Isolation and characterization of polyphenol type-A polymers from cinnamon with insulin-like biological activity.

Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, USDA, ARS, Bldg 307C, Rm 223, Beltsville, Maryland 20705-2350, USA.
Journal of Agricultural and Food Chemistry (Impact Factor: 3.11). 02/2004; 52(1):65-70. DOI: 10.1021/jf034916b
Source: PubMed

ABSTRACT The causes and control of type 2 diabetes mellitus are not clear, but there is strong evidence that dietary factors are involved in its regulation and prevention. We have shown that extracts from cinnamon enhance the activity of insulin. The objective of this study was to isolate and characterize insulin-enhancing complexes from cinnamon that may be involved in the alleviation or possible prevention and control of glucose intolerance and diabetes. Water-soluble polyphenol polymers from cinnamon that increase insulin-dependent in vitro glucose metabolism roughly 20-fold and display antioxidant activity were isolated and characterized by nuclear magnetic resonance and mass spectroscopy. The polymers were composed of monomeric units with a molecular mass of 288. Two trimers with a molecular mass of 864 and a tetramer with a mass of 1152 were isolated. Their protonated molecular masses indicated that they are A type doubly linked procyanidin oligomers of the catechins and/or epicatechins. These polyphenolic polymers found in cinnamon may function as antioxidants, potentiate insulin action, and may be beneficial in the control of glucose intolerance and diabetes.

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    ABSTRACT: Aldosterone administration in rats results in several cardiac alterations. Previous studies have demonstrated that proanthocyanidins, phenolic bioactive compounds, have cardioprotective effects. We studied the potential beneficial effects of the proanthocyanidin-rich almond skin extract (PASE) on the cardiac alterations induced by aldosterone-salt treatment, their effects in mineralocorticoid receptor activity and we sought to confirm proanthocyanidins as the specific component of the extract involved in the beneficial cardiac effects. Male Wistar rats received aldosterone (1 mg/Kg/day) +1% NaCl for 3 weeks. Half of the animals in each group were simultaneously treated with either PASE (100 mg/Kg/day) or spironolactone (200 mg/Kg/day). The ability of PASE to act as an antagonist of the mineralocorticoid receptor was examined using a transactivation assay. High performance liquid chromatography was used to identify and to isolate proanthocyanidins. Hypertension and diastolic dysfunction induced by aldosterone were abolished by treatment with PASE. Expression of the aldosterone mediator SGK-1, together with fibrotic, inflammatory and oxidative mediators were increased by aldosterone-salt treatment; these were reduced by PASE. Aldosterone-salt induced transcriptional activity of the mineralocorticoid receptor was reduced by PASE. HPLC confirmed proanthocyanidins as the compound responsible for the beneficial effects of PASE. The effects of PASE were comparable to those seen with the mineralocorticoid antagonist, spironolactone. The observed responses in the aldosterone-salt treated rats together with the antagonism of transactivation at the mineralocorticoid receptor by PASE provides evidence that the beneficial effect of this proanthocyanidin-rich almond skin extract is via as a mineralocorticoid receptor antagonist with proanthocyanidins identified as the compounds responsible for the beneficial effects of PASE.
    PLoS ONE 01/2014; 9(10):e111104. · 3.53 Impact Factor
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    ABSTRACT: Research thrust to address the problems confronting the use of conventional polymers like high volatile organic compound (VOC) content still remains a challenge. In this context, the authors report the synthesis of a sustainable and biodegradable waterborne hyperbranched polyurethane (WHPU) using polyphenolic tannic acid in lieu of vegetable oil as the biobased component. The chemical structure of WHPU was characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. An UV−visible peak at the wavelength of 282 nm confirmed the presence of catechol moiety in WHPU. WHPU exhibited pronounced thermostability and desirable performance (tensile strength, 6.87 MPa; elongation at break, 315%; scratch hardness, 5.5 kg for 15 wt % tannic acid based WHPU). The radical scavenging and hemolytic assays of WHPU showed their potent antioxidant activity and cytocompatibility with the erythrocytes, respectively. Furthermore, WHPU exhibited bacterial degradation by Pseudomonas aeruginosa. Thus, the above results forward the synthesized WHPU as a potent ecofriendly and sustainable polymeric material by a simple approach that possesses a higher degree of sustainability over a purely petrochemical route. KEYWORDS: Tannic acid, sustainable polymer, low VOC polyurethane, bacterial degradation, antioxidant ■ INTRODUCTION Since its inception, polyurethane has emerged as the material of interest in colossal domains owing to its versatile properties. 1,2 However, the growing consciousness regarding environmental issues has created serious concerns with respect to the use of conventional solvent borne polyurethanes, particularly due to high volatile organic compound (VOC) content. 3−5 The processing and application of solvent borne polyurethanes involve evaporation of organic solvents, which adds to VOC content in the atmosphere. Thus, different environment protection agencies have taken serious steps to reduce VOC emission from the industrial sector and issued guidelines to combat the same. 6 Under such circumstances, a paradigm shift in research has been observed in the develop ecofriendly polymeric materials. As a result of such efforts, waterborne polyurethane (WPU) has emerged out as one of the greener alternatives. 7 WPUs supersede their solvent borne counterparts in terms of nontoxicity, nonflammability, and low or no content of organic solvent. 8−11 Today, WPU has applications across the globe as a coating, adhesive, primer, paint additive, defoamer, associate thickener, pigment paste, biomaterial, etc. 12−14
    ACS Sustainable Chemistry & Engineering. 11/2014; 2(12):2730–2738.
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    ABSTRACT: Introduction: This study aimed to evaluate the effect of oral supplementation of cinnamon on glucose control index and lipid profile in type II diabetic patients. Subjects & Methods: The present study was a randomized trial on 75 patients with type II diabetes mellitus (30 patients in cinnamon group and 45 patients in control group), in Karaj-Iran during 2010 to 2012. The two groups were given 90 days cinnamon and placebo capsules (starch) (500 mg, twice a day after breakfast and lunch). Vein blood samples were taken at the beginning and end of study to measure fasting blood glucose (FBG), two-hour blood glucose (BS2hpp), glycated hemoglobin (HbA1c), insulin serum, Triglyceride, total Cholesterol and its contents. Using HOMA Score, insulin resistance was also measured. The Chi square test, t-test, ANOVA and SPSS software were used to analyze the data. Results: At the end of intervention, a significant reduction was seen in BMI in the cinnamon group compared to placebo (p=0.01).While there wasn’t a significant difference in other variables. Also, in patients receiving cinnamon, the mean of FBG, BS2hpp, HbA1c, serum insulin, HOMA score and BMI was significantly more different than before the intervention (pConclusion: Although it did not appear that oral supplementation of cinnamon, alone reduced the glucose and lipid blood parameters in type II diabetic patients, nevertheless, its supplementation in order to adjust the weight of diabetic patients with conventional therapy is recommended. Keywords Cinnamon; diabetes mellitus; blood glucose; lipoprotein
    Medical Journal of Mashhad University of Medical Sciences. 06/2014; 57:533-541.


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