A topical Chinese herbal mixture improves epidermal permeability barrier function in normal murine skin

Chinese herbal medicine (CHM) has been shown to have beneficial effects for both skin disorders with barrier abnormality and as skin care ingredients. Yet, how CHM exerts their benefits is unclear. As most, if not all, inflammatory dermatoses are accompanied by abnormal permeability barrier function, we assessed the effects of topical CHM extracts on epidermal permeability barrier function and their potential mechanisms. Topical CHM accelerated barrier recovery following acute barrier disruption. Epidermal lipid content and mRNA expression of fatty acid and ceramide synthetic enzymes increased following topical CHM treatment in addition to mRNA levels for the epidermal glucosylceramide transport protein, ATP-binding cassette A12. Likewise, CHM extract increased mRNA expression of antimicrobial peptides both in vivo and in vitro. These results demonstrate that the topical CHM extract enhances epidermal permeability barrier function, suggesting that topical CHM could provide an alternative regimen for the prevention/treatment of inflammatory dermatoses accompanied by barrier abnormalities.