Fucosterol

Abstract: Diabetes mellitus is a group of chronic metabolic disorders characterized by hyperglycemia due to defects in insulin action and/or secretion. It is a worldwide problem which has led to illness and premature mortality for many people, and the number of diabetes cases has been rising sharply. Unluckily, many conventional antidiabetic agents either show limited efficacy or serious mechanism-based side effects. Marine macroalgae possess tremendous nutritional value and have been well-known to cure and prevent diabetes. An increased interest in various bioactive natural products from marine macroalgae, as a potential source of effective antidiabetic agents, has been observed in recent years. The effects of macroalgae may delay the development of diabetes and alter the metabolic abnormalities through various mechanisms of actions. This review provides an overview of marine macroalgae used to prevent and manage diabetes and explores the hypoglycemic properties of macroalgae-derived bioactive compounds such as polyphenol, bromophenols, sulfated polysaccharides, fucoidan, fucosterol, phlorotannins, carotenoid pigments and fucoxanthin with their probable mechanisms behind hypoglycemic activity.

Abstract: Fucoxanthin (Fx) and fucosterol (Fs) are characteristic lipid components of brown seaweeds that afford several health benefits to humans. This article describes the quantitative evaluation of lipids of 15 species of brown seaweeds with specific reference to Fx, Fs, and functional long-chain omega-6/omega-3 polyunsaturated fatty acids (PUFAs). In addition, fatty-acid composition of selected species was also accomplished in the study. Major omega-3 PUFAs in the brown seaweeds analyzed were α-linolenic acid (18:3n-3), octadecatetraenoic acid (18:4n-3), arachidonic acid (20:4n-6), and eicosapentaenoic acid (20:5n-3). Both Fx (mg · g(-1) dry weight [dwt]) and Fs (mg · g(-1) dwt) were determined to be relatively abundant in Sargassum horneri (Turner) C. Agardh (Fx, 3.7 ± 1.6; Fs, 13.4 ± 4.4) and Cystoseira hakodatensis (Yendo) Fensholt (Fx, 2.4 ± 0.9; Fs, 8.9 ± 2.0), as compared with other brown seaweed species. Studies related to seasonal variation in Fx, Fs, and total lipids of six brown algae [S. horneri, C. hakodatensis, Sargassum fusiforme (Harv.) Setch., Sargassum thunbergii (Mertens ex Roth) Kuntze, Analipus japonicus (Harv.) M. J. Wynne, and Melanosiphon intestinalis (D. A. Saunders) M. J. Wynne] indicated that these functional lipid components reached maximum during the period between January and March. The functional lipid components present in these seaweeds have the potential for application as nutraceuticals and novel functional ingredients after their recovery.