Supplementation effect of lycopene on cardiac dysfunction in a diet-induced obesity model: myocardial redox state responses

Abstract

The redox state unbalance corresponds to an important pathogenic pillar in several diseases, such as obesity and its comorbidities. Given the relevance of this event in the pathogenesis of obesity and its complications, several therapeutic strategies using antioxidants have been tested. Lycopene is one of the best antioxidants among carotenoids and although the relationship between lycopene and heart disease has been examined in several clinical and experimental studies, to our knowledge, no study has addressed the effect of lycopene on cardiac oxidative damage in obese rats. The objective of the present study is to evaluate the effect of lycopene supplementation on myocardial redox function and status in a diet-induced obesity model. The study will be conducted in male Wistar rats (n=40, at 30 days of age), randomly separated for receiving two different dietary treatments ad libitum: standard diet + water (Control, n=20) or hypercaloric diet + water with sucrose - 40% (CHO, n=20) for 20 weeks. After this period, all animals will be again randomized into: Control group (C, n=10); Control + lycopene (C + Ly, n=10); hypercaloric diet (CHO, n=10) and hypercaloric diet + lycopene (CHO + Ly, n=10). The lycopene used will be oil-resin mixed with corn oil (10mg/kg body weight/day); untreated groups (C and CHO) will receive corn oil at an equivalent volume (~ 0.5 mL/kg body weight/day), both via gavage, for 10 weeks. At the end of the experiment, the animals will be submitted to systolic blood pressure measurement and then euthanized to obtain samples of blood and myocardium tissue. It will also be studied: adiposity index, insulin resistance, cardiac bioavailability of lycopene and myocardial redox state impairment markers [antioxidant capacity of cardiac tissue, carbonylation and lipid peroxidation malondialdeheyde (MDA)]. In order to study cardiac function, all animals will be submitted to echocardiography at 20th and 30th weeks.