Effect of a proanthocyanidin-rich extract from longan flower on markers of metabolic syndrome in fructose-fed rats.
ABSTRACT Recent evidence strongly suggests that oxidative stress due to redox imbalance is highly associated with metabolic syndrome. The objective of this study was to evaluate the effect of the supplementation of longan flower water extract (LFWE), which showed powerful antioxidative activity in vitro, on markers of metabolic syndrome in a fructose-fed rat model. Male Sprague-Dawley rats were randomly divided into four groups: group C, fed with standard Purina chow; group F, fed with high-fructose diet (HF) alone; group L, fed with HF plus LFWE 125 mg/kg bw per day by gavage; and group H, fed HF plus LFWE 250 mg/kg bw per day by gavage. The dietary manipulation lasted for 14 weeks. Results of our study showed that rats fed with HF resulted in oxidative stress and affected the antioxidant status including plasma thiobarbituric acid and liver antioxidant enzyme activity. Treatment with LFWE significantly augmented the antioxidant system. HF was able to cause insulin resistance and elevation of the blood pressure. The supplementation of LFWE ameliorated insulin resistance by enhancing the expression of insulin signaling pathway related proteins, including insulin receptor substrate-1 and glucose transporter 4. LFWE supplementation was also found to decrease systolic blood pressure. These findings indicate that longan flower water extract may improve the symptoms of metabolic syndrome in fructose-fed rats.
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ABSTRACT: This review analyses the potential beneficial effects of procyanidins, the main class of flavonoids, in situations in which glucose homeostasis is disrupted. Because the disruption of glucose homeostasis can occur as a result of various causes, we critically review the effects of procyanidins based on the specific origin of each type of disruption. Where little or no insulin is present (Type I diabetic animals), summarized studies of procyanidin treatment suggest that procyanidins have a short-lived insulin-mimetic effect on the internal targets of the organism, an effect not reproduced in normoglycemic, normoinsulinemic healthy animals. Insulin resistance (usually linked to hyperinsulinemia) poses a very different situation. Preventive studies using fructose-fed models indicate that procyanidins may be useful in preventing the induction of damage and thus in limiting hyperglycemia. But the results of other studies using models such as high-fat diet treated rats or genetically obese animals are controversial. Although the effects on glucose parameters are hazy, it is known that procyanidins target key tissues involved in its homeostasis. Interestingly, all available data suggest that procyanidins are more effective when administered in one acute load than when mixed with food.Critical reviews in food science and nutrition 07/2012; 52(7):569-84. · 3.73 Impact Factor
Article: Flavonoids and metabolic syndrome.[show abstract] [hide abstract]
ABSTRACT: Increasing evidence indicates that several mechanisms, associated or not with antioxidant actions, are involved in the effects of flavonoids on health. Flavonoid-rich beverages, foods, and extracts, as well as pure flavonoids are studied for the prevention and/or amelioration of metabolic syndrome (MS) and MS-associated diseases. We summarize evidence linking flavonoid consumption with the risk factors defining MS: obesity, hypertriglyceridemia, hypercholesterolemia, hypertension, and insulin resistance. Nevertheless, a number of molecular mechanisms have been identified; the effects of flavonoids modifying major endpoints of MS are still inconclusive. These difficulties are explained by the complex relationships among the risk factors defining MS, the multiple biological targets controlling these risk factors, and the high number of flavonoids (including their metabolites) present in the diet and potentially responsible for the in vivo effects. Consequently, extensive basic and clinical research is warranted to assess the final relevance of flavonoids for MS.Annals of the New York Academy of Sciences 07/2012; 1259:87-94. · 4.38 Impact Factor
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ABSTRACT: Aging is defined as a normal decline in survival with advancing age; however, the recent researches have showed that physiological functions of the body change during the aging process. Majority of the changes are often subject to a higher risk of developing diseases, such as cardiovascular disease, type II diabetes, Alzheimer's disease, Parkinson's disease, as well as the dysregulated immune and inflammatory disorders. Aging process is controlled by a complicated and precise signaling network that involved in energy homeostasis, cellular metabolism and stress resistance. Over the past few decades, research in natural dietary compounds by various organism and animal models provides a new strategy for anti-aging. Natural dietary compounds act through a variety mechanisms to extend lifespan and prevent age-related diseases. This review summarizes the current understanding on signaling pathways of aging and knowledge and underlying mechanism of natural dietary compounds that provide potential application on anti-aging and improve heath in human.Molecular Nutrition & Food Research 11/2011; 56(1):88-115. · 4.31 Impact Factor