Fucoidan Structure and Its Impact on Glucose Metabolism: Implications for Diabetes and Cancer Therapy

Abstract

Fucoidans are complex polysaccharides derived from brown seaweeds which consist of considerable proportions of L-fucose and other monosaccharides, and sulphated ester residues. The search for novel and natural bioproduct drugs (due to toxicity issues associated with chemotherapeutics) has led to the extensive study of fucoidan due to reports of it having several bioactive characteristics. Among other fucoidan bioactivities, antidiabetic and anticancer properties have received the most research attention in the past decade. However, the elucidation of the fucoidan structure and its biological activity is still vague. In addition, research has suggested that there is a link between diabetes and cancer; however, limited data exist where dual chemotherapeutic efforts are elucidated. This review provides an overview of glucose metabolism, which is the central process involved in the progression of both diseases. We also highlight potential therapeutic targets and show the relevance of fucoidan and its derivatives as a candidate for both cancer and diabetes therapy.

Keywords: anticancer; antidiabetic; fucoidan; glucose metabolism; natural bioproducts.

Figure 1

Carbohydrate digestion, absorption and assimilation. For simplicity, the monosaccharides are depicted in different shapes; squares represent galactose, circles glucose and triangles fructose. The steps of carbohydrate digestion are shown with corresponding hydrolytic enzymes (shown in red). The monosaccharide transporter molecules are shown as cylindrical shapes. The highlighted steps can be therapeutic targets for fucoidan. Adapted from [27].

Figure 2

The glycolytic flux process. A summary of the glycolysis pathway with its metabolic intermediates that can be used for various processes by cells. The known glycolytic enzyme inhibitors are presented in red circles and their target enzymes in red. Glucose transporters (GLUTs) and lactate monocarboxylate transporters (MCTs) are shown as transmembrane proteins. Moreover, the enzymes and transporters illustrated may be plausible targets for fucoidan. Adapted from [60].

Figure 3

Shared factors in the progression of diabetes and cancer promotion. Insulin resistance, glycolysis reprogramming and β-cell failure, all increase hyperglycaemia. These also alter pathways protecting tumour cells from apoptosis and encourages tumour proliferation. Fucoidan may be useful in regulating one or more pathways which may directly affect glucose metabolism. Adapted from [11].