Effects of high-intensity interval versus mild-intensity endurance training on metabolic phenotype and corticosterone response in rats fed a high-fat or control diet

Interaction between high-intensity interval training and high-protein diet on gut microbiota composition and body weight in obese male rats

Diet and exercise are two critical factors that regulate gut microbiota, affecting weight management. The present study investigated the effect of 10 weeks of high-intensity interval training (HIIT) and a high-protein diet (HPD) on gut microbiota composition and body weight changes in obese male Wistar rats. Forty obese rats were randomly divided into five groups, including HPD, HIIT + HPD, HIIT + high-fat diet (HFD) (continuing HFD during intervention), obese control 1 (continuing HFD during intervention), obese control 2 (cutting off HFD at the beginning of the intervention and continuing standard diet), and eight non-obese Wistar rats as a non-obese control (NOC) group (standard diet). Microbial community composition and diversity analysis by sequencing 16S rRNA genes derived from the fecal samples, body weight, and Lee index were assessed. The body weight and Lee index in the NOC, HIIT + HFD, HPD, and HIIT + HPD groups were significantly lower than that in the OC1 and OC2 groups along with the lower body weight and Lee index in the HPD and HIIT + HPD groups compared with the HIIT + HFD group. Also, HFD consumption and switching from HFD to a standard diet or HPD increased gut microbiota dysbiosis. Furthermore, HIIT along with HFD increased the adverse effects of HFD on gut microbiota, while the HIIT + HPD increased microbial richness, improved gut microbiota dysbiosis, and changed rats' phenotype to lean. It appears that HFD discontinuation without doing HIIT does not improve gut microbiota dysbiosis. Also, the HIIT + HFD, HPD, and HIIT + HPD slow down HFD-induced weight gain, but HIIT + HPD is a more reliable strategy for weight management due to its beneficial effects on gut microbiota composition.

Immunoinflammatory Response to Acute Noise Stress in Male Rats Adapted with Different Exercise Training

Objective

Noise pollution is a kind of stress that impairs various physiological functions. This study evaluated the effect of high-intensity interval training (HIIT) and moderate-intensity continuous training (MCT) on corticosterone, interleukin-6 (IL-6), and monocyte responses to acute noise stress in male rats.

Design

Forty-two male Wistar rats were divided into seven groups, including control which was assessed at the beginning, control time which was assessed simultaneously with experimental groups (CT), HIIT, MCT, HIIT followed by noise stress (HIIT+S), MCT followed by noise stress (MCT+S), and noise stress. HIIT and MCT were performed for 8 weeks. Noise stress was induced for one session. Blood samples were taken 48 hours after the last exercise session in training and CT groups and immediately after acute noise stress in stress groups of HIIT+S, MCT+S, and noise stress.

Results

In response to acute noise stress, MCT and HIIT adaptations increased corticosterone, while reduced monocytes compared to CT. MCT increased basal corticosterone and IL-6 and decreased monocytes; however, in response to acute noise stress, corticosterone was higher and monocyte count was lower in the HIIT+S group. Regarding the effect of training, corticosterone and monocytes in MCT were higher than in HIIT. The serum level of IL-6 was lower in MCT than CT group, while it was not significantly different between stress groups.

Conclusion

In response to noise stress, previous exercise, especially HIIT, increased stress while did not increase inflammatory and innate immune response.

Exercise regulation of hepatic lipid droplet metabolism

Lipid droplets (LD) are not just lipid stores. They are now recognized as highly dynamic organelles, having a life cycle that includes biogenesis, growth, steady-state, transport, and catabolism. Importantly, LD exhibit different features in terms of size, number, lipid composition, proteins, and interaction with other organelles, and all these features exert an impact on cellular homeostasis. The imbalance of LD function causes non-alcoholic fatty liver disease (NAFLD). Studies show that exercise attenuates NAFLD by decreasing LD content; however, reports show metabolic benefits without changes in LD amount (intrahepatic triglyceride levels) in NAFLD. Due to the multiple effects of exercise in LD features, we think that these metabolic benefits occur through changes in LD features in NAFLD, rather than only the reduction in content. Exercise increases energy mobilization and utilization from storages such as LD, and is one of the non-pharmacological treatments against NAFLD. Therefore, exercise modification of LD could be a target for NAFLD treatment. Here, we review the most up-to-date literature on this topic, and focus on recent findings showing that LD features could play an important role in the severity of NAFLD.

Probiotic Supplementation and High-Intensity Interval Training Modify Anxiety-Like Behaviors and Corticosterone in High-Fat Diet-Induced Obesity Mice

Evidence supports the role of exercise training and probiotics on reducing obesity. Considering the relationship between obesity and high-fat diet with anxiety indices, the aim of this study was to assess the effect of probiotic supplementation and high-intensity interval training (HIIT) on anxiety-like behaviors, corticosterone and obesity indices in high-fat diet (HFD)-induced obesity mice. Thirty male adult C57BL/6 mice were randomly divided into five groups: (1) Control with normal diet (CON), (2) High-fat diet (HFD), (3) HFD + exercise training (HT), (4) HFD + probiotics supplement (HP) and (5) HFD + exercise training +probiotics (HTP). Exercise training consisted of 8 weeks of high-intensity interval training (HIIT) programs. Probiotics supplement included 0.2 mL Lactobacillus rhamnosus GG. Anxiety-like behaviors were measured by open field (OF) and Elevated plus maze (EPM). OF and EPM tests, visceral fat mass (VFM) measurement, and blood sampling for corticosterone were performed after the intervention. Bodyweight was measured at different stages during the intervention. HFD regime in C57BL/6 mice increased bodyweight, VFM, and serum corticosterone levels and anxiety-like behaviors (p < 0.05). HIIT, probiotic and their combination, decreased bodyweight, VFM, and serum corticosterone levels and improved anxiety-like behavior in the HFD mice (p < 0.05). The effect of a combination of HIIT and probiotic on most of the anxiety indices was more than each one separately (p < 0.5). HIIT and probiotic supplements separately or above all in combination, may have beneficial effects in reducing obesity and anxiety indices.

High-intensity interval training is more effective than continuous training to reduce inflammation markers in female rats with cisplatin nephrotoxicity

AIMS

Cisplatin (CP) is an antineoplastic widely used in the treatment of various solid tumors, however, its clinical application is limited by nephrotoxicity. Here, we compared the impact of preconditioning with high-intensity interval training (HIIT) with continuous training of low (LIT) and moderate (MIT) intensity on innate immunity markers in female rats with CP-induced acute kidney injury.

MATERIALS AND METHODS

The rats were divided into five groups (n = 7): saline control and sedentary (C + S); CP and sedentary (CP + S); CP and LIT (CP + LIT); CP and MIT (CP + MIT) and CP and HIIT (CP + HIIT). The training intensity was determined by a maximum running test. At the end of training, the rats received a single dose of CP (5 mg/kg), and 7 days later they were euthanized. We evaluated renal function parameters (serum creatinine, glomerular filtration rate and proteinuria), renal structure, macrophage tissue infiltration, immunolocalization of nuclear transcription factor kappa B (NF-κB), renal levels of tumor necrosis factor-alpha (TNF-α), interleukin 1β (IL-1β), and interleukin 6 (IL-6), and gene expression of monocyte chemoattractant protein-1 (MCP-1), toll-like receptor 4 (TLR4), and NF-κB in renal tissue.

KEY FINDINGS

Although both MIT and HIIT attenuated the degree of renal injury, only the HIIT prevented changes in renal function. The three training protocols mitigated the increase in expression of all inflammatory markers, however, this effect was more pronounced in HIIT.

SIGNIFICANCE

All training protocols promoted renoprotective actions, but HIIT was more effective in mitigating CP-induced acute kidney injury, in part by modulation of important markers of the innate immune response.

The Effect of Swimming on Anxiety-Like Behaviors and Corticosterone in Stressed and Unstressed Rats

This study assessed the effect of swimming training on anxiety-like behaviors and corticosterone. Thirty adult male Wistar rats were randomly assigned to five study conditions: swimming training (ST); exposure to chronic mild stress (CS); exposure to chronic mild stress followed by swimming training (CS + ST); exposure to chronic mild stress followed by a recovery period (CS + recovery); control. The exercise training consisted of 60 min of swimming exercise per day, for five days a week, and four consecutive weeks. A chronic mild stress program (CMS) was applied for a period of four weeks. Anxiety-like behaviors were measured by open field test (OFT). The number of excrements and blood corticosterone were used as physiological parameters of anxiety. To assess corticosterone, blood samples were taken 48 h after the last session of experiments. Compared to other study conditions, the lowest anxiety-like behaviors and corticosterone concentrations were observed in the ST condition in unstressed rats. In stressed rats, as in the ST + CS group, swimming training probably reduced some anxiety behaviors, but the results showed increased corticosterone compared to control and CS + Recovery. Anxiety parameters and corticosterone concentrations were greatest in the CS condition. In the ST group, anxiety parameters were less than for the ST + CS group. In the CS + Recovery group, anxiety parameters were less than for the CS group. In summary, self-paced swimming training could attenuate some anxiety parameters in both stressed and non-stressed rats. The effect of swimming training in unstressed rats was more prominent than in stressed rats. In stressed rats, a period of recovery was more effective than swimming training in reducing corticosterone. Mechanisms of anxiety reduction other than cortisol should be investigated in future research.

Daisaikoto Prevents Post-dieting Weight Regain by Reversing Dysbiosis and Reducing Serum Corticosterone in Mice

Weight loss is often temporary and is generally followed by recurrent weight gain and a relapse of metabolic complications, whose severity may be even greater upon recurrence. Preventing recurrent obesity, understanding the control of the energy balance subsequent to weight loss, and reversing the predisposition to obesity are critical factors that warrant an in-depth study. Several Kampo medicines, including daisaikoto, have traditionally been used to manage obesity, but their mechanisms of action are not well studied and their effects on weight regain are unknown. Here, we investigated the therapeutic potential and mechanism of action of daisaikoto in a mouse model of recurrent obesity. The mouse model was established by feeding mice a high-fat diet, followed by a normal chow, and a second course of the high-fat diet. Daisaikoto inhibited not only obesity and regaining of weight post-dieting, but also dysbiosis, thereby overcoming the predisposition to obesity. Furthermore, we found that recurrent obesity or long-term consumption of the high-fat diet elevated serum glucose, insulin, and corticosterone levels, and that daisaikoto lowered serum cholesterol and free fatty acid levels. These results are consistent with the hypothesis that this medication may inhibit lipid absorption by inhibiting pancreatic lipase. However, daisaikoto had no effect on the body weight of lean mice fed a normal chow, suggesting that although this medicine prevents lipid absorption, it does not cause excessive weight loss. In conclusion, our results elucidate the mechanisms underlying daisaikoto activity, and suggest that it may serve as a safe and effective anti-obesity drug.

Corticosterone in Lizard Egg Yolk Is Reduced by Maternal Diet Restriction but Unaltered by Maternal Exercise

When females face adverse environmental conditions, physiological changes, such as elevated corticosterone levels, to cope with the stressors may also impact their offspring. Such maternal effects are often considered adaptive and may "prime" the offspring for the same adverse environment, but maternal corticosterone levels do not always match that of the eggs produced. We examined how diet restriction and increased locomotor activity, via exercise training, affected steroid hormone levels of female green anole lizards, as well as the hormone levels in the yolk of their eggs. Diet restriction did not affect female hormone levels, but training increased corticosterone levels. Despite this, training did not affect yolk steroid levels, but eggs from females with diet restriction had lower corticosterone levels in yolk. This suggests that two common stressors, food shortage and increased locomotor activity, impact female physiology in a way that is not translated to her offspring.

Dietary supplementation with camu-camu and continuous exercises in the treatment of obesity

ABSTRACT Objective The goal of this study were to investigate the effects of continuous exercise with/or without the ingestion the Camu-camu pulp in a rat model of obesity. Methods Neonate male Wistar rats, receiving monosodium glutamate, subcutaneously were separated into foour groups: sedentary group S (no treatment), exercise group E (continuous swimming training), Camu-camu group C (25mL of pulp of Camu-camu/day) and exercise and Camu-camu group EC (25mL of pulp of Camu-camu/day, continuous swimming). After 12 weeks, the animals were received euthanasia. Results The exercise program was conducted for five days for 12 weeks and the effects of supplementation with or without Camu-camu in obese rats were analyzed, showing that the relative levels of the variables cholesterol, triglycerides, glucose, High Density Lipoprotein and Low Density Lipoprotein and in all groups there was a significant reduction (.<0.001), except for the control group. Body weight and feed intake, epididymal and visceral fat deposits were not significantly different between the means of groups C and E, but these groups showed a significant difference when compared to the EC group (.<0.001). Conclusion The results demonstrate the effectiveness of continuous exercise and diet supplemented with Camu-camu fruit pulp to control obesity.