Effect on the activity levels of the enzyme glucokinase (GK) evaluated in liver tissue of chronic ingestion of sweeteners in animal models, Wistar linneage rats

Abstract

The consumption of nutritive sweeteners has often been associated with harm to the health of those who consume them. Derived from this, food regulation has undergone various changes in its regulations, highlighting the non-alcoholic beverage industry that has implemented the use of non-nutritive sweeteners among its formulations as an alternative to the consumption of this type of carbohydrates. Despite the fact that these sweeteners and preservatives have been approved by various regulations, they continue to generate controversy for reporting carcinogenic effects at high doses, changes in the intestinal microbiota, increase in blood glucose levels or various metabolic alterations. Regarding this last topic, in this investigation the measurement of the levels of the enzymatic activity of glucokinase, GK (first enzyme to act in glycolysis) in the liver tissue was carried out to evaluate the effect of the consumption of sweeteners. There were 8 groups of 80 rats (40 female and 40 male) and 2 basal groups (10 males and 10 females) for a total of 100 rats of the Wistar strain. When obtaining the results of the enzymatic activity, they were compared with respect to control groups (rats that drank only drinking water) and, in this way, it was possible to evaluate the increase or decrease of this activity due to the consumption of these sweeteners. The study covered a duration of 160 days^[1] and at the end of this a humane euthanasia was performed where the livers were extracted for the realization of this study. The sweeteners supplied in this period were: Glucose 14%, fructose 7%, sucrose 10%, acesulfame K 0.05%, mixture of aspartame: acesulfame K 1.55%, saccharin 0.033% and sucralose 0.017%. Among the notable results, it was observed that, for the male rats that drank saccharin and sucralose, there were significant differences with respect to the control group, reporting increases in GK activity levels. For female rats, despite not having a significant difference in terms of GK activity between nutritive and non-nutritive sweeteners with respect to the control group, there was one between non-nutritive sweeteners (acesulfame K and saccharin relative to sucralose). When applying a multifactorial analysis where the sweetener consumed was related to the female or male sex, there were no significant differences between the type of sweetener consumed, but there were in the sex factor. This suggests that gender is indeed a variable for GK activity.

^[1] Although five months were planned for euthanasia, due to staff availability, it was actually 160 days for it (note from authors)