Topical application of Scutellaria baicalensis suppresses 2,4-dinitrochlorobenzene-induced contact dermatitis.

Allergic contact dermatitis (ACD) is a prototypic T-cell-mediated cutaneous inflammatory response. In the present study we describe the anti-allergic effect of topically applied Scutellaria bacalensis aqueous extract (WSBE) in suppressing 2,4-dinitrochlorobenzene (DNCB)-induced ACD in BALB/c mice. Topically applied WSBE attenuated the epidermal thickness and mast cell infiltration into the skin in DNCB-induced contact dermatitis. Furthermore, WSBE suppressed DNCB-induced production of serum IgE as well as IL-4, IFN-γ, and TNF-α in the skin. Topical application of WSBE also ameliorated the significant decrease in dermal glutathione and superoxide dismutase levels. Moreover, present results demonstrated that the baicalin, bioactive compound of WSBE, was able to penetrate into the skin following topical application, which was confirmed by the HPLC analysis using rat model. Taken together, topical application of WSBE exerts beneficial effects in contact dermatitis model, suggesting that WSBE might be a candidate for the treatment of contact dermatitis.