Anti-obesity properties and mechanism of action of flavonoids: A review.

Obesity is a major public health problem, and there is increasing scientific interest in its mechanisms, as well as a search for new compounds with antioxidant and anti-inflammatory properties that can minimize the metabolic complications associated with its pathology. One potential source of these compounds is natural products; Among these, flavonoids are a promising group of natural substances. Flavonoids are active constituents with diverse biological activities and are widely found in plants kingdom. Numerous studies have shown that flavonoids can effectively inhibit obesity and related metabolic disorders. The review synthesizes recent evidence in respect of progress in the understanding of the anti-obesity effects of flavonoids. Such effects which occurs through the modulation of proteins, genes and transcriptional factors involved in decreasing lipogenesis, increasing lipolysis, expenditure energy, stimulating fatty acids B-oxidation, digestion and metabolism of carbohydrates. In addition to mitigating inflammatory responses and suppress oxidative stress. A better understanding of the modulating effects and mechanisms of flavonoids in relation to obesity will allow us to better use these compounds to treat or even prevent obesity and its associated comorbidities.

Ameliorative effects of aqueous extract from rosemary on oxidative stress and inflammation pathways caused by a high-fat diet in C57BL/6 mice.

Rosemary is an herb exhibits biological properties, attenuates inflammation, oxidative stress, and improves lipid profile. Here, we evaluated the effects of rosemary aqueous extract (RE) on mice fed with a high-fat diet (HFD). Male C57BL/6 mice were administered a control diet or HFD for 10 weeks. The treated groups received RE in the diet at different concentrations: 25, 250, and 500 mg/100 g. After 10 weeks, serum concentrations of glucose, lipid, insulin, leptin, adiponectin, and cytokines were evaluated and the oxygen radical absorbance capacity was determined. Histological analysis was performed to determine the concentrations of triacylglycerides (TG), total cholesterol, cytokines, and antioxidant enzymes as well as the expression of genes involved in lipid metabolism, oxidative stress, and inflammation. The dietary RE ameliorated HFD-induced weight gain, adipose tissue weight, glucose intolerance, and insulin, leptin, and free fatty acid levels. Reduction in hepatic TG deposition was observed. The levels of inflammatory cytokines decreased, and the expression of genes involved in lipid metabolism increased. RE mitigated oxidative stress and reduced the production of reactive oxygen species in HepG2 and 3T3-L1 cells. Therefore, RE is a potential therapeutic agent for the prevention of inflammation and oxidative stress outcomes associated with obesity.

Effects of passion fruit peel flour (Passiflora edulis f. flavicarpa O. Deg.) in cafeteria diet-induced metabolic disorders.

ETHNOPHARMACOLOGICAL RELEVANCE: Passiflora edulis f. flavicarpa O. Deg. is a native Brazilian fruit known as sour or yellow passion fruit. From its peel, mainly in the northeast of Brazil, is produced a flour that is largely used as folk medicine to treat diabetes and other metabolic conditions. AIM OF THE STUDY: The aim of the study was to show the effects of P. edulis peel flour (PEPF) in metabolic disorders caused by cafeteria diet in mice. MATERIAL AND METHODS: The antioxidant activity in vitro of PEPF extract was determined by ferric reducing/antioxidant power, ß-carotene/linoleic acid system and nitric oxide scavenging activity assay. C57BL/6 mice divided in 3 groups: Control group, fed on a standard diet (AIN); Cafeteria diet (CAF) group, fed on a cafeteria diet, and PEPF group, fed on a cafeteria diet containing 15% of PEPF, during 16 weeks. The glucose tolerance and insulin sensitivity were evaluated through the glucose tolerance test (GTT) and the insulin tolerance test (ITT). After the intervention period, blood, hepatic, pancreatic and adipose tissues were collected for biochemical and histological analysis. Cholesterol, triglyceride, interleukins and antioxidant enzymes were measured in the liver tissue. RESULTS: PEPF extract presented antioxidant activity in the higher concentrations in the performed assays. The PEPF intake decreased the body weight gain, fat deposition, predominantly in the liver, improved the glucose tolerance and insulin sensitivity in metabolic changes caused by cafeteria diet. CONCLUSION: Together, the data herein obtained points out that P. edulis peel flour supplementation in metabolic syndrome condition induced by CAF-diet, prevents insulin and glucose resistance, hepatic steatosis and adiposity.

Evaluation of the acute toxicity and antidiabetic activity of Coutoubea spicata "nicolau" ethanolic extract and ethyl acetate fraction / Evaluación de la toxicidad aguda y la actividad antidiabética del extracto etanólico y la fracción de acetato de etilo de Coutoubea spicata "nicolau"

In order to understand antidiabetic potential and toxicity, this study aimed to evaluate the acute toxicity and antidiabetic activity of ethanolic extract and ethyl acetate fraction obtained from Coutoubea spicata "nicolau" shoots. Chemical constituents and acute toxicity were investigated. In alloxan-induced diabetic rats, extract and fraction were tested at dose of 100 mg/kg, p.o. Body weight gain, glucose, lipid profile and oxidative stress markers in serum and tissues were determined. In vitro antioxidant activity was performed. Swertiamarin, gentiopicrin, deoxyloganic acid, clovin and robinin, and their p-coumaric ester were identified. Extract and fraction were classified as safe (category 5). In diabetic rats, Coutoubea spicata reduced glycaemia, which was accompanied by body weight recovery gain and attenuation in oxidative stress markers. Fraction showed scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical (ABTS) radicals and reducing power higher than that of the extract. Extract and fraction of Coutoubea spicata didn't present significant toxicity and it can be investigated as a therapeutic alternative in diabetes.

Con el fin de conocer el potencial antidiabético y la toxicidad, este estudio tuvo como objetivo evaluar la toxicidad aguda y la actividad antidiabética del extracto etanólico y la fracción de acetato de etilo obtenidos de los brotes de Coutoubea spicata "Nicolau". Se investigaron los componentes químicos y la toxicidad aguda. En ratas diabéticas inducidas por alloxan, se probaron el extracto y la fracción en dosis de 100 mg/kg, p.o. Se determinó el aumento de peso corporal, la glucosa, el perfil lipídico y los marcadores de estrés oxidativo en suero y tejidos. Se realizó una actividad antioxidante in vitro. Se identificaron la suertiamarina, la gentiopicrina, el ácido desoxilogánico, la clovina y la robinina, así como su éster p-cumárico. El extracto y la fracción se clasificaron como seguros (categoría 5). En ratas diabéticas, Coutoubea spicata redujo la glicemia, lo que se acompañó de una recuperación del peso corporal y de la atenuación de los marcadores de estrés oxidativo. La fracción mostró una actividad de barrido contra los radicales 1,1-difenil-2-picrilhidrazilo (DPPH) y 2,2'-azino-bis (ácido 3-etilbenzotiazolina-6-sulfónico) y un poder reductor superior al del extracto. El extracto y la fracción de Coutoubea spicata no presentaron una toxicidad significativa y pueden ser investigados como alternativa terapéutica en la diabetes.