Assessment of DNA Methylation and Oxidative Changes in the Heart and Brain of Rats Receiving a High-Fat Diet Supplemented with Various Forms of Chromium.

Wojciech Dworzański,Piotr Listos,Jerzy Juśkiewicz,Bartosz Fotschki,Ewelina Cholewińska,Katarzyna Ognik

doi:10.3390/ani10091470

Abstract

Simple SummaryObesity is one of the most prevalent diseases of civilization in the 21st century. This may be due to an increase in the consumption of high-fat diets. For the treatment of obesity, various supplements with chromium (III) are used. Chromium has the ability to regulate carbohydrate and lipid metabolism, which may result in weight loss. Our studies compared the effects of a high-fat diet supplemented with three different forms of chromium-chromium (III) picolinate, chromium (III) -methionine, and nano-sized chromium on oxidative damage of the DNA, proteins, and lipids in the heart and brain of rats. The conducted study showed that the use of a high-fat diet results in oxidation of the DNA, proteins, and lipids in the brain and heart, and the addition of chromium additionally intensifies these processes, especially when used in the form of nanoparticles. Therefore, the results of these studies suggest that one should be careful when using chromium supplementation to counteract obesity, because it may be associated with the risk of deterioration of the functioning of the heart and brain.The aim of the study was to determine how feeding rats a high-fat diet supplemented with various forms of chromium affects DNA methylation and oxidation reactions as well as the histology of heart and brain tissue. The rats received standard diet or high-fat diet and chromium at 0.3 mg/kg body weight (BW) in form of chromium (III) picolinate, chromium (III)-methionine, or nano-sized chromium. The content of malondialdehyde (MDA), protein carbonyl (PC), and 8-hydroxydeoxyguanosine (8-OHDG), the level of global DNA methylation and the activity of selected DNA repair enzymes were determined in the blood. In the brain and heart, the content of MDA, PC, 8-OHDG, and levels of global DNA methylation were determined. The brain was subjected to histological examination. The use of a high-fat diet was found to intensify epigenetic changes and oxidation reactions in the heart and brain. It was concluded that epigenetic changes and oxidation of lipids, proteins, and DNA in the heart and brain of rats resulting from the use of a high-fat diet cannot be limited by supplementing the diet with chromium. It was established that the use of chromium to supplement a high-fat diet intensifies the negative epigenetic and oxidative changes in the heart and brain, especially in the case of chromium nanoparticles.

Highlights

Obesity is one of the most prevalent diseases of civilization in the 21st century
There are reports indicating that excessive fat consumption and obesity adversely affect the nervous system, increasing the risk of dementia and Alzheimer’s disease [5,6]
The initial body weight of the rats used in the experiment was similar in the control and experimental groups and was about 130 g

Summary

Introduction

Obesity is one of the most prevalent diseases of civilization in the 21st century. It can be influenced by genetic, epigenetic, socio-economic, biological, and behavioural factors [1,2]. A high-fat diet seems to be of particular importance in the pathophysiology of obesity. There are reports indicating that excessive fat consumption and obesity adversely affect the nervous system, increasing the risk of dementia and Alzheimer’s disease [5,6]. Impaired functioning of the body due to a high-fat diet is believed to result from the excessive production of reactive oxygen species (ROS) that accompany it [7,8]

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