31 research outputs found
An important issue that has to be addressed: Irisin crosstalk with cancerous tissues
Dear Editor-in-ChiefMany studies have shown that regular physical activity has a significant effect on improving a range of disorders such as metabolic syndrome, cardiovascular disease, and cancer. Regular physical activity improves disease activity in patients by affecting hormones, the reverse cholesterol transport process, factors related to antioxidants and immune defense systems, factors that control cell apoptosis, and more (Myers, Kokkinos, & Nyelin, 2019).Nowadays, the role of muscle-secreting cytokines (in response to physical activity) in fighting diseases has attracted the attention of scientists. Muscle-secreting cytokines (myokines) provide communication between muscle and other tissues and organs such as the brain, adipose tissue, bone, liver, intestines, pancreas, etc., and physical activity is a way to stimulate the secretion of these myokines from the muscle. Myokines are involved in critical processes of the body such as cognition, lipid, and glucose metabolism, browning of white fat, bone formation, endothelial cell function, hypertrophy, skin structure, and tumor growth (Severinsen & Pedersen, 2020); therefore, they can be studied as a mechanism for the effect of physical activity on various diseases.Irisin is a myokine. It is secreted from skeletal muscle in response to physical activity. Physical activity increases the transcriptional activator of PGC1-α and induces the expression of the FNDC5 gene, and subsequently, irisin is released into the blood. Irisin facilitates glucose uptake by skeletal muscle, improves glucose and liver fat metabolism, has a positive effect on hyperlipidemia and hyperglycemia due to obesity and metabolic syndrome, and acts as an insulin-sensitizing hormone (Severinsen & Pedersen, 2020).The role of irisin in cancer treatment is unclear, and further studies are needed. The results of a review study show that regular physical activity increases irisin, but the use of irisin in cancer therapeutics requires further researches (Maalouf & El Khoury, 2019). More studies should be performed to determine the mode of administration of irisin for each cancer type and investigate the amount of use. Moreover, studies on the impact of physical activity on irisin in cancer patients are required
The importance of crosstalk studies in finding mechanisms for the effect of physical activity on health
Dear Editor-in-ChiefNew approaches to endocrinology have confirmed that every cell secretes hormones. These secreted substances are called cytokines. However, they are also named based on their origin. For example, the secretions of adipose and muscle tissue cells are called adipokines and myokines, respectively (Chait & den Hartigh, 2020).The endocrine function of adipose tissue has been determined in some studies. It secretes substances called adipokines. Released adipokines (such as leptin, adiponectin, visfatin, resistin, omentin) act as autocrine/paracrine and endocrine (Landecho et al., 2019). Adipokines play an essential role in regulating glucose and lipid metabolism, energy homeostasis, nutritional behavior, insulin sensitivity, inflammation, the immune system, adipose tissue production, vascular function, coagulation, and other bodily functions (Chait & den Hartigh, 2020). Leptin, for example, regulates body fat mass and obesity (when it increases in the bloodstream) through appetite and satiety receptors (in the hypothalamus). Unlike leptin, adiponectin reduces body fat mass and regulates glucose and lipid homeostasis. The resistin can be thought of as a link between obesity, diabetes, and insulin resistance. The visfatin plays an essential role in inflammatory and infectious diseases through pro-inflammatory and anti-apoptotic ability. Omentin significantly reduces the acute phase protein in endothelial cells and can be considered an anti-inflammatory adipokine (Landecho et al., 2019). In general, adipokines act as a mediator in regulating the function of tissues and other organs such as the liver, skeletal muscle, pancreas, and cardiovascular system. Adipose tissue dysfunction plays a significant role in insulin resistance, type 2 diabetes, cardiovascular disease, and metabolic disease (Balistreri, Caruso, & Candore, 2010).Exercise promotes adaptation to skeletal muscle, adipose tissue and consequently prevents metabolic disorders. Physical activity causes these beneficial effects by altering myokines (skeletal muscle secretions) and adipokines. Adipokines and myokines play a role in facilitating tissue-to-tissue communication (tissue crosstalk) and work together to improve health. Studies show that skeletal muscle releasing myokines during a contraction may influence adipokines (Leal, Lopes, & Batista, 2018). Moreover, Shirvani et al. showed a significant positive correlation between plasma levels of irisin with the nesfatin-1 and a significant negative correlation with resistin. Therefore, physical activity could create metabolic crosstalk between skeletal muscle and adipose tissue (Shirvani & Rahmati-Ahmadabad, 2019). Doing crosstalk research by researchers is crucial to better understand the health-related molecular mechanisms (created by exercise)
Effects of exercise on reverse cholesterol transport: A systemized narrative review of animal studies
Reverse Cholesterol Transport (RCTr) is the mechanism by which excess cholesterol from peripheral tissues is transported to the liver for hepatobiliary excretion, thereby inhibiting foam cell formation and the development of atherosclerosis. Exercise affects RCTr, by influencing high-density lipoprotein cholesterol (HDL) through remodeling and by promoting hepatobiliary sterol excretion. The objectives of this systematized review of animal studies is to summarize the literature and provide an overview of the effects of chronic exercise (at least two weeks) on apolipoproteins (Apo A-I, Apo-E), Paraoxonase-1 (PON1), ATP-binding cassette transporters (ABCA1, ABCG1, ABCG4, ABCG5, ABCG8), scavenger receptor class B type I (SR-BI), cholesteryl ester transfer protein (CETP), low-density lipoprotein receptor (LDLr) and cholesterol 7 alpha-hydroxylase (CYP7A1) and Niemann-Pick C1-like 1 (NPC1L1). Three electronic databases (PubMed, Science Direct and Google Scholar) were searched for eligible studies conducted from the earliest available date to August 2018. Most of studies investigate the effects of low to moderate intensity aerobic training on RCTr elements. The majority were on exercised rats undertaking moderate intensity aerobic training. This review highlights that moderate intensity and longer-term training has a greater effect on RCTr elements than low intensity training. There a few studies examining high intensity training which warrants further investigation. [Abstract copyright: Copyright © 2019. Published by Elsevier Inc.
Effect of resistance training with and without vitamin D calcium chitosan nanoparticle supplements on apoptosis markers in ovariectomized rats: An experimental study
Background: Hormone therapy is one of the most effective treatments for menopausal disorders, but it may increase the risk of breast cancer, coronary heart disease, and pulmonary embolism.
Objective: The present study investigated the effect of resistance training with and without vitamin D calcium (Ca++) chitosan nanoparticles on apoptosis markers in ovariectomized rats.
Materials and Methods: 42 female Wistar rats were divided into 7 groups (n = 6/each). One group was assigned as the healthy controls to show the induction of menopause. The other 6 groups comprised ovariectomized (OVX) animals including: 1) vitamin D + calcium + chitosan + resistance training, 2) saline + estrogen + resistance training, 3) saline + resistance training, 4) vitamin D + calcium + chitosan, 5) saline + estrogen, and 6) OVX + control. 48 hr after the last intervention, the hippocampus tissue was extracted to measure the BCL-2-associated X (BAX), B-cell lymphoma 2 (BCL-2), and caspase-3 gene expression as well as the percentage of dead cells.
Results: OVX rats demonstrated increased BAX gene expression, ratio of BAX gene expression to BCL-2, caspase-3 gene expression, and percentage of dead cells of hippocampal tissue, but decreased BCL-2 gene expression. Resistance training and vitamin D Ca++ chitosan nanoparticle supplements seemed to reverse these changes.
Conclusion: The combination of resistance training and vitamin D Ca++ chitosan nanoparticle supplements may be considered a non-pharmacological treatment for OVX-induced apoptosis.
Key words: Apoptosis, BCL-2-associated X protein, Caspase-3, Estrogen replacement therapy, Hormone replacement therapy
Combined Effects of High-Intensity Aerobic Exercise Training and Ziziphus jujuba Extract on Tissue Nesfatin-1 in Rats
Nesfatin-1 is involved in metabolic/feeding regulation and prevention of cardiovascular disease. Previous studies have shown that exercise and herb supplementation can influence nesfatin-1 concentration. The present study investigated the effects of high-intensity training (HIT) and Ziziphus jujuba (ZJ) extract on tissue nesfatin-1 in rats. Twenty-eight female rats were randomly assigned to one of four groups i.e. 1) Saline-Control (SC), 2) Saline-High Intensity Training (ST), 3) Ziziphus jujuba-Control (ZJC), and 4) Ziziphus jujuba-High Intensity Training (ZJT). Rats performed exercise on a treadmill and/or administered supplements intragastrically for 6 weeks, depending on group category. Seventy-two hours after the last training session, rats were anesthetized. Blood, hypothafi 2lamus tissue, heart and gastrocnemius muscles were sent to the laboratory for analyses. Significantly higher nesfatin-1 gene expression and concentration and ATP concentration were found in trained rat. HIT increased plasma High Density Lipoprotein (HDL) and insulin concentration and reduced plasma Triglyceride (TG) and cortisol. ZJ increased tissue nesftain-1 gene expression and concentration while only increasing heart ATP. The combination of exercise and ZJ showed an additive effect compared to each intervention alone on hypothalamus, heart and gastrocnemius NUCB2 gene expression, heart and gastrocnemius nesfatin-1 concentration, plasma HDL and cortisol concentration. The authors recommend both interventions as a means to improve cardiovascular health in rats with further work needed to confirm similar findings in homo sapiens
Effects of Endurance Training with or without Rosehip Fruits (Rosa canina L) Extraction and D-galactose Solution on Plasmatic Liver Enzymes, Lipid Profiles, Selected Biochemical Variables in Male Rats
Effects of physical activity and obesity on hypertension: A narrative mini-review of the main effective mechanisms
Physical activity (PA) and obesity are effective interventions for hypertension. The current study is a review to explain possible mechanisms related to the effects of PA and obesity on hypertension. To this end, several scientific databases were searched using the keyword "hypertension" and also some English articles related to obesity and PA were investigated. Then, the mechanisms of obesity and PA associated with hypertension were extracted from the collected articles. Overall, obesity causes an increase in renin-angiotensin-aldosterone (RAA) systems, harmful changes in lipid and lipoprotein profile, a decrease in insulin sensitivity, as well as harmful changes in adipokines, oxidative stress, and inflammatory factors. PA improves the above-mentioned changes caused by obesity. Overall, PA mainly via an effect on oxidative stress, inflammation, endothelial cells, the elasticity of arteries, body weight, the activity of the RAA system, activity of parasympathetic and renal function as well as improve the insulin sensitivity has positive effects on hypertension. It should be noted that the effects of PA against hypertension is highly variable and they are related to PA modes, environmental and genetic factors
Eccentric resistance training and beta-hydroxy-beta-methylbutyrate free acid affects muscle PGC-1 alpha expression and serum irisin, nesfatin-1 and resistin in rats
The hypothalamus controls metabolism and feeding behaviour via several signals with other tissues. Exercise and supplements can change hypothalamic signalling pathways, so the present study investigated the influence of eccentric resistance training and β-hydroxy-β-methylbutyrate free acid supplementation on PGC-1α expression, serum irisin, nesfatin-1 and resistin concentrations. Thirty-two male rats (8 weeks old, 200±17 g body mass) were randomly allocated to control, β-hydroxy-β-methylbutyrate free acid supplementation (HMB), eccentric resistance training (ERT), and β-hydroxy-β-methylbutyrate free acid supplementation plus eccentric resistance training (HMB+ERT) groups. Training groups undertook eccentric resistance training (6 weeks, 3 times a week) and supplement groups consumed β-hydroxy-β-methylbutyrate free acid (HMB-FA) orally (76 mg kg-1 day-1). Twenty-four hours after the last training session, serum and triceps brachii muscle samples were collected and sent to the laboratory for analysis. Two-way ANOVA and Pearson correlation were employed (significance level: P<0.05). The results showed that eccentric resistance training increases skeletal muscle PGC-1α gene expression, as well as serum levels of irisin and nesfatin-1 (P=0.001). Eccentric resistance training decreased the serum concentration of resistin (P=0.001). HMB-FA supplementation increased skeletal muscle PGC-1α gene expression (P=0.002), as well as the serum concentration of irisin and nesfatin-1 (P=0.001), but decreased the serum concentration of resistin (P=0.001). Significant correlations were observed between PGC-1α gene expression and serum concentrations of irisin, nesfatin-1 and resistin. HMB-FA supplementation with eccentric resistance training may induce crosstalk between peptide release from other tissues and increases maximal muscle strength. The combination of the two interventions had a more substantial effect than each in isolation
Irisin interaction with adipose tissue secretions by exercise training and flaxseed oil supplement
Abstract Background Previous studies have shown that physical training and natural diet able to change the expression and concentration of peptides and proteins. Myokines and adipokines play an important role in metabolism and metabolic syndrome. Therefore, the purpose of the present study was to investigate the effect of high-intensity interval training (HIIT) and supplementation of flaxseed oil on plasma irisin, nesfatin-1 and resistin in male rats. Methods Forty adult male rats were randomly divided into four groups (ten in each group) including Control-Saline (CS), Training-Saline (TS), Control-FlaxOil supplement (CO), and Training-FlaxOil supplement (TO). The training groups performed for 10 weeks and 5 sessions each week, interval training with 90–95% VO2max on rodent treadmill, and supplement groups received flaxseed oil (300 mg / kg). Five days after the last training session, rats were sacrificed. Blood samples were taken from the heart and plasma was evaluated. Results Exercise Training significantly increased plasma levels of irisin (P = 0.019), nesfatin-1 (P = 0.01), and decreased resistin (P = 0.01). Flaxseed oil significantly reduced plasma resistin levels (P = 0.02). Plasma irisin levels in the supplementation group were higher than all groups (P = 0.041). Conclusion There was a significant positive correlation between plasma levels of irisin with nesfatin-1 and negative correlation with resistin. HIIT program with flaxseed oil as a modality can create a metabolic crosstalk between skeletal muscle and adipose tissues and have health benefits