Purification, Characterization and Anti-psoriasis Effects of Polysaccharides from Dictamnus dasycarpus / 中国实验方剂学杂志

ABSTRACT

Objective:To extract crude polysaccharides from Dictamnus dasycarpus (DDP) for separation and purification, and study its anti-psoriasis effect. Method:After interception of DDP with a molecular weight of less than 10 kDa (DDP-UF) using membrane separation technology, four components (DDP-UF-1, DDP-UF-2, DDP-UF-3, DDP-UF-4) were isolated and purified by DEAE-52 cellulose column. Then, the physical and chemical properties and structural characteristics of DDP-UF-1-4 samples were determined by infrared spectroscopy, high performance gel permeability chromatography (HPGPC), high performance liquid chromatography (HPLC) and scanning electron microscope (SEM). Imiquimod cream was selected to induce mouse models of psoriasis, diethylstilbestrol was used to induce vaginal epithelial cell proliferation in female mice, interleulein-17(IL-17) and IL-23 contents of serum in each mouse group were detected by enzyme-linked immunosorbent assay (ELISA), and skin tissues of the mouse back and vaginal epithelial cells had mitotic index changes by hematoxylin-eosin staining (HE). Result:DDP-UF-1-4 all exhibited the characteristic absorption peaks of polysaccharide, and the molecular weights of DDP-UF-1-4 were 10 948, 40 148, 32 222 and 19 943 Da, respectively. The monosaccharide compositions and mole ratios of DDP-UF-1-4 were mannose-glucose-galactose(32.45∶11.35∶8.69), mannose-rhamnose-glucuronic acid-glucose-xylose(25.68∶23.44∶21.62∶18.86∶3.68), mannose-rhamnose-glucuronic acid-galacturonic acid-xylose-galactose(18.68∶4.61∶3.89∶1.65∶5.36∶6.21), glucuronic acid-galacturonic acid-glucose-xylose-galactose(11.63∶15.26∶5.32∶2.08∶3.46), respectively. SEM showed that the morphological structures of DDP-UF-1-4 were flaky or spongy. The drug groups of DDP-UF-1 and DDP-UF-3 improved the skin condition of the psoriasis mice back, inhibited mitosis of female vaginal epithelial cells and significantly reduced the contents of IL-17 and IL-23 in serum (P<0.05, P<0.01). Conclusion:Both DDP-UF-1 and DDP-UF-3 have good anti-psoriasis effects, which may be related to the inhibition of IL-23/IL-17 signaling pathway.