[Effects of Astragalus polysaccharide on imiquimod-induced psoriasiform dermatitis in mice and its mechanisms].

Objective: To investigate the effects and mechanisms of Astragalus polysaccharide on improving imiquimod-induced psoriasiform dermatitis in mice. Methods: Forty healthy female C57BL/6 mice were randomly divided into 5 groups, including blank control group, model group, astragalus polysaccharide high-dose group (200 mg/kg), medium-dose group (100 mg/kg) and low-dose group (50 mg/kg), with 8 mice in each group. The mice in model group and astragalus polysaccharide treatment group were treated with 5% imiquimod cream on the back to induce psoriasiform dermatitis. PASI score was monitored, and the secretion of inflammatory factors was determined by ELISA. The secretion of inflammatory factors was closely related to the infiltration of macrophages. The infiltration of macrophages in skin was detected by flow cytometry to further explore the effect of different concentrations of APS on psoriasis. Results: Compared with control group, the PASI score and the serum levels of TNF-α, IL-1β and IL-6 were increased significantly (P＜0.05), and the infiltration of macrophages in skin tissue was increased significantly in model group (P＜0.05). Compared with model group, the PASI score was decreased significantly (P＜0.05), and the serum levels of TNF-α, IL-1β and IL-6 were down-regulated significantly in astragalus polysaccharide high-dose and medium-dose groups (P＜0.05). The infiltrating macrophages in skin tissue were decreased significantly in Astragalus polysaccharide high-dose group (P＜0.05). Conclusion: Astragalus polysaccharide improve psoriasiform dermatitis in mice by inhibiting the infiltration of macrophages in skin tissue and decreasing the secretion of TNF-α, IL-1β and IL-6 in serum.目的: 探讨黄芪多糖对咪喹莫特诱导的小鼠银屑病样皮炎的干预作用及其机制。方法: 40只健康雌性C57BL/6小鼠随机分为空白对照组、模型组、黄芪多糖高剂量组(200 mg/kg)、中剂量组(100 mg/kg)和低剂量组(50 mg/kg),共5组,每组8只,利用5%咪喹莫特乳膏涂抹小鼠背部制备银屑病样皮炎模型,监测各组小鼠PASI评分,并采用ELISA测定小鼠炎症因子分泌的变化,通过流式细胞术检测皮炎中巨噬细胞的浸润程度。结果: 与空白对照组比较,模型组小鼠PASI评分明显增加(P＜0.05),血清TNF-α、IL-1β和IL-6水平明显升高(P＜0.05),皮肤组织中浸润的巨噬细胞明显增加(P＜0.05);与模型组比较,黄芪多糖高、中剂量组小鼠PASI评分明显明显减少(P＜0.05),小鼠血清TNF-α、IL-1β和IL-6水平明显下调(P＜0.05);黄芪多糖高剂量组小鼠皮肤组织中浸润的巨噬细胞明显减少(P＜0.05)。结论: 黄芪多糖通过抑制皮肤组织中巨噬细胞浸润,降低血清中TNF-α、IL-1β和IL-6的分泌,来改善小鼠银屑病样皮炎。.