Moderate swimming exercise and caffeine supplementation reduce the levels of inflammatory cytokines without causing oxidative stress in tissues of middle-aged rats

Effects of swimming exercise on neuropathic pain in a rat model: role of glutamate

OBJECTIVE

The pain-reducing effects of the exercise were exerted through different mechanisms. Knowing more clear mechanisms helps to find more approach that is therapeutic. The objective of the present study is the evaluation of cerebrospinal fluid (CSF) glutamate level alteration in neuropathic pain rats and whether physical activity could modulate it.

METHODS

In the present study 104 male Wistar rats weighing 180-220 g were randomly divided into 4 groups (Sham, Sham + Exe, Neuropathy, and Neuropathy + Exe) which in turn each group subdivided into 4 groups according to time points for behavioral testing and CSF sampling (Baseline, 2 weeks, 3 weeks, and 4 weeks). To induction of neuropathy (by chronic constriction injury,), after anesthetizing with a mixture of ketamine (80 mg/kg) and xylazine (10 mg/kg), the animal's right sciatic nerve was exposed and was ligated using four movable catgut chromic suture 4/0. The exercise protocol included 25 min of daily swimming, 5 days a week for 4 weeks. Thermal hyperalgesia and mechanical tactile threshold were detected using the plantar test and Von Frey filaments, respectively. CSF glutamate level was determined using high-performance liquid chromatography.

RESULTS

Findings indicated that mechanical and thermal thresholds significantly (p < 0.01, p < 0.05 respectively) decreased in the neuropathy group against that in sham groups. On the other hand, exercise significantly increased mechanical tactile threshold (p < 0.0012) and thermal threshold (p < 0.05) compared to the neuropathy group. Moreover, CSF glutamate level prominently (p < 0.01) was increased in the neuropathy group compared to the sham group, and swimming exercise significantly (p < 0.001) reduced it.

IN CONCLUSION

The present findings provide new evidence showing that medium-intensity swimming exercise attenuates pain-like behaviors in neuropathic pain animals, which is possibly due to decreasing CSF glutamate level and its neurotransmission.

Exercise induced myelin protein zero improvement in neuropathic pain rats

PURPOSE

Aerobic exercise including swimming plays a suitable role in improving somatosensory injuries. Neuropathic pain is a debilitating condition that occurs following injury or diseases of somatosensory system. In the present study, we tried to investigate the effect of exercise on myelin protein zero of sciatic nerve injured rats.

MATERIALS AND METHODS

Forty male rats (180-220 g) were divided into five groups (intact, sham, sham + exercise, neuropathy, and neuropathy + exercise). Right Sciatic nerve of anesthetized rats was exposed and loosely ligated (four ligations with 1 mm apart) using catgut chromic sutures to induce neuropathy. After 3 days of recovery, swimming exercise began (20 min/day/5 days a week/4 weeks). Mechanical allodynia and thermal hyperalgesia were detected using Von Frey filaments and plantar test, respectively. Sciatic nerve at the place of injury was dissected out to measure the myelin protein zero by western blot analysis. In the intact and sham groups, sciatic nerve removed at the place similar to injured group.

RESULTS

We found that neuropathy significantly (p < 0.05) reduced paw withdrawal mechanical and thermal thresholds and swimming exercise significantly (p < 0.05) increased paw withdrawal mechanical and thermal thresholds compared to the neuropathy group. Moreover, we found that MPZ level significantly (p < 0.01) decreased in neuropathy group against that in sham group, and exercise prominently (p < 0.05) reversed MPZ level towards control level.

CONCLUSIONS

Swimming exercise improves myelin protein zero level in neuropathic rats along with attenuating neuropathic pain. This is a promising approach in improving neuropathological disorders including Charcot-Marie-Tooth and Dejerine-Sottas disease.

The effectiveness of treadmill and swimming exercise in an animal model of osteoarthritis

Introduction: Osteoarthritis (OA) is considered an inflammatory and degenerative joint disease, characterized by loss of hyaline joint cartilage and adjacent bone remodeling with the formation of osteophytes, accompanied by various degrees of functional limitation and reduction in the quality of life of individuals. The objective of this work was to investigate the effects of treatment with physical exercise on the treadmill and swimming in an animal model of osteoarthritis. Methods: Forty-eight male Wistar rats were divided (n=12 per group): Sham (S); Osteoarthritis (OA); Osteoarthritis + Treadmill (OA + T); Osteoarthritis + Swimming (OA + S). The mechanical model of OA was induced by median meniscectomy. Thirty days later, the animals started the physical exercise protocols. Both protocols were performed at moderate intensity. Forty-eight hours after the end of the exercise protocols, all animals were anesthetized and euthanized for histological, molecular, and biochemical parameters analysis. Results: Physical exercise performed on a treadmill was more effective in attenuating the action of pro-inflammatory cytokines (IFN-γ, TNF-α, IL1-β, and IL6) and positively regulating anti-inflammatories such as IL4, IL10, and TGF-β in relation to other groups. Discussion: In addition to maintaining a more balanced oxi-reductive environment within the joint, treadmill exercise provided a more satisfactory morphological outcome regarding the number of chondrocytes in the histological evaluation. As an outcome, better results were found in groups submitted to exercise, mostly treadmill exercise.

Caffeine and Its Antioxidant Properties-It Is All about Dose and Source

Caffeine is the most frequently used substance with a central nervous system stimulant effect, but its consumption is most often due to the intake of foods and drinks that contain it (coffee, tea, chocolate, food supplements with plant extracts of Guarana, Mate herba, Cola nuts). Due to its innocuity, caffeine is a safe xanthine alkaloid for human consumption in a wide range of doses, being used for its central nervous stimulating effect, lipolytic and diuresis-enhancing properties, but also as a permitted ergogenic compound in athletes. In addition to the mechanisms that explain the effects of caffeine on the targeted organ, there are many proposed mechanisms by which this substance would have antioxidant effects. As such, its consumption prevents the occurrence/progression of certain neurodegenerative diseases as well as other medical conditions associated with increased levels of reactive oxygen or nitrogen species. However, most studies that have assessed the beneficial effects of caffeine have used pure caffeine. The question, therefore, arises whether the daily intake of caffeine from food or drink has similar benefits, considering that in foods or drinks with a high caffeine content, there are other substances that could interfere with this action, either by potentiating or decreasing its antioxidant capacity. Natural sources of caffeine often combine plant polyphenols (phenol-carboxylic acids, catechins) with known antioxidant effects; however, stimulant drinks and dietary supplements often contain sugars or artificial sweeteners that can significantly reduce the effects of caffeine on oxidative stress. The objective of this review is to clarify the effects of caffeine in modulating oxidative stress and assess these benefits, considering the source and the dose administered.

JAK-STAT signaling mediates the senescence of cartilage-derived stem/progenitor cells

Aging is a major risk factor for degenerative joint diseases, such as osteoarthritis (OA). Previous studies have confirmed the link between senescent mesenchymal stem cells (MSCs) and OA. Cartilage-derived stem/progenitor cells (CSPCs) with MSCs properties have been extracted from a variety of species. We inferred that the senescence of CSPCs may promote the development of osteoarthritis. However, the cellular and molecular mechanisms of CSPCs senescence remains unknown. In this study, we investigated the role of JAK-STAT signaling pathway in a replicative senescence model of CSPCs. We showed that the late CSPCs (> 15th passage) exhibited distinct senescent phenotypes, including increased proportion of β-gal positive senescent cells and F-actin content, as well as cell cycle arrest. In late CSPCs, the activity of JAK-STAT signaling pathway was significantly increased. Activation of JAK-STAT signaling pathway promoted cell senescence in early CSPCs (< 6th passage). Conversely, pharmacological inhibition or genetic knockdown of JAK-STAT signaling pathway attenuated cell senescence in late CSPCs. In conclusion, our results demonstrated the critical role of JAK-STAT signaling pathway in CSPCs senescence.

Acute Effect of Caffeine on the Synthesis of Pro-Inflammatory Cytokines in the Hypothalamus and Choroid Plexus during Endotoxin-Induced Inflammation in a Female Sheep Model

This study was designed to determine the effect of acute caffeine (CAF) administration, which exerts a broad spectrum of anti-inflammatory activity, on the synthesis of pro-inflammatory cytokines and their receptors in the hypothalamus and choroid plexus (ChP) during acute inflammation caused by the injection of bacterial endotoxin—lipopolysaccharide (LPS). The experiment was performed on 24 female sheep randomly divided into four groups: control; LPS treated (iv.; 400 ng/kg of body mass (bm.)); CAF treated (iv.; 30 mg/kg of bm.); and LPS and CAF treated. The animals were euthanized 3 h after the treatment. It was found that acute administration of CAF suppressed the synthesis of interleukin (IL-1β) and tumor necrosis factor (TNF)α, but did not influence IL-6, in the hypothalamus during LPS-induced inflammation. The injection of CAF reduced the LPS-induced expression of TNF mRNA in the ChP. CAF lowered the gene expression of IL-6 cytokine family signal transducer (IL6ST) and TNF receptor superfamily member 1A (TNFRSF1) in the hypothalamus and IL-1 type II receptor (IL1R2) in the ChP. Our study on the sheep model suggests that CAF may attenuate the inflammatory response at the hypothalamic level and partly influence the inflammatory signal generated by the ChP cells. This suggests the potential of CAF to suppress neuroinflammatory processes induced by peripheral immune/inflammatory challenges.

Caffeic Acid Phenethyl Ester reduces Pro Inflammatory Cytokines in Moderate Swimming Test in Growing Rats Model

Background

Caffeic acid phenethyl ester (CAPE) is a naturally occurring polyphenolic concentrated in propolis of honeybee hives. CAPE has been shown various physiological and pharmacologic properties. The aim of the present study was to investigate the effects of CAPE on proinflammatory markers in growing rats by performing the moderate swimming test.

Methods

A total number of 21 male Wistar albino rats were separated into three groups (n = 7): sedentary: negative control group; exercise: positive control group received vehicle orally and exercise + CAPE: CAPE treated group: treated with CAPE (20 mg/kg) orally 30 min before exercise, for 5 days. The animals were left free to swim in the tank, 20 minutes/day for 5 days. At 24 hours after finishing the experiment, rats were euthanised and blood was collected to analyze the level of serum interleukin IL-6 and tumor necrosis factor-α (TNF-α).

Results

Growing rats subjected to the moderate swimming test and in those treated with CAPE showed a lower level of TNF-α compared to the negative control. More interestingly, the one-way ANOVA data demonstrated a decreased level of proinflammatory IL-6 in the CAPE-treated group compared to the negative control.

Conclusion

Results of this study indicate that short-term administration of CAPE may modulate proinflammatory cytokine profiles during moderate exercise and may serve to boost the anti-inflammatory effects of exercise. Further studies are needed to evaluate the efficacy and safety of long-term administration of CAPE as an adjective anti-inflammatory agent.

Effects of caffeine on brain antioxidant status and mitochondrial respiration in acetaminophen-intoxicated mice

Hepatic encephalopathy is a pathophysiological complication of acute liver failure, which may be triggered by hepatotoxic drugs such as acetaminophen (APAP). Although APAP is safe in therapeutic concentration, APAP overdose may induce neurotoxicity, which is mainly associated with oxidative stress. Caffeine is a compound widely found in numerous natural beverages. However, the neuroprotective effect of caffeine remains unclear during APAP intoxication. The present study aimed to investigate the possible modulatory effects of caffeine on brain after APAP intoxication. Mice received intraperitoneal injections of APAP (250 mg/kg) and/or caffeine (20 mg/kg) and, 4 h after APAP administration, samples of brain and blood were collected for the biochemical analysis. APAP enhanced the transaminase activity levels in plasma, increased oxidative stress biomarkers (lipid peroxidation and reactive oxygen species), promoted an imbalance in endogenous antioxidant system in brain homogenate and increased the mortality. In contrast, APAP did not induce dysfunction of the mitochondrial bioenergetics. Co-treatment with caffeine modulated the biomarkers of oxidative stress as well as antioxidant system in brain. Besides, survival assays demonstrated that caffeine protective effects could be dose- and time-dependent. In addition, caffeine promoted an increase of mitochondrial bioenergetics response in brain by the enhancement of the oxidative phosphorylation, which could promote a better energy supply necessary for brain recovery. In conclusion, caffeine prevented APAP-induced biochemical alterations in brain and reduced lethality in APAP-intoxicated mice, these effects may relate to the preservation of the cellular antioxidant status, and these therapeutic properties could be useful in the treatment of hepatic encephalopathy induced by APAP intoxication.

Chronic aerobic exercise improves insulin sensitivity and modulates Nrf2 and NF‑κB/IκBα pathways in the skeletal muscle of rats fed with a high fat diet

The present study aimed to investigate the molecular mechanisms of the ameliorative effects of chronic aerobic exercise on non-alcoholic steatohepatitis (NASH) in rat skeletal muscle. Female Sprague-Dawley rats (n=6–9 per group) were divided into four groups: i) Rats fed with normal chow; ii) exercise rats fed with normal chow + exercise (run on a rotarod for 30 min per day from 9–12 weeks); iii) rats fed with a high-fat diet (HFD); iv) rats fed with an HFD + exercise. All HFD rats were fed with an HFD consisting of 30% fat from fish oil throughout the study for 12 weeks. Exercise decreased the levels of hepatic lipogenic markers carbohydrate-responsive element-binding protein, fat-specific protein 27 and liver X receptor and improved systemic glucose and insulin intolerance in the NASH animal model. The beneficial effects may have been mediated partly via the tripartite motif-containing family protein 72 (TRIM72)/PI3K/Akt/mTOR pathway, accompanied with an upregulation of glucose transporter 4 in the skeletal muscle. The exercise regimen activated the master regulator of antioxidant enzymes, nuclear factor erythroid 2-related factor 2, with upregulation of superoxide dismutase [Cu-Zn] expression and a corresponding decrease in kelch-like ECH-associated protein 1 expression, but failed to decrease the levels of the oxidative marker malondialdehyde in the HFD rat skeletal muscle. Chronic exercise decreased the expression of the inflammation marker NF-κB, followed by a decrease in interleukin-6 and tumor necrosis factor-α levels, as verified by a corresponding increase in the level of NF-κB inhibitor α expression. Exercise may exert its beneficial effects by improving muscle insulin sensitivity via the TRIM72/PI3K/Akt/mTOR pathway, contributing to the improvement of systemic insulin intolerance, and finally leading to decreased hepatic lipogenesis during NASH. The attenuation of insulin resistance by exercise may be partly achieved through a decrease in the level of inflammation and an increased antioxidant response.

Caffeine and high intensity exercise: Impact on purinergic and cholinergic signalling in lymphocytes and on cytokine levels

This study evaluated the effects of caffeine in combination with high-intensity interval training (HIIT) on sensitivity to glucocorticoids and proliferation of lymphocytes, IL-6 and IL-10 levels and NTPDase, adenosine deaminase (ADA) and acetylcholinesterase (AChE) activity in rat lymphocytes. The animals were divided into groups: control, caffeine 4 mg/kg, caffeine 8 mg/kg, HIIT, HIIT plus caffeine 4 mg/kg and HIIT plus caffeine 8 mg/kg. The rats were trained three times a week for 6 weeks for a total workload 23% of body weight at the end of the experiment. Caffeine was administered orally 30 min before the training session. When lymphocytes were stimulated with phytohaemagglutinin no changes were observed in proliferative response between trained and sedentary animals; however, when caffeine was associated with HIIT an increase in T lymphocyte proliferation and in the sensitivity of lymphocytes to glucocorticoids occurred. ATP and ADP hydrolysis was decreased in the lymphocytes of the animals only trained and caffeine treatment prevented alterations in ATP hydrolysis. HIIT caused an increase in the ADA and AChE activity in lymphocytes and this effect was more pronounced in rats trained and supplemented with caffeine. The level of IL-6 was increased while the level of IL-10 was decreased in trained animals (HIIT) and caffeine was capable of preventing this exercise effect. Our findings suggest that caffeine ingestion attenuates, as least in part, the immune and inflammatory alterations following a prolonged HIIT protocol.

The Effects of Acute and Chronic Sprint-Interval Training on Cytokine Responses Are Independent of Prior Caffeine Intake

We examined the effect of acute and chronic sprint interval training (SIT), with or without prior caffeine intake, on levels of exercise-induced inflammatory plasma cytokines [interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α]. Twenty physically-active men ingested either a placebo (n = 10) or caffeine (n = 10) 1 h before each SIT session(13-s × 30-s sprint/15 s of rest) during six training sessions (2 weeks). The early (before, immediately after, and 45 min after the exercise) and late (24 and 48 h after the exercise) cytokine and creatine kinase (CK) responses were analyzed for the first and last training sessions. Plasma IL-6 and IL-10 peaked 45 min after the exercise, and then returned to basal values within 24 h (p < 0.05) in both groups on both occasions (p > 0.05). On both occasions, and for both groups, plasma TNF-α increased from rest to immediately after the exercise and then decreased at 45 min before reaching values at or below basal levels 48 h after the exercise (p < 0.05). Serum CK increased from rest to 24 and 48 h post-exercise in the first training session (p < 0.05), but did not alter in the last training session for the PLA group (p > 0.05). Serum CK was unchanged in both the first and last training sessions for the CAF group (p > 0.05). Two weeks of SIT induced a late decrease in the IL-6/IL-10 ratio (p < 0.05) regardless of caffeine intake, suggesting an improved overall inflammatory status after training. In conclusion, a single session of SIT induces muscle damage that seems to be mitigated by caffeine intake. Two weeks of SIT improves the late SIT-induced muscle damage and inflammatory status, which seems to be independent of caffeine intake.

Exercise in an animal model of Parkinson's disease: Motor recovery but not restoration of the nigrostriatal pathway

Many clinical studies have reported on the benefits of exercise therapy in patients with Parkinson's disease (PD). Exercise cannot stop the progression of PD or facilitate the recovery of dopamine (DA) neurons in the substantia nigra pars compacta (SNpc) (Bega et al., 2014). To tease apart this paradox, we utilized a progressive MPTP (1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine) mouse model in which we initiated 4weeks of treadmill exercise after the completion of toxin administration (i.e., restoration). We found in our MPTP/exercise (MPTP+EX) group several measures of gait function that recovered compared to the MPTP only group. Although there was a small recovery of tyrosine hydroxylase (TH) positive DA neurons in the SNpc and terminals in the striatum, this increase was not statistically significant. These small changes in TH could not explain the improvement of motor function. The MPTP group had a significant 170% increase in the glycosylated/non-glycosylated dopamine transporter (DAT) and a 200% increase in microglial marker, IBA-1, in the striatum. The MPTP+EX group showed a nearly full recovery of these markers back to the vehicle levels. There was an increase in GLT-1 levels in the striatum due to exercise, with no change in striatal BDNF protein expression. Our data suggest that motor recovery was not prompted by any significant restoration of DA neurons or terminals, but rather the recovery of DAT and dampening the inflammatory response. Although exercise does not promote recovery of nigrostriatal DA, it should be used in conjunction with pharmaceutical methods for controlling PD symptoms.

Role of vitamin A oral supplementation on oxidative stress and inflammatory response in the liver of trained rats

The use of dietary supplements to enhance the benefit of exercise training is a common practice. The liver is the organ where all substances are metabolized, and certain supplements have been associated with liver injury. Vitamin A (VA), a liposoluble vitamin stored in the liver, is commonly used as an antioxidant supplement. Here, we evaluated the effect of chronic VA supplementation on oxidative damage and stress parameters in trained rats. Animals were divided into the following groups: sedentary (SE), sedentary/VA (SE+VA), exercise training (ET), and exercise training/VA (ET+VA). During 8 weeks, animals were subjected to swimming (0%, 2%, 4%, 6% body weight) for 5 days/week and a VA daily intake of 450 retinol equivalents/day. Parameters were evaluated by enzymatic activity analysis, ELISA, and Western blotting. VA caused liver lipid peroxidation and protein damage in exercised rats and inhibited the increase in HSP70 expression acquired with exercise alone. The ET group showed higher levels of antioxidant enzyme activity, and VA inhibited this adaptation. Expression of the pro-inflammatory cytokines, interleukin (IL)-1β, and tumor necrosis factor-α was reduced in the ET+VA group, while the anti-inflammatory cytokine, IL-10, was increased. Western blotting showed that both exercised groups had lower levels of the receptor for advanced glycation end products, suggesting that VA did not affect this receptor. Our study demonstrated that, although VA caused oxidative damage, a controlled administration might exert anti-inflammatory effects. Further studies with higher VA doses and longer ET interventions would elucidate more the effects of the supplementation and exercise on liver parameters.

The effect of swimming exercise on adenine-induced kidney disease in rats, and the influence of curcumin or lisinopril thereon

Patients with chronic kidney disease (CKD) have been reported to benefit from different types of exercises. It has also been shown that the ACE inhibitor lisinopril, and the natural product curcumin are also beneficial in different models of CKD in rats. We assessed the influence of moderate swimming exercise (SE) on rats with adenine-induced CKD, and tested the possible effects of lisinopril and/or curcumin thereon using several physiological, biochemical, histopathological and immunohistochemical parameters. Rats (either sedentary or subjected to SE) were randomly divided into several groups, and given for five weeks either normal food or food mixed with adenine (0.25% w/w) to induce CKD. Some of these groups were also concomitantly treated orally with curcumin (75 mg/kg), or lisinopril (10 mg/kg) and were subjected to moderate SE (45 min/day three days each week). Rats fed adenine showed the typical biochemical, histopathological signs of CKD such as elevations in blood pressure, urinary albumin / creatinine ratio, and plasma urea, creatinine, indoxyl sulfate and phosphorus. SE, curcumin or lisinopril, given singly, significantly ameliorated all the adenine-induced actions. Administering curcumin or lisinopril with SE improved the histopathology of the kidneys, a salutary effect not seen with SE alone. Combining SE to the nephroprotective agents' curcumin or lisinopril might offer additional nephroprotection.

Vitamin A Oral Supplementation Induces Oxidative Stress and Suppresses IL-10 and HSP70 in Skeletal Muscle of Trained Rats

Exercise training intensity is the major variant that influences the relationship between exercise, redox balance, and immune response. Supplement intake is a common practice for oxidative stress prevention; the effects of vitamin A (VA) on exercise training are not yet described, even though this molecule exhibits antioxidant properties. We investigated the role of VA supplementation on redox and immune responses of adult Wistar rats subjected to swimming training. Animals were divided into four groups: sedentary, sedentary + VA, exercise training, and exercise training + VA. Over eight weeks, animals were submitted to intense swimming 5 times/week and a VA daily intake of 450 retinol equivalents/day. VA impaired the total serum antioxidant capacity acquired by exercise, with no change in interleukin-1β and tumor necrosis factor-α levels. In skeletal muscle, VA caused lipid peroxidation and protein damage without differences in antioxidant enzyme activities; however, Western blot analysis showed that expression of superoxide dismutase-1 was downregulated, and upregulation of superoxide dismutase-2 induced by exercise was blunted by VA. Furthermore, VA supplementation decreased anti-inflammatory interleukin-10 and heat shock protein 70 expression, important factors for positive exercise adaptations and tissue damage prevention. Our data showed that VA supplementation did not confer any antioxidative and/or protective effects, attenuating exercise-acquired benefits in the skeletal muscle.

JAK-STAT signaling mediates the senescence of bone marrow-mesenchymal stem cells from systemic lupus erythematosus patients

Previous studies have revealed that bone marrow-mesenchymal stem cells (BM-MSCs) from systemic lupus erythematosus (SLE) patients exhibited early signs of senescence, which may participate in the development of SLE. However, the molecular mechanisms about this phenomenon have not been fully elucidated. In the current study, we aimed to investigate whether Janus kinase (JAK)-signaling transducers and activators of transcription (STAT) signaling mediated the senescence of BM-MSCs from SLE patients. Twelve female SLE patients and healthy subjects were enrolled in the study. All BM-MSCs were isolated by density gradient centrifugation. Western blot analysis was used to test the expression of JAK-STAT signaling molecules. We observed the activity of β-gal of cells, the changes of cytoskeletal structure by F-actin staining, and the distribution of cell cycle by flow cytometry. BM-MSCs from SLE patients showed prominent features of senescence, and abnormal activation of JAK-STAT signaling transduction, high level of phosphorylated JAK2, and STAT3. After stimulation of IFN-γ in normal MSCs, JAK-STAT signaling was activated. The cell volume and the number of senescence-associated β-galactosidase (SA-β-gal) positive in SLE BM-MSCs were increased. The organization of cytoskeleton was nearly disordered. The rate of cell proliferation was decreased. AG490, the inhibitor of JAK2, and knockdown of STAT3 in BM-MSCs, could significantly reverse the senescence. In summary, our study indicated that JAK-STAT signaling pathway may play a critical role in the senescence of SLE BM-MSCs.

Oxidative stress and inflammation: liver responses and adaptations to acute and regular exercise

The liver is remarkably important during exercise outcomes due to its contribution to detoxification, synthesis, and release of biomolecules, and energy supply to the exercising muscles. Recently, liver has been also shown to play an important role in redox status and inflammatory modulation during exercise. However, while several studies have described the adaptations of skeletal muscles to acute and chronic exercise, hepatic changes are still scarcely investigated. Indeed, acute intense exercise challenges the liver with increased reactive oxygen species (ROS) and inflammation onset, whereas regular training induces hepatic antioxidant and anti-inflammatory improvements. Acute and regular exercise protocols in combination with antioxidant and anti-inflammatory supplementation have been also tested to verify hepatic adaptations to exercise. Although positive results have been reported in some acute models, several studies have shown an increased exercise-related stress upon liver. A similar trend has been observed during training: while synergistic effects of training and antioxidant/anti-inflammatory supplementations have been occasionally found, others reported a blunting of relevant adaptations to exercise, following the patterns described in skeletal muscles. This review discusses current data regarding liver responses and adaptation to acute and regular exercise protocols alone or combined with antioxidant and anti-inflammatory supplementation. The understanding of the mechanisms behind these modulations is of interest for both exercise-related health and performance outcomes.

THE EFFECT OF CAFFEINE SUPPLEMENTATION ON TRAINED INDIVIDUALS SUBJECTED TO MAXIMAL TREADMILL TEST

Background:

Intense physical training increases oxidative stress and inflammation, resulting into muscle and cellular damage. The aim of this study was to analyze the effect of caffeine supplementation on trained young individuals subjected to two treadmill maximal tests.

Materials and Methods:

It was a double-blind and crossover study comprising 24 active individuals within the age group 18-30 years. The comparisons were conducted: the effect of exercise (week 1 x 2) and caffeine intake (GC x GP) on thiobarbituric acid (TBARS), interleukin 6 (IL-6), interleukin 10 (IL-10) and superoxide dismutase (SOD) variables during pre-exercise time (30 min. after caffeine or placebo intake) and post-exercise (5 min after treadmill test).

Results:

The comparison between weeks 1 and 2 showed increase in the first week, in the following items: TBARS, IL-6 and IL-10 in the GC and GP groups. The comparison within the same week showed that GC individuals presented lower post-exercise TBARS values in the first and second weeks; IL- 6 presented higher post-exercise values in the GC group in both weeks. The paired analysis comparing pre- and post-exercise, with and without caffeine showed that IL-6 presented higher post-exercise values in the GC group.

Conclusion:

Caffeine used by athletes can decrease oxidative stress. The increased IL-6 suggest that this ergogenic supplement may stimulate muscle hypertrophy, since IL-6 has myokine effect. However, the caffeine effect on IL-6 level and muscle hypertrophy increase should be better investigated in future studies.

Exercise ameliorates high fat diet induced cardiac dysfunction by increasing interleukin 10

Increasing evidence suggests that a sedentary lifestyle and a high fat diet (HFD) leads to cardiomyopathy. Moderate exercise ameliorates cardiac dysfunction, however underlying molecular mechanisms are poorly understood. Increased inflammation due to induction of pro-inflammatory cytokine such as tumor necrosis factor-alpha (TNF-α) and attenuation of anti-inflammatory cytokine such as interleukin 10 (IL-10) contributes to cardiac dysfunction in obese and diabetics. We hypothesized that exercise training ameliorates HFD- induced cardiac dysfunction by mitigating obesity and inflammation through upregulation of IL-10 and downregulation of TNF-α. To test this hypothesis, 8 week old, female C57BL/6J mice were fed with HFD and exercised (swimming 1 h/day for 5 days/week for 8 weeks). The four treatment groups: normal diet (ND), HFD, HFD + exercise (HFD + Ex) and ND + Ex were analyzed for mean body weight, blood glucose level, TNF-α, IL-10, cardiac fibrosis by Masson Trichrome, and cardiac dysfunction by echocardiography. Mean body weights were increased in HFD but comparatively less in HFD + Ex. The level of TNF-α was elevated and IL-10 was downregulated in HFD but ameliorated in HFD + Ex. Cardiac fibrosis increased in HFD and was attenuated by exercise in the HFD + Ex group. The percentage ejection fraction and fractional shortening were decreased in HFD but comparatively increased in HFD + Ex. There was no difference between ND and ND + Ex for the above parameters except an increase in IL-10 level following exercise. Based on these results, we conclude that exercise mitigates HFD- induced cardiomyopathy by decreasing obesity, inducing IL-10, and reducing TNF-α in mice.

The action of pre-exercise low-level laser therapy (LLLT) on the expression of IL-6 and TNF-α proteins and on the functional fitness of elderly rats subjected to aerobic training

The aim of the present study was to determine whether low-level laser therapy (LLLT), when used in conjunction with aerobic training, interferes with the expression of inflammatory markers IL-6 and TNF-α, thereby influencing the performance of old rats participating in swimming. A total of 30 Wistar rats (Rattus norvegicus albinus) were used for this study: 24 aged rats, and 6 young rats. The older animals were randomly divided into four groups designated as follows: aged-control, aged-exercise, aged-LLLT, aged-LLLT/exercise group, and young-control animals. Aerobic capacity (VO2max) was analyzed before and after training period. The aged-exercise and aged-LLLT/exercise groups were trained for 6 weeks. LLLT laser was applied before each training session with 808 nm and 4 J of energy to the indicated groups throughout training. The rats were euthanized, and muscle tissue and serum were collected for muscle cross-sectional area and IL-6 and TNF-α protein analysis. In VO2 showed statistical difference between young- and aged-control groups (used as baseline) (p < 0.05). The same difference can be observed in the young control group compared with all intervention groups (exercise, LLLT and LLLT + exercise). In comparison with the aged-control group, a difference was observed only for comparison with the exercise group (p < 0.05), and exercise associated with LLLT group (p < 0.001). Levels of IL-6 and TNF-α for the aged-exercise and the aged-LLLT/exercise groups were significantly decreased compared to the aged-control group (p < 0.05). Analysis of the transverse section of the gastrocnemius muscle showed a significant difference between the aged-exercise and aged-LLLT/exercise groups (p < 0.001). These results suggest that laser therapy in conjunction with aerobic training may provide a therapeutic approach for reducing the inflammatory markers (IL-6 and TNF-α), however, LLLT without exercise was not able to improve physical performance of aged rats.

Improvement of mitochondrial NAD(+)/FAD(+)-linked state-3 respiration by caffeine attenuates quinolinic acid induced motor impairment in rats: implications in Huntington's disease

BACKGROUND

Chronic quinolinic acid (QA) lesions in rats closely resemble Huntington's disease like conditions. Oxidative stress and mitochondrial dysfunction have long been implicated in the neurotoxic effects of QA acting through N-methyl-d-aspartate (NMDA) receptors. Reports suggest that inhibition of adenosine A2A receptor function elicits neuroprotective effect in QA induced neurotoxicity in rats. Caffeine, a preferential A2A receptor antagonist imitates antioxidant like actions and exerts neuroprotective effects in various neurodegenerative conditions. Thus, the present study was designed to evaluate the neuroprotective effects of caffeine against QA induced neurotoxicity in rats.

METHODS

In the present study, QA (200nmol/2μl saline) has been administered bilaterally to the striatum of rats followed by chronic caffeine (10, 20 and 40mg/kg) administration for 21 days. Motor performance of the animals was evaluated in weekly intervals and subsequently after 21 days, the animals were sacrificed and measurement of mitochondrial complexes activity, respiration rate and endogenous antioxidant levels were carried out in the striatal region.

RESULTS

Single intrastriatal QA administration resulted in drastic reduction in body weight, marked motor impairment (decreased total locomotor activity in actophotometer and impaired grip strength in rotarod), increased oxidative stress, impaired mitochondrial complexes activities and decreased state 3 respiration (NAD(+)/FAD(+)-linked) in rats. However, chronic treatment of caffeine for 21 days significantly attenuated the QA induced behavioural, biochemical and mitochondrial alterations displaying neuroprotective efficacy.

CONCLUSION

The study highlights the possible involvement of A2A receptor antagonism in the neuroprotective effect of caffeine against QA induced mitochondrial dysfunction and oxidative stress in rats.

Does swimming exercise affect experimental chronic kidney disease in rats treated with gum acacia?

Different modes of exercise are reported to be beneficial in subjects with chronic kidney disease (CKD). Similar benefits have also been ascribed to the dietary supplement gum acacia (GA). Using several physiological, biochemical, immunological, and histopathological measurements, we assessed the effect of swimming exercise (SE) on adenine –induced CKD, and tested whether SE would influence the salutary action of GA in rats with CKD. Eight groups of rats were used, the first four of which were fed normal chow for 5 weeks, feed mixed with adenine (0.25% w/w) to induce CKD, GA in the drinking water (15% w/v), or were given adenine plus GA, as above. Another four groups were similarly treated, but were subjected to SE during the experimental period, while the first four groups remained sedentary. The pre-SE program lasted for four days (before the start of the experimental treatments), during which the rats were made to swim for 5 to 10 min, and then gradually extended to 20 min per day. Thereafter, the rats in the 5^th, 6^th, 7^th, and 8^th groups started to receive their respective treatments, and were subjected to SE three days a week for 45 min each. Adenine induced the typical signs of CKD as confirmed by histopathology, and the other measurements, and GA significantly ameliorated all these signs. SE did not affect the salutary action of GA on renal histology, but it partially improved some of the above biochemical and physiological analytes, suggesting that addition of this mode of exercise to GA supplementation may improve further the benefits of GA supplementation.

Caffeine intake may modulate inflammation markers in trained rats

Caffeine is presented in many commercial products and has been proven to induce ergogenic effects in exercise, mainly related to redox status homeostasis, inflammation and oxidative stress-related adaptation mechanisms. However, most studies have mainly focused on muscle adaptations, and the role of caffeine in different tissues during exercise training has not been fully described. The aim of this study was therefore, to analyze the effects of chronic caffeine intake and exercise training on liver mitochondria functioning and plasma inflammation markers. Rats were divided into control, control/caffeine, exercise, and exercise/caffeine groups. Exercise groups underwent four weeks of swimming training and caffeine groups were supplemented with 6 mg/kg/day. Liver mitochondrial swelling and complex I activity, and plasma myeloperoxidase (MPO) and acetylcholinesterase (AChE) activities were measured. An anti-inflammatory effect of exercise was evidenced by reduced plasma MPO activity. Additionally, caffeine intake alone and combined with exercise decreased the plasma AChE and MPO activities. The per se anti-inflammatory effect of caffeine intake should be highlighted considering its widespread use as an ergogenic aid. Therefore, caffeine seems to interfere on exercise-induced adaptations and could also be used in different exercise-related health treatments.