New insights into seaweed polyphenols on glucose homeostasis

Figures & data

Figure 1. Mechanism of glucose homeostasis.

Figure 2. Structures of major polyphenols found in plant and seaweeds (Corona, 2011).

Figure 3. Chemical structures of different phlorotannins from marine algae (Singh & Bharate, 2006; Thomas & Kim, 2011).

Table 1. Summary of bioactive phlorotannins (polyphenols) isolated from brown marine algae.

Phlorotannins	Marine Algae	References
2-Phloroeckol	E. bicyclis	Okada et al. (2004)
	E. stolonifera	Jung et al. (2008)
6,6′-Bieckol	E. cava,	Artan et al. (2008)
	I. okamurae	Yoon et al. (2009)
6,8′-Bieckol	E. stolonifera	Yoon (2008)
7-Phloroeckol	E. stolonifera	Jung et al. (2008)
	A. nodosum	Nwosu et al. (2011)
8,8′-Bieckol	E. bicyclis, E. cava	Shibata et al. (2008)
	E. kurome
Deshydroxyfuhalols	S. spinuligerum	Glombitza and Keusgen (1995)
Dieckol	E. bicyclis	Nakamura et al. (1996)
Dioxinodehydroeckol	E. stolonifera	Jung et al. (2008)
Diphlorethohydroxycarmalol	I. okamurae	Heo et al. (2009)
Eckol	E. kurome	Fukuyama et al. (1989)
Eckostolonol	E. stolonifera	Iwai K. (2008)
Fucodiphloroethol G	E. cava	Ham et al. (2007)
Fucophlorethols	C. retroflexa	Sailler and Glombitza (1999)
	C. torulosa,	Glombitza et al. (1997)
	S. spinuligerum
Fuhalols	S. spinuligerum	Glombitza and Keusgen (1995)
Phlorethols	C. retroflexa	Sailler and Glombitza (1999)
Phlorofucofuroeckol A	E. kurome,	Fukuyama et al. (1990)
	E. stolonifera	Iwai (2008)
Phlorofucofuroeckol B	E. arborea	Sugiura et al. (2006)
Phloroglucinol	E. cava	Glombitza et al. (1973)
Triphlorethol B	E. stolonifera	Jung et al. (2008)
Triphlorethol A	E. cava	Kang et al. (2005)

Table 2. An overview of the antidiabetic properties of the brown marine algae.

Organism	Phlorotannins	Inhibitory/regulatory activity	References
Eisenia bicyclis	Phlorofucofuroeckol A, Dieckol, 8,8′-bieckol	α-Fucosidase, α-galactosidase, α-mannosidasem	Shibata et al. (2002)
Eisenia bicyclis	Phlorofucofuroeckol A, Dieckol, 8,8′-bieckol	α-Glucosidase, α-amylase	Okada et al. (2004)
A. nodosum	Ethanolic extract	α-Glucosidase, reduction of liver glycogen levels	Zhang et al. (2007)
Ecklonia stolonifera	Methanolic extract	Decrease in plasma glucose levels, Lipid peroxidation	Iwai (2008)
E. stolonifera	Phlorofucofuroeckol A	Inhibition of ACE, AGE, RLAR, ROS	Jung et al. (2008)
E. cava	Dieckol	α-Glucosidase, α-amylase	Li et al. (2009)
Ishige okamurae	Diphlorethohydroxycarmalol	α-Glucosidase, α-amylase, no cytotoxicity evidenced	Heo et al. (2009)
A. nodosum	Methanolic extract	α-Glucosidase, α-amylase, Plasma glucose levels, Insulin sensitivity index	Apostolidis and Lee (2010)
E. cava	Methanolic extract	Plasma glucose levels	Kang et al. (2010)
E. cava	Dieckol	α-Glucosidase, α-amylase, no cytotoxicity evidenced	Lee et al. (2010)
Ishige okamurae	Methanolic extract	Insulin resistance, enhanced Fasting blood glucose levels, glucokinase activity, decrease in G6Pase and PEPCK activity	Min et al. (2011)
Palmaria,		α-Glucosidase, α-amylase
Ascophyllum	Methanolic extract	α-Glucosidase	Nwosu et al. (2011)
Alaria		α-Glucosidase, α-amylase

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