Effects of Curcumin Supplementation on Inflammatory Markers, Muscle Damage, and Sports Performance during Acute Physical Exercise in Sedentary Individuals

Exhaustive and acute unusual physical exercise leads to muscle damage. Curcumin has been widely studied due to the variety of its biological activities, attributed to its antioxidant and anti-inflammatory properties. Furthermore, it has shown positive effects on physical exercise practitioners. However, there is no literature consensus on the beneficial effects of curcumin in acute physical activities performed by sedentary individuals. Therefore, we systematically reviewed evidence from clinical trials on the main effects of curcumin supplementation on inflammatory markers, sports performance, and muscle damage during acute physical exercises in these individuals. We searched PubMed/MEDLINE, Scopus, Web of Science, and Embase databases, and only original studies were analyzed according to the PRISMA guidelines. The included studies were limited to supplementation of curcumin during acute exercise. A total of 5 studies were selected. Methodological quality assessments were examined using the SYRCLE’s risk-of-bias tool. Most studies have shown positive effects of curcumin supplementation in sedentary individuals undergoing acute physical exercise. Overall, participants supplemented with curcumin showed less muscle damage, reduced inflammation, and better muscle performance. The studies showed heterogeneous data and exhibited methodological limitations; therefore, further research is necessary to ensure curcumin supplementation benefits during acute and high-intensity physical exercises. Additionally, mechanistic and highly controlled studies are required to improve the quality of the evidence and to elucidate other possible mechanisms. This study is registered with Prospero number CRD42021262718.

A Single Session of Exercise Reduces Blood Pressure Reactivity to Stress: a Systematic Review With Meta-analysis

Stressful situations are common in everyday life and disturb homeostasis. So, an exercise session is a strategy to mitigate blood pressure (BP) peaks in response to stress (i.e., BP reactivity), decreasing the cardiovascular risk of these individuals. This is a systematic review with a meta-analysis that aims to verify the effects of a single session of physical exercises on BP reactivity to stress. The searches were realized in digital databases (PUBMED, LILACS, EMBASE and PsycInfo) and 28 studies were included, totaling 846 individuals (meta-analysis stage: k = 24, n = 710). As for exercise characteristics, 23 of the 28 studies focused on aerobic exercises, and 24 studies focused on low to moderate intensities. Favorable metanalytic results (standardized mean differences through random-effects approach) for the exercises were found, with attenuated reactivity in systolic BP (pooled effect size = -0.35 [-0.46; -0.23], representing average reductions of 3.8 ± 3.5 mmHg), diastolic BP (pooled effect size = -0.49 [-0.68; -0.30], representing average reductions of 3.1 ± 3.6 mmHg), and mean BP (pooled effect size = -0.48 [-0.70; -0.26], representing average reductions of 4.1 ± 3.0 mmHg). So, acute physical exercise lowers systolic, diastolic, and mean blood pressure reactivity in response to stressor tasks.

Serum Heat Shock Protein (HSP70) Changes In Horses After An Acute Exercise

Heat shock proteins (HSP) play critical roles in the body’s self-defense under a variety of stresses. In particular, HSP70 is a key regulator of normal physiological processes including physical exercise. Exercise is associated with transient increases of HSP expression in rodents, humans and horses, but so far little is presently known about the effects of acute high-intensity exercise or training on the release of HSP70 in the blood of horses. The aim of the study was to investigate the effect of acute exercise as racehorse intensive training and gallop race on serum HSP70 levels. The research was carried out on 12 trained horses performing regularly training and gallop race. Serum HSP70 levels were analyzed by ELISA assay before and immediately after the end of both training and gallop race sessions. Results showed significant increased levels of serum HSP70, both after the end of the whole training session and gallop race, compared to basal values. A physiological stress associated with acute physical exercise seems to activate HSP70 pathway also in horses, suggesting the presence of an adaptation process to a stress of a novel homeostatic condition. Further investigations, at different times after the end of the exercise, could be useful to understand if HSP70 may be considered a new approach to monitoring exercise training and adaptive mechanisms in horses.

Influence of a Maximal Incremental Test Until Exhaustion on the Urinary Excretion of Steroid Hormones in Trained Cyclists

This study aimed to assess the effect of a maximum incremental stress test through urinary concentrations of steroid hormones in trained cyclists. Twenty male cyclists participated in the study (23.83 ± 2.3 years; 1.76 ± 0.03 m; 66.94 ± 3.59 kg; training volume: 20.50 ± 2.35 h/week). Athletes performed a maximum incremental test until exhaustion on a cycle ergometer and urine samples were collected at three different time points: before, immediately after, and 48 h after the test. Lactate, creatinine and urinary concentrations of testicular and adrenal androgens were obtained as well as urinary concentrations of glucocorticoid hormones. An increase in lactate was observed after the test (p < 0.01). There were decreases in the urinary excretion of androgenic hormones after the test, which were significant in testosterone, androsterone, androstenedione, total adrenal androgen and total testicular androgen (p < 0.05). The values were restored after 48 h (p < 0.05). Urinary cortisol concentrations decreased after the test (p < 0.05). A decrease was also observed in the ratio of anabolic/catabolic hormones (p < 0.05) increasing 48 h after the test (p < 0.05). Increased acute physical exercise until exhaustion causes variations in the urinary excretions of steroid hormones which were restored 48 h after exercise. Urinary excretion of steroid hormones could be a valid method of monitoring training loads.

Aerobic Training Modulates the Increase in Plasma Concentrations of Cytokines in response to a Session of Exercise

Acute physical exercise can modulate immune function. For example, acute exercise is known to increase the circulating concentration of cytokines. Exercise is also known to modulate immune function chronically. It is not known whether exercise training can result in training of the immune system. Here, we investigated the effects of six weeks of aerobic training on cytokine responses induced by acute exercise until fatigue. Twelve healthy men performed a fatiguing exercise at the anaerobic threshold (AT) intensity. After the training period, the participants performed another bout of acute exercise at the same duration and intensity of the pretraining situation. The analysis was made at the beginning, end, and at 10, 30, and 60 minutes during the recovery period. Training at AT induced a gain of 11.2% of exercise capacity. Before training, a single bout of acute exercise induced a significant increase in plasma levels of cytokines, including IL-6, TNF-α, sTNFR1, IL-10, CXCL10, BDNF, leptin, resistin, and adiponectin. After six weeks of aerobic training, levels of IL-6, sTNFR1, BDNF, and leptin increased to a lesser extent after an acute bout exercise at the same absolute intensity as the pretraining period. Responses to the same relative exercise intensity were similar to those observed before exercise. These results show that aerobic training is associated with training of acute immune responses to acute exercise until fatigue.

The Effect of Acute Physical Exercise on NK-Cell Cytolytic Activity: A Systematic Review and Meta-Analysis

Background Data on changes in natural killer cell cytolytic activity (NKCA) in response to acute physical exercise are contradictory. Objective The aim of this systematic review, meta-analysis and meta-regression is to (1) examine the effect of acute physical exercise on NKCA, (2) shed more light on the moderating factors, and (3) test the assumption of NKCA suppression subsequent to performing sports. Methods Two comparisons of NKCA were performed: (1) pre- versus post-exercise and (2) pre-exercise versus recovery. Data were acquired through a systematic search of MEDLINE (via PubMed), Scopus, and SportDiscus. Studies were eligible for inclusion if the effect of acute physical exercise was assessed including a passive control group and reporting NKCA prior to and immediately after the trial, and during the first 2 h of recovery. To better explain between-study heterogeneity, a moderator analysis was conducted. Results Pooled estimate from 12 studies reporting 18 effect sizes show that NKCA is largely elevated by acute physical exercise (Hedges’ g = 1.02, 95% CI 0.59–1.46, p < 0.01). Meta-regressions reveal that this effect is larger for endurance versus resistance exercise and increases with the intensity of exercise (both p < 0.01), whereas the blood material used in the assay (p = 0.71), and the quantitative change in NK-cell count (R2 = 0%, p = 0.55) do not play a significant role. Physical exercise does not affect the level of NKCA after the recovery period (g = 0.06, 95% CI − 0.37 to 0.50, p < 0.76). Conclusions This work provides solid evidence for elevated NKCA through performing sports which returns to baseline during the first 1–2 h of recovery, but not below the pre-exercise values providing counterevidence to the assumption of temporarily reduced NKCA. Remarkably, the functional change in NKCA exists independently from the quantitative change in NK-cell count. PROSPERO registration number: CRD42020134257.

The effect of acute exercise on interleukin-6 and hypothalamic–pituitary–adrenal axis responses in patients with coronary artery disease

Vulnerability to stress-induced inflammation has been linked to a dysfunctional hypothalamus–pituitary–adrenal (HPA) axis. In the present study, patients with known or suspected coronary artery disease (CAD) were assessed with respect to inflammatory and HPA axis response to acute physical exercise. An exercise stress test was combined with SPECT myocardial perfusion imaging. Plasma and saliva samples were collected before and 30 min after exercise. Interleukin (IL)-6 and adrenocorticotropic hormone (ACTH) were measured in plasma, while cortisol was measured in both plasma and saliva. In total, 124 patients were included of whom 29% had a prior history of CAD and/or a myocardial perfusion deficit. The levels of exercise intensity and duration were comparable in CAD and non-CAD patients. However, in CAD patients, IL-6 increased after exercise (p = 0.019) while no differences were seen in HPA axis variables. Conversely, patients without CAD exhibited increased levels of ACTH (p = 0.003) and cortisol (p = 0.004 in plasma, p = 0.006 in saliva), but no change in IL-6. We conclude that the IL-6 response to acute physical exercise is exaggerated in CAD patients and may be out of balance due to HPA axis hypoactivity. It remains to be further investigated whether this imbalance is a potential diagnostic and therapeutic target in CAD.

Acute exercise impacts AhR and PD-1 levels of CD8+ T-cells—Exploratory results from a randomized cross-over trial comparing endurance versus resistance exercise

Purpose The programmed cell death protein 1 (PD-1) has become a promising target in cancer immunotherapy. PD-1 expression of CD8+ T-cells may be increased via the exploitation of aryl hydrocarbon receptor (AhR) signaling with kynurenine (KYN) as a ligand. Since exercise affects KYN metabolism, we exploratory investigated the influence of acute exercise bouts on AhR and PD-1 levels of CD8+ T-cells. Method In this study, 24 healthy males (age: 24.6 ± 3.9 years; weight 83.9 ± 10.5 kg; height: 182.4 ± 6.2 cm) completed a single bout of endurance (EE) and resistance exercise (RE) in a randomly assigned order on separate days. Blood samples were drawn before (t0), after (t1), and 1 h after (t2) both conditions. T-cell populations, the level of cytoplasmic AhR, and surface PD-1 were assessed by flow cytometry. Results T-cell populations changed over time, indicated by an increase in the absolute numbers of CD3+ lymphocytes after EE (p < .001) and RE (p = .036) and in PD-1+ CD8+ T-cells after EE (p = .021). Proportions of T-cell populations changed only after EE (t0–t2: p = .029; t1-t2: p = .006). The level of cytoplasmic AhR decreased immediately after exercise in both exercise conditions (EE: p = .009; RE: p = .036). The level of surface PD-1 decreased 1 h after EE (p = .005). Conclusion We analyzed the level of surface PD-1 and cytoplasmic AhR following acute physical exercise for the first time. Especially EE was observed to impact both AhR and PD-1 levels, undermining its role as the AhR-PD-1 axis modulator. These results provide new insights into the impact of exercise on AhR-signaling, which could potentially be relevant for various chronic diseases.

Hepatic LC3 II/I ratio is not modulated in exercised mice

Autophagy plays an essential role in body homeostasis achievement. One of the main proteins involved in this process is the LC3I, which, after lipidation, leads to the formation of LC3II that participates in the formation and maturation of autophagosome. This descriptive study verified the responses of LC3II to LC3I proteins, as well as the time-course of this ratio in mice livers after different types of acute physical exercise protocols. Eight-week-old male C57BL/6 mice were maintained three per cage with controlled temperature (22±2 °C) on a 12:12-h light-dark normal cycle with food (Purina chow) and water ad libitum. Mice were randomly divided into four groups: control (CT, sedentary mice), resistance (RE, submitted to a single bout of resistance exercise), endurance (EE, submitted to a single bout of endurance exercise), and concurrent (CE, submitted to a single bout of endurance combined with resistance exercise). The mice livers were extracted and used for the immunoblotting technique. The hepatic LC3B II/I ratio for the RE and EE groups were not altered during the different time-points. For the CE group, there was a decrease in this ratio 12h after exercise compared to time 0 and 18h. Also, the hepatic LC3B II/I ratios were not different among the acute physical exercise protocols along the time-course. The hepatic LC3B II/I ratio was not influenced by the endurance and resistance protocols but decreased in response to the concurrent protocol at 12h after the stimulus.