Volume 29, Issue 1 (3-2022)                   RJMS 2022, 29(1): 60-69 | Back to browse issues page

Research code: مقاله مستخرج از رساله دکتری است
Ethics code: IR.IAU.SARI.REC.1399.029
Clinical trials code: مقاله مستخرج از رساله دکتری است

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Associate Professor, Department of Exercise Physiology, Islamic Azad University, Sari Branch, Mazandaran, Iran , parvin.farzanegi@gmail.com
Abstract:   (940 Views)
Background & Aims: Cooking with re heated oils result in the release of acrylamide from starch at higher doses than the recommended limits. Heterocyclic amine is another toxin that is produced in this process, which is formed through the heating and cooking process form the protein substances when amino acids and creatine simultaneously react at high cooking temperatures (barbecued/fried foods). Reheated oils contain oxidized monomers, dimers, polymers, free radicals, reactive oxygen species (ROS), hydroperoxidases and aldehydes. These products have detrimental effects on human health and can cause harmful changes in body organs. Mitochondrial dynamics and morphology have increasingly been shown to be regulated by ROS. ROS are central to redox homeostasis-the balance between reduction and oxidation reactions via the gain or loss of electrons. Mitochondrial dynamics factors include Opa1 protein (optic atrophy 1) and mitofusin 1 and 2 (Mfn1 and 2), dynamin-related protein (Drp-1) and fusion protein 1. Deviation towards fusion optimizes mitochondrial function and is useful in maintaining long-term bioenergy capacity. Conversely, deviation toward division leads to the removal of the damaged part of the mitochondria. Exercise has recently been recognized as an effective way to increase mitochondrial function, and the role of exercise in improving mitochondrial damage and oxidative stress in various diseases has been reported. On the other hand, Recently, attempts have been made to diminish the adverse effects of acrolein in the reheated oils through exercise training and its synergistic effects with supplementations. Today, herbal supplements are considered highly effective in the reduction of oxidative stress and inflammation. Octopamine supplementation has been reported to have antioxidant properties. Octopamine is used as a food ingredient, as well as medicinal and dietary supplementation. Octopamine is an adrenergic substance with a sympathetic function. Weight loss and adrenergic actions are associated with metabolic changes. Some of the main functions of octopamine are in antioxidant and anti-inflammatory processes, weight loss, fat burning, and anticancer treatments. On the other hand, recent findings have indicated that exercise training could decrease oxidative stress and inflammation and improve antioxidant enzymes. Meanwhile, some studies have reported that exercise training has no significant impact on inflammation and oxidative stress. The aim of present study was to investigate the effect of aerobic training and octopamine on the gene expression of mitochondrial fission and fusion markers of soleus muscle of male rats fed with repeated heated oil.
Methods: In an experimental study, 15 male wistar rats (age: 20 weeks, weight: 300-350 g) were randomly divided into five groups, healthy control (n=3), intoxication (DFO, n=3), aerobic training + intoxication (n=3), octopamine + intoxication (n=3) and aerobic training + octopamine + intoxication (n=3). The exercise training program was conducted for four weeks at moderate intensity every other day. The intensity of exercise training in the first week reached 50% of the maximum consumed oxygen, while it reached 65% of the maximum consumed oxygen in the last week. In order for the animals to adapt to the exercise protocol, an adaptation exercise training session was implemented at the speed of nine meters per minute for 20 minutes during one week before the main exercise training program. The duration of exercise training was 20 minutes, with the intensity set at 16 meters per minute on the first day and 26 meters per minute on the last day of the intervention.
For supplementation, octopamine (Sigma-Aldrich, USA) was used for four weeks and was administered via intraperitoneal injection at the dose of 81 µmol/kg five days per week (IP solution with 9% normal saline). For preparation of the rations with hot oil, eight liters of sunflower oil was heated for four consecutive days eight hours per day at the temperature of 190-200°C (3), and every 30 minutes, foods such as chicken nuggets, potatoes, chicken, and protein products (e.g., sausages), were immersed in the oil. On the fourth day, the oil was preserved until the start of the experiment to be used as the intoxication agent and administered orally to the animals via gavage as the feed for four weeks. 48 hours after the last training session and 8 hours of fasting, all the rats were anesthetized with chloroform and then sacrificed. Soleus muscle tissue was immediately removed from the body and stored in a nitrogen tank at -80 ° C. Gene expression of Drp-1 and Mfn2 were measured by Real time & PCR and MDA concentration was measured by ELISA test. One-way ANOVA and Toky post hoc test were used to analysis the data. The significant level was set at p<0.05.
Results: The results showed that consumption of reheated oil induced significant decrease in gene expression of Mfn-2 (P<0.05), significant increase in Drp-1 and MDA (P<0.05) compared to healthy control group. Aerobic training+ octopamine caused the significant decrease in gene expression of DRP-1 (P<0.05), no significant increase in Mfn-2 (P>0.05) and no significant decrease MDA concentration (P>0.05) in comparison with DFO group. Octopamine significantly decreased the gene expression of Mfn-2 than DFO group (P <0.05).
Conclusion: Mitochondrial oxygen species reduce the synthesis of new mitochondria and the mitochondrial network During the oil heating process, and since this reduction reduces antioxidant defense, it results in oxidative stress in the cell. In confirmation of this, the consumption of reheated oil led to an increase in MDA levels that indicates an increase in oxidative stress. Consumption of reheated oil impairs the mitochondrial dynamic and alter the balance between mitochondrial fusion and fission, as they cause oxidative stress, thus reducing mitochondrial content and disrupting mitochondria. Maintaining a balance between mitochondrial fusion and fission is important for maintaining mitochondrial health in muscles. However, direct comparisons between the effects of reheated oil consumption and mitochondrial dysfunction and the effect of aerobic exercise and octopamine on the gene expression of mitochondrial dynamic in muscle are difficult due to the lack of access to similar studies. Studies have shown that octopamine, with properties similar to epinephrine, can selectively and strongly bind to β3 adrenoceptors and increase lipolysis and fat metabolism in general. Fat loss is associated with a decrease in oxidative stress and subsequent improve mitochondrial dynamics. Aerobic exercise can also increase Mfn2 gene expression by stimulating epinephrine, increasing β3 adrenoceptor gene expression, increasing fat catabolism, and reducing fat-induced oxidative stress, all of which interact physiologically to increase Mfn2 gene expression. Therefore, the use of aerobic exercise and octopamine as a stimulant to reduce fat and subsequently reduce ROS and maintain mitochondrial activity and homeostasis. According to the results, aerobic training and octopamine supplementation might have significant effects on the improvement of mitochondrial dynamics dysfunction caused by the use of reheated oils in the muscle tissue. Given the scarcity of data in this regard and limitations of our study regarding the loss of the laboratory rats, it is recommended that the current study be replicated using more samples in order to obtain more generalizable findings in the future.
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Type of Study: Research | Subject: Exercise Physiology

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