Effects of Salvia microphylla on skin barrier function and atopic dermatitis-related inflammation in human HaCaT cells

Abstract

BackgroundSalvia microphylla has been used to treat gynecological disease and insomnia, and is known to have variety of biological activities, including antimutagenicity, lipase inhibition, and insecticidal effects.ObjectiveThis study investigated the effect of Salvia microphylla 50% ethanol extract (SME50s) on atopic dermatitis-related inflammation and skin barrier function in human keratinocytes.ResultsHaCaT cells were first used to confirm that SME50 enhanced skin barrier function. We found that SME50 induced the proliferation and migration of HaCaT cells, especially at 400 mu g/mL. Furthermore, SME50 also considerably enhanced phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK) 1/2, p38 MAPK, c-JUN N-terminal kinase (JNK), and serine/threonine-specific protein kinase (AKT) in HaCaT cells. Moreover, SME50 also stimulated Type I collagen synthesis and reduced MMP-1 production. We then confirmed that the mRNA expression levels of filaggrin (FLG), involucrin (IVL), and loricrin (LOR), all of which play important roles in the structure and function of the skin barrier, had significantly increased. Next, we used TNF-alpha/IFN-gamma stimulated HaCaT cells to confirm the atopic dermatitis-related inflammatory effect of SME50. Moreover, exogenous SME50 also significantly reduced proinflammatory cytokines (i.e., TNF-alpha, IL-1 beta, and IL-6) in these cells. Furthermore, downregulation of the MAPK signaling pathway reduced phosphorylation of nuclear factor-kappa B (NF-kappa B), a transcription factor that modulates inflammatory proteins such as JNK, ERK1/2, and AKT. We also observed considerably reduced expression of MDC, TARC, and RANTE, and significantly increased expression of FLG, IVL, and LOR in TNF-alpha/IFN gamma-stimulated HaCaT cells.ConclusionTaken together, these results show that SME50 enhances skin barrier function and can alleviate inflammatory diseases such as atopic dermatitis. These results therefore suggest that SME50 may be useful as a functional cosmetic material for atopic management.