engleski

The effect of high-fat diet and retinoic acid application on oxidative stress, inflammation and insulin resistance in Lewis rats

Introduction: Long term high-fat diet (HFD) results in gain of body weight, adiposity, and inflammation in the organism. As the main causes of obesity, along with the genetic predisposition of individuals, there is also an overdose of food intake and insufficient energy consumption. Obesity is manifested in increased body mass, elevated levels of free fatty acids (FFS) in the blood, chronic systemic inflammation in the body and excessive production of free radicals, most important of which are the superoxide anion (O2-), hydrogen peroxide (H2O2) and reactive nitrogen species (RNS), often accompanied with insulin resistance which can lead to the development of numerous metabolic and cardiovascular diseases. Adipose tissue is not only a tissue that storages lipid acids and triacylglycerol, but also tissue that secretes biologically active supstances and hormons that interfere inflammatory response in the organism. Obesity is accompanied with increased production of proinflammatory cytokines, reduced serum level of antidiabetic and anti inflammatory adiponectin and increased level of leptin, increased macrofage infiltration in adipose tissue, especially M1 subpopulation that induces insulin resistance by secreting proinflammatory cytokines, such as TNFα. Retinoic acid has inhibitorry effect on adipogenesis. Methods: Analysis includeded 80 Wistar rats from Department of Animal Physiology Zagreb breeding. Half of the animals were fed high fat diet (HFD, 45% saturated fatty acid) and half standard laboratory diet (STD) during 30 days. 13 – cis retinoic acid (13cRA) was applied orally to 12 – 16 animals from each group in the concentration of 7.5 mg/kg and 15 mg/kg on a daily basis during 30 days, to the control animals destilated water was applied. After sacrifice, serum for haematological, biochemical analyses, inflammatory cytokines, leptin and adiponectin concentration were taken. Also, liver and kidney were stored for oxidative stress analysis (glutathione, lipid peroxidation and catalase activity). Results: HFD feeding caused hyperlipidemia and insulin resistance, and worsened liver and kidney functions. HFD feeding also potentiated inflammation and oxidative stress while 13 cRA has a protective effect. HFD feeding and 13cRA affected biochemical parameters in serum of Lewis rats. Conclusion: According to the the present results, we surmised that 13cRA can prevent HFD- induced inflammation and oxidative stress, and may be useful in the prevention of hyperlipidemia-associated inflammation and oxidative stress.

obesity ; metabolic syndrome ; oxidative stress ; 13 - cis retinoic acid ; rats

nije evidentirano