Effect of lycopene supplementation in experimental model of diet-induced obesity

Abstract

Most of studies regarding obesity have been shown increase of oxidative event. This event results in deficiency of antioxidant defense and /or increase in reactive species (oxygen, nitrogen). The enzymatic system, nicotinamide adenine dinucleotide phosphate oxidase (NADPH-oxidase) is well known as source of reactive species in vessels, cardiomyocytes and fibroblasts, but is unknown the activity this enzyme in adipose tissue of obese subjects. It has been recently recognized that accumulated fat acts as a generator organ of autocrine factors, which participate of obesity pathogenesis. In parallel, few studies have been evaluated the effect of the important dietetic antioxidant lycopene on obesity and in diseases associate with this pathology. The aim this study is to evaluate the oxidative stress level and the role of lycopene supplementation in diet-induced obesity model. The study will be conducted with male Wistar rats (n=28) randomly separated for receiving control diet (C) or hypercaloric diet (H) for six weeks. After this period, all animals will be again randomized into: C (n=7), C supplemented with Lycopene (C+L, n=7), H (n=7), and H supplemented with lycopene (H+L, n=7). The lycopene used will be oil-resin mixed with corn oil (10mg/Kg body weight/day); untreated groups (C and H) will receive corn oil at an equivalent volume (~ 0.5 mL/kg/day), both via gavage, for six weeks. Food and water will be offered ad libitum, and the consumption will be daily recorded. Body weight will be weekly measured. The blood of all the animals will be submitted to laboratorial evaluation (glucose, insulin, triglycerides and total cholesterol), lycopene concentration, antioxidant capacity (TAP), DNA damage (Comet assay). The renal function will be evaluated in the plasma and urine. It will be evaluated NADPH-oxidase activity in adipose tissue, the total body fat and TAP and protein oxidation in heart. All analyzes will be perform at the end of experiment.It is expected that the results may contribute with information about the effect of chronic administration of lycopene on oxidative stress markers (NADPH-oxidase activity, total antioxidant performance, oxidative DNA damage, protein oxidation) and on clinical and laboratorial signs of obesity. Once identified this effect, potential therapeutic strategies using this antioxidant may be possible to attenuate lesions in obese patients. (AU)