Abstract: The present work aims to decrease the molecular weight and expand the utilization of a Laminaria japonica polysaccharide LJP61A. The trifluoroacetic acid (TFA) and hydrochloric acid (HCl) were employed to degrade LJP61A, and two degradation products, DLJP-1 and DLJP-2, were generated. Based on this, the changes of the molecular weight, solubility, chemical composition, and triple-helix structure of LJP61A after degradation were determined. Additionally, the oxidized low density lipoprotein (Ox-LDL)-induced macrophage foam cell formation was used as the experimental model, and the inhibitory effects of the degradation products on macrophage foam cell formation were clarified at the cellular level. The results revealed that both TFA and HCl at low concentrations could degrade LJP61A effectively with lower molecular weights and higher solubilities. Meanwhile, neither degradation altered the primary functional groups and monosaccharide composition of LJP61A. Moreover, the triple-helix structure of LJP61A remained unaffected by TFA hydrolysis, whereas no triple-helix structure was detected in HCl hydrolysates. At the cellular level, it was demonstrated that the degradation products were nontoxic to RAW264.7 cells, and the inhibitory effects of LJP61A on macrophage foam cell formation increased significantly after TFA hydrolysis. However, the HCl hydrolysis decreased the activity of LJP61A. In conclusion, this research offers a strategy for the performance optimization and activity improvement of LJP61A and provides a theoretical basis for the degradation and development of natural bioactive polysaccharides.
Keywords: Laminaria japonica polysaccharides; degradation; structure; macrophage foam cell formation
合肥工业大学学报自科版