Indomethacin in Combination with Exercise Leads to Muscle and Brain Inflammation in Mice

Brain oxidative stress mediates anxiety-like behavior induced by indomethacin in zebrafish: protective effect of alpha-tocopherol

RATIONALE

Indomethacin (INDO) is a widely utilized non-steroidal anti-inflammatory drug (NSAID) with recognized effect on the central nervous system. Although previous reports demonstrate that prolonged treatment with indomethacin can lead to behavioral alterations such as anxiety disorder, the biochemical effect exerted by this drug on the brain are not fully understood.

OBJECTIVES

The aim of present study was to evaluate if anxiety-like behavior elicited by indomethacin is mediated by brains oxidative stress as well as if alpha-tocopherol, a potent antioxidant, is able to prevent the behavioral and biochemical alterations induced by indomethacin treatment.

METHODS

Zebrafish were utilized as experimental model and subdivided into control, INDO 1 mg/Kg, INDO 2 mg/Kg, INDO 3 g/Kg, α-TP 2 mg/Kg, α-TP 2 mg/Kg + INDO 1 mg/Kg and α-TP + INDO 2 mg/Kg groups. Vertical distributions elicited by novelty and brain oxidative stress were utilized to determinate behavioral and biochemical alterations elicited by indomethacin treatment, respectively.

RESULTS

Our results showed that treatment with indomethacin 3 mg/kg induces animal death. No changes in animal survival were observed in animals treated with lower doses of indomethacin. Indomethacin induced significant anxiogenic-like behavior as well as intense oxidative stress in zebrafish brain. Treatment with alpha-tocopherol was able to prevent anxiety-like behavior and brain oxidative stress induced by indomethacin.

CONCLUSIONS

Data presented in current study demonstrated for the first time that indomethacin induces anxiety-like behavior mediated by brain oxidative stress in zebrafish as well as that pre-treatment with alpha-tocopherol is able to prevent these collateral effects.

Investigation of the biochemical and histopathological effects of vitamin C, selenium, and therapeutic ultrasound on muscle damage in rats

Muscle injury is a common type of soft tissue injury. Increased oxidative damage has been reported after muscle injuries. Therapeutic ultrasound is commonly used for such injuries. This study compared the efficacy of therapeutic ultrasound treatment and various antioxidant agents in experimental muscle injuries. For this purpose, some serum enzymes, oxidative stress, and inflammatory markers were evaluated together with histopathological examinations. Six groups were formed with 6 male Wistar albino rats in each group. These groups were control, only injury (OI), ultrasound (U), vitamin C (Vit C), selenium (S), and mixture (M). Muscle injury was caused by a laceration of the gastrocnemius muscle in all groups except the control group. No treatment was performed in the OI group. At the end of the 6-day application, all rats were sacrificed. As for serum enzymes, CK, ALT, and AST levels returned to control values in almost all treatment groups. Total oxidative status (TOS) and oxidative stress index (OSI) increased in the OI group, while they decreased in the S and M groups. In addition, the decrease in MPO activity in the blood tissue of the Vit C group was statistically significant. There were no significant changes between groups in terms of serum inflammatory markers and histological findings. This study has shown that the ingestion of vitamin C and selenium may contribute to the treatment of muscle injury in addition to therapeutic ultrasound treatment. However, further studies are needed to support these results.

Compression Socks Reduce Running-Induced Intestinal Damage

Zadow, EK, Edwards, KH, Kitic, CM, Fell, JW, Adams, MJ, Singh, I, Kundur, A, Johnstone, ANB, Crilly, J, Bulmer, AC, Halson, SL, and, and Wu, SSX. Compression socks reduce running-induced intestinal damage. J Strength Cond Res XX(X): 000-000, 2020-Exercise is associated with a reduction in splanchnic blood flow that leads to the disruption of intestinal epithelium integrity, contributing to exercise-induced gastrointestinal syndrome. Strategies that promote intestinal blood flow during exercise may reduce intestinal damage, which may be advantageous for subsequent recovery and performance. This study aimed to explore if exercise-associated intestinal damage was influenced by wearing compression garments, which may improve central blood flow. Subjects were randomly allocated to wear compression socks (n = 23) or no compression socks (control, n = 23) during a marathon race. Blood samples were collected 24 hours before and immediately after marathon and analyzed for intestinal fatty acid-binding protein (I-FABP) concentration as a marker of intestinal damage. The magnitude of increase in postmarathon plasma I-FABP concentration was significantly greater in control group (107%; 95% confidence interval [CI], 72-428%) when compared with runners wearing compression socks (38%; 95% CI, 20-120%; p = 0.046; d = 0.59). Wearing compression socks during a marathon run reduced exercise-associated intestinal damage. Compression socks may prove an effective strategy to minimize the intestinal damage component of exercise-induced gastrointestinal syndrome.

Pharmacological targeting of age-related changes in skeletal muscle tissue

Sarcopenia, the age-related loss of skeletal muscle mass and function, increases the risk of developing chronic diseases in older individuals and is a strong predictor of disability and death. Because of the ongoing demographic transition, age-related muscle weakness is responsible for an alarming and increasing contribution to health care costs in Western countries. Exercise-based interventions are most successful in preventing the decline in skeletal muscle mass and in preserving or ameliorating functional capacities with increasing age. However, other treatment options are still scarce. In this review, we explore currently applied nutritional and pharmacological approaches to mitigate age-related muscle wasting, and discuss potential future therapeutic avenues.

Impact of drugs with anti-inflammatory effects on skeletal muscle and inflammation: A systematic literature review

BACKGROUND

Ageing-related low-grade inflammation is suggested to aggravate sarcopenia and frailty. This systematic review investigates the influence that drugs with anti-inflammatory effects (AIDs) have on inflammation and skeletal muscle.

METHODS

PubMed and Web of Science were systematically screened for articles reporting the effects of AIDs on inflammation on one hand and on muscle mass and/or performance on the other.

RESULTS

Twenty-eight articles were included. These articles were heterogeneous in terms of the subjects studied, intervention components, setting, and outcome measures. Articles on older humans with acute inflammation showed evidence that celecoxib and piroxicam could reduce inflammation and improve performance and that ibuprofen improves exercise-induced muscle hypertrophy and gains in strength. In younger humans, only the effects of AIDs combined with exercise were investigated; no significant benefits of non-selective COX-inhibitors were reported, but improved strength gains with etanercept and reduced muscle soreness with celecoxib were noted. Indomethacin increased acute exercise-induced inflammation and reduced satellite cell differentiation in exercising muscle. Most articles did not systematically report occurrences of side effects.

CONCLUSIONS

Although AIDs showed significant reduction in inflammation-induced muscle weakness in older hospitalised patients with acute inflammation, robust evidence is still lacking. When combined with exercise, AIDs presented a protective effect against age-related loss of muscle mass, thus enhancing muscle mass and performance. The mechanism regulating muscle strength and its mass seems to differ between individuals of old and young age. However, the effects seem drug-specific and dose-dependent and appear to be influenced by subjects' trainability and the clinical context. In addition, the balance between benefits and harm remains unclear.

Intestinal damage following short-duration exercise at the same relative intensity is similar in temperate and hot environments

Increasing temperature and exercise disrupt tight junctions of the gastrointestinal tract although the contribution of environmental temperature to intestinal damage when exercising is unknown. This study investigated the effect of 2 different environmental temperatures on intestinal damage when exercising at the same relative intensity. Twelve men (mean ± SD; body mass, 81.98 ± 7.95 kg; height, 182.6 ± 7.4 cm) completed randomised cycling trials (45 min, 70% maximal oxygen uptake) in 30 °C/40% relative humidity (RH) and 20 °C/40%RH. A subset of participants (n = 5) also completed a seated passive trial (30 °C/40%RH). Rectal temperature and thermal sensation (TSS) were recorded during each trial and venous blood samples collected at pre- and post-trial for the analysis of intestinal fatty acid-binding protein (I-FABP) level as a marker of intestinal damage. Oxygen uptake was similar between 30 °C and 20 °C exercise trials, as intended (p = 0.94). I-FABP increased after exercise at 30 °C (pre-exercise: 585 ± 188 pg·mL^-1; postexercise: 954 ± 411 pg·mL^-1) and 20 °C (pre-exercise: 571 ± 175 pg·mL^-1; postexercise: 852 ± 317 pg·mL^-1) (p < 0.0001) but the magnitude of damage was similar between temperatures (p = 0.58). There was no significant increase in I-FABP concentration following passive heat exposure (p = 0.59). Rectal temperature increased during exercise trials (p < 0.001), but not the passive trial (p = 0.084). TSS increased more when exercising in 30 °C compared with 20 °C (p < 0.001). There was an increase in TSS during the passive heat trial (p = 0.03). Intestinal damage, as measured by I-FABP, following exercise in the heat was similar to when exercising in a cooler environment at the same relative intensity. Passive heat exposure did not increase I-FABP. It is suggested that when exercising in conditions of compensable heat stress, the increase in intestinal damage is predominantly attributable to the exercise component, rather than environmental conditions.

Immune-regulating effects of exercise on cigarette smoke-induced inflammation

Long-term cigarette smoking (LTCS) represents an important risk factor for cardiac infarction and stroke and the central risk factor for the development of a bronchial carcinoma, smoking-associated interstitial lung fibrosis, and chronic obstructive pulmonary disease. The pathophysiologic development of these diseases is suggested to be promoted by chronic and progressive inflammation. Cigarette smoking induces repetitive inflammatory insults followed by a chronic and progressive activation of the immune system. In the pulmonary system of cigarette smokers, oxidative stress, cellular damage, and a chronic activation of pattern recognition receptors are described which are followed by the translocation of the NF-kB, the release of pro-inflammatory cytokines, chemokines, matrix metalloproteases, and damage-associated molecular patterns. In parallel, smoke pollutants cross directly through the alveolus-capillary interface and spread through the systemic bloodstream targeting different organs. Consequently, LTCS induces a systemic low-grade inflammation and increased oxidative stress in the vascular system. In blood, these processes promote an increased coagulation and endothelial dysfunction. In muscle tissue, inflammatory processes activate catabolic signaling pathways followed by muscle wasting and sarcopenia. In brain, several characteristics of neuroinflammation were described. Regular exercise training has been shown to be an effective nonpharmacological treatment strategy in smoke-induced pulmonary diseases. It is well established that exercise training exerts immune-regulating effects by activating anti-inflammatory signaling pathways. In this regard, the release of myokines from contracting skeletal muscle, the elevations of cortisol and adrenalin, the reduced expression of Toll-like receptors, and the increased mobilization of immune-regulating leukocyte subtypes might be of vital importance. Exercise training also increases the local and systemic antioxidative capacity and several compensatory mechanisms in tissues such as an increased anabolic signaling in muscle or an increased compliance of the vascular system. Accordingly, regular exercise training seems to protect long-term smokers against some important negative local and systemic consequences of smoking. Data suggest that it seems to be important to start exercise training as early as possible.

Synthesis, toxicity study and anti-inflammatory effect of MHTP, a new tetrahydroisoquinoline alkaloid

The alkaloid 2-methoxy-4-(7-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl)phenol (MHTP) was synthesized to prospect new compounds with therapeutic properties. Thus, the goal of this study was to evaluate the MHTP anti-inflammatory effect by in vivo and in vitro assays. The MHTP toxicity was analyzed. We found that MHTP pre-treatment (2.5-10 mg/kg) showed antiedematogenic effect (p < 0.05) in carrageenan-induced paw edema by inhibiting the PGE2 action independently of mast cell degranulation or histamine activity. MHTP also diminished (p < 0.01) total leukocyte migration in 41.5% into peritoneal cavity during carrageenan-induced peritonitis, reducing polymorphonuclear cells (PMNs) (59.6%) and proteins levels (29.4%). MHTP in an experimental model of acute lung injury inhibited (p < 0.001) total inflammatory cell migration into the lungs and PMNs in 58% and 67.5%, respectively. Additionally, MHTP did not present cytotoxicity at concentrations of 10, 25 or 50 μM but decreased (p < 0.001) the NO production in 24%, 47% and 39%, respectively. The alkaloid also reduced (p < 0.001, in lipopolysaccharide (LPS)-stimulated macrophages (1 μg/mL), IL-1β, IL-6 and IL-10 levels in 35.7%, 31.0% and 33.4%, respectively. The results obtained in this study allow us to conclude that the inedited synthetic alkaloid, MHTP has anti-inflammatory effect by inhibiting PGE2 function as well as inhibiting inflammatory cell migration to the inflamed site and attenuated the acute lung injury disease by inhibiting the migration of neutrophil to the lung. However, further studies will be carried out to demonstrate the mechanisms of action of the molecule and explore its potential as a future drug to treat inflammatory processes.

Modulating exercise-induced hormesis: Does less equal more?

Hormesis encompasses the notion that low levels of stress stimulate or upregulate existing cellular and molecular pathways that improve the capacity of cells and organisms to withstand greater stress. This notion underlies much of what we know about how exercise conditions the body and induces long-term adaptations. During exercise, the body is exposed to various forms of stress, including thermal, metabolic, hypoxic, oxidative, and mechanical stress. These stressors activate biochemical messengers, which in turn activate various signaling pathways that regulate gene expression and adaptive responses. Historically, antioxidant supplements, nonsteroidal anti-inflammatory drugs, and cryotherapy have been favored to attenuate or counteract exercise-induced oxidative stress and inflammation. However, reactive oxygen species and inflammatory mediators are key signaling molecules in muscle, and such strategies may mitigate adaptations to exercise. Conversely, withholding dietary carbohydrate and restricting muscle blood flow during exercise may augment adaptations to exercise. In this review article, we combine, integrate, and apply knowledge about the fundamental mechanisms of exercise adaptation. We also critically evaluate the rationale for using interventions that target these mechanisms under the overarching concept of hormesis. There is currently insufficient evidence to establish whether these treatments exert dose-dependent effects on muscle adaptation. However, there appears to be some dissociation between the biochemical/molecular effects and functional/performance outcomes of some of these treatments. Although several of these treatments influence common kinases, transcription factors, and proteins, it remains to be determined if these interventions complement or negate each other, and whether such effects are strong enough to influence adaptations to exercise.