Beibei Luo

Metabolomics approach to assessing plasma 13- and 9-hydroxy-octadecadienoic acid and linoleic acid metabolite responses to 75-km cycling.

Bioactive oxidized linoleic acid metabolites (OXLAMs) include 13- and 9-hydroxy-octadecadienoic acid (13-HODE + 9-HODE) and have been linked to oxidative stress, inflammation, and numerous pathological and physiological states. The purpose of this study was to measure changes in plasma 13-HODE + 9-HODE following a 75-km cycling bout and identify potential linkages to linoleate metabolism and established biomarkers of oxidative stress (F2-isoprostanes) and inflammation (cytokines) using a metabolomics approach. Trained male cyclists (N = 19, age 38.0 ± 1.6 yr, wattsmax 304 ± 10.5) engaged in a 75-km cycling time trial on their own bicycles using electromagnetically braked cycling ergometers (2.71 ± 0.07 h). Blood samples were collected preexercise, immediately post-, 1.5 h post-, and 21 h postexercise, and analyzed for plasma cytokines (IL-6, IL-8, IL-10, tumor necrosis factor-α, monocyte chemoattractant protein-1, granulocyte colony-stimulating factor), F2-isoprostanes, and shifts in metabolites using global metabolomics procedures with gas chromatography mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS). 13-HODE + 9-HODE increased 3.1-fold and 1.7-fold immediately post- and 1.5 h postexercise (both P < 0.001) and returned to preexercise levels by 21-h postexercise. Post-75-km cycling plasma levels of 13-HODE + 9-HODE were not significantly correlated with increases in plasma cytokines but were positively correlated with postexercise F2-isoprostanes (r = 0.75, P < 0.001), linoleate (r = 0.54, P = 0.016), arachidate (r = 0.77, P < 0.001), 12,13-dihydroxy-9Z-octadecenoate (12,13-DiHOME) (r = 0.60, P = 0.006), dihomo-linolenate (r = 0.57, P = 0.011), and adrenate (r = 0.56, P = 0.013). These findings indicate that prolonged and intensive exercise caused a transient, 3.1-fold increase in the stable linoleic acid oxidation product 13-HODE + 9-HODE and was related to increases in F2-isoprostanes, linoleate, and fatty acids in the linoleate conversion pathway. These data support the use of 13-HODE + 9-HODE as an oxidative stress biomarker in acute exercise investigations.

Immune and inflammation responses to a 3-day period of intensified running versus cycling

Functional overreaching has been linked to alterations in immunity and host pathogen defense, but little is known as to whether or not running and cycling evoke different responses. This study compared inflammation, muscle damage and soreness, and innate immune function responses to a 3-day period of intensified exercise in trained long distance runners (N=13, age 34.4±2.4year) and cyclists (N=22, age 36.6±1.7year, P=0.452). Upper respiratory tract infection (URTI) symptomatology was monitored for 12weeks using the Wisconsin Upper Respiratory Symptom Survey (WURSS), and subjects from both athletic groups came to the lab during week five and exercised 2.5h/day for 3days in a row at 70% VO2max. Blood samples were collected before and after the 3-day period of exercise, with recovery samples collected 1-, 14-, and 38h-post-exercise. Samples were analyzed for muscle damage [creatine kinase (CK), myoglobin (MYO)], inflammation (CRP, IL-6, IL-8, IL-10, MCP), and innate immunity [granulocyte and monocyte phagocytosis (GR-PHAG and MO-PHAG) and oxidative burst activity (GR-OBA and MO-OBA)]. Runners compared to cyclists experienced significantly more muscle damage (CK 133% and MYO 404% higher post-3days exercise), inflammation (CRP 87%, IL-6 256%, IL 8 61%, IL-10 32%, MCP 29%), and delayed onset of muscle soreness (DOMS, 87%). The 3-day period of exercise caused significant downturns in GR-PHAG, MO-PHAG, GR-OBA, MO-OBA by 14- and 38h-recovery, but the pattern of change did not differ between groups. No group differences were measured for 12-week URTI severity (18.3±5.6 and 16.6±4.0, P=0.803) and symptom scores (33.4±12.6 and 24.7±5.8, P=0.477). These data indicate that a 3-day period of functional overreaching results in substantially more muscle damage and soreness, and systemic inflammation in runners compared to cyclists, but without group differences for 12-week URTI symptomatology and post-exercise decrements in innate immune function.

Evaluation of Rhodiola rosea supplementation on skeletal muscle damage and inflammation in runners following a competitive marathon

Adaptogens modulate intracellular signaling and increase expression of heat shock protein 72 (HSP72). Rhodiola rosea (RR) is a medicinal plant with demonstrated adaptogenic properties. The purpose of this study was to measure the influence of RR supplementation on exercise-induced muscle damage, delayed onset of muscle soreness (DOMS), plasma cytokines, and extracellular HSP72 (eHSP72) in experienced runners completing a marathon. Experienced marathon runners were randomized to RR (n=24, 6 female, 18 male) or placebo (n=24, 7 female, 17 male) groups and under double-blinded conditions ingested 600mg/day RR extract or placebo for 30days prior to, the day of, and seven days post-marathon. Blood samples were collected, and vertical jump and DOMS assessed the day before, 15min post- and 1.5h post-marathon. DOMS was also assessed for seven days post-marathon. Marathon race performance did not differ between RR and placebo groups (3.87±0.12h and 3.93±0.12h, respectively, p=0.722). Vertical jump decreased post-marathon (time effect, p<0.001) with no difference between groups (interaction effect, p=0.673). Post-marathon DOMS increased significantly (p<0.001) but the pattern of change did not differ between groups (p=0.700). Myoglobin (Mb), creatine phosphokinase (CPK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), interleukin (IL)-6, IL-8, IL-10, monocyte chemotactic protein-1 (MCP-1), granulocyte-colony-stimulating factor (G-CSF), C-reactive protein (CRP), and eHSP72 all increased post-marathon (all p<0.001), with no group differences over time (all p>0.300). In conclusion, RR supplementation (600mg/day) for 30days before running a marathon did not attenuate the post-marathon decrease in muscle function, or increases in muscle damage, DOMS, eHSP72, or plasma cytokines in experienced runners.

Influence of Pistachios on Performance and Exercise-Induced Inflammation, Oxidative Stress, Immune Dysfunction, and Metabolite Shifts in Cyclists: A Randomized, Crossover Trial

Objectives Pistachio nut ingestion (3 oz./d, two weeks) was tested for effects on exercise performance and 21-h post-exercise recovery from inflammation, oxidative stress, immune dysfunction, and metabolite shifts. Methods Using a randomized, crossover approach, cyclists (N = 19) engaged in two 75-km time trials after 2-weeks pistachio or no pistachio supplementation, with a 2-week washout period. Subjects came to the lab in an overnight fasted state, and ingested water only or 3 oz. pistachios with water before and during exercise. Blood samples were collected 45 min pre-exercise, and immediately post-, 1.5-h post-, and 21-h post-exercise, and analyzed for plasma cytokines, C-reactive protein (CRP), F2-isoprostanes (F2-IsoP), granulocyte phagocytosis (GPHAG) and oxidative burst activity (GOBA), and shifts in metabolites. Results Performance time for the 75-km time trial was 4.8% slower under pistachio conditions (2.84±0.11 and 2.71±0.07 h, respectively, P = 0.034). Significant time effects were shown for plasma cytokines, CRP, F2-IsoP, GPHAG, and GOBA, with few group differences. Metabolomics analysis revealed 423 detectable compounds of known identity, with significant interaction effects for 19 metabolites, especially raffinose, (12Z)-9,10-Dihydroxyoctadec-12-enoate (9,10-DiHOME), and sucrose. Dietary intake of raffinose was 2.19±0.15 and 0.35±0.08 mg/d during the pistachio and no pistachio periods, and metabolomics revealed that colon raffinose and sucrose translocated to the circulation during exercise due to increased gut permeability. The post-exercise increase in plasma raffinose correlated significantly with 9,10-DiHOME and other oxidative stress metabolites. Conclusions In summary, 2-weeks pistachio nut ingestion was associated with reduced 75-km cycling time trial performance and increased post-exercise plasma levels of raffinose, sucrose, and metabolites related to leukotoxic effects and oxidative stress. Trial Registration ClinicalTrials.gov NCT01821820

The effects of moderate exercise on chronic stress-induced intestinal barrier dysfunction and antimicrobial defense.

The purpose of this study was to examine the effect of moderate exercise on repeated restraint stress (RRS)-induced intestinal barrier dysfunction and explore possible mechanisms in a mouse model. Male Balb/c mice (6weeks) were randomized into 7 groups: CON functioned as controls with no intervention; RRS was subjected to 6h per day RRS for 7 consecutive days; RRS+SWIM received 30min per day of swimming prior to RRS; CON+SWIM only received 30min per day of swimming; and the other groups received one session of 30min swimming prior to sacrifice at 1-, 3- and 6h recovery. Intestinal permeability was quantified with FITC-dextran. Bacterial translocation was determined by quantification of bacterial colony forming units (CFUs) in cultured mesenteric lymph nodes (MLN), and with fluorescence in situ hybridization (FISH). Antimicrobial related gene expression at baseline and 1h after one session of 30min swimming was tested by quantitative real-time polymerase chain reaction (Q-PCR) in small intestinal segments. Protein expression of 5 genes with statistically significant increase was measured at baseline, and 1-, 3- and 6h post-swimming using enzyme-linked immunosorbent assay (ELISA). Thirty minutes per day of swimming before RRS attenuated bacterial translocations and maintained intestinal permeability. Gene expression and protein levels for four antimicrobial peptides (α-defensin 5, β-defensin 1, RegIIIβ and RegIIIγ) were significantly increased after one 30min swimming session. In conclusion, moderate exercise attenuated chronic stress-induced intestinal barrier dysfunction in mice, possibly due to augmentation of antimicrobial responses in the small intestine.

A commercialized dietary supplement alleviates joint pain in community adults: a double-blind, placebo-controlled community trial

BackgroundThe purpose of this study was to assess the effect of 8-weeks ingestion of a commercialized joint pain dietary supplement (InstaflexTM Joint Support, Direct Digital, Charlotte, NC) compared to placebo on joint pain, stiffness, and function in adults with self-reported joint pain. InstaflexTM is a joint pain supplement containing glucosamine sulfate, methylsufonlylmethane (MSM), white willow bark extract (15% salicin), ginger root concentrate, boswella serrata extract (65% boswellic acid), turmeric root extract, cayenne, and hyaluronic acid.MethodsSubjects included 100 men and women, ages 50-75 years, with a history (>3 months) of joint pain, and were randomized to Instaflex™ or placebo (3 colored gel capsules per day for 8 weeks, double-blind administration). Subjects agreed to avoid the use of non-steroidal anti-inflammatory drugs (NSAID) and all other medications and supplements targeted for joint pain. Primary outcome measures were obtained pre- and post-study and included joint pain severity, stiffness, and function (Western Ontario and McMaster Universities [WOMAC]), and secondary outcome measures included health-related quality of life (Short Form 36 or SF-36), systemic inflammation (serum C-reactive protein and 9 plasma cytokines), and physical function (6-minute walk test). Joint pain symptom severity was assessed bi-weekly using a 12-point Likert visual scale (12-VS).ResultsJoint pain severity was significantly reduced in Instaflex™ compared to placebo (8-week WOMAC, ↓37% versus ↓16%, respectively, interaction effect P = 0.025), with group differences using the 12-VS emerging by week 4 of the study (interaction effect, P = 0.0125). Improvements in ability to perform daily activities and stiffness scores in Instaflex™ compared to placebo were most evident for the 74% of subjects reporting knee pain (8-week WOMAC function score, ↓39% versus ↓14%, respectively, interaction effect P = 0.027; stiffness score, ↓30% versus ↓12%, respectively, interaction effect P = 0.081). Patterns of change in SF-36, systemic inflammation biomarkers, and the 6-minute walk test did not differ significantly between groups during the 8-week studyConclusionsResults from this randomized, double blind, placebo-controlled community trial support the use of the Instaflex™ dietary supplement in alleviating joint pain severity in middle-aged and older adults, with mitigation of difficulty performing daily activities most apparent in subjects with knee pain.Trial registrationClinicalTrials.gov Identifier: NCT01956500

Vitamin D2 supplementation amplifies eccentric exercise-induced muscle damage in NASCAR pit crew athletes.

This study determined if 6-weeks vitamin D2 supplementation (vitD2, 3800 IU/day) had an influence on muscle function, eccentric exercise-induced muscle damage (EIMD), and delayed onset of muscle soreness (DOMS) in National Association for Stock Car Auto Racing (NASCAR) NASCAR pit crew athletes. Subjects were randomized to vitD2 (n = 13) and placebo (n = 15), and ingested supplements (double-blind) for six weeks. Blood samples were collected and muscle function tests conducted pre- and post-study (leg-back and hand grip dynamometer strength tests, body weight bench press to exhaustion, vertical jump, 30-s Wingate test). Post-study, subjects engaged in 90 min eccentric-based exercise, with blood samples and DOMS ratings obtained immediately after and 1- and 2-days post-exercise. Six weeks vitD2 increased serum 25(OH)D2 456% and decreased 25(OH)D3 21% versus placebo (p < 0.001, p = 0.036, respectively), with no influence on muscle function test scores. The post-study eccentric exercise bout induced EIMD and DOMS, with higher muscle damage biomarkers measured in vitD2 compared to placebo (myoglobin 252%, 122% increase, respectively, p = 0.001; creatine phosphokinase 24 h post-exercise, 169%, 32%, p < 0.001), with no differences for DOMS. In summary, 6-weeks vitD2 (3800 IU/day) significantly increased 25(OH)D2 and decreased 25(OH)D3, had no effect on muscle function tests, and amplified muscle damage markers in NASCAR pit crew athletes following eccentric exercise.

Dietary Glutamine Supplementation Partly Reverses Impaired Macrophage Function Resulting From Overload Training in Rats

The aim of this study was to evaluate the effect of overload training on the function of peritoneal macrophages in rats, and to test the hypothesis that glutamine in vivo supplementation would partly reverse the eventual functional alterations induced by overload training in these cells. Forty male Wistar rats were randomly divided into 5 groups: control group (C), overload training group (E1), overload training and restore one week group (E2), glutamine-supplementation group (EG1), and glutamine-supplementation and restore 1-week group (EG2). All rats, except those placed on sedentary control were subjected to 11 weeks of overload training protocol. Blood hemoglobin, serum testosterone, and corticosterone of rats were measured. Moreover, the functions (chemotaxis, phagocytosis, cytokines synthesis, reactive oxygen species generation) of peritoneal macrophages were determined. Data showed that blood hemoglobin, serum testosterone, corticosterone and body weight in the overload training group decreased significantly as compared with the control group. Meanwhile, the chemotaxis capacity (decreased by 31%, p = .003), the phagocytosis capacity (decreased by 27%, p = .005), the reactive oxygen species (ROS) generation (decreased by 35%, p = .003) and the cytokines response capability of macrophages were inhibited by overload training. However, the hindering of phagocytosis and the cytokines response capability of macrophages induced by overload training could be ameliorated and reversed respectively, by dietary glutamine supplementation. These results suggest that overload training impairs the function of peritoneal macrophages, which is essential for the microbicidal actions of macrophages. This may represent a novel mechanism of immunodepression induced by overload training. Nonetheless, dietary glutamine supplementation could partly reverse the impaired macrophage function resulting from overload training.

Time-dependent gene expression analysis after mouse skeletal muscle contusion

Background Though the mechanisms of skeletal muscle regeneration are deeply understood, those involved in muscle contusion, one of the most common muscle injuries in sports medicine clinics, are not. The objective of this study is to explore the mechanisms involved in muscle regeneration after contusion injury. Methods In this study, a total of 72 mice were used. Eight of them were randomly chosen for the control group, while the rest were subjected to muscle contusion. Subsequently, their gastrocnemius muscles were harvested at different time points. The changes in muscle morphology were assessed by hematoxylin and eosin (HE) stain. In addition, the gene expression was analyzed by real-time polymerase chain reaction. Results The data showed that the expression of many genes, i.e., specific markers of immune cells and satellite cells, regulatory factors for muscle regeneration, cytokines, and chemokines, increased in the early stages of recovery, especially in the first 3 days. Furthermore, there were strict rules in the expression of these genes. However, almost all the genes returned to normal at 14 days post-injury. Conclusion The sequence of immune cells invaded after muscle contusion was neutrophils, M1 macrophages and M2 macrophages. Some CC (CCL2, CCL3, and CCL4) and CXC (CXCL10) chemokines may be involved in the chemotaxis of these immune cells. HGF may be the primary factor to activate the satellite cells after muscle contusion. Moreover, 2 weeks are needed to recover when acute contusion happens as used in this study.