Cardioprotective effect of the quercetin on cardiovascular remodeling and atherosclerosis in rodents fed a high-fat diet: A systematic review.

Cardiovascular diseases (CVD) are the leading cause of death globally, estimated at 17.9 million premature deaths. Several risk factors contribute to the development of CVD, including unhealthy diet rich in saturated fat. Quercetin (Q) is a important natural flavonoid with cardioprotective effect. However, it is crucial to understand and clarify which dosages and intervention times quercetin promotes better cardioprotective effects when exposed to a High-Fat Diet (HFD). We aim was to carry out a review to identify and compare experimental studies that investigated the quercetin effect on cardiac parameters in rodents fed a HFD. This literature search was performed through the specialized databases PubMed, Embase, Web of Science and Lilacs in May 2022. The following information was collected and assessed: Species of animals, dietary fat content, intervention protocol (quercetin), and main results of alterations associated with cardiac change. A total of 116 articles were selected from the database and 30 articles were included in this study. The administration form of quercetin was used in the diet supplemented in 73.4% (n = 22) of the studies. The dosage ranged between 10 and 100 mg/kg, 0.01%-0.36%, and 4-8 g/kg diet. The treatment time ranged between 14 and 63 days in 48.4% studies and most of the selected studies observed changes in the: Serum concentrations of lipids (60%, n = 18) mainly decrease in TC and TG, left ventricle (LV) (16.13%, n = 5) includes attenuation of the cardiac hypertrophy; inhibition of atherosclerotic progression (32%, n = 10) with decrease in lesions and plaque formation; improvement in the expression of gene and protein associated with cardiac functionality and oxidative stress (51.6%; n = 16). Quercetin supplementation at different concentrations/doses promotes important cardioprotective effects in experimental models exposed to a HFD. The supplemented diet was shown to be the better administration option. The methodological variation presented in the articles selected in this review proves that the most appropriate intervention protocol, as well as the most effective route of administration, promotes these effects.

Effects of a high-fat diet on the bone structure of Wistar rats: a systematic review.

CONTEXT: Saturated fats found in diets known as high-fat, cafeteria, or Western diets appear to have a negative effect on bone structure; however, few studies have focused on investigating this association, and the data available in the literature remain controversial. OBJECTIVE: The aim of the current review was to investigate the effects of a high-fat dietary intake on the bone structure of Wistar rats. DATA SOURCES: A search for articles was carried out in the Pubmed/MEDLINE, Web of Science, Embase, and Scopus databases. DATA EXTRACTION: In total, 447 articles were found in the initial search; 5 articles were included in the systematic review, after application of the exclusion criteria. DATA ANALYSIS: The review was guided by the PICOS strategy and based on the PRISMA protocol for animal reviews. CONCLUSION: High-fat diets appear to affect bone structure of Wistar rats. Diet composition and exposure time are the factors determining the strength of the effect.

Perinatal and post-weaning exposure to a high-fat diet causes histomorphometric, neuroplastic, and histopathological changes in the rat ileum.

Exposure to a diet with a high saturated fat content can influence the characteristics of the gastrointestinal tract, causing losses in the absorption of nutrients and favoring the appearance of diseases. The objective was to assess the effects of a high-fat diet (HFD) in the perinatal (pregnancy and lactation) and post-weaning period on the histomorphometry, neuroplasticity, and histopathology of the ileum. Wistar rats were divided into four subgroups: Control/Control (CC, n = 10) rats fed a control diet (C) throughout the trial period; Control/HFD (CH, n = 9) rats fed diet C (perinatal) and HFD after weaning; HFD/Control (HC, n = 10) rats fed HFD (perinatal) and diet C (post-weaning); HFD/HFD (HH, n = 9) rats fed HFD throughout the experimental period. There was atrophy of the Ileum wall with a reduction in the muscular tunic, submucosa, and mucosa thickness in the HH group of 37%, 28%, and 46%, respectively (p < 0.0001). The depth of the crypts decreased by 29% (p < 0.0001) and height increased by 5% (p < 0.0013). Villus height decreased by 41% and 18% in HH and HC groups (p < 0.0001) and width decreased by 11% in the HH (p < 0.0001). The height of the enterocytes decreased by 18% in the HH (p < 0.0001). There was a decrease in the area of the myenteric and submucosal plexus ganglia in the HH and HC groups (p < 0.0001). The number, occupation, and granules of Paneth cells increased in the HH and HC groups (p < 0.0001). Intraepithelial lymphocytes (IELs) increased in all groups exposed to the HFD. Goblet cells decreased in groups CH and HH (p < 0.0001). The evidence from this study suggests that the HFD had altered the histomorphometry, neuroplasticity, and histopathology of the ileum of the rats.

Exposure to a high-fat diet during intrauterine life and post-birth causes cardiac histomorphometric changes in rats: A systematic review.

Cardiac histomorphometric changes are conditions present as an adaptive response to increased cardiovascular demand, such as in obesity or the consumption of a high-fat diet. Epidemiologic studies show an increase in maternal obese individuals, with repercussions on offspring cardiovascular health. OBJECTIVE: The goal of this study was to systematically review studies that evaluated cardiac histomorphometric changes in rodents exposed to a high-fat diet. DATA SOURCE: PubMed, Embase, Science Direct, Web of Science and Lilacs. DATA EXTRACTION: Animal species, percentage of dietary fat, period and time of exposure and main cardiac change results were extracted. DATA ANALYSIS: A total of 1687 studies were found, and 20 met the inclusion criteria for this systematic review. A maternal high-fat diet was started 3 to 4 weeks before mating in most (70%) of the studies. Nutritional manipulation of offspring was initiated during pregnancy and maintained until the end of lactation in most (45%) of the studies. The fat percentage of high-fat diets ranged between 20% and 62%. The studies showed increases in cardiomyocytes, left ventricle size, and whole heart hypertrophy. Some studies showed increased thickness of the middle intima layer of the aorta and atherosclerosis. Studies that maintained a high-fat diet after the lactation period also showed an increase in cardiac hypertrophy. CONCLUSION: Maternal exposure to a hyperlipidic diet in the fetal stages of cardiac development causes cardiac hypertrophy in offspring. The high variation in the dietary fat and the difference in the time and period of exposure of the offspring to the high - fat diet suggest the high degree of sensitivity of the cardiac structure.

High-fat diet promotes hypothalamic inflammation in animal models: a systematic review.

CONTEXT: Hypothalamic inflammation and dysfunction may be induced by high-fat diets. However, the mechanisms involved in this process have not been fully elucidated. OBJECTIVE: To evidence, in animal models, of how a high-fat diet influence the mechanisms involved in hypothalamic inflammation. DATA SOURCES: Scopus, PubMed/Medline, Web of Science, Science Direct, and Embase databases were searched. DATA EXTRACTION: The exclusion criteria were human studies, studies with medicinal products or other substances not related to food, paper reviews, studies that used a surgical intervention or an intervention with food to reverse hypothalamic inflammation, and studies with genetically modified animals. The identified studies were evaluated according to the following inclusion criteria: animal studies, studies in which a control group was included in the experimental design, and studies in which markers of inflammation in the hypothalamus were evaluated. DATA ANALYSIS: A total of 322 studies were found, of which 9 met the inclusion criteria for a systematic review, conducted in accordance with the PRISMA guidelines, and were included in this review. CONCLUSION: The exposure of rodents to high-fat diets promoted an increase in levels of several pro-inflammatory cytokines and other proteins involved in the inflammatory process in the hypothalamus. This process was associated with increased glial cell activity.

Does a high-fat diet-induced obesity model brown adipose tissue thermogenesis? A systematic review.

INTRODUCTION: In this systematic review, we analysed studies that assessed the brown adipose tissue (BAT) activity in the high-fat/cafeteria diet model of obesity in rats. MATERIAL AND METHODS: Scopus, PubMed, Embase, and ScienceDirect databases were searched from January 2017 to November 2017. Using specific combinations of medical subject heading (MeSH) descriptors, seven papers remained after the inclusion and exclusion criteria. RESULTS: Most papers showed an increase in BAT thermogenesis in rodents fed high-fat/cafeteria diet. Some studies did not mention the diet composition or housing temperature, and the most of them investigated the thermogenesis superficially, being limited to the analysis of the UCP 1 expression. CONCLUSIONS: Despite the consolidated use of high-fat/cafeteria diets as a model to induce obesity, the identification of the energy expenditure arm has been slow, especially the direct quantitative assessment of the contribution of BAT to the increase in metabolic rate in rats fed a cafeteria/high-fat diet.