rosmarinic-acid and Dermatitis--Atopic

Rosmarinic acid is known to have anti-inflammatory and immunomodulatory activities. This study was performed to evaluate the effect of rosmarinic acid on atopic dermatitis (AD), one of the inflammatory disorders of the skin. Twenty-one subjects (14 women and seven men, 5-28 years of age) with mild AD participated in this study. Rosmarinic acid (0.3%) emulsion was topically applied to the elbow flexures of AD patients twice a day (once in the morning and once in the evening). All subjects were evaluated for skin conditions before treatment at the first visit, and then at 4 and 8 weeks after treatment. According to local Severity Scoring of Atopic Dermatitis index results, erythema on antecubital fossa was significantly reduced at 4 and 8 weeks (P < 0.05). Transepidermal water loss of the antecubital fossa was significantly reduced at 8 weeks compared to before treatment (P < 0.05). The results from self-questionnaires on the efficacy of rosmarinic acid indicated that dryness, pruritus and general AD symptoms improved. Our investigation into the AD-mitigating effect of rosmarinic acid through in vivo experiments demonstrated the possible clinical use of rosmarinic acid as a therapeutic agent for AD.

Topics: Administration, Cutaneous; Adolescent; Adult; Child; Child, Preschool; Cinnamates; Depsides; Dermatitis, Atopic; Double-Blind Method; Female; Humans; Male; Ointment Bases; Rosmarinic Acid; Young Adult

Atopic dermatitis (AD) is one of the most common skin diseases, and its incidence is increasing in industrialized countries. Furthermore, the epicutaneous application of a hapten, such as 2,4-dinitrofluorobenzene (DNFB), evokes an AD-like lesion in NC/Nga mice under specific pathogen-free (SPF) conditions. Rosmarinic acid (RA) is a secondary metabolite that is frequently found in herbs, and has anti-inflammatory, anti-oxidant, and anti-microbial effects. In this study, we studied whether RA is an effective treatment against DNFB-induced AD-like skin lesions in NC/Nga mice. RA at 1 or 5 μM was found to suppress the productions of interferon (IFN)-γ and interleukin (IL)-4 significantly by activated CD4(+) T cells. Furthermore, an intraperitoneal injection of RA at 10 or 50 mg/kg significantly inhibited skin lesion development and ear thickness and total serum IgE level increases in DNFB-treated NC/Nga mice. In addition, intraperitoneal administered RA at 10 or 50 mg/kg significantly inhibited the infiltrations of CD4(+) T, CD8(+) T, and mast cells into DNFB-induced skin lesions in NC/Nga mice. This study suggests that RA suppresses the development of AD-like dermatitis in DNFB-treated NC/Nga mice by reducing IFN-γ and IL-4 production by activated T cells and total serum IgE levels.

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cinnamates; Depsides; Dermatitis, Atopic; Dinitrofluorobenzene; Haptens; Immunoglobulin E; Interferon-gamma; Interleukin-4; Lymphocyte Activation; Male; Mast Cells; Mice; Rosmarinic Acid; Skin; Skin Diseases