Effects of baicalin cream in two mouse models: 2,4-dinitrofluorobenzene-induced contact hypersensitivity and mouse tail test for psoriasis.

BACKGROUND Scutellaria baicalensis is a Chinese herbal medicine that has been used for centuries to treat psoriasis. Baicalin is one of the major flavonoids and bioactive components of S. baicalensis and is responsible for the pharmacologic actions of the plant. OBJECTIVE This study aimed to investigate the anti-inflammatory effect and keratinocyte differentiation-inducing activity of baicalin in vivo. METHODS Baicalin was formulated into topical creams at concentrations of 1%, 3%, and 5%. The anti-inflammatory effect of baicalin cream was evaluated in 2,4-dinitrofluorobenzene (DNFB)-induced contact hypersensitivity (CHS) mice, and its keratinocyte-modulating action was assessed using the mouse tail model for psoriasis. RESULTS During the topical application of baicalin cream, no evidence of irritant effect was observed in both tests. In the inflammation model, mice exposed to baicalin cream displayed a reduction in DNFB-induced CHS responses compared with vehicle-treated animals, showing that the topical application of baicalin cream exerted an anti-inflammatory effect. In the second model, baicalin cream dose-dependently increased the orthokeratosis of granular layers and the relative epidermal thickness of mouse tail skin, indicative of the keratinocyte differentiation-inducing activity of this topical preparation. CONCLUSIONS Taking the in vivo findings together, the present study indicated that baicalin cream may be a promising antipsoriatic agent worthy of further investigation for psoriasis treatment.