Topical application of two condensed tannins from the root of Rosa multiflora Thunberg for the treatment of atopic dermatitis (AD) in NC/Nga mice.

Recently, the isolation of several condensed tannins from the roots of Rosa multiflora Thunberg, a traditional herbal therapy in oriental medicine for rheumatoid arthritis and scabies, was described. Two of the major condensed tannins - procyanidin B-3 (ProB3) and ent-guibourtinidol-(4β → 6)-catechin (RM-1) - were then applied topically to atopic dermatitis-like skin lesions on NC/Nga mice in order to assess their immunomodulatory properties. Both ProB3 and RM-1 significantly reduced the serum levels of eosinophils, IgE and certain Th2 cytokines (IL-4, 5 and 13) (p < 0.05 or 0.01). Additionally, ProB3 and RM-1 significantly reduced both the mRNA and protein expression of COX-2 and iNOS in mouse skin tissues (p < 0.01). Such results strongly suggest that ProB3 and RM-1 may be useful in the treatment allergic skin conditions, most notably atopic dermatitis.