Bioactive Polysaccharides from Blue Honeysuckle Berries: Structural Properties and Digestive Enzyme Inhibition Activities

The physicochemical and bioactive properties of polysaccharides from blue honeysuckle (Lonicera caerulea L.) berries were comprehensively investigated. Fourier transform infrared spectroscopy confirmed that both samples were acid heteropolysaccharides. High-performance liquid chromatography detailed a monosaccharide profile of arabinose, galacturonic acid, rhamnose, galactose, and glucose in specific molar ratios. High-performance gel permeation chromatography further revealed variations in molecular weight and distribution among the samples. Functionally, the polysaccharides exhibited significant in vitro antioxidant capacity. For the first time, the polysaccharides are shown to inhibit pancreatic lipase, in addition to α-amylase and α-glucosidase, demonstrating potent inhibitory activity with low IC50 values (2.80 ± 0.12 mg/mL). This bioactivity, particularly toward lipase, was correlated with structural properties such as monosaccharide profile and molecular weight. These results highlight the potential of these polysaccharides as functional food ingredients for managing hyperglycemia and obesity and provide novel insights into their structure–activity relationships.