Effects of topically applied Korean red ginseng and its genuine constituents on atopic dermatitis-like skin lesions in NC/Nga mice

Ginseng (the root of Panax ginseng C.A. Meyer, family Araliaceae) possesses various biological activities, including anti-inflammatory and anti-tumor actions. However, their topical effect on atopic dermatitis (AD) has not been studied yet. The aim of this study was to examine the therapeutic effects of topical Korean red ginseng saponin fraction (KRGS) and its genuine constituents on AD-like skin lesions in an AD mouse model. The therapeutic effect of topical KRGS and ginsenosides in 2-chloro-1,3,5-trinitrobenzene (TNCB)-treated NC/Nga mice was assessed by measuring the skin severity scores, ear thickness, histological changes of lesional skin including mast cell count, tissue tumor necrosis factor (TNF)-α, interleukin (IL)-4, and interferon (IFN)-γ mRNA expression, and total serum IgE. Topical administration of 0.1% KRGS, 0.1% Rh2 and 0.1% Rh2+0.1% Rg3 significantly reduced the clinical skin severity scores, ear thickness and mast cell infiltration in the TNCB-induced AD-like skin lesions. Topical application of KRGS and its constituents significantly reduced TNCB-induced increase in ear TNF-α and IL-4 mRNA expression, but not IFN-γ mRNA expression. There was little change of serum total IgE level by topical KRGS and its constituents. In this study, topical KRGS and ginsenosides Rh2 and Rg3 were found to exert an anti-inflammatory effect in vivo and proved to be beneficial in an animal model of AD. Our results suggest that KRGS and its ginsenosides Rh2 and Rg3 have potential as a topical agent for the treatment of AD.