Topical application of Rosa multiflora root extract improves atopic dermatitis-like skin lesions induced by mite antigen in NC/Nga mice.

The roots of Rosa multiflora THUNB. (RM) has been used in oriental traditional medicines as remedies for scabies, rheumatic arthralgia and stomatitis which were practicably related with today's inflammatory and allergic diseases. In the present study, we evaluated whether RM root extract (RME) and its major constituent, 2-(3,4-dihydroxyphenyl)-6-(4-hydroxyphenyl)-8-(2,4-dihydroxyphenyl)-2,3-trans-6,7-cis-7,8-trans-3,4,7,8-tetrahydro-2H,6H-pyrano[2,3-f] chromene-3,7,9-triol (RM-3) belongs to condensed tannins, improve atopic dermatitis (AD)-like skin lesions in NC/Nga mice induced by mite antigen. Topical application of RME as well as RM-3 improved skin severity and suppressed mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) on skin tissues, in addition, significantly reduced T helper 2 (Th2) immune responses via interleukin 10 (IL-10) up-regulation. Thus, RME, contains lots of condensed tannins such as RM-3 which possesses potent anti-inflammtory and immune-modulatory effects, may be useful for treatment of skin allergies and can be developed as new alternative herbal therapy against AD.