Anti-obesity effect of resveratrol-amplified grape skin extracts on 3T3-L1 adipocytes differentiation

Resveratrol (3,4,5-trihydroxy-trans-stilbene), a phytoalexin found in grape skin, grape products, and peanuts as well as red wine, has been reported to have various biological and pharmacological properties. The purpose of this study was to investigate the anti-obesity effect of resveratrol-amplified grape skin extracts on adipocytes. The anti-obesity effects of grape skin extracts were investigated by measuring proliferation and differentiation in 3T3-L1 cells. The effect of grape skin ethanol extracts on cell proliferation was detected by the MTS assay. The morphological changes and degree of adipogenesis of preadipocyte 3T3-L1 cells were measured by Oil Red-O staining assay. Treatment with extracts of resveratrol-amplified grape skin decreased lipid accumulation and glycerol-3-phosphate dehydrogenase activity without affecting 3T3-L1 cell viability. Grape skin extract treatment resulted in significantly attenuated expression of key adipogenic transcription factors, including peroxisome proliferator-activated receptor, CCAAT/enhancer-binding proteins, and their target genes (FAS, aP2, SCD-1, and LPL). These results indicate that resveratrol-amplified grape skin extracts may be useful for preventing obesity by regulating lipid metabolism.

Estudo das alterações cardiovasculares e metabólicas em modelo experimental de programação metaboólica: efeito de extrato da casca de uva vitis vinífera / Study of cardiovascular and metabolic changes in experimental model of metabolic programming: effect of extract of grape skins vitis vinífera

Estudos epidemiológicos e experimentais têm sugerido que fatores de risco cardiovasculares podem ser parcialmente atribuídos às influências do ambiente em que vive o indivíduo, e que a nutrição materna influencia na programação de alterações metabólicas e cardiovasculares no indivíduo adulto e que caracterizam a síndrome metabólica (SM). Em contrapartida, estudos prévios de nosso laboratório demonstram que o extrato da casca de uva Vitis labrusca (GSE) possui efeito vasodilatador, antihipertensivo e antioxidante. Desta forma, o objetivo deste estudo foi avaliar o efeito do tratamento oral com GSE (200mg/kg/dia), sobre as alterações cardiovasculares e metabólicas e extresse oxidativo observados na prole adulta (fêmea e machos) com 3 e 6 meses, cujas mães foram submetidas a uma dieta rica em gordura (hiperlipídica) durante a lactação. Quatro grupos de ratas foram alimentados com dietas experimentais: controle (7% de gordura); controle + GSE (7% de gordura + GSE), hiperlipídica (24% de gordura); hiperlipídica + GSE (24% de gordura + GSE) durante a lactação. Após o desmame, todos os filhotes passaram a ser alimentados com uma dieta controle e foram sacrificados aos 3 ou 6 meses de idade. A pressão arterial sistólica (PAS) foi medida por pletismografia de cauda e o efeito vasodilatador da acetilcolina (ACh) foi avaliado em leito arterial mesentérico (LAM) perfundido. Foram avaliados o peso corporal, adiposidade (intra-abdominal e gonadal), níveis plasmáticos de colesterol total, triglicerídeos, glicose e insulina, e a resistência à insulina (RI) foi calculada pelo índice de HOMA IR. As expressões do IRS-1, Akt e GLUT-4 foram determinadas em músculo soleus. O dano oxidativo, níveis de nitritos e a atividade das enzimas antioxidantes: superóxido dismutase, catalise e glutationa peroxidase foram dosados no plasma e homogenato de LAM. A PAS e tecido adiposo foram aumentados nas proles adultas de ambos os sexos e idades do grupo hiperlipídico e revertidos...

Epidemiological and experimental studies have suggested that cardiovascular risk factors can be partly attributed to the influences of the environment in which the individual lives, and that maternal nutrition influences the programming of metabolic and cardiovascular diseases in adults characterizing the metabolic syndrome. On the other hand, previus studies from our laboratory show that the skin extract of grape Vitis labrusca (GSE) has antihypertensive, antioxidant and vasodilator effects. Thus, the aim of this study was to evaluate the effect of oral treatment with GSE (200mg/kg/day) on the cardiovascular and metabolic disorders and oxidative stress observed in adult offspring (female and male) at 3 or 6 months whose mothers were fed a high fat diet (HF) during lactation. Four groups of rats were fed experimental diets: control (7% fat), control + GSE (7% fat + GSE), diet (24% fat), HF + GSE (24% fat + GSE) during lactation. After weaning, all pups have become fed a control diet and were sacrificed at 3 or 6 months of age. Systolic blood pressure (SBP) was measured by plethysmography and the vasodilator effect of acethylcholine (ACh) was studied in perfused mesenteric arterial bed (MAB). We determined the body weight, adiposity, plasma total cholesterol, triglycerides, glucose, insulin, and insulin resistance was calculated by HOMA IR. The expression of IRS-1, Akt and GLUT-4 were determined in soleus muscle. Oxidative damage, nitrite levels and antioxidant enzyme activity: superoxide dismutase, catalase and glutathione peroxidase were measured in plasma and homogenate of mesentery bed. The SBP and adipose tissue were increased in adult offspring of both sex and ages of the HF group and reversed by treatment with GSE. The vasodilator response to ACh was not different between groups of both sex, but was reduced by aging. In offspring females and males of the HF group were also observed increased levels of triglycerides, glucose and insulin resistance...

Effect of dietary supplementation of grape skin and seeds on liver fibrosis induced by dimethylnitrosamine in rats

Grape is one of the most popular and widely cultivated fruits in the world. Although grape skin and seeds are waste product of the winery and grape juice industry, these wastes contain large amounts of phytochemicals such as flavonoids, phenolic acids, and anthocyanidins, which play an important role as chemopreventive and anticancer agents. We evaluated efficacies of grape skin and seeds on hepatic injury induced by dimethylnitrosamine (DMN) in rats. Treatment with DMN significantly increased levels of serum alanine transaminase, aspartate transaminase, alkaline phosphatase, and bilirubin. Diet supplementation with grape skin or seeds (10% daily for 4 weeks) prevented these elevations. The grape skin and seeds also restored serum albumin and total protein levels, and reduced the hepatic level of hydroxyproline and malondialdehyde. Furthermore, grape skin and seeds reduced DMN-induced collagen accumulation, as estimated by histological analysis of liver tissue stained with Sirius red. Grape skin and seeds also reduced hepatic stellate cell activation, as assessed by alpha-smooth muscle actin staining. In conclusion, grape skin and seeds exhibited in vivo hepatoprotective and antifibrogenic effects against DMN-induced liver injury, suggesting that grape skin and seeds may be useful in preventing the development of hepatic fibrosis.

Grape skin improves antioxidant capacity in rats fed a high fat diet

This study was conducted to investigate the effect of dietary grape skin on lipid peroxidation and antioxidant defense system in rats fed high fat diet. The Sprague-Dawley rats were fed either control (5% fat) diet or high fat (25% fat) diet which was based on AIN-93 diet for 2 weeks, and then they were grouped as control group (C), control + 5% grape skin group (CS), high-fat group (HF), high fat + 5% grape skin group (HFS) with 10 rats each and fed corresponding diets for 4 weeks. The hepatic thiobarbituric acid reacting substances (TBARS) were increased in high fat group as compared with control group, but reduced by grape skin. The serum total antioxidant status, and activities of hepatic catalase and superoxide dismutase, xanthine oxidase and glucose-6-phosphatase were increased by supplementation of grape skin. Glutathione peroxidase activity was significantly higher in CS group than in C group. Grape skin feeding tended to increase the concentration of total glutathione, especially in control group. The ratio of reduced glutathione to oxidized glutathione was lower in high fat groups than in control groups. The ratio was increased by dietary supplementation of grape skin in control group. These results suggest that dietary supplementation of grape skin would be effective on protection of oxidative damage by lipid peroxidation through improvement of antioxidant defense system in rats fed high fat diet as well as rats with low fat diet.

Subsídios para o estabelecimento de metodologia para o controle de corantes naturais em alimentos / A contribution to the method for controlling natural dyes for foods

Dezessete amostras de corante urucum, 6 de cúrcuma, 9 de cochonilha, 10 de vermelho de beterraba, 4 de antocianinas de casca de uva e 4 de clorofilina cúprica, num total de 50 amostras de corantes naturais, foram analisadas para verificar se estes corantes atendiam às Normas de Identidade e Qualidade estabeleci das pela "Food Agricultural Organization/World Health Organization". Para todas as amostras foram traçados espectros de absorção na região do ultravioleta e visível para caracterização do corante natural. Também foram pesquisadas impurezas, tais como arsênico e chumbo, além de adulterantes, como corantes artificiais. Do total de 50 amostras analisadas, 20 apresentaram especificações fora dos padrões de Identidade e Qualidade da "FAO/WHO", bem como dos padrões propostos nas monografias de um grupo brasileiro de estudo de corantes naturais para alimentos (AU).