Effect of sweetener consumption on fatty acid synthase (FAS) enzyme activity of livers from rats of HSD lineage: Han Wistar

Abstract

The media constantly bombards consumers about the daily intake of “calorie-free” beverages known as “light drinks,” arguing that they can be useful to reduce energy consumption, and thus, reduce the risk of metabolic syndrome. However, its consumption is increasingly common and excessive, caused by the lack of knowledge of the biochemical repercussions that it could have in the long term. Therefore, it is necessary to carry out studies to elucidate the possible metabolic effects that they may cause to human beings using model animals instead of people and to inform them so that they can make informed decisions. In this research, the foundations were established to know if there is an overstimulation of the enzyme fatty acid synthase (FAS) with respect to sweeteners supplied "ad libitum" chronically to rats of the Wistar HsdHan: WIST strain using a control group. who only consumed drinking water, evaluating the influence of sweeteners consumed during lipogenesis. The rodents, male rats (n=80) and female rats (n=80), were fed a normal balanced diet (Teklad Global® 18s, 500I Rodent Diet^®) and were provided with drinks with nutritive and non-nutritive sweeteners “ad libitum” for two periods. The first one was from weaning to 160 days and the second from weaning to 480 days of experimentation and after them the euthanasias were carried out. Each group had n=10 rodents, separated by group and sex and in the second period n=5 were left. The concentrations of the sweeteners supplied were: Sucrose 10% (m/v), fructose 7% (m/v), glucose 14% (m/v), acesulfame K 0.05% (m/v), commercial mixture acesulfame-aspartame 1.55% (m/v), sucralose 0.017% (m/v) and saccharin 0.033% (m/v). After the two experimental periods, samples of their liver tissue were taken to evaluate the enzyme. The general trend observed was that the highest levels of activity were determined in the groups that drank nutritious sweeteners (fructose, glucose, and sucrose). It was noted that female rats were more susceptible to the effects of non-nutritive sweeteners. Saccharin, despite being a non-nutritive sweetener, increased hepatic lipogenesis. It was found that the consumption of sweeteners modified the values of FAS, one of the key enzymes of lipogenesis, which is one of the main pathways of energy metabolism. It is recommended that future research investigate whether the adipose tissue content also increased, since in this research only the liver tissue of the specimens used in this study was analyzed.