The polysaccharides extracted from Nerium indicum Mill have good immunomodulatory activity

LI Meifeng; JIAO Yukun; LIU Hongju; ZHANG Shaojie

doi:10.20227/j.cnki.2096-3610.2025.05.007

Abstract：Objective This study aimed to investigate the structure and immunomodulatory activity of polysaccharide from Nerium indicum Mill.Methods A crude polysaccharide of Nerium indicum Mill(NMP80)was obtained by water extraction and ethanol precipitation.The molecular weight,monosaccharide composition,sugar content,uronic acid content,protein content and polysaccharide characteristic functional groups of NMP80 were detected by high performance gel chromatography,high performance liquid chromatography,phenol sulfuric acid method,sulfuric acid carbazole method,BCA protein assay,ultraviolet spectroscopy and infrared spectroscopy;Using MTT colorimetric assay and neutral red uptake experiment to study the cytotoxicity and phagocytic activity of NMP80 on macrophages;Using a chloramphenicol induced zebrafish immune suppression model,the effects of NMP80 on zebrafish neutrophils,macrophages,NO,and ROS generation were detected by stereomicroscopy,neutral red staining,DAF-FM DA fluorescence probe method,and DCFH-DA fluorescence probe method.Results The molecular weight range of NMP80 was 5 900～65 900,with a sugar content of 70.2%,a uronic acid content of 9.2%,and a protein content of 0.8%.It was mainly composed of mannose,xylose,glucuronic acid,galacturonic acid,glucose,galactose,xylose,and arabinose,with a molar ratio of 10∶5.6∶16.5∶0.9∶1.1∶14.3∶3.1∶48.4;NMP80 can significantly enhance the cell viability and phagocytic activity of macrophages;NMP80 can promote the secretion of nitric oxide and reactive oxygen species in the immunosuppressive model zebrafish,significantly increase the number of neutrophils and macrophages in zebrafish.Conclusion The polysaccharide extracted from Nerium indicum Mill exhibits a great immune enhancing effect.