ascophyllum and Diabetes-Mellitus--Type-2

Metabolic syndrome is characterized by the coexistence of different metabolic disorders which increase the risk of developing type 2 diabetes mellitus and cardiovascular diseases. Therefore, metabolic syndrome leads to a reduction in patients' quality of life as well as to an increase in morbidity and mortality. In the last few decades, it has been demonstrated that seaweeds exert multiple beneficial effects by virtue of their micro- and macronutrient content, which could help in the management of cardiovascular and metabolic diseases. This review aims to provide an updated overview on the potential of brown seaweeds for the prevention and management of metabolic syndrome and its associated diseases, based on the most recent evidence obtained from in vitro and in vivo preclinical and clinical studies. Owing to their great potential for health benefits, brown seaweeds are successfully used in some nutraceuticals and functional foods for treating metabolic syndrome comorbidities. However, some issues still need to be tackled and deepened to improve the knowledge of their ADME/Tox profile in humans, in particular by finding validated indexes of their absorption and obtaining reliable information on their efficacy and long-term safety.

Topics: Animals; Ascophyllum; Diabetes Mellitus, Type 2; Dietary Supplements; Fucus; Functional Food; Humans; Laminaria; Metabolic Syndrome; Obesity; Plant Extracts; Polyphenols; Seaweed; Undaria

Edible seaweeds have been consumed by Asian coastal communities since ancient times.

Topics: alpha-Amylases; alpha-Glucosidases; Animals; Ascophyllum; Blood Glucose; Carbohydrate Metabolism; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Fucus; Glycoside Hydrolase Inhibitors; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Plant Extracts; Seaweed

Ascophyllum nodosum is a brown seaweed that grows abundantly in the US Northeast coastal region. This study examined the seasonal variation of A. nodosum in phenolic contents and subsequent antioxidant, α-glucosidase and α-amylase inhibitory activities. A. nodosum was harvested monthly and extracted in hot water and the resulting extracts were spray-dried. The results indicate a clear seasonal variation in terms of phenolic content, with June and July being the highest (36.4 and 37 mg/g, respectively) and May the lowest (21.8 mg/g). The antioxidant activities, in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, correlated with the phenolic contents observed (r = 0.81), with the month of July being the highest (58%) and April the lowest (26%). Similarly in terms of Trolox equivalent, July had the highest activity (15.53 μM) and April and May the lowest (8.40 and 8.27 μM, respectively). α-glucosidase inhibitory activity exhibited a pattern similar to the phenolic contents observed with July having the highest inhibitory activity (IC(70) 2.23 μg) and April the lowest (IC(70) 26.13 μg), resulting in an inverse correlation between IC(70) values and total phenolic content (r = -0.89). Such seasonal variation is believed to be caused by temperature-related stress considering that A. nodosum is a cold water species.

Topics: alpha-Amylases; Antioxidants; Ascophyllum; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Free Radical Scavengers; Glycoside Hydrolase Inhibitors; Phenols; Seasons; Temperature

Ascophyllum nodosum is a brown seaweed that grows abundantly in the Northeast coastal region. In this study, the potential of A. nodosum for type 2 diabetes management through antioxidant-mediated alpha-glucosidase and alpha-amylase inhibition was investigated. After the initial screening of 4 locally harvested seaweeds, A. nodosum was chosen for its highest phenolic content and was subjected to water extraction. Among extraction ratios of 50 g to 100 to 1000 mL at room temperature, 50 g/400 mL yielded the highest phenolic content of 4.5 mg/g wet weight. For evaluation of extraction temperature ranging from 20 to 80 degrees C, 50 g/400 mL was chosen as a minimum amount of extractant. Among temperatures studied, extraction at 80 degrees C resulted in the highest total phenolic contents (4.2 mg/g wet weight). All extracts had similar levels of antioxidant activity in the range of 60% to 70% in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The 80 degrees C extract had the highest alpha-glucosidase and alpha-amylase inhibitory activity with IC(50) of 0.24 and 1.34 microg phenolics, respectively, compared to the IC(50) of acarbose, reference inhibitor, being 0.37 and 0.68 microg. The results show that fresh A. nodosum has strong alpha-glucosidase and mild alpha-amylase inhibitory activities that correlated with phenolic contents. This study suggests a nutraceutical potential of A. nodosum based on phytochemical antioxidant and antihyperglycemia activities.

Topics: Antioxidants; Ascophyllum; Diabetes Mellitus, Type 2; Dietary Supplements; Enzyme Inhibitors; Eukaryota; Free Radical Scavengers; Glycoside Hydrolase Inhibitors; Hot Temperature; Osmolar Concentration; Pancreatic alpha-Amylases; Phenols; Species Specificity