Leisure-time regular exercise and prevention of the side effects of immune system activity in middle-aged healthy subjects

Regular exercise is recommended to improve immune system function and antioxidant activity, while conversely, it may cause inflammation by increasing neutrophil-derived main enzyme, myeloperoxidase, which produces reactive oxygen species. The present study aimed to investigate changes in myeloperoxidase level, its influence on total oxidant status, and the capacity of the antioxidant defence system to counteract oxidative stress in middle-aged men participating in leisure-time regular exercise compared to untrained peer subjects. Twenty trained (age 53.58±2.94 years, body mass index (BMI) 25.47±1.6) and 17 untrained (age 54.17±2.83 years, BMI 27.83±1.12) healthy middle-aged men participated in this study [Rasht, Gilan, Iran]. Participants performed a modified Bruce treadmill test as a model of progressive exercise training. Blood samples were taken before, immediately after, and one hour after the end of the test. A mixed ANOVA and Bonferroni post hoc test was used for the analysis of variables. A significant difference was observed in myeloperoxidase levels between groups, while the trained group showed a significantly lower concentration than the untrained group (P<0.018). This result was also consistent with the lower total oxidant status in this group (P<0.001). Total antioxidant capacity changed significantly in both groups with higher concentration in the trained group (P<0.001). The leisure-time regular exercise can reduce myeloperoxidase concentration and total oxidant status in healthy middle-aged men while increasing the total antioxidant capacity, which may potentially protect them from the side effects of immune system activity induced by exercise training.

Effects of concurrent training on irisin and fibronectin type-III domain containing 5 (FNDC5) expression in visceral adipose tissue in type-2 diabetic rats

CONTEXT

Evidence suggests that myokines could have clinical implications for metabolic diseases such as type-2 diabetes.

OBJECTIVE

We investigated the effects of concurrent training (CT) on irisin and fibronectin type-III domain containing five (FNDC5) expressions in visceral adipose tissue (VAT) in type-2 diabetic rats.

MATERIALS AND METHODS

Eighteen male Wistar rats (ages four to eight weeks) became diabetic using nicotinamide and streptozotocin and were assigned to either a control (CON) or a CT group using a randomised block design. The CT group exercised on a motor-driven treadmill at 60 to 75 per cent of VO_2max (0% grade) for 10-40 min/day (aerobic training) and performed 10 climbs on a 1-meter ladder utilising weighted resistance of 30-100% of body mass (resistance exercise) for 5 days/week over 8 weeks. Forty-eight hours after the last training session, the VAT of rats was removed and washed. FNDC5-relative gene expression and irisin were measured by the reverse transcription polymerase chain reaction (RT-PCR) method and enzyme-linked immunosorbent assay (ELISA) kit. Additionally, insulin resistance and plasma insulin and glucose levels were determined.

RESULTS

Our findings revealed that CT significantly increased FNDC5-relative gene expression in the VAT of type-2 diabetic rats compared to controls. Furthermore, eight weeks of CT improved insulin resistance and insulin and glucose levels but did not significantly alter irisin levels in type-2 diabetic rats.

DISCUSSION AND CONCLUSION

The results of this study demonstrated that CT increased FNDC5 mRNA and improved insulin resistance, insulin, and glucose levels. Also observed were increased trends (non-significant, p = .051) in irisin levels. Hence, CT may play a role in attenuating metabolic disorders such as obesity and type-2 diabetes.

Effects of L-citrulline supplementation on nitric oxide and antioxidant markers after high-intensity interval exercise in young men: a randomized controlled trial

L-citrulline (L-Cit) is a nonessential amino acid that stimulates nitric oxide (NO) production and improves exercise performance by reducing muscle damage indices; however, the direct benefits of L-Cit on antioxidant markers are unclear. The aim of this study was to examine antioxidant responses to high-intensity interval exercise following acute L-Cit supplementation. Nine young men (21 ± 1 years) participated in a double-blind crossover study in which they received 12 g of L-Cit and placebo (PL) an hour prior to high-intensity interval exercise on two occasions, separated by a seven-day washout period. Blood samples were obtained before (PRE), immediately after (IP), 10 (10P), and 30 min after exercise (30P) from the cubital vein using standard procedures. Serum concentrations of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and NO metabolites (NOx) were measured. The exercise protocol significantly elevated SOD (p = 0.01) and GPx (p = 0.048) from PRE to 10P in the L-Cit group with greater changes than the PL group. CAT concentrations increased IP (p = 0.014) and remained elevated at 10P (p = 0.03) and 30P (p = 0.015) in both the L-Cit and PL conditions. NOx concentrations increased IP (p = 0.05) in the L-Cit group with greater changes than PL group in PRE to IP, PRE to 10P, and PRE to 30P (p < 0.05). Our data indicate that L-Cit supplementation (single 12 g dose pre-exercise) induces improvements in antioxidant markers following a session of high-intensity interval exercise in young men.

Effect of Eight Weeks of Aerobic Progressive Training with Capsaicin on Changes in PGC-1α and UPC-1 Expression in Visceral Adipose Tissue of Obese Rats With Diet

Objective: Decreased physical activity coupled with increased High‐Fat Diet (HFD) intake prompts obesity. Current research suggests that changing White Adipose Tissue (WAT) to brown promotes energy expenditure to counter obesity. The purpose of this study was to investigate the effects of aerobic Progressive training and Capsaicin (Cap) on Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and Uncoupling protein-1 (UPC-1) gene expression in rat fed a high-fat diet. Methods: 40 male Wistar rats aged 8-12 weeks, were fed a Normal Diet (ND) (n=8) or HFD (n=32) for 8 weeks. After 8 weeks, rats were divided into 5 groups: ND, HFD, High-Fat Diet-Training (HFDT), High-Fat Diet-Capsaicin (HFDCap), high-fat diet-training-capsaicin (HFDTCap). Training groups have performed a progressive aerobic running program on a motor-driven treadmill for eight weeks. Capsaicin (4 mg/kg/day) were administered orally, by gavage, once a day. PGC-1α and UCP-1 gene expression levels in the VAT were measured by Real-time PCR method. Results: The results of this study showed that PGC-1α and UCP-expression was decreased in HFD group compared to ND group. Also, the expression of PGC-1α and UPC-1 in HFDT, HFDCap and HFDTCap groups was significantly increased compared to HFD. The expression of PGC-1α and UPC-1 in HFDTCap was also significantly increased compared to HFDT and HFDCap groups. Conclusion: Possibly, eight weeks of progressive training combined with capsaicin administration has an effect on the browning of visceral adipose tissue in HFD rats by increasing expression of PGC-1α and UCP-1.

Lipocalin-2: Response to a Progressive Treadmill Protocol in Obese and Normal-weight Men

Purpose

Lipocalin-2 (Lcn2), a newer adipocyte-secreted acute phase protein, was recently reported to be correlated with potential effects on obesity and inflammation. The reaction of this protein to progressive exercise has not been evaluated yet. This study was designed to compare the serum Lcn2 and high-sensitivity C-reactive protein (hs-CRP) levels after participating in an acute bout of treadmill protocol in obese and normal-weight men.

Methods

Nine obese (aged: 43.2±4.6 yrs and body mass index (BMI): 31.4±1.6 kg/m²) and 9 normal-weight (aged: 42.9±4.4 yrs and BMI: 23.03±1.7 kg/m²; mean ± SD) sedentary men selected randomly from volunteers performed a single bout of exercise according to the treadmill Bruce protocol.

Results

Before the exercise, Lcn2 level was higher in obese than normal-weight individuals (P<0.05). A significant increase in Lcn2, hs-CRP, white blood cells (WBC) and insulin resistance index was observed after the exercise in both groups (P<0.05). The level of Lcn2, hs-CRP and WBC increase was more significant in obese individuals than normal-weight subjects after the exercise (P<0.05).

Conclusions

It seems that the levels of Lcn2 and other inflammatory markers elevated in obese and normal-weight men after participating in an exhaustive progressive exercise. These changes in obese men were considerable.