Inhibitory effects of polysaccharide-rich extract of Phragmites rhizoma on atopic dermatitis-like skin lesions in NC/Nga mice

AimsPhragmites rhizoma was reported to have anti-oxidative and free radical scavenging activity. It also has been traditionally used to suppress inflammation. In the present study, we aimed to evaluate the topical effects of the polysaccharide-rich extract of P. rhizoma (PEP) on atopic dermatitis.Main methodsWe induced AD-like skin lesions by an extract of the house-dust mite Dermatophagoides farinae (Dfb) in NC/Nga mice, and then performed macroscopic analysis, immunohistochemical staining and measurement of total serum IgE and cytokine production by ELISA.Key findingsTopically applied PEP suppressed dermatitis with a decrease in dermatitis score and scratch number. The histological manifestations of atopic skin lesions including thickened epidermis and increased numbers of mast cells, polymorphonuclear leukocytes and nerve fibers were significantly attenuated. The activation of IgE and the levels of cytokines such as IFN-γ IL-4 and IL-10 were also decreased.SignificanceOur results indicated that PEP might have an inhibitory effect on atopic dermatitis-like lesion and be a promising natural resource in the treatment of atopic dermatitis.