Jabuticaba (Myrciaria trunciflora) extract improves metabolic and behavioral markers of obese rats fed on a hypercaloric diet.

BACKGROUND: Obesity is a metabolic disease that affects many individuals around the world, related to imbalance between energy consumption and expenditure, which can lead to comorbidities. A healthy diet can significantly contribute to the prevention or treatment of this condition. Jabuticaba is an emerging fruit presenting a wide range of bioactive compounds and is being extensively studied due to its effects on lipid metabolism. The aim of this study was to evaluate the jabuticaba extract in the anxious-like behavior and in the lipid and oxidative metabolism in the context of obesity. METHODS: Forty male Wistar rats divided into five groups were used. The animals received a standard diet and/or a hypercaloric diet and after 60 days of induction, interventions were carried out with jabuticaba extract (5% and 10%) via gavage for 30 days. RESULTS: It can be observed that the jabuticaba extract was able to reverse the anxious behavior observed in obese animals and modulate parameters of lipid and oxidative metabolism. We observed a reduction in cholesterol and triglyceride levels compared to obese animals. Furthermore, we observed an improvement in oxidative parameters, with a reduction in protein carbonylation in the liver and modulation of antioxidant enzymes such as superoxide dismutase and catalase. Contrary to expectations, we did not observe changes in leptin, adiponectin and tumor necrosis factor alpha (TNF-α) levels. CONCLUSION: Our work demonstrates that jabuticaba extract can improve metabolic, oxidative and behavioral changes in animals with obesity. © 2024 Society of Chemical Industry.

Diethylnitrosamine-Induced Liver Tumorigenesis in Mice Under High-Hat High-Sucrose Diet: Stepwise High-Resolution Ultrasound Imaging and Histopathological Correlations.

The hepatotoxic N-nitroso compound diethylnitrosamine (DEN) administered intraperitoneally (i.p.) induces liver neoplasms in rodents that reproducibly recapitulate some aspects of human hepatocarcinogenesis. In particular, DEN drives the stepwise formation of pre-neoplastic and neoplastic (benign or malignant) hepatocellular lesions reminiscent of the initiation-promotion-progression sequence typical of chemical carcinogenesis. In humans, the development of hepatocellular carcinoma (HCC) is also a multi-step process triggered by continuous hepatocellular injury, chronic inflammation, and compensatory hyperplasia that fuel the emergence of dysplastic liver lesions followed by the formation of early HCC. The DEN-induced liver tumorigenesis model represents a versatile preclinical tool that enables the study of many tumor development modifiers (genetic background, gene knockout or overexpression, diets, pollutants, or drugs) with a thorough follow-up of the multistage process on live animals by means of high-resolution imaging. Here, we provide a comprehensive protocol for the induction of hepatocellular neoplasms in wild-type C57BL/6J male mice following i.p. DEN injection (25 mg/kg) at 14 days of age and 36 weeks feeding of a high-fat high-sucrose (HFHS) diet. We emphasize the use of ultrasound liver imaging to follow tumor development and provide histopathological correlations. We also discuss the extrinsic and intrinsic factors known to modify the course of liver tumorigenesis in this model.

Signs of Glucagon Resistance After a 2-Week Hypercaloric Diet Intervention.

CONTEXT: Hyperglucagonemia is observed in individuals with obesity and contributes to the hyperglycemia of patients with type 2 diabetes. Hyperglucagonemia may develop due to steatosis-induced hepatic glucagon resistance resulting in impaired hepatic amino acid turnover and ensuing elevations of circulating glucagonotropic amino acids. OBJECTIVE: We evaluated whether glucagon resistance could be induced in healthy individuals by a hypercaloric diet intervention designed to increase hepatic fat content. METHODS: We recruited 20 healthy male individuals to follow a hypercaloric diet and a sedentary lifestyle for 2 weeks. Amino acid concentrations in response to infusion of glucagon were assessed during a pancreatic clamp with somatostatin and basal insulin. The reversibility of any metabolic changes was assessed 8 weeks after the intervention. Hepatic steatosis was assessed by magnetic resonance spectroscopy. RESULTS: The intervention led to increased hepatic fat content (382% [206%; 705%], P < .01). Glucagon infusion led to a decrease in the concentration of total amino acids on all experimental days, but the percentage change in total amino acids was reduced (-2.5% ± 0.5% vs -0.2% ± 0.7%, P = .015) and the average slope of the decline in the total amino acid concentration was less steep (-2.0 ± 1.2 vs -1.2 ± 0.3 µM/min, P = .016) after the intervention compared to baseline. The changes were normalized at follow-up. CONCLUSION: Our results indicate that short-term unhealthy behavior, which increases hepatic fat content, causes a reversible resistance to the effect of glucagon on amino acid concentrations in healthy individuals, which may explain the hyperglucagonemia associated with obesity and diabetes.

Effects of carnosine supplementation on markers for the pathophysiological development of metabolic dysfunction-associated steatotic liver disease in a diet-induced model.

Consumption of diets high in sugar and fat is related to the development of Metabolic dysfunction-associated steatotic liver disease (MASLD). Carnosine (CAR) is a dipeptide with antioxidant and anti-inflammatory action and has been studied for treating diseases. This work aimed to evaluate the effects of CAR on diet-induced MASLD in rats. Male Wistar rats were distributed into 2 groups (17 weeks): normocaloric (Co, n = 12), and hypercaloric diet rich in lipids and simple carbohydrates (MASLD, n = 12). After, the animals were redistributed to begin the treatment with CAR (4 weeks): Co (n = 6), Co + CAR (n = 6), MASLD (n = 6), and MASLD + CAR (n = 6), administered intraperitoneally (250 mg/kg). Evaluations included nutritional, hormonal and metabolic parameters; hepatic steatosis, inflammatory and oxidative markers. MASLD group had a higher adiposity index, systolic blood pressure, glucose, plasma and liver triglycerides and cholesterol, insulin, hepatic steatosis, oxidative markers, and lower PPAR-α (Peroxisome Proliferator-activated receptor α), compared to the Co. CAR attenuated plasma and hepatic triglyceride and cholesterol levels, hepatic steatosis, CD68+ macrophages, and hepatic oxidative markers, in addition to increasing HDL cholesterol levels and PPAR-α, compared to the untreated MASLD group. CAR acts in importants pathophysiological processes of MASLD and may be a therapeutic compound to control the disease.

Effect of Low-Dose Progesterone on Glycemic Metabolism, Morphology and Function of Adipose Tissue and Pancreatic Islets in Diet-Induced Obese Female Mice.

BACKGROUND: Obesity is a worldwide concern due to its global rapid expansion and remarkable impact on individual's health by predisposing to several other diseases. About twice as many women as men suffer from severe obesity and, in fact, there are stages in a woman's life when weight gain and adiposity can result in greater damage to health. For example, obesity triples the chance of a woman developing gestational diabetes. Many hormones promote the metabolic adaptations of pregnancy, including progesterone, whose role in female obesity is still not well known despite being involved in many physiological and pathological processes. METHODS: Here we investigated whether progesterone treatment at low dose can worsen the glucose metabolism and the morpho functional aspects of adipose tissue and pancreas in obese females. Mice were assigned into four groups: normocaloric diet control (NO-CO), high-fat and -fructose diet control (HFF-CO), normocaloric diet plus progesterone (NO-PG) and high-fat and -fructose diet plus progesterone (HFF-PG) for 10 weeks. Infusion of progesterone (0.25 mg/kg/day) was done by osmotic minipump in the last 21 days of protocol. RESULTS: Animals fed a hypercaloric diet exhibited obesity with increased body weight (p < 0.0001), adipocyte hypertrophy (p < 0.0001), hyperglycemia (p = 0.03), and glucose intolerance (p = 0.001). HFF-CO and HFF-PG groups showed lower adiponectin concentration (p < 0.0001) and glucose-stimulated insulin secretion (p = 0.03), without differences in islet size. Progesterone attenuated glucose intolerance in the HFF-PG group (p = 0.03), however, did not change morphology or endocrine function of adipose tissue and pancreatic islets. CONCLUSIONS: Taken together, our results showed that low dose of progesterone does not worsen the effects of hypercaloric diet in glycemic metabolism, morphology and function of adipose tissue and pancreatic islets in female animals. These results may improve the understanding of the mechanisms underlying the pathogenesis of obesity in women and eventually open new avenues for therapeutic strategies and better comprehension of the interactions between progesterone effects and obesity.

Chemical Characterization, Antilipidemic Effect and Anti-Obesity Activity of Ludwigia octovalvis in a Murine Model of Metabolic Syndrome.

Ludwigia octovalvis (Jacq.) P.H. Raven is widely used in traditional medicine for different illnesses, including diabetes and hypertension. However, its impact on lipotoxicity and metabolic syndrome in vivo has not been addressed. Therefore, the aim of this study was to evaluate the effects of this plant on the metabolic syndrome parameters in a C57BL6J mouse hypercaloric diet model. L. octovalvis hydroalcoholic extract and its ethyl acetate fraction (25 mg/kg/day) were used for sub-chronic assessment (10 weeks). Additionally, four subfractions (25 mg/kg) were evaluated in the postprandial triglyceridemia test in healthy C57BL6J mice. The hydroalcoholic extract and ethyl acetate fraction significantly decreased body weight gain (-6.9 g and -1.5 g), fasting glycemia (-46.1 and -31.2 mg/dL), systolic (-26.0 and -22.5 mmHg) and diastolic (-8.1 and 16.2 mmHg) blood pressure, free fatty acid concentration (-13.8 and -8.0 µg/mL) and insulin-resistance (measured by TyG index, -0.207 and -0.18), compared to the negative control. A postprandial triglyceridemia test showed that the effects in the sub-chronic model are due, at least in part, to improvement in this parameter. L. octovalvis treatments, particularly the hydroalcoholic extract, improve MS alterations and decrease free fatty acid concentration. These effects are possibly due to high contents of corilagin and ellagic acid.

Neonatal hyperoxia leads to white adipose tissue remodeling and susceptibility to hypercaloric diet.

Individuals born preterm are at higher risk of cardiovascular and metabolic diseases in adulthood, through mechanisms not completely understood. White adipose tissue in humans and rodents is a dynamic endocrine organ and a critical player in the regulation of metabolic homeostasis. However, the impact of preterm birth on white adipose tissue remains unknown. Using a well-established rodent model of preterm birth-related conditions in which newborn rats are exposed during postnatal days 3-10 to 80% of oxygen, we evaluated the impact of transient neonatal hyperoxia on adult perirenal white adipose tissue (pWAT) and liver. We further assessed the effect of a second hit with a high-fat high-fructose hypercaloric diet (HFFD). We evaluated 4-month-old adult male rats after 2 months of HFFD. Neonatal hyperoxia led to pWAT fibrosis and macrophage infiltration without modification in body weight, pWAT weight, or adipocyte size. In animals exposed to neonatal hyperoxia vs. room air control, HFFD resulted in adipocyte hypertrophy, lipid accumulation in the liver, and increased circulating triglycerides. Overall, preterm birth-related conditions had long-lasting effects on the composition and morphology of pWAT, along with a higher susceptibility to the deleterious impact of a hypercaloric diet. These changes suggest a developmental pathway to long-term metabolic risk factors observed clinically in adults born preterm through programming of white adipose tissue.

Effects of different maternal diets on adipose tissue inflammation and liver tissue oxidative stress in dams and their female offspring.

Pregnancy and lactation are important stages of fetal development. Therefore, this study investigated how different maternal diets offered during gestation and lactation periods affect adipose tissue inflammation and liver tissue oxidative stress of dams and their female offspring. Female BALB/c albino mice (60 days old) were randomized into three groups receiving a standard (CONT), hypercaloric (HD), or restricted (RD) diet during the pregnancy. After birth, female offspring weaned at 21 days were divided into two groups that received a standard or restricted diet (CONT/CONT, CONT/RD, RD/CONT, RD/RD, HD/CONT, and HD/RD) until 100 days old. Histological, oxidative parameters and inflammatory infiltrate of dams' and offspring's liver and adipose tissue were evaluated. HD dams presented non-alcoholic steatohepatitis (NASH) diagnosis and an increase in tumor necrosis factor-alpha (TNF-α) concentrations when compared to the RD and CONT dams, indicating a pro-inflammatory state. High concentrations of malondialdehyde (MDA) formation and catalase (CAT) activity in HD when compared to the CONT in the liver. SOD activity decreased in RD mice compared to CONT, and the SOD/CAT ratio was decreased in the RD and HD in comparison to the CONT. The maternal diet leads to an increase in SOD in RD/RD compared to HD/RD. RD-fed dams showed an increase in inflammatory infiltrates compared to CONT, evidencing changes caused by a restrictive diet. In the HD/CONT offspring, we verified an increase in inflammatory infiltrates in relation to the offspring fed a standard diet. In conclusion, HD, and RD, during pregnancy and lactation, altered the liver and adipose tissues of mothers. Furthermore, the maternal diet negatively impacts the offspring's adipose tissue but does not cause liver damage in these animals in adult life.

Short-term Cafeteria Diet Is Associated with Fat Mass Accumulation, Systemic and Amygdala Inflammation, and Anxiety-like Behavior in Adult Male Wistar Rats.

Obesity is linked to metabolic, hormonal and biochemical alterations, and is also a risk factor for behavioral disorders. Evidence suggests that these disorders may be related to the consumption of hypercaloric diets, fat mass accumulation and changes in inflammation and redox status. Although much is known about the chronic effects of hypercaloric diets on mental health, few studies have evaluated the consequences of short-term exposure of these diets on behavior. The aim of this study was to evaluate nutritional, behavioral (anxiety-like), inflammatory and redox status parameters in adult male Wistar rats exposed to short-term cafeteria diet. Adult Wistar male rats (90 days-old; n = 12/group) received, during 14 days, the diets: Control- standard diet; Simple Cafeteria Diet (SCD)- homogeneous cafeteria diet. Varied Cafeteria Diet (VCD)- cafeteria diet with rotation and variation. Nutritional analyzes and tests for anxiety-like behaviors were performed, in addition to inflammatory and redox status measurements in blood and amygdala. The SCD group showed higher fat energy intake, while the VCD group consumed more energy from carbohydrates. SCD and VCD showed higher fat mass accumulation, in addition to higher levels of TNFα, INFγ, TBARS and FRAP in the blood. Also, SCD and VCD groups reported high levels of TNFα in the amygdala. Regarding behavioral evaluations, SCD and VCD groups showed anxiogenesis in the elevated plus maze, light-dark box, and open field tests. Therefore, the two cafeteria diets induced obesity and systemic inflammation, which in turn, resulted in an increase in amygdala TNFα levels and anxiety-like behaviors in Wistar rats.

Diet triggers specific responses of hypothalamic astrocytes in time and region dependent manner.

Hypothalamic astrocytes are particularly affected by energy-dense food consumption. How the anatomical location of these glial cells and their spatial molecular distribution in the arcuate nucleus of the hypothalamus (ARC) determine the cellular response to a high caloric diet remains unclear. In this study, we investigated their distinctive molecular responses following exposure to a high-fat high-sugar (HFHS) diet, specifically in the ARC. Using RNA sequencing and proteomics, we showed that astrocytes have a distinct transcriptomic and proteomic profile dependent on their anatomical location, with a major proteomic reprogramming in hypothalamic astrocytes. By ARC single-cell sequencing, we observed that a HFHS diet dictates time- and cell- specific transcriptomic responses, revealing that astrocytes have the most distinct regulatory pattern compared to other cell types. Lastly, we topographically and molecularly characterized astrocytes expressing glial fibrillary acidic protein and/or aldehyde dehydrogenase 1 family member L1 in the ARC, of which the abundance was significantly increased, as well as the alteration in their spatial and molecular profiles, with a HFHS diet. Together, our results provide a detailed multi-omics view on the spatial and temporal changes of astrocytes particularly in the ARC during different time points of adaptation to a high calorie diet.