Homocysteine, Erectile dysfunction, Skin care, and Blood sugarAugust 2017
Potent alpha-glucosidase inhibitors purified from the red alga Grateloupia elliptica.
Diabetes mellitus is a most serious and chronic disease whose incidence rates are increasing with incidences of obesity and aging of the general population over the world. One therapeutic approach for decreasing postprandial hyperglycemia is to retard absorption of glucose by inhibition of alpha-glucosidase. Two bromophenols, 2,4,6-tribromophenol and 2,4-dibromophenol, were purified from the red alga Grateloupia elliptica. IC(50) values of 2,4,6-tribromophenol and 2,4-dibromophenol were 60.3 and 110.4 microM against Saccharomyces cerevisiae alpha-glucosidase, and 130.3 and 230.3 microM against Bacillus stearothermophilus alpha-glucosidase, respectively. In addition, both mildly inhibited rat-intestinal sucrase (IC(50) of 4.2 and 3.6mM) and rat-intestinal maltase (IC(50) of 5.0 and 4.8mM). Therefore, bromophenols of G. elliptica have potential as natural nutraceuticals to prevent diabetes mellitus because of their high alpha-glucosidase inhibitory activity.
Phytochemistry. 2008 Nov;69(16):2820-5
Nutraceutical effects of fucoxanthin for obesity and diabetes therapy: a review.
Obesity, which results from an imbalance between energy intake and energy expenditure, has become a major health risk factor worldwide, causing numerous and various diseases such as diabetes, hypertension, and cardiovascular diseases. Fucoxanthin, a specific carotenoid in brown algae, has garnered much attention for its anti-obesity and anti-diabetic effects attributable to a unique mechanism. Fucoxanthin induces uncoupling protein 1 (UCP1) expression in white adipose tissue (WAT). That inner membrane mitochondrial protein, UCP1, can dissipate energy through oxidation of fatty acids and heat production. Furthermore, fucoxanthin improves insulin resistance and ameliorates blood glucose levels through down-regulation of adipocytokines related to insulin resistance in WAT and up-regulation of glucose transporter 4 (GLUT4) in skeletal muscle. Algae fucoxanthin is a beneficial compound for the prevention of the metabolic syndrome.
J Oleo Sci. 2015;64(2):125-32
Popular edible seaweed, Gelidium amansii prevents against diet-induced obesity.
The popular edible seaweed, Gelidium amansii is broadly used as food worldwide. To determine whether G. amansii extract (GAE) has protective effects on obesity, mice fed a high-fat diet (HFD) treated with GAE (1 and 3%) were studied. After 12 weeks of GAE treatment, body weight was greatly decreased in mice fed a high-fat diet. This effect could be due to decreased adipogenesis, as evidenced by the fact that GAE suppressed adipogenic gene expression in adipocytes. In addition, blood glucose and serum insulin levels were reduced by GAE treatment in mice fed a high-fat diet, suggesting improvement in glucose metabolism. GAE supplementation also led to a significant decrease in total cholesterol and triglyceride levels. These data are further confirmed by H&E staining. Our findings indicate that Gelidium amansii prevents against the development of diet-induced obesity, and further implicate that GAE supplementation could be the therapeutical option for treatment of metabolic disorder such as obesity.
Food Chem Toxicol. 2016 Apr;90:181-7
Anti-obesity effects of seaweeds of Jeju Island on the differentiation of 3T3-L1 preadipocytes and obese mice fed a high-fat diet.
The seaweeds were collected from the coast of Jeju Island, South Korea. We investigated ethanol extracts from seaweed as potential antiobesity agents by testing their effect on adipogenic differentiation in 3T3-L1 cells. Among the red algae extracts tested, the Plocamium telfairiae extract (PTE) showed the highest inhibitory effect on lipogenesis in adipocytes and, thus, was selected as a potential antiobesity agent. PTE treatment significantly decreased the expression of the adipogenic-specific proteins peroxisome proliferator-activated receptor-g, CCAAT/enhancer-binding protein-a, sterol regulatory element-binding protein 1, and fatty acid-binding protein 4 compared with that in the untreated 3T3-L1 cells. PTE also inhibited high-fat diet (HFD)-induced obesity in male C57BL/6 mice. Oral administration of PTE significantly reduced the body weight, fatty liver, amount of white adipose tissue, and levels of triglyceride and glucose in the tested animals. Taken together, these data demonstrate that PTE can be developed as a therapeutic agent for obesity.
Food Chem Toxicol. 2016 Apr;90:36-44
Compartmentalization and regulation of insulin signaling to GLUT4 by the cytoskeleton.
One of the early events in the development of Type 2 diabetes appears to be an inhibition of insulin-mediated GLUT4 redistribution to the cell surface in tissues that express GLUT4. Understanding this process, and how it begins to breakdown in the development of insulin resistance is quite important as we face treatment and prevention of metabolic diseases. Over the past few years, and increasing number of laboratories have produced compelling data to demonstrate a role for both the actin and microtubule networks in the regulation of insulin-mediated GLUT4 redistribution to the cell surface. In this review, we explore this process from insulin-signal transduction to fusion of GLUT4 membrane vesicles, focusing on studies that have implicated a role for the cytoskeleton. We see from this body of work that both the actin network and the microtubule cytoskeleton play roles as targets of insulin action and effectors of insulin signaling leading to changes in GLUT4 redistribution to the cell surface and insulin-mediated glucose uptake.
Vitam Horm. 2009;80:193-215
The molecular basis of insulin-stimulated glucose uptake: signalling, trafficking and potential drug targets.
The search for the underlying mechanism through which insulin regulates glucose uptake into peripheral tissues has unveiled a highly intricate network of molecules that function in concert to elicit the redistribution or 'translocation' of the glucose transporter isoform GLUT4 from intracellular membranes to the cell surface. Following recent technological advances within this field, this review aims to bring together the key molecular players that are thought to be involved in GLUT4 translocation and will attempt to address the spatial relationship between the signalling and trafficking components of this event. We will also explore the degree to which components of the insulin signalling and GLUT4 trafficking machinery may serve as potential targets for the development of orally available insulin mimics for the treatment of diabetes mellitus.
J Endocrinol. 2009 Oct;203(1):1-18