Selenized Lonicera caerulea L. polysaccharide was obtained by microwave-assisted HNO₃-Na₂SeO₃ method and purified by column chromatography. The selenium content of the selenized polysaccharide was (0.184 ± 0.03) mg/g with an average molecular mass of 58828.3 kDa, and the polysaccharide was composed of galacturonic acid, rhamnose, arabinose, mannose, glucose and galactose with a molar ratio of 1:3.06:6.18:0.29:1.78:13.01. Nuclear magnetic resonance analysis showed six glycosidic bonds to be present in the selenized polysaccharide, namely →3)-β-D-galactose-(1→; →4)-β-D-mannose-(1→; →6)-α-D-glucose-(1→; →4)-α-D-galacturonic acid-(1→; →2,4)-α-L-rhamnose-(1→; and α-L-arabinose-(1→. The selenized polysaccharide at a concentration of 10.0 mg/mL reduced the oxidative hemolysis of erythrocytes induced by H₂O₂ by 32.52%, reactive oxygen species (ROS) level by 44.93%, and malondialdehyde (MDA) content by 17.04 nmol/mL, and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) by 163.93, 9.95 U/mg and 20.07 mU/mg protein, respectively. Therefore, the selenized polysaccharide from L. caerulea L. fruit can protect erythrocyte against oxidative damage.

Total polyphenol-selenium nanoparticles (TP-SeNPs) were prepared with blueberry pomace polyphenols, prepared by ultrasonic assisted aqueous two-phase extraction and purified by using macroporous resin X-5. The structure of TP-SeNPs was characterized by energy dispersive X-ray (EDX) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD), and the antibacterial activity was measured. The results showed that selenium salt was reduced into elementary selenium, and hydrogen bond-like interactions existed between the O-H groups of polyphenols and nanoselenium atoms. Additionally, TP-SeNPs were stable as an amorphous solid which was nearly spherically dispersed. The inhibitory effect of TP-SeNPs was better against Gram-positive bacteria than against Gram-negative bacteria. The minimum inhibitory concentration (MIC) against Listeria monocytogene was 0.06 mg/mL. TP-SeNPs effectively inhibited the formation of L. monocytogene biofilms, and destroyed the permeability and integrity of the cell wall and membrane, and caused leakage of cell contents, thereby leading to the death of L. monocytogene. This study offers a new idea for the application of blueberry pomace and selenium nanoparticles, and provides a theoretical basis for the development of selenium nanoparticles with antimicrobial activity.