Improvement of atopic dermatitis with topical application of Spirodela polyrhiza.

BACKGROUND

Spirodela polyrhiza has been used as a traditional remedy for the treatment of urticarial, acute nephritis, inflammation, as well as skin disease.

OBJECTIVE

Atopic dermatitis (AD) is characterized hyperplasia of skin lesion and increase of serum immunoglobulin E (IgE) level. In this study, the topical effects of S. polyrhiza (SP) on 2, 4-dinitrochlorobenzene (DNCB)-induced AD mice model were investigated by several experiments.

METHODS

BALB/c mice were randomly divided into five groups as NOR, CON, DEX, SP 1, and SP 100 groups (n=5, respectively). To induce atopic dermatitis-like skin lesions, DNCB had been applied on shaved dorsal skin. SP was topically treated to DNCB-induced mice as 1 and 100mg/mL concentrations. Histological changes were showed by hematoxylin and eosin (H&E) staining and the infiltration of mast cells was detected by toluidine blue staining. In addition, the level of IgE and each cytokines were measured and expressions of inflammatory signaling factors were analyzed by western blotting assay.

RESULTS

SP treatment improved a hyperplasia of epidermis and dermis in DNCB-induced AD-like skin lesion. The infiltration of mast cells was also decreased by treatment of SP. In addition, SP reduced the level of IgE in serum and attenuated the secretion of cytokines such as interleukin (IL)-4, IL-6, and tumor necrosis factor (TNF)-α. Treatment of SP also inhibited the expressions of pro-inflammatory mediators including nuclear factor-κB (NF-κB), phosphor-IκB-α, and mitogen-activated protein kinase (MAPK)s.

CONCLUSIONS

From these data, we propose that SP ameliorates AD via modulation of pro-inflammatory mediators. SP may have the potential to be used as an alternative for treatment of AD.