Hypothalamic free fatty acid receptor-1 regulates whole-body energy balance.

OBJECTIVE: Free fatty acid receptor-1 (FFAR1) is a medium- and long-chain fatty acid sensing G protein-coupled receptor that is highly expressed in the hypothalamus. Here, we investigated the central role of FFAR1 on energy balance. METHODS: Central FFAR1 agonism and virogenic knockdown were performed in mice. Energy balance studies, infrared thermographic analysis of brown adipose tissue (BAT) and molecular analysis of the hypothalamus, BAT, white adipose tissue (WAT) and liver were carried out. RESULTS: Pharmacological stimulation of FFAR1, using central administration of its agonist TUG-905 in diet-induced obese mice, decreases body weight and is associated with increased energy expenditure, BAT thermogenesis and browning of subcutaneous WAT (sWAT), as well as reduced AMP-activated protein kinase (AMPK) levels, reduced inflammation, and decreased endoplasmic reticulum (ER) stress in the hypothalamus. As FFAR1 is expressed in distinct hypothalamic neuronal subpopulations, we used an AAV vector expressing a shRNA to specifically knockdown Ffar1 in proopiomelanocortin (POMC) neurons of the arcuate nucleus of the hypothalamus (ARC) of obese mice. Our data showed that knockdown of Ffar1 in POMC neurons promoted hyperphagia and body weight gain. In parallel, these mice developed hepatic insulin resistance and steatosis. CONCLUSIONS: FFAR1 emerges as a new hypothalamic nutrient sensor regulating whole body energy balance. Moreover, pharmacological activation of FFAR1 could provide a therapeutic advance in the management of obesity and its associated metabolic disorders.

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.

Maternal obesity damages the median eminence blood-brain barrier structure and function in the progeny: the beneficial impact of cross-fostering by lean mothers.

Maternal obesity is an important risk factor for obesity, cardiovascular, and metabolic diseases in the offspring. Studies have shown that it leads to hypothalamic inflammation in the progeny, affecting the function of neurons regulating food intake and energy expenditure. In adult mice fed a high-fat diet, one of the hypothalamic abnormalities that contribute to the development of obesity is the damage of the blood-brain barrier (BBB) at the median eminence-arcuate nucleus (ME-ARC) interface; however, how the hypothalamic BBB is affected in the offspring of obese mothers requires further investigation. Here, we used confocal and transmission electron microscopy, transcript expression analysis, glucose tolerance testing, and a cross-fostering intervention to determine the impact of maternal obesity and breastfeeding on BBB integrity at the ME-ARC interface. The offspring of obese mothers were born smaller; conversely, at weaning, they presented larger body mass and glucose intolerance. In addition, maternal obesity-induced structural and functional damage of the offspring's ME-ARC BBB. By a cross-fostering intervention, some of the defects in barrier integrity and metabolism seen during development in an obesogenic diet were recovered. The offspring of obese dams breastfed by lean dams presented a reduction of body mass and glucose intolerance as compared to the offspring continuously exposed to an obesogenic environment during intrauterine and perinatal life; this was accompanied by partial recovery of the anatomical structure of the ME-ARC interface, and by the normalization of transcript expression of genes coding for hypothalamic neurotransmitters involved in energy balance and BBB integrity. Thus, maternal obesity promotes structural and functional damage of the hypothalamic BBB, which is, in part, reverted by lactation by lean mothers.NEW & NOTEWORTHY Maternal dietary habits directly influence offspring health. In this study, we aimed at determining the impact of maternal obesity on BBB integrity. We show that DIO offspring presented a leakier ME-BBB, accompanied by changes in the expression of transcripts encoding for endothelial and tanycytic proteins, as well as of hypothalamic neuropeptides. Breastfeeding in lean dams was sufficient to protect the offspring from ME-BBB disruption, providing a preventive strategy of nutritional intervention during early life.

Small extracellular vesicle targeting of hypothalamic AMPKα1 promotes weight loss in leptin receptor deficient mice.

BACKGROUND AND AIMS: Leptin receptor (LEPR) deficiency promotes severe obesity and metabolic disorders. However, the current therapeutic options against this syndrome are scarce. METHODS: db/db mice and their wildtypes were systemically treated with neuronal-targeted small extracellular vesicles (sEVs) harboring a plasmid encoding a dominant negative mutant of AMP-activated protein kinase alpha 1 (AMPKα1-DN) driven by steroidogenic factor 1 (SF1) promoter; this approach allowed to modulate AMPK activity, specifically in SF1 cells of the ventromedial nucleus of the hypothalamus (VMH). Animals were metabolically phenotyped. RESULTS: db/db mice intravenously injected with SF1-AMPKα1-DN loaded sEVs showed a marked feeding-independent weight loss and decreased adiposity, associated with increased sympathetic tone, brown adipose tissue (BAT) thermogenesis and browning of white adipose tissue (WAT). CONCLUSION: Overall, this evidence indicates that specific modulation of hypothalamic AMPK using a sEV-based technology may be a suitable strategy against genetic forms of obesity, such as LEPR deficiency.

Orally Induced Hyperthyroidism Regulates Hypothalamic AMP-Activated Protein Kinase.

Besides their direct effects on peripheral metabolic tissues, thyroid hormones (TH) act on the hypothalamus to modulate energy homeostasis. However, since most of the hypothalamic actions of TH have been addressed in studies with direct central administration, the estimation of the relative contribution of the central vs. peripheral effects in physiologic conditions of peripheral release (or administration) of TH remains unclear. In this study we used two different models of peripherally induced hyperthyroidism (i.e., T4 and T3 oral administration) to assess and compare the serum and hypothalamic TH status and relate them to the metabolic effects of the treatment. Peripheral TH treatment affected feeding behavior, overall growth, core body temperature, body composition, brown adipose tissue (BAT) morphology and uncoupling protein 1 (UCP1) levels and metabolic activity, white adipose tissue (WAT) browning and liver metabolism. This resulted in an increased overall uncoupling capacity and a shift of the lipid metabolism from WAT accumulation to BAT fueling. Both peripheral treatment protocols induced significant changes in TH concentrations within the hypothalamus, with T3 eliciting a downregulation of hypothalamic AMP-activated protein kinase (AMPK), supporting the existence of a central action of peripheral TH. Altogether, these data suggest that peripherally administered TH modulate energy balance by various mechanisms; they also provide a unifying vision of the centrally mediated and the direct local metabolic effect of TH in the context of hyperthyroidism.

Small extracellular vesicle-mediated targeting of hypothalamic AMPKα1 corrects obesity through BAT activation.

Current pharmacological therapies for treating obesity are of limited efficacy. Genetic ablation or loss of function of AMP-activated protein kinase alpha 1 (AMPKα1) in steroidogenic factor 1 (SF1) neurons of the ventromedial nucleus of the hypothalamus (VMH) induces feeding-independent resistance to obesity due to sympathetic activation of brown adipose tissue (BAT) thermogenesis. Here, we show that body weight of obese mice can be reduced by intravenous injection of small extracellular vesicles (sEVs) delivering a plasmid encoding an AMPKα1 dominant negative mutant (AMPKα1-DN) targeted to VMH-SF1 neurons. The beneficial effect of SF1-AMPKα1-DN-loaded sEVs is feeding-independent and involves sympathetic nerve activation and increased UCP1-dependent thermogenesis in BAT. Our results underscore the potential of sEVs to specifically target AMPK in hypothalamic neurons and introduce a broader strategy to manipulate body weight and reduce obesity.

Mechanisms Mediating the Actions of Fatty Acids in the Hypothalamus.

Selected neurons of the hypothalamus are equipped with molecules specialized in sensing the energy status of the organism. Upon activation or inhibition by central and systemic factors, such as neurotransmitters, hormones, cytokines, and nutrients, these molecules play important roles in the regulation of neuronal responses that control whole-body energy homeostasis. Dietary fats can control hypothalamic function by acting upon distinct energy sensing systems. They can be metabolized inside neurons, producing signals that control the expression of neurotransmitters involved in energy homeostasis; moreover, excessive amounts of certain fatty acids can activate inflammatory signaling in microglia, astrocytes, and neurons, leading to functional abnormalities and, eventually, neuronal apoptosis. In addition, recent studies have identified lipid-sensing G-protein-coupled receptors in the hypothalamus, revealing their involvement in the regulation of caloric intake and energy expenditure, as well as in the hypothalamic inflammatory response that occurs in obesity. Because of advances in the generation of synthetic ligands for this class of receptors, it is expected that pharmacological modulation of selected lipid-sensing G-protein-coupled receptors in the central nervous system could provide therapeutic advances in obesity and other metabolic diseases. Here we review seminal work in this field.

Hypothalamic expression of the atypical chemokine receptor ACKR2 is involved in the systemic regulation of glucose tolerance.

In experimental obesity, the hypothalamus is affected by an inflammatory response activated by dietary saturated fats. This inflammation is triggered as early as one day after exposure to a high-fat diet, and during its progression, there is recruitment of inflammatory cells from the systemic circulation. The objective of the present study was identifying chemokines potentially involved in the development of hypothalamic diet-induced inflammation. In order to identify chemokines potentially involved in this process, we performed a real-time PCR array that determined Ackr2 as one of the transcripts undergoing differential regulation in obese-prone as compared to obese-resistant mice fed a high-fat diet for three days. ACKR2 is a decoy receptor that acts as an inhibitor of the signals generated by several CC inflammatory chemokines. Our results show that Ackr2 expression is rapidly induced after exposure to dietary fats both in obese-prone and obese-resistant mice. In immunofluorescence studies, ACKR2 was detected in hypothalamic neurons expressing POMC and NPY and also in microglia and astrocytes. The lentiviral overexpression of ACKR2 in the hypothalamus reduced diet-induced hypothalamic inflammation; however, there was no change in spontaneous caloric intake and body mass. Nevertheless, the overexpression of ACKR2 resulted in improvement of glucose tolerance, which was accompanied by reduced insulin secretion and increased whole body insulin sensitivity. Thus, ACKR2 is a decoy chemokine receptor expressed in most hypothalamic cells that is modulated by dietary intervention and acts to reduce diet-induced inflammation, leading to improved glucose tolerance due to improved insulin action.

Inhibition of hypothalamic leukemia inhibitory factor exacerbates diet-induced obesity phenotype.

BACKGROUND: The consumption of large amounts of dietary fats can trigger an inflammatory response in the hypothalamus and contribute to the dysfunctional control of caloric intake and energy expenditure commonly present in obesity. The objective of this study was to identify chemokine-related transcripts that could be involved in the early stages of diet-induced hypothalamic inflammation. METHODS: We used immunoblot, PCR array, real-time PCR, immunofluorescence staining, glucose and insulin tolerance tests, and determination of general metabolic parameters to evaluate markers of inflammation, body mass variation, and glucose tolerance in mice fed a high-fat diet. RESULTS: Using a real-time PCR array, we identified leukemia inhibitory factor as a chemokine/cytokine undergoing a rapid increase in the hypothalamus of obesity-resistant and a rapid decrease in the hypothalamus of obesity-prone mice fed a high-fat diet for 1 day. We hypothesized that the increased hypothalamic expression of leukemia inhibitory factor could contribute to the protective phenotype of obesity-resistant mice. To test this hypothesis, we immunoneutralized hypothalamic leukemia inhibitory factor and evaluated inflammatory and metabolic parameters. The immunoneutralization of leukemia inhibitory factor in the hypothalamus of obesity-resistant mice resulted in increased body mass gain and increased adiposity. Body mass gain was mostly due to increased caloric intake and reduced spontaneous physical activity. This modification in the phenotype was accompanied by increased expression of inflammatory cytokines in the hypothalamus. In addition, the inhibition of hypothalamic leukemia inhibitory factor was accompanied by glucose intolerance and insulin resistance. CONCLUSION: Hypothalamic expression of leukemia inhibitory factor may protect mice from the development of diet-induced obesity; the inhibition of this protein in the hypothalamus transforms obesity-resistant into obesity-prone mice.

Polyunsaturated fatty acid receptors, GPR40 and GPR120, are expressed in the hypothalamus and control energy homeostasis and inflammation.

BACKGROUND: The consumption of large amounts of dietary fats is one of the most important environmental factors contributing to the development of obesity and metabolic disorders. GPR120 and GPR40 are polyunsaturated fatty acid receptors that exert a number of systemic effects that are beneficial for metabolic and inflammatory diseases. Here, we evaluate the expression and potential role of hypothalamic GPR120 and GPR40 as targets for the treatment of obesity. METHODS: Male Swiss (6-weeks old), were fed with a high fat diet (HFD, 60% of kcal from fat) for 4 weeks. Next, mice underwent stereotaxic surgery to place an indwelling cannula into the right lateral ventricle. intracerebroventricular (icv)-cannulated mice were treated twice a day for 6 days with 2.0 µL saline or GPR40 and GPR120 agonists: GW9508, TUG1197, or TUG905 (2.0 µL, 1.0 mM). Food intake and body mass were measured during the treatment period. At the end of the experiment, the hypothalamus was collected for real-time PCR analysis. RESULTS: We show that both receptors are expressed in the hypothalamus; GPR120 is primarily present in microglia, whereas GPR40 is expressed in neurons. Upon intracerebroventricular treatment, GW9508, a non-specific agonist for both receptors, reduced energy efficiency and the expression of inflammatory genes in the hypothalamus. Reducing GPR120 hypothalamic expression using a lentivirus-based approach resulted in the loss of the anti-inflammatory effect of GW9508 and increased energy efficiency. Intracerebroventricular treatment with the GPR120- and GPR40-specific agonists TUG1197 and TUG905, respectively, resulted in milder effects than those produced by GW9508. CONCLUSIONS: GPR120 and GPR40 act in concert in the hypothalamus to reduce energy efficiency and regulate the inflammation associated with obesity. The combined activation of both receptors in the hypothalamus results in better metabolic outcomes than the isolated activation of either receptor alone.

Leptin, Neuroinflammation and Obesity.

Hypothalamic resistance to adipostatic actions of leptin is a hallmark of obesity. Studies have revealed that hypothalamic inflammation, triggered in response to the consumption of large amounts of dietary fat, is an important mechanism in the development of leptin resistance. In this chapter, we will review the work that paved the way linking neuroinflammation of the hypothalamus and defective leptin action in obesity.

Passiflora edulis peel intake improves insulin sensitivity, increasing incretins and hypothalamic satietogenic neuropeptide in rats on a high-fat diet.

OBJECTIVE: This study aimed to investigate the effect of Passiflora edulis peel flour (PEPF) intake on hypothalamic neuropeptides messenger RNA expression, insulin sensitivity, and other metabolic parameters in Sprague-Dawley rats fed a high-fat (HF) diet. METHODS: Sprague-Dawley rats were divided in 3 groups: a control group, fed on a normal fat diet; a HF group, fed on a high-fat diet (35% fat [w/w]); and a high-fat Passiflora flour (HFPF) group, fed on a HF diet containing PEPF. The rats from the HFPF group as well as the HF group were kept on an HF diet for the first 4 wk to induce metabolic conditions related to obesity. Then the HFPF group was switched to a HF diet containing PEPF for additional 6 wk. Other groups were kept on normal-fat and HF diet without addition of PEPF during the whole period of experiment. The glucose tolerance and insulin sensitivity were evaluated through the glucose tolerance test (GTT) and the insulin tolerance test (ITT). Gut hormones and adipokines were measured through an immunoassay. The hypothalamic neuropeptides expression was assessed by real-time polymerase chain reaction. RESULTS: The PEPF intake increased the hypothalamic cocaine- and amphetamine-regulated transcript expression (CART) (P < 0.05), counteracted cumulative body weight gain (P < 0.001), decreased adiposity (P < 0.05) and leptin level (P < 0.01), whereas increased adiponectin (P < 0.01), glucose-dependent insulinotropic polypeptide (P < 0.01), and glucagon-like peptide-1 (GLP-1) (P < 0.001) improved the insulin sensitivity in diet-induced obesity rats by increasing the kITT (glucose disappearance rate) (P < 0.01), which was calculated during the ITT. Other gut hormones (peptide tyrosine tyrosine, pancreatic polypeptide, and amylin) and interleukins (IL) (IL-6, tumor necrosis factor-α, IL-1ß, and monocyte chemoattractant protein-1) were not changed by the PEPF intake. CONCLUSION: Our findings provide a further understanding of how the PEPF works as a dietary component to improve glucose homeostasis and demonstrate a molecular mechanism that may increase satiety by PEPF in diet-induced obesity.

Freeze-dried jaboticaba peel powder improves insulin sensitivity in high-fat-fed mice.

The peel of the native Brazilian fruit jaboticaba is rich in anthocyanins, which are known for their anti-obesity effects in animal models. The aim of the present study was to evaluate the effects of freeze-dried jaboticaba peel powder (FDJPP) on a number of metabolic parameters in a model of diet-induced obesity. Mice (n 8 per group) were initially fed on a high-fat diet (HFD, 35% w/w) for 4 weeks and then switched to a HFD supplemented with FDJPP (1, 2 or 4% w/w) for an additional 6 weeks. Energy intake, weight loss, glucose tolerance, insulin resistance and lipid profile were determined, and the results were evaluated using ANOVA and Tukey's tests. The FDJPP exerted no protective effect on HFD-induced weight gain, hyperleptinaemia and glucose intolerance. However, the supplementation was effective to reduce insulin resistance, as evidenced in the insulin tolerance test, and subsequently confirmed by improved signal transduction through the insulin receptor/insulin receptor substrate-1/Akt/forkhead box protein pathway and by the attenuation of HFD-induced inflammation in the liver, verified by lower expressions of IL-1b and IL-6 and decreased phosphorylated IkB-a protein levels in all jaboticaba-treated mice. These results suggest that FDJPP may exert a protective role against obesity-associated insulin resistance.

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.

La cáscara de jaboticaba liofilizada, una rica fuente de antocianinas, no influyó en la ganancia de peso ni en el contenido de lípidos en roedores La jaboticaba, una fruta nativa de la Selva Atlántica de Brasil, es una fuente importante de antocianinas. Las antocianinas han sido recientemente identificadas como moduladoras del metabolismo de lípidos y del gasto energético en vivo. Este estudio tuvo como objetivo evaluar el uso de la cáscara de jaboticaba liofilizada en polvo en el tratamiento de la obesidad, en distintos modelos experimentales. Ratones Swiss y ratas Sprague-Dawley obesos, recibieron dietas con alto contenido de grasas, a las que se añadió 1, 2 y 4% de cáscara de jaboticaba en polvo, durante 6 semanas. Se determinó el consumo de energía, el aumento de peso y la composición corporal de los animales, y los resultados fueron sometidos a análisis de varianza y prueba de Tukey, con p <0,05. El consumo de energía fue superior en los grupos de ratones Swiss de los grupos con 2% y 4% de cáscara de jaboticaba. En el aumento del peso, los ratones Swiss del grupo con 2% de piel de jaboticaba aumentaron más en peso total comparados a los otros grupos experimentales; mientras que no se observaron diferencias significativas entre los grupos respecto a la composición de la masa grasa. Entre los grupos de ratas Sprague-Dawley no se dieron diferencias significativas en ninguno de los parámetros evaluados. Por lo tanto, se concluye que la adición de 1, 2 y 4% de cáscara de jaboticaba liofilizada, a la dieta, no fue eficaz para el tratamiento de la obesidad, tanto en ratones Swiss como en ratas Sprague-Dawley.

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.

In vivo antimutagenic properties of transgenic and conventional soybeans.

The goal of the this study was to evaluate the mutagenic/antimutagenic effects of conventional (BRS133) and transgenic (BRS 245 RR) soybeans (CS and TS, respectively) in vivo using the bone marrow micronucleus (MN) test, histopathological analysis, chromosome aberration test (CAT), and mitotic index (MI) determination. Six-week-old male Swiss mice were fed with pelleted commercial diet mixed with CS or TS at 10% or 20%. Two experimental designs (MN and CAT) were conducted simultaneously with 10 groups each during a 15-day period. Animals were treated with pelleted commercial diet, CS (10% or 20%), or TS (10% or 20%), and on day 14 they also received cyclophosphamide (CP) (50 mg/kg i.p.). The 10% and 20% CS and TS diets did not significantly decrease the frequencies of micronucleated polychromatic erythrocytes in bone marrow induced by CP. However, the CAT indicated that the 10% and 20% CS diets significantly (P < .05) protected nucleated bone marrow cells against chemical-induced mutagenesis and also produced a significant (P < .05) decrease in the total percentage of spontaneous aberrations. Among the treatments with TS, only the 10% TS diet reduced the percentage of total aberrations induced by CP. The results also indicated that the treatment with 20% TS alone significantly (P < .05) decreased the MI, indicating cytotoxic effects related to the treatment. Taken together, our results suggest that, under the tested conditions, TS and CS have antimutagenic properties and are not toxic.

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.