Attenuation of intestinal inflammation of polysaccharides from the seeds of Plantago asiatica L. as affected by ultrasonication

Ultrasound treatment was applied to modify the physicochemical properties of polysaccharides from the seeds of Plantago asiatica L. The initial polysaccharides concentration of 10 mg/mL, ultrasonic power of 800 W, and different treatment time (15 s, 30 s, 1 min, 2 min) were used. After irradiation, the average molecular weight (Mw) and polydispersity index of relative molecular mass (PID) of polysaccharides decreased. The apparent viscosity of degraded polysaccharides dropped compared with native polysaccharides. By using dextran sodium sulphate (DSS) colitis mouse model, enhanced intestinal anti‐inflammatory activity of degraded polysaccharides was proved by a significant reduction in the degree of neutrophil infiltration, indicated by decreased macrophage inflammatory protein‐2 secretion, and levels of inflammatory cytokines (TNF‐α and IL‐4) in inflamed colon. These results suggested that ultrasound treatment is a viable modification technology for high Mw polymer materials with high anti‐inflammatory activity. PRACTICAL APPLICATIONS: Ulcerative colitis (UC) is a chronic and nonspecific inflammatory disorder of the colonic mucosa, and assumed to be an autoimmune disease. PLCP was found to be one of the active ingredients responsible for many of the observed bioactivities including anti‐inflammation, anticomplement and facilitating defecation. However, it's extremely complex structure with high molecular weights and high viscosity hampered its applications. In this study, ultrasound irradiation was used to depolymerize PLCP, and its attenuation of intestinal inflammation was also studied.