Efeito do consumo crônico do adoçante natural stevia (S. rebaudiana Bertoni) sobre parâmetros metabólicos e atividade mitocondrial do tecido adiposo branco de camundongos obesos hiperalimentados durante a lactação

Abstract

Obesity is defined as an accumulation of body adipose tissue correlated with increased morbidity and mortality. In order to reduce calorie consumption and improve fitness, the population has increased the consumption of non-caloric sweeteners. The sweeteners may be natural or artificial, and it is now known that these are not inert compounds and some types have a positive correlation with increased body mass and obesity. Stevia rebaudiana Bertoni is a South America native plant that has a high sweetening power, for this reason it is used in the production of Stevia natural sweetener. Recent experimental studies show the positive role of this sweetener in metabolic parameters due to its ability to activate sweet taste receptors (T1R2/T1R3) present in the taste buds and other organs, influencing the adipogenesis process. In this way, it is necessary to investigate the effect of Stevia sweetener consumption on energy metabolism and its relation to the process of adipogenesis. Hyperalimentated Swiss mice were used. To induce hyperalimentation, litters were reduced to 3 male offspring per infant on the 3rd day of postnatal life (hyperalimentated group - OG). The control litters were adjusted in 6 pups per infant (control group - CG). At 90 days of age, the control and hyperalimentary groups were divided into two subgroups, (CG-ST and OG-ST) or control and hyper-fed groups that received pure water (CG-WA and OG-WA). The animals were sacrificed at 180 days of age. We evaluated food and water consumption by the animals throughout the study. The body composition was measured by magnetic resonance imaging and we verified the weight of some tissues such as liver and white adipose tissue. We analyzed some biochemical parameters such as glycemia, triglycerides and total cholesterol. Through Western Blotting and PCR, we quantified the content of some proteins of the insulin signaling pathway and lipid metabolism. Mitochondrial metabolism was analyzed through high resolution respirometry and ATP dosing. Data demonstrated that hypernutrition induces an increase in body mass, epididymal fat and hyperglycemia in adult animals. Stevia sweetener consumption was able to decrease body mass and epididymal fat in OG-ST, as well as improve glycemic response and increase insulin receptor 1 (IRS-1) content. In contrast, CG-ST showed an increase in these anthropometric parameters and an increase in body fat percentage without altering the IRS-1 content. Thus, our work suggests that the chronic consumption of the natural sweetener produced with Stevia promotes different metabolic alterations according to the nutritional state of the animal, improving glycemic homeostasis and anthropometric parameters in overnutrition adult animals during the lactation period.