Hypothalamic astrocytic-BMAL1 regulates energy homeostasis in a sex-dependent manner.

Here, we demonstrate that hypothalamic astrocytic BMAL1 computes cyclic metabolic information to optimize energetic resources in a sexually dimorphic manner. Knockdown of BMAL1 in female astrocytes leads to negative energy balance and alters basal metabolic cycles without affecting circadian locomotor activity. Thus, astrocytic BMAL1 contributes to the control of energy balance through the modulation of the metabolic rate, hepatic and white adipose tissue lipogenesis, and the activity of brown adipose tissue. Importantly, most of these alterations are specific to hypothalamic astrocytic BMAL1. Moreover, female mice with BMAL1 knockdown in astrocytes exhibited a "male-like" metabolic obese phenotype when fed a high-fat diet. Overall, our results suggest a sexually dimorphic effect of astrocytic BMAL1 on the regulation of energy homeostasis, which may be of interest in the physiopathology of obesity and related comorbidities.

Redução do peso e da glicemia resultante da suplementação de ácido linoleico conjugado e fitosteróis à dieta hiperlipídica de camundongos / Weight and blood glucose reduction resulting from conjugated linoleic acid and phytosterols supplementation on hiperlipidic diets of mice

O objetivo deste estudo foi avaliar as possíveis alterações causadas pela ingestão de ácido linoleico conjugado (CLA) e de fitosteróis no ganho de peso, na glicemia e no perfil lipídico de camundongos alimentados com dieta hiperlipídica. Durante nove semanas, vinte e cinco camundongos Swiss machos receberam dietas hiperlipídicas suplementadas com CLA e/ou fitosteróis, na concentração de 2 por cento. Foram aferidos consumo alimentar, ganho de peso, glicemia em jejum, além dos níveis séricos de colesterol total, triglicérides, HDL colesterol e ácidos graxos livres. O grupo suplementado com CLA e fitosteróis apresentou menor ganho de peso e bom controle glicêmico, quando comparado aos demais grupos. Os resultados encontrados incentivam a continuação de pesquisas que investiguem os efeitos biológicos causados pela suplementação concomitante de CLA e fitosteróis, com possível aplicação na indústria de alimentos.

The aim of this study was to evaluate the possible changes caused by conjugated linoleic acid (CLA) and phytosterols intake in weight gain, blood glucose levels and lipid profile on mice fed with high fat diet. Twenty-five male Swiss mice received for nine weeks high fat diets supplemented with 2 percent of CLA and/or phytosterols. Feed intake, weight gain, blood glucose, total cholesterol, triglycerides, HDL cholesterol and free fatty acids were determined. The group supplemented with CLA and phytosterols gained less weight and showed better glycemic control compared to other groups. The results encourage further research to investigate the biological effects caused by supplementation of CLA and phytosterols, with possible application in food industry.

Freeze-dried jaboticaba peel powder rich in anthocyanins did not reduce weight gain and lipid content in mice and rats.

Jaboticaba, a native fruit from Brazilian Atlantic Forest, is an important source of anthocyanins. Anthocyanins have been recently identified as modulators of lipid metabolism and energy expenditure 'in vivo'. The purpose of this study was to evaluate the effect of the freeze-dried jaboticaba peel powder on obesity treatment in different experimental models. Obese Swiss mice and obese Sprague-Dawley rats were fed a high-fat diet supplemented with 1, 2 and 4% freeze-dried jaboticaba peel powder for 6 weeks. Energy intake, weight gain and body composition were determined, and the results were analyzed using variance and Tukey's tests (p < 0.05). The energy intake was higher in mice groups supplemented with 2% and 4% of jaboticaba peel. In relation to weight gain, the mice supplemented with 2% of jaboticaba peel had higher total weight gain than the other experimental groups, while no significant difference in the fat mass accumulation was observed among the groups. The rats did not show significant differences in the evaluated parameters. These results suggest that the supplementation with freeze-dried jaboticaba peel powder, at concentrations of 1, 2 and 4%, was not effective in the reduction of energy intake, weight gain and body fat both in mice and in rats.

Influence of Marolo (Annona crassiflora Mart.) pulp intake on the modulation of mutagenic/antimutagenic processes and its action on oxidative stress in vivo.

Brazilian savanna constitutes a valuable ecoregion that contributes to the supply of fruit known worldwide for its nutritional value and peculiar flavors. Among them, the Marolo (Annona crassiflora Mart.) fruit is known for its use in folk medicine. In order to establish the safety of Marolo for human consumption, this study evaluated the following: the chemical composition of Marolo pulp; its mutagenic and antimutagenic activities using micronucleus test; and the oxidative stress induced in the livers of mice fed a diet containing 1%, 10% or 20% pulp. It was observed that the chemical composition of marolo pulp was similar to that of common fruit; nevertheless, its lipidic content and energetic values were higher. In the mice fed experimental diets, the biochemical parameters of the blood serum showed normal levels of glucose, triglycerides, and cholesterol. The micronucleus test indicated neither mutagenic nor antimutagenic effects of Marolo consumption on bone marrow cells but showed potentialization of cyclophosphamide (CP). The oxidative stress levels observed indicated that CP was not exerting a great influence on the induction of reactive oxygen species. As the whole fruit is a complex matrix, the interactions between its components could be responsible for its negative and positive biological effects.