Abstract
As a strategy to prevent the well-known immunosuppressant effects of cyclophosphamide (CY), the immunomodulatory activity of the polysaccharide isolated from Urtica macrorrhiza Hand.-Mazz. (UMHMPS) was investigated in the present study. The chemical properties of UMHMPS, including total carbohydrates, uronic acid, protein contents, monosaccharide compositions, molecular weight and structural confirmation, were investigated. The immunomodulatory activity of UMHMPS was evaluated using a CY-induced immunosuppression mouse model. The results revealed that UMHMPS, which is composed of rhamnose, gluconic acid, galactose acid, galactose and xylose, exhibited potent immunomodulatory activity and low toxicity in mice. It increased the secretions of secretory immunoglobulin A, interferon (IFN)-γ and interleukin (IL)-4, and maintained the balance of the ratios of IFN-γ/IL-4 and cluster of differentiation (CD)3+/CD19+ cells in Peyer's patches. Furthermore, it increased the expression of Toll-like receptor (TLR)-4, indicating that TLR4 may be one of the receptors of UMHMPS. Therefore, the present study provides evidence for the potential use of UMHMPS as an immune enhancement drug in chemotherapy.