Stevia rebaudiana Bertoni, an American plant used as sweetener: Study of its effects on body mass control and glycemia reduction in Wistar male and female rats.

Stevia rebaudiana Bertoni water extracts have been used as a natural sweetener and customary medicine by the indigenous inhabitants of South America for several hundred years. This plant was sent to Europe in the 16th century and was described by Peter Jacob Esteve in Spain. Recently the food industry has started to employ S. rebaudiana as sweetener using its glycosides after purification. Advertisement claims that Stevia glycosides is good for controling body mass and reducing glycemia. This study's objective was to evaluate the effect of S. rebaudiana leaf extract on Wistar rats as animal model to prove its effectiveness on body mass control, glycemia reduction, and other biochemical parameters. Three groups were randomly formed with 24 males and 24 females: A blank group without any sweetener, a control group drinking water with 10% glucose, and the test group ingesting a 0.94% water extract of S. rebaudiana. Body mass measurements as well as food and drink consumption were daily performed. The experiment lasted 120 days after the specimens were weaned and got used to eating solid food. Euthanasia was done and blood serum was collected to evaluate the following biochemical parameters: Glucose, triglycerides, cholesterol, insulin, glucagon, leptin, ghrelin, and glucose-dependent insulinotropic peptide, GIP. Results indicated that only female rats had statistical differences in body mass gain. No relevant effects either positive or negative were found in the biochemical parameters measured. The crude extracts of S. rebaudiana did not show any relevant changes in biochemical and hormonal profiles, changes nor body mass with respect to the blank and control groups of young and healthy rats in the age range of infancy to youth. According to the results obtained, the therapeutic properties that have been associated to S. rebaudiana consumption especially for body mass control and glycemia reduction, did not occur in young and healthy male and female rats in equivalent age to infants, young children, and youths.

Chronic intake of nutritive sweeteners and saccharin increases levels of glycolytic and lipogenic enzymes in rat liver.

There are doubts about the impact of non-nutritive sweeteners consumption on lipogenic and glycolytic metabolism. Therefore, the objective was to determine the effects of chronic consumption of sweeteners on the activity levels of the enzymes glucokinase (GK), phosphofructokinase-1 (PFK-1), pyruvate kinase (PKL), acetyl coenzyme A carboxylase (ACC), and fatty acid synthase (FAS) in livers' extracts. Groups of male and female Wistar rats drank solutions of sweeteners for 480 days: Sucrose 10%, glucose 14%, fructose 7%, acesulfame K 0.05%, aspartame:acesulfame mixture 1.55%, sucralose 0.017%, saccharin 0.033%, and a control group. The enzymatic activity in livers' extracts was determined. Likewise, the levels of glucose, triglycerides, insulin, glucagon, and leptin were determined. In both genders, there were significant differences in the levels of enzymatic activity, hormonal, and biochemical parameters due to sweeteners consumption. The highest glycolytic and lipogenic enzyme activity levels were observed in the groups that ingested nutritive sweeteners and saccharin.

Effects on weaned male Wistar rats after 104, 197, and 288 days of chronic consumption of nutritive and non-nutritive additives in water.

ABSTRACT: It has been suggested that the consumption of artificial sweeteners is related to greater body mass gain and diverse metabolic alterations. In this study, the effect of chronic consumption of nutritive sweeteners (fructose 7% and sucrose 10%) and non-nutritive or low-calorie sweeteners (acesulfame 0.015%, aspartame 0.3%, aspartame:acesulfame mixture 0.04%, saccharin 0.3%, and sucralose 0.19%), in drinking water, as well as a control group with no sweeteners, was evaluated. Body mass gain and glucose, insulin, triglycerides, and total cholesterol levels in blood were the parameters considered. For this purpose, 120 weaned male Wistar rats of the HsdHan:WIST line were used, 15 per group in first stage, then 10 and 5 per group for 2nd and 3rd stages, respectively. Body mass gain, food intake, and beverage consumption were daily quantified. After 104, 197, and 288 days of experimentation the concentrations of glucose, triglycerides, cholesterol, and insulin were determined. Only in the first stage there were significant differences in the body mass gain. In the three stages there were significant differences in the patterns of beverage intake and food consumption. The trend was the same in all 3 stages: rats drank more in the groups of drinks sweetened with nutritive sweeteners and ate more in the groups that drank non-nutritive artificial sweeteners. Regarding the biochemical profile, no sweetener either nutritive or non-nutritive caused that the serum levels of glucose, triglycerides, and cholesterol were at pathological levels. It is concluded that the sweeteners by themselves can modify certain biochemical parameters but not at a pathological level. Furthermore, by themselves they are not capable of triggering excess of body mass or obesity in the early and medium stages of life when consumed together with a balanced diet.

Consumption of sweeteners at different stages of life: effects on body mass, food and drink intake in male and female Wistar rats.

The consumption of non-nutritive sweeteners has increased in the last decades. However, there are doubts about its consumption and its impact on body mass and metabolic alterations. For this reason, this study investigates the effects of the consumption of nutritive and non-nutritive sweeteners on body mass in different life stages of male and female Wistar rats: Childhood, adolescence, young adult, adulthood, and aged. For this purpose, 8 groups of male and female rats were used (10 per group/gender): sucrose 10%, glucose 14%, fructose 7%, acesulfame K 0.05%, aspartame:acesulfame mixture 1.55%, sucralose 0.017%, saccharin 0.033%, and a control group. Only in aged male rats (504 days) there were significant differences in body mass. In both genders, there were differences in food, drink, and energy intake along all life stage. It is concluded that non-nutritive sweeteners when consumed together with a balanced diet did not cause a greater body mass gain.

Chitosan from shrimp residues with a saturated solution of calcium chloride in methanol and water.

Calcium chloride, methanol, and water in stoichiometric amounts were used for the extraction of chitosan from shrimp residues (Farfantepenaeus aztecus). Chitosan was characterized by FT-IR, TGA, XRD, SEM, elemental analysis, and 13C-NMR. The yield of chitosan with medium molecular mass was 65.90% (mass of extracted chitosan/mass of shrimp residues when the extraction was assisted with stirring at 60 °C for 20 min and ultrasound at 60 °C for 30 min. The extracted chitosan had a % DD of 64.06 and 65.87% (13C-NMR and FT-IR, respectively), thermal decomposition stage at 375 °C, porous on its surface, and calcite as the main mineral found. The experimental results revealed that the saturated solution of calcium chloride in methanol and water could be an alternative for the extraction of mineralized chitosan from shrimp residues with thermal stability and porosity.