Effect of the topical application of an ethanol extract of quince seeds on the development of atopic dermatitis-like symptoms in NC/Nga mice.

BACKGROUND: Quince (Cydonia oblonga Miller) is a deciduous shrub belonging to the Rosaceae family. Quince seed extract has long been used as a cosmetic ingredient for its moisturizing effect. However, little is known about whether quince seed extract has therapeutic effects on keratinocyte-associated skin inflammation. METHODS: In the present study, we investigated the effect of the topical application of ethanol extract of quince seeds (QSEtE) on atopic dermatitis (AD) symptoms in NC/Nga mice. The direct effect of QSEtE on keratinocytes was evaluated using the human keratinocyte cell line HaCaT. RESULTS: The preliminary application of QSEtE markedly reduced house dust mite allergen-induced skin lesions. The expression of thymus- and activation-regulated chemokine (TARC) in dorsal skin was downregulated. QSEtE directly suppressed the expression and production of TARC in HaCaT cells. CONCLUSIONS: The results suggest that the topical application of QSEtE is effective in preventing the onset of and ameliorating the atopic symptoms of keratinocyte-associated skin inflammation by suppressing TARC production in keratinocytes.

Inhibitory effects and molecular mechanisms of garlic organosulfur compounds on the production of inflammatory mediators.

SCOPE: Garlic is used for both culinary and medicinal purposes by many cultures. The garlic organosulfur compounds (GOSCs) are thought to be bioactive components. This study aims to clarify the antiinflammatory effects and molecular mechanisms of GOSCs in both cell and animal models. METHODS AND RESULTS: RAW264.7 cells were treated with six kinds of GOSCs to screen their influence on cyclooxygenase-2 and inducible nitric oxide synthase expression by Western blotting. Prostaglandin E2 and nitrite were measured by ELISA and Griess reaction, respectively. Cytokines in culture medium were assayed by the multiplex technology. Proteins were detected by Western blotting. Mouse paw edema was induced by LPS. The results revealed that diallyl trisulfide (DATS) was a strongest inhibitor for cyclooxygenase and inducible nitric oxide synthase among GOSCs, and reduced the levels of LPS-induced IL-6, IL-10, IL-12(p70), KC, MCP-1, and TNF-α. Cellular signaling analysis revealed that DATS downregulated AKT1/TGF-ß-activated kinase-mediated mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. Furthermore, DATS activated Nrf2-mediated expression of HO-1 and NQO1 and reduced LPS-induced intracellular reactive oxygen species, which may contribute to suppress inflammatory mediator production. Finally, in vivo data demonstrated that DATS attenuated LPS-induced mouse paw edema. CONCLUSION: DATS as a potential inhibitor revealed antiinflammatory effect in both cell and animal models by downregulating AKT1/TGF-ß-activated kinase-mediated NFκB and MAPK signaling pathways.