Profiling the activity of edible European macroalgae towards pharmacological targets for type 2 diabetes mellitus

In traditional medicine marine extracts are extensively used as therapies for diabetes. With the increasing rate of incidence of type 2 diabetes mellitus and rising cost of treatments, we investigated the anti-diabetic properties of extracts of common edible seaweeds in Europe including their ability to inhibit alpha-glucosidase and dipeptidyl peptidase 4 (DPP-4) enzymatic activity, block sodium glucose transporter-2 (SGLT-2) activity and stimulate glucagon-like peptide-1 (GLP-1) secretion and synthesis. The most promising seaweed extracts were tested for anti-hyperglycaemic activity <i>in vivo</i>. Some brown seaweed (Phaeophyceae) extracts had inhibitory effects on alpha-glucosidase ranging from 13.9 ± 0.2% to 89.5 ± 0.4% (p Alaria esculenta and water extracts of <i>Laminaria digitata</i> strongly inhibited DPP-4 activity by 91.3 ± 0.1% and 90.0 ± 0.2%, respectively (p Ulva rigida (Chlorophyta) had the greatest potential to stimulate GLP-1 secretion and GLP-1 synthesis (p Porphyra linearis (Rhodophyta) significantly reduced the overall glycaemic excursion during an oral glucose tolerance test in normal mice (p