title: An insight into the role of barrier related skin proteins.
abstract: It is well-known that intercellular lipids in the stratum corneum (SC) of the skin play an important role in maintaining barrier function, and many types of penetration enhancers affecting lipids are used in topical products to improve transdermal drug permeability. Recently, it was reported that functional proteins in tight junctions of the epidermis are important for barrier function. In this study, the effects of penetration enhancers such as fatty esters, amines/amides, and alcohols on the barrier function of the skin were evaluated in rat skin and normal human-derived epidermal keratinocytes (NHEK). All penetration enhancers decreased the electrical impedance (EI), however, the potencies of some penetration enhancers were not equal between rat skin and NHEK. The differences were clarified by immunohistochemical studies: some fatty esters decreased the immunoreactivity of involucrin and keratin 10 in the upper layer of the epidermis, while alcohols decreased the immunoreactivity of desmoglein-1, claudin-1, and E-cadherin located in the lower layer of the epidermis. From these results, it is suggested that penetration enhancers show new action mechanisms disturbing barrier-related proteins in epidermis, which are classified into two categories depending on their action sites.
authors.affiliation: Fuji Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 332-1. Ohnoshinden, Fuji-City, Shizuoka 417-8650, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Wato
authors.forename: Takuya
authors.initials: T
authors.lastname: Hara
authors.forename: Kenjirou
authors.initials: K
authors.lastname: Yamana
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakao
authors.forename: Toshio
authors.initials: T
authors.lastname: Inagi
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Terada
mesh_terms: D000818:Animals; D017097:Electric Impedance; D004817:Epidermis / Q000378:metabolism; D005079:Excipients; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000378:metabolism; D008297:Male; D010539:Permeability; D011506:Proteins / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012869:Skin Absorption / Q000187:drug effects*; D012879:Skin Physiological Phenomena
chemical_list: D005079:Excipients; D011506:Proteins