Effect of Oral Administration of Scutellaria baicalensis Root Extract on Atopic Dermatitis-like Skin Lesion Induced by Oxazolone in Mice

Abstract

Atopic dermatitis (AD) is a relapsing skin disease associated with chronic inflammation and its prevalence has been increased especially in industrialized countries. Recently, several studies have reported that oral administration of herbal extracts has preventive or therapeutic effects on AD. We investigated the effects of several food materials on oxazolone-induced AD murine model. Among them, Scutellaria baicalensis root extract showed lower total IgE level in serum in the preliminary studies. Scutellaria baicalensis is a widely used traditional herbal medicine in China and Korea. The root of Scutellaria baicalensis contains flavonoids and exhibits various beneficial bioactivities such as anti-inflammatory and anti-allergic effects. Therefore, we evaluated the effect of oral administration of methanolic extract from Scutellaria baicalensis root (SB) on the development of atopic dermatitis-like skin lesions in hairless mice induced by discontinuous oxazolone application. Mice were orally administered SB 250, 500 mg/kg b.w. per day, or dexamethasone 1 mg/kg b.w. per day for 33 days. Oral administration of SB inhibited the development of clinical symptoms, and reduced dermal mast cell infiltration. However, SB administration did not show definite suppressive effect on the elevation of serum total IgE level in the experimental condition. Furthermore, IL-6 level in serum and the mRNA expressions of IL-4, IL-13, IL-12, IFN-γ, TGF-β, and Foxp3 in draining lymph nodes were not significantly affected by SB administration. In conclusion, SB may alleviate atopic dermatitis via the inhibition of mast cell infiltration.