Indicators Of Muscle Damage Research Articles

Myotoxicity of Crotoxin on C2C12 Myoblasts and its Inhibition by Crotalus Neutralizing Factor versus Enhanced Resistance in Myotubes: Exploring Toxicity and Membrane Potential.

Crotalus Neutralizing Factor (CNF) is a γ-type Phospholipase A2 (PLA2) inhibitor present in the blood of Crotalus durissus terrificus snake. Particularly, CNF inhibits the toxic action of Crotoxin (CTX), which is a major neurotoxin found in C. d. terrificus venom. CTX induces also myotoxic action and demonstrates high selectivity for skeletal muscle fibers. Consequently, CTX can diffuse beyond the site of infection, which can potentially evoke rhabdomyolysis. The present study has evaluated the effects of CTX on myoblasts and myotubes of muscle cells C2C12 in vitro and the effect of CNF on CTX-induced damage. Cytotoxicity assays were performed by measuring the mitochondrial enzyme dehydrogenase levels. Furthermore, creatine kinase and lactate dehydrogenase levels were used as indicators of muscle damage. Crotoxin has been found to have cytotoxic effects on C2C12 myoblast cells, while CNF has not shown toxic effects on these cells. Furthermore, the findings have shown CNF (50 μg/mL) to abolish CTX toxicity in myoblasts. The myotubes, differentiated cells, showed no change in mitochondrial respiration when exposed to CNF or CTX, showing greater resistance to the toxic actions of crotoxin. The data have confirmed the potential of CNF as an anti-myotoxic agent to prevent CTX-damaged myoblasts and increase resistance to the toxic effects of crotoxin on differentiated cells.

The effect of 12-week high-dose Colostrum Bovinum supplementation on immunological, hematological and biochemical markers in endurance athletes: a randomized crossover placebo-controlled study.

Bovine colostrum (COL) is assumed to be one of the strongest natural immune stimulants. Regular ingestion of COL may contribute to improved immune response in athletes exposed to high training loads. Twenty-eight endurance-trained males aged 31.1 ± 10.2 years (body mass 81.9 ± 9.0kg; height 1.82 ± 0.06m) completed this randomized double-blind placebo(PLA)-controlled crossover study aimed at investigating the effect of 12-week COL supplementation (25gCOL·day-1) on resting (REST), exercise-induced (POST-EX), and short-term post-exercise recovery (REC; 1h after test exercise) changes in selected saliva and blood immunoglobulins (Ig), white blood cell (WBC) count and differential; as well as blood hematological, nutritional status and muscle damage indices. The protocol assumed 4 study visits - before/after supplementation with COL (COLPRE and COLPOST ) and PLA (PLAPRE and PLAPOST ). During testing sessions, incremental rowing test to exhaustion and swimming-specific performance test were introduced as exercise stimuli. At COLPOST visit the secretory IgA (SIgA) concentration in saliva was significantly higher at POST-EX and REC compared to REST (p<0.05). COL supplementation had no effect on blood IgA, IgE, IgD, IgG, and IgM concentrations. Furthermore, after COL supplementation decrease of hematocrit at REC (p<0.05) was revealed. 12-week supplementation with 25 gCOL·day-1 in endurance-trained male athletes resulted in a favorable increase in post-exercise concentration of salivary SIgA. COL seems to be a potential stimulator of local immune defense after exercise-induced homeostasis disturbances. Nevertheless, the lack of effect on blood markers indicates the need for further research in the area of mechanisms underlying the effect of the supposed COL immunological capacity.

Effects of Supplementation with Omega-3 and Omega-6 Polyunsaturated Fatty Acids and Antioxidant Vitamins, Combined with High-Intensity Functional Training, on Exercise Performance and Body Composition: A Randomized, Double-Blind, Placebo-Controlled Trial.

The aim of this study was to investigate the effects of a supplement rich in ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) and antioxidant vitamins on physical performance and body composition following a period of high-intensity functional training (HIFT). Nineteen healthy young adults (nine males, ten females) underwent an 8-week HIFT program (3 days·week-1) where they were randomized 1:1 into either the supplement group (SG)-n = 10, receiving a 20 mL daily dose of a dietary cocktail formula (Neuroaspis™ PLP10) containing a mixture of ω-3 and ω-6 PUFAs (12,150 mg), vitamin A (0.6 mg), vitamin E (22 mg), and γ-tocopherol (760 mg)-or the placebo group (PG)-n = 9, receiving a 20 mL daily dose of virgin olive oil. Body composition, cardiorespiratory fitness, muscle strength, and muscle endurance were assessed before and after the training period. Body mass did not change, but muscle mass increased by 1.7 ± 1.9% or 0.40 ± 0.53 kg in the SG (p = 0.021) and decreased by 1.2 ± 1.6% or 0.28 ± 0.43 kg (p = 0.097) in the PG, compared with baseline. VO2max, vertical jump, squat 1RM, bench press 1RM, and muscle endurance increased similarly in both groups. The effects of HIFT on physical performance parameters, muscle damage, and inflammation indices were not affected by the supplementation. In conclusion, HIFT combined with high doses of ω-3 and ω-6 PUFAs and antioxidant vitamins resulted in a small but significant increase in muscle mass and fat reduction compared with HIFT alone.

Characterization of acute effects of football competition on hamstring muscles by muscle functional MRI techniques.

Muscle functional MRI identifies changes in metabolic activity in each muscle and provides a quantitative index of muscle activation and damage. No previous studies have analyzed the hamstrings activation over a football match. This study aimed at detecting different patterns of hamstring muscles activation after a football game, and to examine inter- and intramuscular differences (proximal-middle-distal) in hamstring muscles activation using transverse relaxation time (T2)-weighted magnetic resonance images. Eleven healthy football players were recruited for this study. T2 relaxation time mapping-MRI was performed before (2 hours) and immediately after a match (on average 13 min). The T2 values of each hamstring muscle at the distal, middle, and proximal portions were measured. The primary outcome measure was the increase in T2 relaxation time value after a match. Linear mixed models were used to detect differences pre and postmatch. MRI examination showed that there was no obvious abnormality in the shape and the conventional T2 weighted signal of the hamstring muscles after a match. On the other hand, muscle functional MRI T2 analysis revealed that T2 relaxation time significantly increased at distal and middle portions of the semitendinosus muscle (p = 0.0003 in both cases). By employing T2 relaxation time mapping, we have identified alterations within the hamstring muscles being the semitendinosus as the most engaged muscle, particularly within its middle and distal thirds. This investigation underscores the utility of T2 relaxation time mapping in evaluating muscle activation patterns during football matches, facilitating the detection of anomalous activation patterns that may warrant injury reduction interventions.

Almond Consumption Modestly Improves Pain Ratings, Muscle Force Production, and Biochemical Markers of Muscle Damage Following Downhill Running in Mildly Overweight, Middle-Aged Adults: A Randomized, Crossover Trial

BackgroundAlmonds promote cardiometabolic health benefits; however, the ergogenic effect of almond supplementation on exercise recovery is less explored. ObjectivesWe evaluated the impacts of raw, shelled, almonds on pain, muscle force production, and biochemical indices of muscle damage and inflammation during recovery from eccentrically biased exercise. MethodsUsing a randomized, crossover design, 26 healthy adults (37 ± 6 y) ran downhill (–10%) for 30 min at a heart rate corresponding to 65%–70% of maximal oxygen consumption followed by 3-d recovery periods after 8-wk adaptations to either ALMOND (2 oz/d) or isocaloric pretzel (CONTROL) feedings. Volunteers consumed the study food immediately following the run and each day during recovery. Fasted blood samples were collected, and pain and muscle function were tested before the downhill run and over 72 h of recovery. ResultsDownhill running elicited moderate muscle damage (Time: P < 0.001; η2 = 0.395) with creatine kinase (CK) peaking after 24 h (CONTROL: Δ + 180% from baseline compared with ALMOND: Δ + 171% from baseline). CK was reduced after 72 h in ALMOND (Δ – 50% from peak; P < 0.05) but not CONTROL (Δ – 33% from peak; P > 0.05). Maximal torque at 120°/s of flexion was greater (Trial: P = 0.004; η2 = 0.315) in ALMOND compared with CONTROL at 24 h (Δ + 12% between trials; P < 0.05) and 72 h (Δ + 9% between trials; P < 0.05) timepoints. Pain during maximal contraction was lower (Trial: P < 0.026; η2 = 0.225) in ALMOND compared with CONTROL after 24 h (Δ – 37% between trials; P < 0.05) and 48 h (Δ – 33% between trials; P < 0.05). No differences (P > 0.05) in vertical jump force, C-reactive protein concentrations, myoglobin concentrations, and total antioxidant capacity were observed between trials. ConclusionsThis study demonstrates that 2.0 oz/d of almonds modestly reduces pain, better maintains muscle strength, and reduces the CK response to eccentric-based exercise. This apparent effect of almond ingestion on exercise recovery has the potential to promote increased exercise adherence, which should be investigated in future studies.This trial was registered at the clinicaltrials.gov as NCT04787718.

Bioimpedance analysis for identifying new indicators of exercise-induced muscle damage

A noninvasive, immediate, and convenient method for assessing muscle tissue status during exercise-induced muscle damage (EIMD) has not been established. This study was designed to assess and determine parameters suitable for measuring EIMD after eccentric exercise, using multi-frequency bioimpedance analysis (BIA). Thirty-five young male participants performed dumbbell exercises with their left arm, and their BIA parameters were measured at various time points up to 168 h post exercise using a multi-frequency BIA device. At all-time points, intra and extracellular water content was greater in the left arm than in the right arm, whereas the impedance, reactance, resistance, and phase angle were lower in the left arm than in the right arm. Established EIMD indices, such as maximal isometric voluntary contraction, were measured and used in correlational analyses. Only reactance was correlated with biomarkers, indicating muscle damage (r = − 0.56 to − 0.49). Furthermore, reactance was found to correlate well with indirect indicators of EIMD, suggesting that it may be a suitable marker for evaluating EIMD. However, the relationship with the limited evaluation indices employed in this study is constrained. Future studies should investigate the correlation between reactance and direct damage indicators, such as structural damage, observed in biopsies.

Pre-exercise cryotherapy reduces myoglobin and creatine kinase levels after eccentric muscle stress in young women.

Introduction: The aim of this study was to investigate the effect of pre-exercise whole-body cryotherapy (WBC) on muscle damage indicators following eccentric treadmill exercise in young women. Methods: Twenty-seven participants underwent two 1-h downhill treadmill runs, replicating 60% of their maximal oxygen uptake, with a 4-week intermission for recovery and treatment application. In this intermission, one group underwent 20 sessions of WBC, delivered five times a week at -120°C for 3min each, while the comparison group received no such treatment. Markers of muscle injury-serum myoglobin concentration, creatine kinase and lactate dehydrogenase activity and also uric acid, and cell-free DNA concentration-were measured before and after downhill runs. Results: The study observed a notable reduction in post-exercise myoglobin and CK levels in the WBC group after the second running session. Discussion: The results suggest that WBC can have a protective effects against muscle damage resulting from eccentric exercise.

Effect of Spirulina Nigrita® Supplementation on Indices of Exercise-Induced Muscle Damage after Eccentric Protocol of Upper Limbs in Apparently Healthy Volunteers.

Spirulina is a supplement with antioxidant and anti-inflammatory properties that may enhance performance and recovery after intense exercise. The present study aimed to investigate the effects of Spirulina Nigrita® on physical performance, and recovery markers after intense eccentric exercise in healthy moderately physically active volunteers. In a double-blind crossover design, participants were supplemented either with spirulina (42 mg Kg-1 BW per day) or a placebo for 15 days before conducting an eccentric exercise protocol using the non-dominant arm. A six-week washout period was required between conditions. Performance and mobility markers such as isometric peak torque (PTQ), ligament range of motion (ROM), and perceived muscle discomfort (VAS) were assessed and blood samples (CK, LDH) were obtained at 1, 24, 48, and 72 h post-exercise. No significant differences were noticed between the two conditions on any of the investigated markers, indicating that spirulina supplementation has no positive effect on isometric muscle performance or alleviation of exercise-induced muscle damage (EIMD) symptoms in the specific population.

Doxycycline-Mediated Inhibition of Snake Venom Phospholipase and Metalloproteinase.

Warfighters are exposed to life-threatening injuries daily and according to the Joint Trauma System Military Clinical Practice Guideline-Global Snake Envenomation Management snakebites are a concerning threat in all theaters of operation. Snake venom is a complex mixture of toxins including phospholipases A2 (PLA2) and snake venom metalloproteinases (SVMP) that produce myotoxic, hemotoxic, and cytotoxic injuries. Antibody-based antivenom is the standard of care but new approaches including small-molecule inhibitors have gained attention in recent years. Doxycycline is an effective inhibitor of human metalloproteinases and PLA2. The enzymatic activities of 3 phylogenetically distinct snakes: Agkistrodon piscivorus, Naja kaouthia, and Daboia russelii were tested under inhibitory conditions using doxycycline. Enzymatic activity of PLA2 and SVMP was measured in N. kaouthia, D. russelii, and A. piscivorus venom alone and with doxycycline using EnzChek Phospholipase A2 and Gelatinase Assay Kits. A 1-way ANOVA with Tukey's post-hoc test was used to conduct comparative analysis. The median lethal dose of the venoms, the effective dose of doxycycline, and creatine kinase (CK) inhibition levels were measured in a murine model with adult Bagg Albino (BALB/c) mice using intramuscular injections. Median lethal and effective doses were determined using Spearman-Karber's method and a 1-way ANOVA with Tukey's post-hoc test was used to compare CK inhibition levels. Phospholipases A2 activity was reduced to 1.5% to 44.0% in all 3 venoms in a dose-dependent manner using 0.32, 0.16, and 0.08 mg/mL doxycycline when compared to venom-only controls (P < .0001) (Fig.1A). Snake venom metalloproteinases activity was reduced to 4% to 62% in all 3 venoms in a dose-dependent manner using 0.32, 0.16, and 0.08 mg/mL doxycycline (P < .0001) (Fig.1B). The lethal dose (LD50) values of the venoms in the murine model were calculated as follows: A. piscivorus = 20.29 mg/kg (Fig.2A), N. kaouthia = 0.38 mg/kg (Fig.2B), and D. russelii = 7.92 mg/kg (Fig.2C). The effective dose (ED50) of doxycycline in A. piscivorus was calculated to be 20.82 mg/kg and 72.07 mg/kg when treating D. russelii venom. No ED50 could be calculated when treating N. kaouthia venom (Fig.3). Creatine kinase activity was significantly decreased in all 3 venoms treated with doxycycline (P < .0001) (Fig.4). Doxycycline reduced PLA2- and SVMP-related lethality, particularly in A. piscivorus envenomings and in a limited capacity with D. russelii revealing its promise as a treatment for snakebites. In addition, CK activity, a common indicator of muscle damage was inhibited in mice that received doxycycline-treated venom. The doxycycline concentrations identified in the ED50 studies correspond to 1,456 to 5,061 mg dosages for a 70 kg human. Factors including venom yield and snake species would affect the actual dosage needed. Studies into high-dose doxycycline safety and its effectiveness against several snake species is needed to fully translate its use into humans. Based on this work, doxycycline could be used as a treatment en route to higher echelons of care, providing protection from muscle damage and reducing lethality in different snake species.

Nutritional knowledge, eating habits, factors affecting muscle damage, and antioxidant enzyme levels of Korean wrestlers.

The aim in this study was to investigate the diet and nutritional knowledge of elite Korean wrestlers and verify the differences in their exercise performance , muscle damage indicators, and antioxidant enzyme levels according to wrestler level. A 7-day dietary and nutrition knowledge survey was administered to 30 adult male elite wrestlers (national team: n=11; professional team: n=19). The Wingate test was conducted for 60 seconds to analyze muscle damage indicators and antioxidant levels. Blood and blood lactate concentration analyses were performed four times; the statistical significance level of all data was p<0.05. Significant differences were found in general nutrition knowledge questionnaire (GNKQ) scores (p=0.043), diet (p=0.001), anaerobic performance (p=0.001), muscle damage indicators (p=0.026), antioxidant levels, and blood lactic acid concentrations (30 min after exercise, p=0.007; 90 min after exercise, p=0.038) between the national and the professional groups. To the findings confirm the relationship between the differences in diet, nutrition, and motor function for wrestlers of different expertise levels. In a follow-up, a comprehensive study on nutrition knowledge, athlete training , and weight loss is needed that considers a wider scope of subjects and analyzes additional variables.

How Does Altering the Volume-Load of Plyometric Exercises Affect the Inflammatory Response, Oxidative Stress, and Muscle Damage in Male Soccer Players?

Incorporating plyometric exercises (PE) into soccer players' conditioning routines is vital for boosting their performance. Nevertheless, the effects of PE sessions with diverse volume loads on inflammation, oxidative stress, and muscle damage are not yet clearly understood. This study aimed to examine the effects of altering the volume-loads of PE on indicators of oxidative muscle damage and inflammation. The study involved forty young male soccer players who were randomly assigned to three different volume-loads of PE (Low volume-load [100 jumps]: LVL, n = 10; Moderate volume-load [150 jumps]: MVL, n = 10; and High volume-load [200 jumps]: HVL, n = 10) and a control group (CON = 10). The levels of various biomarkers including delayed onset muscle soreness (DOMS), serum lactate dehydrogenase (LDH), creatine kinase (CK), 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDA), protein carbonyl (PC), leukocytes, neutrophils, interleukin-6 (IL-6), and C-reactive protein (CRP) were measured at different time points. These measurements were taken at rest, immediately after completion of PE, and 24-, 48-, and 72-hours post-PE. The CK, LDH, DOMS, 8-OHdG, MDA, and PC levels were significantly increased (p < 0.05) after the PE protocol, reaching their peak values between 24 to 48 hours post-PE for all the volume-loaded groups. The levels of leukocytes, neutrophils, and IL-6 also increased after the PE session but returned to resting values within 24 hours post-PE. On the other hand, CRP levels increased at 24 hours post-PE for all the treatment groups (p < 0.05). The changes observed in the indicators of muscle damage and inflammation in response to different volume-loads of PE was not significant. However, the HVL and MVL indicated significant differences compared to LVL in the 8-OHdG (at 48-hour) and MDA (at 72-hour). Athletes engaging in higher volume-loads demonstrated more pronounced responses in terms of biochemical variables (specifically, LVL < MVL < HVL); however, these changes were not statistically significant (except 8-OHdG and MDA).

Robotic-assisted total hip arthroplasty in patients with developmental dysplasia of the hip.

Due to the morphological diversity of deformities, technical difficulties, improperly designed components, and so on, THA remains a challenging task in dysplastic hips, especially in highly dislocated hips. The purpose of this study was to comprehensively evaluate the clinical outcomes of robot-assisted THA in patients with DDH through a large cohort study, including the precision of acetabular cup positioning, indicators of inflammatory response, indicators of muscle damage, and complications. We retrospectively analyzed patients with DDH who underwent THA in our prospectively constructed joint registry between August 2018 and August 2022. Finally, 147 manual THAs and 147 robotic-assisted THAs were included in the final analysis. Patient demographics, indicators of inflammation, indicators of muscle damage, operative time, Harris hip scores (HHS), and forgotten joint score (FJS) were recorded for analysis. The precision of the positioning of the acetabular component was assessed with plain radiographs. In the Crowe II/III groups, the reconstructed center of rotation (COR) in the robotic-assisted group was closer to the anatomical COR with less variation than the manual group (absolute horizontal distances of COR 3.5 ± 2.8 vs. 5.4 ± 4.9 mm, p < 0.05; absolute vertical distances of COR 6.4 ± 4.1 vs. 11.7 ± 8.2 mm, p = 0.001). For all Crowe subtypes, the robotic-assisted THA significantly increased the proportion of acetabular cups located in the safety zone within 5° (all p < 0.05). Interleukin-6 and creatine kinase levels were slightly lower and significantly different in the robotic-assisted group at three days postoperatively (all p < 0.05). Compared to the manual technique, the robot-assisted technique improved the precision and reproducibility of acetabular component positioning, particularly in DDH patients with Crowe types II/III. The robotic-assisted technique did not increase operative time, bleeding, complications, or revision rates, and had a slighter early inflammatory response and muscle damage.

The Effect of Contrast Water Therapy on Dehydration during Endurance Training Camps in Moderate-Altitude Environments.

The effects of contrast water therapy (CWT) on dehydration at moderate altitudes during training camps remain unknown. We hypothesized that CWT reduces dehydration resulting from training at moderate altitudes and improves performance, akin to conditions at sea level. A 13-day endurance training camp was held at a moderate altitude of 1100 m and included 22 university athletes, who were divided into two groups (CWT group, n = 12; control (CON) group, n = 10). The sample size was calculated based on an α level of 0.05, power (1 β) of 0.8, and effect size of 0.25 based on two-way ANOVA. Longitudinal changes over 13 days were compared using a two-group comparison model. Additionally, 16 athletes participated in an additional performance verification analysis. Subjective fatigue, body mass, and water content (total body water (TBW), extracellular water (ECW), and intracellular water) were measured using bioimpedance analysis every morning, and the titin N-terminal fragment in urine (UTF) was measured as an index of muscle damage. For performance verification, 10 consecutive jump performances (with the reactive strength index (RSI) as an indicator) were evaluated as neuromuscular function indices. The results indicated that the UTF did not significantly differ between the two groups. Moreover, the ECW/TBW values, indicative of dehydration, on days 4 and 5 in the CWT group were significantly lower than those in the CON group. However, there was no significant difference in RSI between the two groups. Therefore, although CWT reduces dehydration in the early stages of the training camp, it may not affect performance.

Enhancing recovery from plyometric circuit training: The synergistic impact of dynamic stretching, BCAA supplementation, and sports massage on DOMS

Understanding the significance of efficient post-exercise recovery methods in alleviating muscle damage and addressing delayed onset muscle soreness (DOMS) among athletes following plyometric circuit training. The study aimed to determine the effect of dynamic stretching in water (active pool-based) and sports massage (SM) on muscle damage indices post-plyometric circuit training. A total of 30 participants were divided into three control groups and one experimental group, who were given two recovery protocols (APB + BCAA and sports massage) after the trial. Data were statistically analysed using a one-way ANOVA test with post-test measurements and a Bonferroni test (P &lt; 0.05). It is concluded that statistically the APB + BCAA post-hoc test with SM did not show any significance. However, on average, APB + BCAA was preferable at reducing DOMS symptoms; measurements 3 and 4 in the intervention groups also showed a significant effect on the control group. The study findings underscore the valuable contribution of active recovery in water and the use of supplements in improving initial recovery outcomes after strenuous exercise or sports, aligning with the exercise recovery principle that highlights the inseparable relationship between nutrition and soft tissue modalities.

The Effect of Massage on the Exhausted Aerobic Exercise-Induced Muscle Damage Indicators in Healthy Young Men

Background: Muscle damage and soreness caused by intense exercise are problems experienced by sedentary people whose suitable solution is an essential topic in research. Objectives: This study aimed to evaluate the effect of massage on the response of recovery creatine kinase (CK) and lactate dehydrogenase (LDH) following exhausted aerobic exercise. Methods: A total of 20 sedentary university male students (26.9 ± 2.7 y, BMI: 23.1 ± 1.6) participated voluntarily in the study. The subjects were randomly divided into two groups of exercise with massage group (mas, n = 10) and a control group (con, n = 10). Subjects run on a treadmill to the point of exhaustion. After that, the group had effleurage and petrissage massage for 20 min. Then, serum CK and LDH were measured, and the results were extracted using analysis of variance with repeated measures and post hoc Bonferroni test at the P &lt; 0.05 level. Results: Both groups significantly increased CK and LDH levels after the exercise session. There was no significant difference between the two groups immediately after the massage intervention (P &gt; 0.05). In addition, there was a significant difference between the two groups 24 and 48 hours after massage in the control (P &gt; 0.05), while there was no significant change in the massage group (P &lt; 0.05). Conclusions: Based on the results, massage intervention prevented the increase of CK and LDH levels at 24 and 48 hours after the exhaustive exercise session, which indicates the beneficial effect of massage.

Identification of EIMD Level Differences Between Long- and Short Head of Biceps Brachii Using Echo Intensity and GLCM Texture Features

ABSTRACT Purpose: This study aimed to compare the time-course changes of exercise-induced muscle damage (EIMD) levels in the long head of biceps brachii (LHB) and short head of the biceps brachii (SHB) using echo intensity (EI) and to determine the efficiency of the gray level co-occurrence matrix (GLCM) texture parameters. Methods: The participants performed 30 maximal eccentric contractions of the elbow flexor. Along with muscle damage indicators, including circumference, range of motion, muscle soreness, and maximal voluntary isometric contraction (MVIC), the EI and GLCM texture features of the LHB and SHB was also assessed using B-mode ultrasonography. All measurements were assessed pre- and immediately post-exercise and after 24, 48, 72, and 96 h. Results: The muscle damage indicators indicated significant changes after the eccentric contractions (p < 0.01 for circumference, range of motion, muscle soreness, and MVIC). The EI of LHB significantly increased following the contractions (p < 0.01), but that of SHB did not (p > 0.05). In contrast, for the GLCM texture parameters, there were significant changes in the SHB (p < 0.01 for homogeneity, energy, and entropy). Conclusion: Thus, this study demonstrated that EIMD severity is different between LHB and SHB even within the same muscle. In the GLCM features, the time course of SHB after eccentric contraction revealed different patterns compared with those of LHB. Therefore, even if there are no changes in EI within a target muscle following muscle contractions, new information on muscle quality can be obtained through GLCM analysis.

Bryum billardieri Schwaegr. against EV71 infection: in vitro and in vivo antiviral effects, identification of molecular mechanisms and active monomers.

Enterovirus 71 (EV71) commonly causes symptoms such as hand, foot, and mouth disease (HFMD) in infants and children and may lead to neurological disease and even death in severe cases. Appropriate vaccines for the prevention of HFMD are available in the clinic; however, they present different and serious adverse effects that cannot guarantee compliance and efficacy. The purpose of this study was to analyze the potential mechanism of Bryum billardieri Schwaegr. (BBS) against EV71 and analyze its potential active components. A previous in vitro antiviral assay was used to determine the best extraction method for the active site of BBS against EV71, and the results showed that the antiviral activity of BBS was more pronounced in the fraction that was extracted by aqueous extraction and alcoholic precipitation and then obtained by purification on a silica gel column (dichloromethane:methanol = 0:100). In addition, the therapeutic effects of BBS on EV71-infected mice were further investigated by in vivo pharmacological experiments. BBS reduced the lung index, viral titer, and degree of EV71-induced lung, brain, and skeletal muscle damage. The mechanism of anti-EV71 activity of BBS was also investigated by using ELISA and qRT-PCR, and it was found that BBS exerted its action mainly by regulating the expression of TLR3, TLR4, TNF-α, IL-2, and IFN-γ by modulating the activation of NF-κB and JAK2/STAT1 signaling pathways. Finally, the chemical structures of the active monomers in BBS were determined by using UPLC-MS and NMR techniques. The study revealed that one of the monomers on which BBS exerts its antiviral activity is saponarin. In conclusion, the results of this study suggest that BBS is considered a natural anti-EV71 product with enormous potential, and saponarin would be its non-negligible active monomer.

Fish oil supplementation fails to modulate indices of muscle damage and muscle repair during acute recovery from eccentric exercise in trained young males

ABSTRACT We aimed to investigate the influence of 4-wk of fish oil (FO) supplementation on markers of muscle damage, inflammation, muscle soreness, and muscle function during acute recovery from eccentric exercise in moderately trained males. Sixteen moderately-trained males ingested 5 g/d of FO (n = 8) or soybean oil (placebo) capsules (n = 8) for 4-wk prior to- and 3-d following an acute eccentric exercise bout. Eccentric exercise consisted of 12 sets of isokinetic knee extension and knee flexion. Indices of muscle damage, soreness, function and inflammation were measured at baseline and during exercise recovery. Eccentric exercise elicited an increase in muscle soreness (p < 0.010) and thigh volume (p < 0.001), and reduced peak isometric torque by 31.7 ± 6.9%, (p < 0.05, 95% CI 10.6–52.8) during 3-d of recovery. Blood omega-3 polyunsaturated fatty acid concentration was 14.9 ± 2.4% higher in FO than PLA (p < 0.01, 95% CI 9.8–20.1). However, FO did not ameliorate the cumulative creatine kinase response (expressed as AUC; p = 0.368), inflammation (p = 0.400), muscle soreness (p > 0.140), or muscle function (p > 0.249) following eccentric exercise. FO supplementation confers no clear benefit in terms of ameliorating the degree of muscle damage, or facilitating the muscle repair process, during acute eccentric exercise recovery. These data suggest that FO supplementation does not provide an effective nutritional strategy to promote exercise recovery, at least in moderately-trained young men. Abbreviations: ANOVA: Analysis of variance; AUC: Area under curve; CI: Confidence interval; CK: Creatine kinase; CMJ: Countermovement jump; COX: Cyclooxygenase; CRP: C-reactive protein; DHA: Docosahexaenoic acid; DOMS: Delayed-onset muscle soreness; EIMD: Exercise-induced muscle damage; En%: Energy percent; EPA: Eicosapentaenoic acid; FO: Fish oil; IL-6: Interleukin-6; LDH: Lactate dehydrogenase; LOX: Lipoxygenase; Mb: Myoglobin; mTOR: Mechanistic target of rapamycin; PLA: Placebo; ROM: Range of motion; ROS: Reactive oxygen species; SD: Standard deviation; SEM: Standard error of the mean; TNF-α: Tumour necrosis factor alpha; VAS: Visual analogue scale; Ω3-PUFA: Omega-3 polyunsaturated fatty acids; Ω6-PUFA: Omega-6 polyunsaturated fatty acids Highlights The anti-inflammatory properties of omega-3 polyunsaturated fatty acids, alongside their propensity to incorporate into the muscle phospholipid membrane underpins the idea that fish oil supplementation may attenuate muscle damage and promote muscle repair following eccentric-based exercise. Four weeks of high-dose (5 g/d) fish oil supplementation prior to eccentric exercise failed to attenuate the rise in creatine kinase concentration and muscle soreness during acute exercise recovery in physically-active young men. Future studies are warranted to investigate the efficacy of combining omega-3 polyunsaturated fatty acids with other nutrients (i.e. protein/amino acids) for the promotion of muscle recovery following eccentric-based damaging exercise.

Effect of curcumin supplementation on inflammatory status and muscle damage in competitive female soccer players: a placebo-controlled, singleblind, nonrandomized, crossover pilot study.

Curcumin, a major component of turmeric, has anti-inflammatory and antioxidative properties, which are associated with protective effects against muscle damage. This study examined the effects of dietary curcumin on inflammation and muscle damage in female competitive soccer players. A single-blinded, placebo-controlled, nonrandomized, crossover pilot study was conducted. Six competitive female soccer players (20.0 ± 2.0 yearsold) who participated in a 2-week preseason training program were assigned to two conditions: placebo and curcumin. The participants ingested a placebo or curcumin dosage (270 mg/day) during 2 weeks of preseason training, with 1 week of washout. Fasting blood samples were collected under resting conditions before (day 0) and after (day 15) the training period to examine changes in the concentration of interleukin 6 (IL-6), an inflammatory marker, and indices reflective of muscle damage. Curcumin decreased the concentration of IL-6 released (mean decrease, -30.2 ± 28.1%), whereas no decrease was observed in the placebo condition (13.4 ± 17.4%). Changes in plasma IL-6 concentrations were significantly greater in the curcumin condition than in the placebo condition (p &lt; 0.05). However, curcumin supplementation had no significant effects on muscle damage indices. The present study shows that curcumin supplementation could attenuate inflammation, as indicated by IL-6 concentrations, in competitive female soccer players during the training period.

Effects of muscle damage indicators and antioxidant capacity after interval training on the 800-m records of adolescent middle-distance runners.

To examine the effect of 10-week interval training (IT) at varying intensities on serum muscle damage indicators and antioxidant capacity and determine its effect on the 800-m records of adolescent middle-distance runners. Twenty male high-school middle-distance runners were randomized between the high-intensity IT (HIIT; n=10) and the medium-intensity IT (MIIT; n=10) groups. Three sessions/week for 10 weeks (total of 30 sessions) were performed; one session of IT was for 60 min. The high and medium exercise intensities were set at 90%-95% and 60%-70% heart rate reserve (HRR), respectively. Intensity at rest was 40% HRR for both groups. Weight training was performed at 60%-70% of one repetition maximum for two sessions/week. The changes in serum muscle damage indicators and antioxidant capacity in the two groups were measured, and their effects on the 800-m records were analyzed. The 10-week training reduced serum muscle damage indicators in middle-distance runners, but only the HIIT group displayed a decrease in creatine kinase. For the change in antioxidant capacity, the two groups demonstrated no significant change in malondialdehyde (MDA), whereas the HIIT group exhibited a significant increase in super-oxide dismutase (SOD). IT also reduced the 800-m records in middle-distance running, and the effect was stronger in the HIIT group. In conclusion, 10-week HIIT can have a positive effect on muscle damage indicators, showed a significant increase in SOD as a key indicator of anti-oxidant capacity, and improved the 800-m records in middle-distance runners.