A novel hypoglycemic agent: polysaccharides from laver (Porphyra spp.)

Area of Science:

• Food Science
• Biochemistry
• Pharmacology

Background:

• Type-II diabetes mellitus (T2DM) is a global health concern requiring effective management strategies.
• Inhibiting intestinal alpha-amylase is a key approach to control postprandial hyperglycemia.
• Red seaweed (Porphyra spp.) contains polysaccharides with potential alpha-amylase inhibitory (α-AI) activity.

Purpose of the Study:

• To isolate and characterize novel alpha-amylase inhibitors from red seaweed.
• To evaluate the efficacy of these inhibitors in managing blood glucose levels.

Main Methods:

• Extraction of crude polysaccharides from red seaweed using hot water.
• Degradation of polysaccharides to low-molecular-weight fractions using hydrogen peroxide.
• Separation and purification of the active polysaccharide (PD-1).
• In vitro assessment of α-amylase inhibition and binding mode.
• In vivo evaluation of PD-1's effect on postprandial blood glucose in rats.

Main Results:

• A novel polysaccharide, PD-1, was isolated from red seaweed extracts.
• PD-1 demonstrated potent α-amylase inhibition with an IC50 of 12.72 mg mL-1 and 98.78% activity.
• PD-1 exhibited competitive binding to α-amylase.
• In vivo studies confirmed PD-1's ability to suppress postprandial blood glucose in normal and diabetic rats.

Conclusions:

• Red seaweed is a viable source for novel alpha-amylase inhibitors.
• The isolated polysaccharide PD-1 is effective in inhibiting α-amylase and managing blood glucose.
• PD-1 holds potential as a functional food ingredient for T2DM management.