amelioration by suppressing the expression of ItgaM, MMP9, and Itga4 mRNA within circulating leukocytes and moderating tissue levels of pro-inflammatory cytokines in arsenic-exposed thymus and spleen.

Effects of 8-week strength training on basal hormone levels, sex hormone binding globulin, insulin-like growth factor binding protein-3, oxidative stress markers, and IL-6 levels in adolescent athletes

PURPOSE

The aim of the study was to investigate how 8-week strength training affects adolescent athletes' basal hormone concentrations, sex hormone binding globulin (SHBG), insulin-like growth factor binding protein-3 (IGFBP-3), cytokine, and oxidative stress markers.

METHODS

Twenty adolescent handball players participated in this study. The participants were randomly divided into the strength training group (ST, n = 10) and the control group (C, n = 10). ST participates in strength training 3 sessions a week for 8 weeks and C participates only in handball training. We quantified serum basal hormone concentration, SHBG, IGFBP3, oxidative stress markers, and IL-6 in each subject's blood samples before and after 8 weeks of strength training.

RESULTS

Interestingly, while insulin-like growth factor-1 (IGF-1) concentration declined in group C (p < 0.05), it did not in ST (p > 0.05). Furthermore, the basal concentration of growth hormone (GH), total testosterone (T), cortisol (Cor), total antioxidant status (TAS), and serum-free androgen index (FAI) basal concentration did not change in ST and C. Basal IGFBP-3 and SHBG concentrations decreased only in ST (p < 0.05), but not in C (p > 0.05). Serum-free testosterone (FT) levels increased in ST and C (p > 0.05). Total oxidant status (TOS) and oxidative stress index (OSI) reduced ST and C (p < 0.05). Serum interleukin-6 (IL-6) levels did not alter groups ST and C.

CONCLUSION

Strength training did not affect basal serum concentrations of T, GH, IGF-1, COR, IL-6, and TAS, but it caused a decrease in SHBG and IGFBP3 concentrations in ST. Increased basal FT concentration and improved serum TOS may not depend on strength training.

Beyond muscles: Investigating immunoregulatory myokines in acute resistance exercise - A systematic review and meta-analysis

Myokines, released from the muscle, enable communication between the working muscles and other tissues. Their release during physical exercise is assumed to depend on immune-hormonal-metabolic interactions concerning mode (endurance or resistance exercise), duration, and intensity. This meta-analysis aims to examine the acute changes of circulating myokines inducing immunoregulatory effects caused by a bout of resistance exercise and to consider potential moderators of the results. Based on this selection strategy, a systematic literature search was conducted for resistance exercise intervention studies measuring interleukin (IL-) 6, IL-10, IL-1ra, tumor necrosis factor (TNF-) α, IL-15, IL-7, transforming growth factor (TGF-) β1, and fractalkines (FKN) before and immediately after resistance exercise in healthy individuals. Random-effects meta-analysis was performed for each myokine. We identified a moderate positive effect of resistance exercise for IL-6 and IL-1ra. Regarding IL-15 and TNF-α, small to moderate effects were found. For IL-10, no significant effect was observed. Due to no data, meta-analyses for IL-7, TGF-β1, and FKN could not be performed. No moderators (training status, type of exercise, risk of bias, age, sex, time of day, exercise volume, exercise intensity, exercise dose) of the results were detected for all tested myokines. Taken together, this systematic review and meta-analysis showed immediate positive effects of an acute resistance exercise session on IL-6, IL-1ra, TNF-α, and IL-15 levels.

Physical exercise in kidney disease: A commonly undervalued treatment modality

BACKGROUND

Physical inactivity has been identified as a risk factor for multiple disorders and a strong association exists between chronic kidney disease (CKD) and a sedentary lifestyle. Even though physical activity is crucial in the development and progression of disease, the general focus of the current medical practice is the pharmacological perspective of diseases with inadequate emphasis on lifestyle intervention.

METHODS

In this narrative review we explain the pathophysiological mechanisms underlying the beneficial effects of physical exercise on CKD in addition to discussing the clinical studies and trials centred on physical exercise in patients with CKD.

RESULTS

Physical activity influences several pathophysiological mechanisms including inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism. While exercise can initially induce stress responses like inflammation and oxidative stress, long-term physical activity leads to protective countermeasures and overall improved health. Trials in pre-dialysis CKD patients show that exercise can lead to reductions in body weight, inflammation markers and fasting plasma glucose. Furthermore, it improves patients' functional capacity, cardiorespiratory fitness and quality of life. The effects of exercise on kidney function have been inconsistent in these trials. In haemodialysis, peritoneal dialysis and kidney transplant patients exercise interventions improve cardiorespiratory fitness, walking capacity and quality of life. Combined training shows the best performance to increase peak oxygen uptake in haemodialysis patients. In kidney transplant recipients, exercise improves walking performance, quality of life and potentially arterial stiffness. However, exercise does not affect glucose metabolism, serum cholesterol and inflammation biomarkers. Long-term, adequately powered trials are needed to determine the long-term feasibility, and effects on quality of life and major clinical outcomes, including mortality and cardiovascular risk, in all CKD stages and particularly in kidney transplant patients, a scarcely investigated population.

CONCLUSION

Physical exercise plays a crucial role in ameliorating inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism, and contributes significantly to the quality of life for patients with CKD, irrespective of the treatment and stage. Its direct impact on kidney function remains uncertain. Further extensive, long-term trials to conclusively determine the effect of exercise on major clinical outcomes such as mortality and cardiovascular risk remain a research priority.

Dose-response effect of L-citrulline on skeletal muscle damage after acute eccentric exercise: an in vivo study in mice

Background

Eccentric exercise may trigger mechanical stress, resulting in muscle damage that may decrease athletic performance. L-citrulline potentially prevents skeletal muscle damage after acute eccentric exercise. This study aimed to assess the dose-response effect of L-citrulline as a preventive therapy for skeletal muscle damage in mice after acute eccentric exercise.

Methods

This is a controlled laboratory in vivo study with a post-test-only design. Male mice (BALB/c, n = 25) were randomized into the following groups: a normal control (C1) (n = 5); a negative control (C2) with downhill running and placebo intervention (n = 5); treatment groups: T1 (n = 5), T2 (n = 5), and T3 (n = 5), were subjected to downhill running and 250, 500, and 1,000 mg/kg of L-citrulline, respectively, for seven days. Blood plasma was used to determine the levels of TNNI2 and gastrocnemius muscle tissue NOX2, IL-6, and caspase 3 using ELISA. NF-κB and HSP-70 expressions were determined by immunohistochemistry.

Results

Skeletal muscle damage (plasma TNNI2 levels) in mice after eccentric exercise was lower after 250 and 500 mg/kg of L-citrulline. Further, changes in oxidative stress markers, NOX2, were reduced after a 1,000 mg/kg dose. However, a lower level of change has been observed in levels of cellular response markers (NF-κB, HSP-70, IL-6, and caspase 3) after administration of L-citrulline doses of 250, 500, and 1,000 mg/kg.

Conclusion

L-citrulline may prevent skeletal muscle damage in mice after acute eccentric exercise through antioxidant effects as well as inflammatory and apoptotic pathways. In relation to dose-related effects, it was found that L-citrulline doses of 250, 500, and 1,000 mg/kg significantly influenced the expression of NF-κB and HSP-70, as well as the levels of IL-6 and caspase 3. Meanwhile, only doses of 250 and 500 mg/kg had an impact on TNNI2 levels, and the 1,000 mg/kg dose affected NOX2 levels.

The exercise IL-6 enigma in cancer

Interleukin (IL)-6 elicits both anticancer and procancer effects depending on the context, which we have termed the 'exercise IL-6 enigma'. IL-6 is released from skeletal muscles during exercise to regulate short-term energy availability. Exercise-induced IL-6 provokes biological effects that may protect against cancer by improving insulin sensitivity, stimulating the production of anti-inflammatory cytokines, mobilising immune cells, and reducing DNA damage in early malignant cells. By contrast, IL-6 continuously produced by leukocytes in inflammatory sites drives tumorigenesis by promoting chronic inflammation and activating tumour-promoting signalling pathways. How can a molecule have such opposing effects on cancer? Here, we review the roles of IL-6 in chronic inflammation, tumorigenesis, and exercise-associated cancer prevention and define the factors that underpin the exercise IL-6 enigma.

Anti-Inflammatory Effect of Vitamin C during the Postoperative Period in Patients Subjected to Total Knee Arthroplasty: A Randomized Controlled Trial

Vitamin C, a potent reducing and antioxidant agent, plays an important role in the body, aiding in the growth of cartilage and bones. It is also involved in mechanisms that help reduce inflammation and its effects on the body. In addition, vitamin C decreases pro-inflammatory cytokines, such as IL-6, which produce acute-phase proteins such as CRP and influence inflammatory markers such as ESR. We carried out a study with 110 patients who underwent total knee replacement surgery. We divided the patients into two groups, in which the intervention group received 15 g of parenteral vitamin C during the immediate postoperative period while the control group did not. Patients who received 15 g of vitamin C after total knee replacement surgery had decreased inflammatory markers, specifically CRP and ESR. Overall, administering vitamin C in the post-surgical period results in improved management of inflammation, as evidenced by a decrease in CRP and ESR values. This leads to faster recovery and better healing outcomes for patients undergoing total knee replacement surgery. Furthermore, the beneficial effects of vitamin C in reducing proinflammatory cytokines, reducing the need for opioid analgesics, and its mild adverse effects make it a promising adjuvant in managing postoperative recovery.

Voluntary exercise does not always suppress lung cancer progression

Physical exercise can lower lung cancer incidence. However, its effect on lung cancer progression is less understood. Studies on exercising mice have shown decreased ectopic lung cancer growth through the secretion of interleukin-6 from muscles and the recruitment of natural killer (NK) cells to tumors. We asked if exercise suppresses lung cancer in an orthotopic model also. Single-housed C57Bl/6 male mice in cages with running wheels were tail vein-injected with LLC1.1 lung cancer cells, and lung tumor nodules were analyzed. Exercise did not affect lung cancer. Therefore, we also tested the effect of exercise on a subcutaneous LLC1 tumor and a tail vein-injected B16F10 melanoma model. Except for one case of excessive exercise, tumor progression was not influenced. Moderately exercising mice did not increase IL-6 or recruit NK cells to the tumor. Our data suggest that the exercise dose may dictate how efficiently the immune system is stimulated and controls tumor progression.

Review of the health-promoting effects of exercise and the involvement of myokines

Exercise reduces the risk of obesity-based, lifestyle-related diseases, such as metabolic abnormalities and cardiovascular diseases. The present review covers the health-promoting effects of exercise from the point of view of the physiologically active factor myokine, which is secreted by skeletal muscle, and focuses on the skeletal muscle as a new endocrine organ. Myokines have various effects, such as preventing metabolic syndrome by breaking down fat, preventing diabetes by improving glucose metabolism, and preventing progression of arteriosclerosis, dementia, and osteoporosis by enhancing bone metabolism. These substances also stabilize blood pressure, prevent cancer, increase immunity against infections, and prevent the development of age-associated diseases. Myokines are secreted by skeletal muscle into blood vessels, allowing them to exert systemic endocrine effects in organs throughout the body. Myokines are involved in bodily homeostasis and adaptation to the environment, and function by a mechanism similar to that of the skeletal muscle mass regulatory mechanism. Determining the relationships between multiple organs and their biological significance is important for exercise and health research. Progress in this field is expected to result in the identification of pathological mechanisms of action, development of new drugs, evaluation of the effectiveness of biomarkers over a wide range, and future improvement in healthcare.

Effect of Kinesio tape and Compression sleeves on delayed onset of muscle soreness: a single-blinded randomized controlled trial

BACKGROUND

Both Kinesio Tape (KT) and Compression Sleeves (CS) can relieve Delayed Onset Muscle Soreness (DOMS) to a certain extent, but there is no study report on the difference in the effectiveness of the KT and CS whether the effect is better when used at the same time. The purpose of this study was to compare the effects of KT and CS on the recovery of muscle soreness, isokinetic strength, and body fatigue after DOMS.

METHODS

In this single-blinded randomized controlled trial, 32 participants aged 18 to 24 years were randomly divided into Control group (CG), Compression Sleeves group (CSG), Kinesio Tape group (KTG), Compression Sleeves and Kinesio Tape group (CSKTG), between October 2021 and January 2022. KTG uses Kinesio Tape, CSG wears Compression Sleeves, and CSKTG uses both Compression Sleeves and Kinesio Tape. Outcomes were performed at five-time points (baseline, 0 h, 24 h, 48 h, 72 h), Primary outcome was pain level Visual Analogue Scale (VAS), and Secondary outcomes were Interleukin 6, Peak Torque/Body Weight, Work Fatigue. Statistical analyses were performed using the repeated measures analysis of variance method.

SETTING

Laboratory.

RESULTS

After the intervention, VAS reached the highest at 24 h after exercise-induced muscle soreness, while the KTG and CSG at each time point were less than CG, and the scores of CSKTG at 24 h and 48 h were less than those of KTG and CSG in the same period (P < 0.05). Interleukin 6, at 24 h, CSKTG is lower than KTG 0.71(95%CI: 0.43 to 1.86) and CG 1.68(95%CI: 0.06 to 3.29). Peak Torque/Body Weight, at 24 h, CG was lower than CSKTG 0.99(95%CI: 0.42 to 1.56), KTG 0.94(95%CI: 0.37 to 1.52), and CSG 0.72(95%CI: 0.14 to 1.29); at 72 h, CG was lower than CSKTG 0.65(95%CI: 0.13 to 1.17) and KTG 0.58(95%CI: 0.06 to 1.10). Work Fatigue, at 24 h, CG was lower than KTG 0.10(95%CI: 0.02 to 1.78) and CSKTG 0.01(95%CI: -0.07 to 0.09). At 48 h, CG was lower than KTG 0.10(95%CI: 0.13 to 1.17) and CSKTG 0.11(95%CI: 0.03 to 0.18).

CONCLUSIONS

Kinesio Tape can significantly reduce DOMS pain, and Kinesio Tape has a better recovery effect on Delayed Onset Muscle Soreness than Compression Sleeves. Kinesio Tape combined with Compression Sleeves is helpful to alleviate the Delayed Onset Muscle Soreness pain, speeding up the recovery of muscle strength, and shortening the recovery time after Delayed Onset Muscle Soreness.

TRIAL REGISTRATION

Registration number: This study was also registered on 11/10/2021, at the Chinese Clinical Trial Registry (ChiCTR2100051973).

IL-6 signaling in acute exercise and chronic training: Potential consequences for health and athletic performance

The cytokine interleukin-6 (IL-6) is involved in a diverse set of physiological processes. Traditionally, IL-6 has been thought of in terms of its inflammatory actions during the acute phase response and in chronic conditions such as rheumatoid arthritis and obesity. However, IL-6 is also an important signaling molecule during exercise, being acutely released from working muscle fibers with increased exercise duration, intensity, and muscle glycogen depletion. In this context, IL-6 enables muscle-organ crosstalk, facilitating a coordinated response to help maintain muscle energy homeostasis, while also having anti-inflammatory actions. The range of actions of IL-6 can be explained by its dichotomous signaling pathways. Classical signaling involves IL-6 binding to a cell-surface receptor (mbIL-6R; present on only a small number of cell types) and is the predominant signaling mechanism during exercise. Trans-signaling involves IL-6 binding to a soluble version of its receptor (sIL-6R), with the resulting complex having a much greater half-life and the ability to signal in all cell types. Trans-signaling drives the inflammatory actions of IL-6 and is the predominant pathway in disease. A single nucleotide polymorphism (rs2228145) on the IL-6R gene can modify the classical/trans-signaling balance through increasing the levels of sIL-6R. This SNP has clinical significance, having been linked to inflammatory conditions such as rheumatoid arthritis and type 1 diabetes, as well as to the severity of symptoms experienced with COVID-19. This review will describe how acute exercise, chronic training and the rs2228145 SNP can modify the IL-6 signaling pathway and the consequent implications for health and athletic performance.

Antioxidative and Anti-Inflammatory Activity of Ascorbic Acid

Ascorbic acid, as a one of the basic exogenous vitamins, occurs in the body in the form of ascorbate, known for its strong antioxidant and anti-inflammatory properties. The presented review shows not only the importance of ascorbate as a free radical scavenger but also summarizes its antioxidant action based on other mechanisms, including the activation of intracellular antioxidant systems and its effect on the NFκB/TNFα pathway and apoptosis. Ascorbate interacts with small-molecule antioxidants, including tocopherol, glutathione, and thioredoxin; it can also stimulate biosynthesis and the activation of antioxidant enzymes, such as superoxide dismutase, catalase, or glutathione peroxidase. Moreover, ascorbate promotes the activity of transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this regard, both DNA, proteins, and lipids are protected against oxidation, leading to an inflammatory reaction and even cell death. Although ascorbate has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in the prevention of DNA mutation, inflammation, and cell apoptosis, especially in relation to cancer cells, is controversial.

Relationship between Exercise Intensity and IL-6 Increase during an 80 km Long-Distance Running Race

Background: IL-6 plasma concentration (IL-6PC) reflects the systemic inflammation related to exercise intensity level. This study aims to describe the IL-6PC kinetics during a long-distance running race. IL-6PC was measured in 20 male runners before (0 km), at each refreshment point (at 21 and 53 km, i.e., k₂₁ and k₅₃, respectively) and at the end of an 80 km long-distance run (k₈₀). Methods: IL-6PC variations (absolute and relative values in each of the three sections (S)) were calculated over S1 (0_k₂₁), S2 (k₂₁_k₅₃) and S3 (k₅₃_k₈₀) and compared with the exercise intensity (duration*race speed) within each section. Results: The mean IL-6PC increased during the run: 2.1 ± 0.6 ng.L⁻¹ at 0 km, 21.0 ± 11.3 ng.L⁻¹ at k₂₁, 38.9 ± 13.0 ng.L⁻¹ at k₅₃ and 49.8 ± 11.9 ng.L⁻¹ at k₈₀. Exercise intensity increased between S1 (24.2 ± 0.5) and S2 (51.9 ± 3.2) (p = 0.04) but not between S2 and S3 (67.4 ± 4.5) (p = 0.69). IL-6PC variation was associated with exercise intensity within S1 (p = 0.03) and S2 (p = 2 × 10⁻³) and showed at least a trend within S3 (p = 0.06). Conclusions: IL-6PC increases that occur during the early stages of a long-distance run are associated with the running intensity, and then IL-6PC remain stable after the reduction in intensity related to the decrease in running speed.

Effects of Hypoxia-Hyperoxia Preconditioning on Indicators of Muscle Damage After Acute Resistance Exercise in Male Athletes

Purpose

The purpose of this study was to investigate the effects of acute repeated hypoxia–hyperoxia preconditioning on resistance exercise (RE)-induced muscle damage in male athletes.

Methods

Eleven young male athletes participated in this randomized double-blind counter-balanced crossover study, and were divided into Normoxia (N) and Hypoxia–Hyperoxia (HH) trials. Subjects of the respective trials were supplied with normoxic (FiO₂ = 0.21), or alternating hypoxic/hyperoxic air (FiO₂ = 0.10/0.99, 5 min each) for 60 min. Thirty minutes after preconditioning, subjects performed acute bouts of RE consisting of bench press, deadlift, and squats. Each exercise included 6 sets of 10 repetitions at 75% one-repetition maximum (1RM) with 2 min rest between sets. After a 2-week washout period, subjects changed trials and completed the same study procedure after the alternate preconditioning. Muscle soreness, maximal voluntary contraction (MVC), and circulating biochemical markers were tested before preconditioning (baseline) and during recovery at 0, 24, and 48 h after exercise.

Results

Acute RE significantly increased levels of muscle soreness, creatine kinase (CK) and myoglobin (Mb), and decreased levels of peak knee extension torque in the N trial. Muscle soreness, CK, and Mb levels of the HH trial were significantly lower than that of the N trial after exercise. Interestingly, interleukin-6 (IL-6) levels of the HH trial increased significantly 0 h after exercise compared to baseline and were significantly higher than that of the N trial 0 and 24 h after exercise. However, no significant differences of thiobarbituric acid reactive substances (TBARS), cortisol, testosterone, peak torque, and average power levels were found between N and HH trials during recovery.

Conclusion

Our data suggest that pre-exercise treatment of alternating hypoxic/hyperoxic air could attenuate muscle damage and pain after acute RE, but has no effect on muscle strength recovery in young male athletes.

Sequential Submaximal Training in Elite Male Rowers Does Not Result in Amplified Increases in Interleukin-6 or Hepcidin

Previous research investigating single bouts of exercise have identified baseline iron status and circulating concentrations of interleukin-6 (IL-6) as contributors to the magnitude of postexercise hepcidin increase. The current study examined the effects of repeated training bouts in close succession on IL-6 and hepcidin responses. In a randomized, crossover design, 16 elite male rowers completed two trials, a week apart, with either high (1,000 mg) or low (<50 mg) calcium pre-exercise meals. Each trial involved two, submaximal 90-min rowing ergometer sessions, 2.5 hr apart, with venous blood sampled at baseline; pre-exercise; and 0, 1, 2, and 3 hr after each session. Peak elevations in IL-6 (approximately 7.5-fold, p < .0001) and hepcidin (approximately threefold, p < .0001) concentrations relative to baseline were seen at 2 and 3 hr after the first session, respectively. Following the second session, concentrations of both IL-6 and hepcidin remained elevated above baseline, exhibiting a plateau rather than an additive increase (2 hr post first session vs. 2 hr post second session, p = 1.00). Pre-exercise calcium resulted in a slightly greater elevation in hepcidin across all time points compared with control (p = .0005); however, no effect on IL-6 was evident (p = .27). Performing multiple submaximal training sessions in close succession with adequate nutritional support does not result in an amplified increase in IL-6 or hepcidin concentrations following the second session in male elite rowers. Although effects of calcium intake require further investigation, athletes should continue to prioritize iron consumption around morning exercise prior to exercise-induced hepcidin elevations to maximize absorption.

Effects of Red-Fleshed Pitaya (Selenicereus polyrhizus) Ingestion after Strenuous Exercise on Creatine Kinase and Mitochondrial Function in Rat Muscle Cells

BACKGROUND: Free radicals formed during strenuous exercise through an increase in reactive oxygen species induce damage to tissues (e.g., muscle and liver) and cause oxidative damage to cells, resulting in mitochondrial dysfunction. AIM: As an effective method to repair mitochondrial muscle cell function, this study investigated the effects of red-fleshed pitaya (RFP) ingestion on creatine kinase (CK), which is a biomarker for muscle tissue damage, and malondialdehyde (MDA) levels during strenuous exercise. METHODS: This study involved 25 3-month-old male rats with an average weight of 200 g. The RFP extract was obtained through ethanol extraction and concentrated using an air-drying method. Rats were randomly allocated into five groups as follows: Two control groups (K1 [no-exercise, no RFP] and K2 [exercise, no RFP]) and three test groups (P1, P2, and P3; subjected to exercise and treated with 75, 150, and 300 mg kg−1 body weight of RFP, respectively). The exercise was in the form of swimming for 20 min 3 times/week for 31 days. CK and MDA were measured through an enzyme-linked immunosorbent assay, and histopathological examinations were performed through hematoxylin and eosin staining of rat muscles. RESULTS: The MDA levels after the ingestion of RFP extracts were compared between the K2 group and the P1, P2, and P3 groups. The results showed significant differences (p < 0.05 for P1 and P2, and p < 0.01 for P3), indicating the production of free radicals and CK, with features of damaged muscle cells based on histopathology. Ingestion of the RFP extract led to improvements in soleus muscle cells, resulting in cell function repair. CONCLUSION: Levels of MDA and CK increased during exercise, which caused significant muscle damage. However, after treatment with the RFP extract, the levels of both markers decreased. Thus, strenuous exercise causes an increase in reactive oxygen species, resulting in increased free radical levels. RFP ingestion decreased oxidative stress levels, thus repairing mitochondrial cell function.

Effects of the combination of vitamins C and E supplementation on oxidative stress, inflammation, muscle soreness, and muscle strength following acute physical exercise: meta-analyses of randomized controlled trials

Background:The combined supplementation of vitamins C and E potentially can mitigate oxidative stress (OS) and accelerate recovery following exercise. However, there is little evidence and a lack of consensus on the effects of these vitamins for this purpose. The objective of this systematic review was to summarize the evidence on the effects of the combined supplementation of vitamins C and E in OS, inflammatory markers, muscle damage, muscle soreness, and musculoskeletal functionality following acute exercise. Methods: The search was carried out from inception until March 2021, on MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science, and SPORT Discus. We included placebo-controlled randomized clinical trials (RCTs) that evaluated the effects of combined supplementation of vitamins C and E in OS, inflammatory markers, muscle damage, muscle soreness, and muscle strength following a single bout of exercise. Random-effect meta-analyses were used to compare pre to post-exercise mean changes in subjects who received supplementation with vitamins C and E or placebo versus controls. Data are presented as standard mean difference (SMD) and 95% confidence interval (95% CI). Results: Eighteen RCTs, accounting for data from 322 individuals, were included. The use of vitamins attenuated lipid peroxidation (SMD= -0.703; 95% CI= -1.035 to -0.372; p < 0.001), IL-6 (SMD= -0.576; 95%CI= -1.036 to -0.117; p = 0.014), and cortisol levels (SMD= -0.918; 95%CI= -1.475 to -0.361; p = 0.001) immediately, and creatine kinase levels 48 h following exercise (SMD= -0.991; 95%CI= -1.611 to -0.372; p = 0.002). Supplementing the combination of vitamins had no effects on protein carbonyls, reduced/oxidized glutathione ratio, catalase, interleukin-1Ra, C-reactive protein, lactate dehydrogenase, muscle soreness, and muscle strength. Conclusion: Prior supplementation of the combination of vitamins C and E attenuates OS (lipid peroxidation), the inflammatory response (interleukin-6), cortisol levels, and muscle damage (creatine kinase) following a session of exercise.

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.

Mitochondria-targeted antioxidant supplementation does not affect muscle soreness or recovery of maximal voluntary isometric contraction force following muscle-damaging exercise in untrained men: a randomised clinical trial

Unaccustomed exercise causes muscle damage resulting in loss of muscle function, which may be attributable to exercise-induced increases in skeletal muscle reactive oxygen species (ROS). This study examined the effect of mitochondria-targeted antioxidant supplementation on recovery of muscle function following exercise. Thirty-two untrained men received MitoQ (20 mg/day) or a placebo for 14 days before performing 300 maximal eccentric contractions of the knee extensor muscles of one leg. Muscle function was assessed using isokinetic dynamometry before, immediately after, and 24, 48, 72, and 168 hours after exercise. Muscle soreness was assessed using a visual analogue scale 24, 48, 72, and 168 hours after exercise. Blood samples were collected before, immediately after, and 2, 24, 48, 72, and 168 hours after exercise and urine samples were collected before and during the 48 hours after exercise. The reduction in maximal voluntary isometric contraction force and peak concentric torque following exercise was unaffected by MitoQ while recovery of peak eccentric torque was delayed in the MitoQ group. Exercise-induced increases in urine F2-isoprostanes were unaffected by MitoQ. MitoQ augmented exercise-induced increases in plasma CK levels while plasma IL-6 was similar between groups. Muscle soreness was not affected by MitoQ. These results indicate that MitoQ does not attenuate post-exercise muscle soreness and may delay recovery of muscle function following eccentric exercise. Novelty: • Post-exercise recovery of maximal voluntary isometric contraction force and peak concentric torque were unaffected by MitoQ. • MitoQ delayed post-exercise recovery of peak eccentric torque. • Post-exercise muscle soreness was unaffected by MitoQ.

Effects of Exercise Training on the Autonomic Nervous System with a Focus on Anti-Inflammatory and Antioxidants Effects

Studies show that the autonomic nervous system (ANS) has an important impact on health in general. In response to environmental demands, homeostatic processes are often compromised, therefore determining an increase in the sympathetic nervous system (SNS)’s functions and a decrease in the parasympathetic nervous system (PNS)’s functions. In modern societies, chronic stress associated with an unhealthy lifestyle contributes to ANS dysfunction. In this review, we provide a brief introduction to the ANS network, its connections to the HPA axis and its stress responses and give an overview of the critical implications of ANS in health and disease—focused specifically on the immune system, cardiovascular, oxidative stress and metabolic dysregulation. The hypothalamic–pituitary–adrenal axis (HPA), the SNS and more recently the PNS have been identified as regulating the immune system. The HPA axis and PNS have anti-inflammatory effects and the SNS has been shown to have both pro- and anti-inflammatory effects. The positive impact of physical exercise (PE) is well known and has been studied by many researchers, but its negative impact has been less studied. Depending on the type, duration and individual characteristics of the person doing the exercise (age, gender, disease status, etc.), PE can be considered a physiological stressor. The negative impact of PE seems to be connected with the oxidative stress induced by effort.

Interleukin 6 as an energy allocator in muscle tissue

Extensive research has shown that interleukin 6 (IL-6) is a multifunctional molecule that is both proinflammatory and anti-inflammatory, depending on the context. Here, we combine an evolutionary perspective with physiological data to propose that IL-6's context-dependent effects on metabolism reflect its adaptive role for short-term energy allocation. This energy-allocation role is especially salient during physical activity, when skeletal muscle releases large amounts of IL-6. We predict that during bouts of physical activity, myokine IL-6 fulfills the three main characteristics of a short-term energy allocator: it is secreted from muscle in response to an energy deficit, it liberates somatic energy through lipolysis and it enhances muscular energy uptake and transiently downregulates immune function. We then extend this model of energy allocation beyond myokine IL-6 to reinterpret the roles that IL-6 plays in chronic inflammation, as well as during COVID-19-associated hyperinflammation and multiorgan failure.

Chronic Aerobic Training at Different Volumes in the Modulation of Macrophage Function and in vivo Infection of BALB/c Mice by Leishmania major

Physical inactivity is one of the main causes of chronic diseases; however, strenuous exercise can induce immunosuppression. Several studies suggest that moderate amounts of exercise lead to a Th1 response, favoring the resolution of infections caused by intracellular microorganisms, while high volumes of exercise tend to direct the response to Th2, favoring infection by them. Leishmaniasis is a parasitic disease promoted by parasites of the Leishmania genus, with clinical manifestations that vary according to the species of the parasite and the immune response of the host. The experimental Leishmania major–BALB/C mouse model provides a good model for the resistance (Th1 response) or susceptibility (Th2 response) that determines the progression of this infection. The aim of this study was to evaluate the effect of aerobic training at different volumes on modulation of in vitro macrophage infection by L. major, as well as to assess the effect of high volume (HV) aerobic training on the development of L. major in vivo in BALB/c mice. Uninfected animals were submitted to various exercise volumes: none (SED), light (LV), moderate (MV), high (HV), very high (VHV), and tapering (TAP). The macrophages of these animals were infected by L. major and the LV and MV groups showed a decrease in the infection factor, while the VHV showed an increase in the infection factor, when treated with LPS. The cytokine concentration pattern measured in the supernatants of these macrophages suggested a predominant Th1 response profile in the LV and MV groups, while the Th2 profile predominated in the VHV and TAP groups. Groups of BALB/C mice infected with L. major were subjected to high volume (iHV) or non-periodized high volume (iNPHV) exercise or kept sedentary (iSED). The exercised animals suffered a significant increase in injuries caused by the parasites. The animals in the group submitted to high volume exercise (iHV) showed visceralization of the infection. These data strongly suggest that a very high volume of aerobic training increased the susceptibility of BALB/C mice to L. major infection, while moderate distribution of training loads promoted immunological balance, better controlling the infection by this parasite.

Effects of Euterpe edulis Martius on inflammatory responses to high-intensity intermittent exercise: Crossover randomized trial

OBJECTIVE

High-intensity intermittent exercise (HIIE) may enhance the antiinflammatory status. The juçara fruit juice (JFJ) has well-established antioxidant and antiinflammatory properties. This study investigated the effect of JFJ consumption on the inflammatory response to HIIE in physically active subjects.

METHODS

In a randomized crossover design, 15 men were assigned to drink 250 mL of either JFJ or water (control) 1 h before a cycling HIIE session (seven sets of 60 s at 100% peak power output; 75 s recovery between sets). Blood samples were obtained before and at 0, 30, and 60 min post-HIIE, and the serum was analyzed for interleukin (IL)-6, IL-1β, IL-8, IL-10, tumor necrosis factor-α, and cortisol.

RESULTS

After HIIE, the IL-6 levels were higher than baseline (percent change) at 30 min (P = 0.041) and 60 min (P = 0.038) for the control, but were unaffected by JFJ. IL-10 was higher in the JFJ group than in the control at 30 min (d = ‒0.63). Tumor necrosis factor-α was lower than baseline at 30 min for the control (d = ‒0.71) and at 60 min for the JFJ group (d = ‒0.60). For control, cortisol increased to higher than the baseline at 30 and 60 min (d = 0.54 and d = 0.76, respectively). For the JFJ group, the cortisol levels were significantly higher than the baseline at 30 min (P = 0.022). Performance during sprints was higher in the JFJ group than in the control (P = 0.002). In the control group, performance was with both IL-6 (semipartial correlation; sr = -0.59, large effect size) and cortisol at 0 h (sr = -0.52, large effect size).

CONCLUSIONS

JFJ intake attenuated the antiinflammatory response to HIIE, possibly resulting from a lower degree of muscle stress.

Marine phytoplankton improves recovery and sustains immune function in humans and lowers proinflammatory immunoregulatory cytokines in a rat model

Purpose

This study investigated the effects of marine phytoplankton supplementation (Oceanix®, Tetraselmis chuii) on 1) maximal isometric strength and immune function in healthy humans following a oneweek high-intensity resistance-training program and 2) the proinflammatory cytokine response to exercise in a rat model.

Methods

In the human trial, 22 healthy male and female participants were randomly divided into marine phytoplankton and placebo groups. Following baseline testing, participants underwent a 14-day supplement loading phase before completing five consecutive days of intense resistance training. In the rat model, rats were randomly divided into four groups (n=7 per condition): (i) control, (ii) exercise, (iii) exercise + marine phytoplankton (2.55 mg/kg/day), or (iv) exercise + marine phytoplankton (5.1 mg/kg/day). Rats in the exercising groups performed treadmill exercise 5 days per week for 6 weeks.

Results

In the human model, marine phytoplankton prevented significant declines in the isometric peak rate of force development compared to placebo. Additionally, salivary immunoglobulin A concentration was significantly lower following the resistance training protocol in the placebo group but not in the marine phytoplankton group. Marine phytoplankton in exercising rats decreased intramuscular levels and serum concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) and intramuscular concentrations of malondialdehyde.

Conclusion

Marine phytoplankton prevented decrements in indices of functional exercise recovery and immune function. Mechanistically, these outcomes could be prompted by modulating the oxidative stress and proinflammatory cytokine response to exercise.

Cancer Related Anemia: An Integrated Multitarget Approach and Lifestyle Interventions

Cancer is often accompanied by worsening of the patient's iron profile, and the resulting anemia could be a factor that negatively impacts antineoplastic treatment efficacy and patient survival. The first line of therapy is usually based on oral or intravenous iron supplementation; however, many patients remain anemic and do not respond. The key might lie in the pathogenesis of the anemia itself. Cancer-related anemia (CRA) is characterized by a decreased circulating serum iron concentration and transferrin saturation despite ample iron stores, pointing to a more complex problem related to iron homeostatic regulation and additional factors such as chronic inflammatory status. This review explores our current understanding of iron homeostasis in cancer, shedding light on the modulatory role of hepcidin in intestinal iron absorption, iron recycling, mobilization from liver deposits, and inducible regulators by infections and inflammation. The underlying relationship between CRA and systemic low-grade inflammation will be discussed, and an integrated multitarget approach based on nutrition and exercise to improve iron utilization by reducing low-grade inflammation, modulating the immune response, and supporting antioxidant mechanisms will also be proposed. Indeed, a Mediterranean-based diet, nutritional supplements and exercise are suggested as potential individualized strategies and as a complementary approach to conventional CRA therapy.

Decrease in Cellular Nanovesicles Concentration in Blood of Athletes More Than 15 Hours After Marathon

Introduction

Cellular nanovesicles (CNVs), that are shed from cells, have been recognized as promising indicators of health status. We analyzed the effect of long-distance running on concentration of CNVs, along with some standard blood parameters, in 27 athletes two days before and >15 hours after physical effort.

Methods

CNVs were isolated by repetitive centrifugation and washing of samples, and assessed by flow cytometry. Cholinesterase (ChE) and glutathione S-transferase (GST) activity were measured spectrophotometrically. Interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations were measured using enzyme-linked immunosorbent assay (ELISA). C-reactive protein (CRP) was measured with immunoturbidimetric determination and lipidogram parameters were measured by enzymatic colorimetric assay. Flow cytometry was used for blood cell count and mean platelet volume (MPV) measurement.

Results

More than 15 hours after physical effort a decrease was found in CNVs' concentration in isolates from blood (46%; p<0.05), in ChE activity in whole blood (47%; p<0.001), in plasma (34%; p<0.01), and in erythrocyte suspension (54%; p<0.001), as well as in GST activity in erythrocyte suspension (16%; p<0.01) and in IL-6 concentration in plasma (63%; p<0.05). We found no change in GST activity in plasma and in TNF-α concentration in plasma. Correlations (>0.8; p<0.001) between CNVs' concentration and ChE activity, and GST activity, respectively, in erythrocyte suspension were found.

Conclusion

We found that >15 hours post-physical effort, CNVs' concentration was below the initial value, concomitant with other measured parameters: ChE and GST activity as well as IL-6 concentration, indicating a favorable effect of physical effort on health status. CNVs' concentration and ChE activity in isolates from peripheral blood proved to have potential as indicators of the response of the human body to inflammation after physical effort. Physical activity should be considered as an important factor in preparation of subjects for blood sampling in procedures focusing on CNV-containing diagnostic and therapeutic compounds.

Wet-cupping induces anti-inflammatory action in response to vigorous exercise among martial arts athletes: A pilot study

PURPOSE

The aim of the present study was to investigate potential anti-inflammatory effects of wet-cupping prior to a moderate-to-vigorous exercise test among martial arts athletes.

METHODS

Twenty-one male karate athletes voluntarily participated in this study and were randomly divided into 3 groups: vigorous exercise (VE, n = 7), cupping (CT, n = 7) and cupping plus vigorous exercise (VECT, n = 7). Participants in exercise groups performed an exercise test while participants in CT received cupping therapy, and participants in VECT received cupping therapy plus exercise. Inflammatory markers (i.e., interlukin-6, IL-6, and tumor necrosis factor-α, TNF-α) were assessed prior to, immediately, 30 min, and 24 h after cupping therapy, vigorous exercise test, and their combination.

RESULTS

IL-6 values were significantly lower immediately after cupping intervention in CT as compared to baseline (P < 0.025). IL-6 significantly increased immediately and 30 min post-exercise in VE in comparison with baseline (P < 0.025). IL-6 was also significantly higher at 24 h post-exercise in CTVE as compared to baseline (P < 0.025). TNF-α values were significantly lower in CT as compared to VE and CTVE at immediately and 30 min post-exercise (P < 0.01). TNF-α significantly decreased immediately and 30 min after cupping intervention in CT as compared to baseline (P < 0.01). Conversely, TNF-α significantly increased immediately after exercise in VE as compared to baseline (P < 0.025). TNF-α also significantly increased at 30 min and 24 h post-exercise in CTVE in comparison with baseline (P < 0.025).

CONCLUSION

Our findings showed that exercise-induced augmentation in inflammatory markers were lower in athletes who received cupping therapy, suggesting such therapy may be an avenue to mitigate the inflammatory response to vigorous exercise among martial arts athletes. A large-scale clinical study is needed to confirm the findings of the present study.

Moving human muscle physiology research forward: an evaluation of fiber type-specific protein research methodologies

Human skeletal muscle is a heterogeneous tissue composed of multiple fiber types that express unique contractile and metabolic properties. While analysis of mixed fiber samples predominates and holds value, increasing attention has been directed toward studying proteins segregated by fiber type, a methodological distinction termed “fiber type-specific.” Fiber type-specific protein studies have the advantage of uncovering key molecular effects that are often missed in mixed fiber homogenate studies but also require greater time and resource-intensive methods, particularly when applied to human muscle. This review summarizes and compares current methods used for fiber type-specific protein analysis, highlighting their advantages and disadvantages for human muscle studies, in addition to recent advances in these techniques. These methods can be grouped into three categories based on the initial processing of the tissue: 1) muscle-specific fiber homogenates, 2) cross sections of fiber bundles, and 3) isolated single fibers, with various subtechniques for performing fiber type identification and protein quantification. The relative implementation for each unique methodological approach is analyzed from 83 fiber type-specific studies of proteins in live human muscle found in the literature to date. These studies have investigated several proteins involved in a wide range of cellular functions that are important to muscle tissue. The second half of this review summarizes key findings from this ensemble of fiber type-specific human protein studies. We highlight examples of where this analytical approach has helped to improve understanding of important physiological topics such as insulin sensitivity, muscle hypertrophy, muscle fatigue, and adaptation to different exercise programs.

The Effects of Antioxidant Vitamins on Proinflammatory Cytokines and Some Biochemical Parameters of Power Plant Workers: A Double-Blind Randomized Controlled Clinical Trial

Some epidemiological studies have suggested that exposure to extremely low-frequency magnetic fields (ELF-MFs) can affect the immune system. This study aimed to investigate the effects of antioxidant vitamin consumption on proinflammatory cytokines and biochemical parameters changes. In this randomized, controlled double-blinded trial study, power plant workers exposed to ELF-MFs were enrolled based on inclusion criteria. Ninety-one eligible subjects were randomly divided into four groups: the first group (400 units of vitamin E/day), second group (1,000 mg of vitamin C/day), third group (400 units of vitamin E and 1,000 mg of vitamin C/day), and control group. The intervention was conducted for 3 months. Proinflammatory cytokines interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α), and biochemical parameters (fasting blood sugar, total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol [HDL-c], total protein, and albumin) were measured among the participants' serums, before and after the intervention. The mean level of IL-6 in all vitamin-receiving groups, the mean level of IL-1β in vitamin C and E&C groups, and the mean level of TNF-α in the vitamin C group, decreased significantly after intervention. The arithmetic means of the effect sizes for IL-1β, IL-6, and TNF-α were 0.71, 0.57, and 0.2, respectively. The level of HDL-c in the vitamin E and vitamin E&C groups and the level of triglyceride in the vitamin C group significantly increased after the intervention. Taking antioxidant vitamins can prevent an increase of proinflammatory cytokines induced by prolonged exposure to ELF-MFs. Bioelectromagnetics. 2021;42:18-26. © 2020 Bioelectromagnetics Society.

Muscle-Organ Crosstalk: The Emerging Roles of Myokines

Physical activity decreases the risk of a network of diseases, and exercise may be prescribed as medicine for lifestyle-related disorders such as type 2 diabetes, dementia, cardiovascular diseases, and cancer. During the past couple of decades, it has been apparent that skeletal muscle works as an endocrine organ, which can produce and secrete hundreds of myokines that exert their effects in either autocrine, paracrine, or endocrine manners. Recent advances show that skeletal muscle produces myokines in response to exercise, which allow for crosstalk between the muscle and other organs, including brain, adipose tissue, bone, liver, gut, pancreas, vascular bed, and skin, as well as communication within the muscle itself. Although only few myokines have been allocated to a specific function in humans, it has been identified that the biological roles of myokines include effects on, for example, cognition, lipid and glucose metabolism, browning of white fat, bone formation, endothelial cell function, hypertrophy, skin structure, and tumor growth. This suggests that myokines may be useful biomarkers for monitoring exercise prescription for people with, for example, cancer, diabetes, or neurodegenerative diseases.

Myokines: a descriptive review

In the last years, scientists have shown that skeletal muscle is not a pure locomotor unit or responsible for propulsion and posture. Skeletal muscle encompasses one of the major organs of the body (constituting about 40% of the body mass in non-obese men). It regulates energy and metabolic processes and is now recognized as an organ capable of producing molecules with vital functions. These molecules are termed myokines, a new field of research in the health sciences, and represent an open field of discoveries and applications in several areas. The aim of this review was to show the role of some well-known myokines in the maintenance of homeostasis. Our search was performed in databases such as Medline/Pubmed, Embase and Scielo. Some relevant myokines are interleukin-6 (IL-6), IL-8, IL-15, irisin, myostatin, fibroblast growth factor 21 (FGF21), leukemia inhibitory factor (LIF), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor-1 (IGF-1). They are related to play a positive or negative role in muscle function and metabolism homeostasis. They are associated with the regulation of glucose and lipid metabolism, the deposition of fat in the adipose tissue, and the "browning" of the white adipose tissue. For these reasons, they can interfere with the prevention of obesity, diabetes, metabolic syndrome, and cardiovascular diseases. The discovery of the myokines has opened a new direction in understanding the effects of exercises on humans.

Redox Signaling in Widespread Health Benefits of Exercise

Significance: Exercise-induced reactive oxygen species (ROS) production activates multiple intracellular signaling pathways through genomic and nongenomic mechanisms that are responsible for the beneficial effects of exercise in muscle. Beyond the positive effect of exercise on skeletal muscle cells, other tissues such as white and brown adipose, liver, central nervous system, endothelial, heart, and endocrine organ tissues are also responsive to exercise. Recent Advances: Crosstalk between different cells is essential to achieve homeostasis and to promote the benefits of exercise through paracrine or endocrine signaling. This crosstalk can be mediated by different effectors that include the secretion of metabolites of muscle contraction, myokines, and exosomes. During the past 20 years, it has been demonstrated that contracting muscle cells produce and secrete different classes of myokines, which functionally link muscle with nearly all other cell types. Critical Issues: The redox signaling behind this exercise-induced crosstalk is now being decoded. Many of these widespread beneficial effects of exercise require not only a complex ROS-dependent intramuscular signaling cascade but simultaneously, an integrated network with many remote tissues. Future Directions: Strong evidence suggests that the powerful beneficial effect of regular physical activity for preventing (or treating) a large range of disorders might also rely on ROS-mediated signaling. Within a contracting muscle, ROS signaling may control exosomes and myokines secretion. In remote tissues, exercise generates regular and synchronized ROS waves, creating a transient pro-oxidative environment in many cells. These new concepts integrate exercise, ROS-mediated signaling, and the widespread health benefits of exercise.

The Emerging Roles of Nicotinamide Adenine Dinucleotide Phosphate Oxidase 2 in Skeletal Muscle Redox Signaling and Metabolism

Significance: Skeletal muscle is a crucial tissue to whole-body locomotion and metabolic health. Reactive oxygen species (ROS) have emerged as intracellular messengers participating in both physiological and pathological adaptations in skeletal muscle. A complex interplay between ROS-producing enzymes and antioxidant networks exists in different subcellular compartments of mature skeletal muscle. Recent evidence suggests that nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are a major source of contraction- and insulin-stimulated oxidants production, but they may paradoxically also contribute to muscle insulin resistance and atrophy. Recent Advances: Pharmacological and molecular biological tools, including redox-sensitive probes and transgenic mouse models, have generated novel insights into compartmentalized redox signaling and suggested that NOX2 contributes to redox control of skeletal muscle metabolism. Critical Issues: Major outstanding questions in skeletal muscle include where NOX2 activation occurs under different conditions in health and disease, how NOX2 activation is regulated, how superoxide/hydrogen peroxide generated by NOX2 reaches the cytosol, what the signaling mediators are downstream of NOX2, and the role of NOX2 for different physiological and pathophysiological processes. Future Directions: Future research should utilize and expand the current redox-signaling toolbox to clarify the NOX2-dependent mechanisms in skeletal muscle and determine whether the proposed functions of NOX2 in cells and animal models are conserved into humans.

Neuromuscular Electrical Stimulation: A New Therapeutic Option for Chronic Diseases Based on Contraction-Induced Myokine Secretion

Myokines are peptides known to modulate brain neuroplasticity, adipocyte metabolism, bone mineralization, endothelium repair and cell growth arrest in colon and breast cancer, among other processes. Repeated skeletal muscle contraction induces the production and secretion of myokines, which have a wide range of functions in different tissues and organs. This new role of skeletal muscle as a secretory organ means skeletal muscle contraction could be a key player in the prevention and/or management of chronic disease. However, some individuals are not capable of optimal physical exercise in terms of adequate duration, intensity or muscles involved, and therefore they may be virtually deprived of at least some of the physiological benefits induced by exercise. Neuromuscular electrical stimulation (NMES) is emerging as an effective physical exercise substitute for myokine induction. NMES is safe and efficient and has been shown to improve muscle strength, functional capacity, and quality of life. This alternative exercise modality elicits hypertrophy and neuromuscular adaptations of skeletal muscles. NMES stimulates circulating myokine secretion, promoting a cascade of endocrine, paracrine, and autocrine effects. We review the current evidence supporting NMES as an effective physical exercise substitute for inducing myokine production and its potential applications in health and disease.

Glucose Ingestion Inhibits Endurance Exercise-Induced IL-6 Producing Macrophage Infiltration in Mice Muscle

Background: Carbohydrate (CHO) supplementation during exercise attenuates exercise-induced increases in plasma Interleukin (IL)-6 concentration. However, the effects of CHO supplementation on muscle IL-6 production during endurance exercise is controversial. The purpose of this study was to investigate the effects of CHO supplementation on muscle IL-6 production during endurance exercise with a special focus on the IL-6 producing cells. Methods: C57BL/6J mice were divided into three groups—sedentary with water ingestion group as the control (Con; n = 10), exercise with water ingestion group (Ex; n = 10), and exercise with 6% glucose ingestion group (Ex + glucose; n = 10). The Ex and Ex + glucose groups completed 3 h of treadmill running (24 m/min, 7% incline) and were sacrificed immediately after exercise. Results: The exercise-induced increases of plasma IL-6 concentration and gastrocnemius IL-6 gene expression were attenuated by glucose ingestion. However, the increases of soleus IL-6 gene expression and gastrocnemius and soleus IL-6 protein expression were not attenuated by glucose ingestion. Furthermore, we observed that macrophages that infiltrated muscle produce IL-6 and glucose ingestion attenuated the infiltration of IL-6-producing macrophages. Conclusion: This study revealed that infiltrating macrophages may be one type of IL-6-producing cells during endurance exercise, and the infiltration of these cells in muscle was attenuated by glucose ingestion. However, the effects of glucose ingestion on muscle IL-6 production were limited.

TRPC channels in exercise-mimetic therapy

Physical exercise yields beneficial effects on all types of muscle cells, which are essential for the maintenance of cardiovascular homeostasis and good blood circulation. Daily moderate exercise increases systemic antioxidative capacity, which can lead to the prevention of the onset and progression of oxidative stress-related diseases. Therefore, exercise is now widely accepted as one of the best therapeutic strategies for the treatment of ischemic (hypoxic) diseases. Canonical transient receptor potential (TRPC) proteins are non-selective cation channels activated by mechanical stress and/or stimulation of phospholipase C-coupled surface receptors. TRPC channels, especially diacylglycerol-activated TRPC channels (TRPC3 and TRPC6; TRPC3/6), play a key role in the development of cardiovascular remodeling. We have recently found that physical interaction between TRPC3 and NADPH oxidase (Nox) 2 under hypoxic stress promotes Nox2-dependent reactive oxygen species (ROS) production and mediates rodent cardiac plasticity, and inhibition of the TRPC3-Nox2 protein complex results in enhancement of myocardial compliance and flexibility similar to that observed in exercise-treated hearts. In this review, we describe current understanding of the roles of TRPC channels in striated muscle (patho)physiology and propose that targeting TRPC-based protein complexes could be a new strategy to imitate exercise therapy.

Neutralization of Interleukin-1β following Diffuse Traumatic Brain Injury in the Mouse Attenuates the Loss of Mature Oligodendrocytes

Traumatic brain injury (TBI) commonly results in injury to the components of the white matter tracts, causing post-injury cognitive deficits. The myelin-producing oligodendrocytes (OLs) are vulnerable to TBI, although may potentially be replaced by proliferating oligodendrocyte progenitor cells (OPCs). The cytokine interleukin-1β (IL-1β) is a key mediator of the complex inflammatory response, and when neutralized in experimental TBI, behavioral outcome was improved. To evaluate the role of IL-1β on oligodendrocyte cell death and OPC proliferation, 116 adult male mice subjected to sham injury or the central fluid percussion injury (cFPI) model of traumatic axonal injury, were analyzed at two, seven, and 14 days post-injury. At 30 min post-injury, mice were randomly administered an IL-1β neutralizing or a control antibody. OPC proliferation (5-ethynyl 2'- deoxyuridine (EdU)/Olig2 co-labeling) and mature oligodendrocyte cell loss was evaluated in injured white matter tracts. Microglia/macrophages immunohistochemistry and ramification using Sholl analysis were also evaluated. Neutralizing IL-1β resulted in attenuated cell death, indicated by cleaved caspase-3 expression, and attenuated loss of mature OLs from two to seven days post-injury in brain-injured animals. IL-1β neutralization also attenuated the early, two day post-injury increase of microglia/macrophage immunoreactivity and altered their ramification. The proliferation of OPCs in brain-injured animals was not altered, however. Our data suggest that IL-1β is involved in the TBI-induced loss of OLs and early microglia/macrophage activation, although not the OPC proliferation. Attenuated oligodendrocyte cell loss may contribute to the improved behavioral outcome observed by IL-1β neutralization in this mouse model of diffuse TBI.

Vitamin C is not the Missing Link Between Cigarette Smoking and Spinal Pain

STUDY DESIGN

A nationwide cross-sectional study.

OBJECTIVES

To measure the associations between cigarette smoking (defined as serum cotinine concentration >15 ng/mL) and the 3-month prevalence of spinal pain (neck pain, low back pain, low back pain with pain below knee, and self-reported diagnosis of arthritis/rheumatism) and related limitations, and to verify whether these associations are mediated by serum concentrations of vitamin C.

SUMMARY OF BACKGROUND DATA

Cigarette smoking has been consistently associated with back pain, but this association has never been explained. Because vitamin C has recently been reported to be associated with spinal pain and related functional limitations, and the metabolism of vitamin C differs between smokers and nonsmokers, we hypothesized that the prevalence of spinal pain and related limitations might be greater among smokers because they are more susceptible to be in a state of hypovitaminosis C.

METHODS

We conducted secondary analyses of National Health and Nutrition Examination Survey (NHANES) 2003 to 2004 data on 4438 individuals aged ≥20 years.

RESULTS

Serum concentrations of vitamin C and cotinine were strongly and inversely correlated (r = -0.35, P < 0.0001). Smoking was statistically associated with the prevalence of neck pain [adjusted odds ratio: aOR: 1.25; 95% confidence interval (95% CI): 1.06-1.47], low back pain (aOR: 1.20; 95% CI: 1.04-1.39), and low back pain with pain below knee (aOR: 1.58; 95% CI: 1.13-2.22) and related limitations, with a dose-response relationship (P < 0.05). However, the associations between smoking and spinal pain were not mediated by concentrations of vitamin C.

CONCLUSION

These results confirm the relationship between smoking and spinal pain, but they do not support a mediating effect of vitamin C on this relationship.

LEVEL OF EVIDENCE

2.

A Vitamin E-Enriched Antioxidant Diet Interferes with the Acute Adaptation of the Liver to Physical Exercise in Mice

Physical exercise is beneficial for general health and is an effective treatment for metabolic disorders. Vitamin E is widely used as dietary supplement and is considered to improve non-alcoholic fatty liver disease by reducing inflammation and dyslipidemia. However, increased vitamin E intake may interfere with adaptation to exercise training. Here, we explored how vitamin E alters the acute exercise response of the liver, an organ that plays an essential metabolic role during physical activity. Mice fed a control or an α-tocopherol-enriched diet were subjected to a non-exhaustive treadmill run. We assessed the acute transcriptional response of the liver as well as glucocorticoid signalling and plasma free fatty acids (FFA) and performed indirect calorimetry. Vitamin E interfered with the exercise-induced increase in FFA and upregulation of hepatic metabolic regulators, and it shifted the transcriptional profile of exercised mice towards lipid and cholesterol synthesis while reducing inflammation. Energy utilization, as well as corticosterone levels and signalling were similar, arguing against acute differences in substrate oxidation or glucocorticoid action. Our results show that high-dose vitamin E alters the metabolic and inflammatory response of the liver to physical exercise. The interference with these processes may suggest a cautious use of vitamin E as dietary supplement.

Dietary Onion or Ginger Modulates the Stress Response and Susceptibility to Vibrio harveyi JML1 Infection in Brown-marbled Grouper Epinephelus fuscoguttatus Juveniles

Onion Allium cepa and ginger Zingiber officinale have health-promoting properties that qualify them as functional foods. The effect of repeated acute stressors was examined in juvenile Brown-marbled Grouper Epinephelus fuscoguttatus that were fed four diets supplemented with onion at 1.8%, ginger at 1.8%, vitamin C at 0.86%, and β-glucan at 0.8% of the diet. The non-supplemented diet served as the control. After 12 weeks of feeding, fish were exposed to stressors and were experimentally infected with a fish pathogen, the bacterium Vibrio harveyi JML1. After repeated exposure to hypoxia, cortisol levels rose significantly in the non-supplemented fish compared to those fed onion, ginger, β-glucan, or vitamin C. Within groups, postexposure cortisol levels in the onion-, ginger-, and vitamin C-fed fish did not change relative to pre-stress levels, whereas significant increases in poststress values were observed in the control and β-glucan groups. The net cortisol increase was also significantly greater in the non-supplemented group compared to the supplemented groups. The net cortisol increase did not vary among the supplemented groups except that the β-glucan-fed group exhibited a higher net increase than the onion-fed group. Similarly, repeated acute exposure to osmotic stress significantly increased the plasma cortisol level in the non-supplemented group compared to groups that received supplements; no differences were found in the supplemented groups except the β-glucan group. Within groups, significant increases in poststress values relative to pre-stress levels were found only in the control and β-glucan groups. Repeated acute exposure to hypoxia significantly increased cumulative mortality in the control group compared to the supplemented groups (except the β-glucan group), whereas repeated exposure to acute osmotic stress significantly increased cumulative mortality only in the control group 10 d after infection with V. harveyi JML1. Based on our collective results, most of the supplemented groups performed better than the control, but the best supplements were onion and ginger in terms of enhancing stress tolerance and increasing survival of Brown-marbled Grouper upon infection with V. harveyi JML1.

Preliminary Evaluation of a Cycling Cleat Designed for Diabetic Foot Ulcers

BACKGROUND

Offloading devices for diabetic foot ulcers (DFU) generally restrict exercise. In addition to traditional health benefits, exercise could benefit DFU by increasing blood flow and acting as thermotherapy. This study functionally evaluated a cycling cleat designed for forefoot DFU.

METHODS

Fifteen individuals at risk of developing a DFU used a recumbent stationary bicycle to complete one 5-minute cycling bout with the DFU cleat on their study foot and one 5-minute bout without it. Foot stress was evaluated by plantar pressure insoles during cycling. Laser Doppler perfusion monitored blood flow to the hallux. Infrared photographs measured foot temperature before and after each cycling bout.

RESULTS

The specialized cleat significantly reduced forefoot plantar pressure (9.9 kPa versus 62.6 kPa, P < .05) and pressure time integral (15.4 versus 76.4 kPa*sec, P < .05). Irrespective of footwear condition, perfusion to the hallux increased (3.97 ± 1.2 versus 6.9 ± 1.4 tissue perfusion units, P < .05) after exercise. Infrared images revealed no changes in foot temperature.

CONCLUSIONS

The specialized cleat allowed participants to exercise with minimal forefoot stress. The observed increase in perfusion suggests that healing might improve if patients with active DFU were to use the cleat. Potential thermotherapy for DFU was not supported by this study. Evaluation of the device among individuals with active DFU is now warranted.

Anti-inflammatory effects of exercise: role in diabetes and cardiovascular disease

BACKGROUND

Persistent inflammation is involved in the pathogenesis of chronic diseases such as type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD).

AIMS

The aim of this review was to provide the reader with an update of the mechanisms whereby exercise-induced cytokines may impact cardiometabolic diseases.

RESULTS

Evidence exists that interleukin (IL)-1β is involved in pancreatic β-cell damage, whereas TNF-α is a key molecule in peripheral insulin resistance. In addition, TNF-α appears to be involved in the pathogenesis of atherosclerosis and heart failure. A marked increase in IL-6 and IL-10 is provoked by exercise and exerts direct anti-inflammatory effects by an inhibition of TNF-α and by stimulating IL-1ra, thereby limiting IL-1β signalling. Moreover, muscle-derived IL-6 appears to have direct anti-inflammatory effects and serves as a mechanism to improve glucose tolerance. In addition, indirect anti-inflammatory effects of long-term exercise are mediated via improvements in body composition.

CONCLUSION

Physical activity represents a natural, strong anti-inflammatory strategy with minor side effects and should be integrated in the management of patients with cardiometabolic diseases.

Effect of a 2000-m running test on antioxidant and cytokine response in plasma and circulating cells

Exercise intensity usually correlates with increased oxidative stress and enhanced cytokine production. However, it is unknown if all types of exercise that induce muscle damage can cause a parallel response in the oxidation balance and cytokine production. To this end, the effect of a 2000-m running test in a group of volunteers that regularly train in aerobic routines was studied. Different circulating parameters were measured, oxidative stress markers (protein carbonyls and malondialdehyde), antioxidant enzyme activity, and cytokine levels in plasma as well as in the main circulating cells of blood samples obtained in basal conditions and after test execution. As a result, the test caused muscle damage evidenced by an increase in circulating creatine kinase and myoglobin. This was accompanied by an increase in protein carbonyls in plasma and peripheral blood mononuclear cells. Activities of antioxidant enzymes (catalase, glutathione peroxidase and reductase, superoxide dismutase) were elevated in peripheral blood mononuclear cells, neutrophils, and erythrocytes after the test. Regarding cytokine production, interleukin-6, interleukin-8, interleukin-10, and tumor necrosis factor-α exhibited no significant changes after the test. Results suggest that this short but intense running exercise (2000 m) can induce muscle damage and elicit a good balance between oxidant/antioxidant responses with no changes in the circulating concentration of pro-inflammatory cytokines.

A system model of the effects of exercise on plasma Interleukin-6 dynamics in healthy individuals: Role of skeletal muscle and adipose tissue

Interleukin-6 (IL-6) has been recently shown to play a central role in glucose homeostasis, since it stimulates the production and secretion of Glucagon-like Peptide-1 (GLP-1) from intestinal L-cells and pancreas, leading to an enhanced insulin response. In resting conditions, IL-6 is mainly produced by the adipose tissue whereas, during exercise, skeletal muscle contractions stimulate a marked IL-6 secretion as well. Available mathematical models describing the effects of exercise on glucose homeostasis, however, do not account for this IL-6 contribution. This study aimed at developing and validating a system model of exercise’s effects on plasma IL-6 dynamics in healthy humans, combining the contributions of both adipose tissue and skeletal muscle. A two-compartment description was adopted to model plasma IL-6 changes in response to oxygen uptake’s variation during an exercise bout. The free parameters of the model were estimated by means of a cross-validation procedure performed on four different datasets. A low coefficient of variation (<10%) was found for each parameter and the physiologically meaningful parameters were all consistent with literature data. Moreover, plasma IL-6 dynamics during exercise and post-exercise were consistent with literature data from exercise protocols differing in intensity, duration and modality. The model successfully emulated the physiological effects of exercise on plasma IL-6 levels and provided a reliable description of the role of skeletal muscle and adipose tissue on the dynamics of plasma IL-6. The system model here proposed is suitable to simulate IL-6 response to different exercise modalities. Its future integration with existing models of GLP-1-induced insulin secretion might provide a more reliable description of exercise’s effects on glucose homeostasis and hence support the definition of more tailored interventions for the treatment of type 2 diabetes.

Examination of levels pentraxin-3, interleukin-6, and C-reactive protein in rat model acute and chronic exercise

Different types of exercise occurs damage at the cellular level in the muscles. Muscle damage caused by exercise is determined creatine kinase, myoglobin, and increase in levels of acute phase protein and interleukin in blood. The purpose of this study was investigated the levels of pentraxin-3 (PTX-3), interleukin-6 (IL-6), and C-reactive protein (CRP) following acute and chronic exercising in rats. Twenty-six Wistar Albino male rats were divided in to three groups. A treadmill exercise was performed 3 days/week, 10 min/day for 1 week in acute groups. In chronic group, exercise performed 7 days/week, 60 min/day for 4 weeks. At the end of the experiment, plasma PTX-3, IL-6, and CRP levels were measured. In current study, the PTX-3, IL-6, and CRP levels not observed statistically significant difference among control, acute, and chronic groups. The levels IL-6 and CRP were not significantly different between acute and chronic exercise groups (P>0.05). However, the level of PTX-3 was found to be higher in the chronic group compared to the acute group (P<0.05). The PTX-3 level increase on chronic exercise-induced muscle damage. Accorting to our results, we think that PTX-3 may have a protect role on muscle damage during chronic exercises.