lignans and Dermatitis--Atopic

Magnolia officinalis constitutes a traditional Korean medicine used for the treatment of atopic dermatitis, and honokiol is an active diphenyl compound present in Magnolia officinalis.. The aim of the study was to investigate the therapeutic effects of honokiol on atopic dermatitis in vivo.. The therapeutic effects of honokiol were evaluated in a 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis model.. Administration of honokiol (10 mg/kg) significantly suppressed mast cell accumulation and inflammation induced by DNCB in skin tissues. Moreover, DNCB-induced increases in serum immunoglobulin E levels were reversed by honokiol treatment. In addition, DNCB-induced elevation of inflammatory cytokines (interleukin (IL)-4, IL-13, IL-17, and interferon-γ) in the skin and lymph nodes was significantly ameliorated by honokiol administration. Furthermore, the increase in lymph nodes sizes induced by DNCB treatment was reduced by honokiol administration.. DNCB-induced atopic responses in the ears and lymph nodes were significantly suppressed by honokiol treatment. These results suggested that honokiol is a potential therapeutic agent for atopic dermatitis.

Topics: Animals; Biphenyl Compounds; Cytokines; Dermatitis, Atopic; Dinitrochlorobenzene; Immunoglobulin E; Inflammation; Lignans; Magnolia; Male; Mast Cells; Mice; Mice, Inbred BALB C

Atopic dermatitis (AD) is a severe inflammatory skin disease caused by a combination of genetic, immune, and environmental factors. Intestinal microbiome disorders and changes in the immune microenvironment are associated with AD. We observed that gut bacterial metabolite enterolactone (ENL) was significantly reduced in AD model mice. Notably, patients with early childhood-onset AD exhibited decreased sera ENL level compared to the healthy controls, and the ENL level was negatively correlated with the SCORAD index. Secoisolariciresinol-diglycoside (SDG) is a natural dietary lignan of flaxseeds that can be converted by intestinal bacteria to ENL. Repeated applications of 2,4-dinitrochlorobenzene (DNCB) were performed on the ear and dorsal skin of mice to induce AD-like symptoms and skin lesions. Oral administration of SDG significantly decreased serum IgE levels and limited skin inflammation in the DNCB-induced AD mice. In addition, SDG treatment strongly limited the Th2 responses in AD mice. Moreover, we demonstrated that the IL-4 production was significantly suppressed by ENL under Th2 polarization conditions via the JAK-STAT6 signaling pathway in a concentration-dependent manner. We concluded that SDG and its derived metabolite ENL ameliorated AD development by reducing the Th2 immune response. These results suggested that SDG and ENL might be exploited as potential therapeutic candidates for AD treatment.

Topics: 4-Butyrolactone; Animals; Anti-Inflammatory Agents; Butylene Glycols; Child, Preschool; Dermatitis, Atopic; Dinitrochlorobenzene; Glucosides; Humans; Immunity; Lignans; Mice; Mice, Inbred BALB C; Skin

Forsythia suspensa is used in traditional medicine to treat inflammation. To clarify the anti-inflammatory and anti-allergic effects of F. suspensa fruits, we determined the therapeutic effects of crude extract, fractions, and a constituent from F. suspensa fruits on a murine atopic dermatitis (AD) model.. We investigated the inhibitory effects of F. suspensa extract (FSE), extract fractions, and the constituent matairesinol on histamine release from MC/9 mast cells activated by compound 48/80 and the development of AD-like skin lesions and symptoms in NC/Nga mice exposed to Dermatophagoides farinae (mite) extract. High performance liquid chromatography (HPLC) analysis of FSE and its fractions were evaluated using matairesinol standard.. FSE, FSE methylene chloride fraction (FSE-MC), and FSE water fraction (FSE-water) inhibited compound 48/80-induced histamine release from MC/9 mast cells. Topical application of FSE or FSE-MC to NC/Nga mice exposed to Dermatophagoides farinae suppressed the development of AD-like skin lesions. Quantitative HPLC analysis of FSE and FSE-MC identified the presence of matairesinol. Topical application of matairesinol to NC/Nga mice effectively reduced AD symptoms, inhibited inflammatory cell infiltration, and lowered immunoglobulin E levels in serum. Further study demonstrated that DfE-induced changes in IL-4 and IFN-γ mRNA expression in the ears of NC/Nga mice were reversed by matairesinol application.. These results indicate that the F. suspensa and its constituent matairesinol might be a therapeutic candidate for treating allergic inflammatory disorders such as AD.

Topics: Allergens; Animals; Anti-Allergic Agents; Anti-Inflammatory Agents; Dermatitis, Atopic; Dermatophagoides farinae; Disease Models, Animal; Forsythia; Fruit; Furans; Immunoglobulin E; Interferon-gamma; Interleukin-4; Lignans; Male; Mice; Phytotherapy; Plant Extracts; Skin