Topical application of Moringa oleifera leaf extract ameliorates experimentally induced atopic dermatitis by the regulation of Th1/Th2/Th17 balance.

BACKGROUND: Moringa oleifera (M. oleifera) is widely cultivated in tropical and subtropical regions and has been used as a vegetable and in traditional medicine. In this study, the anti-atopic dermatitis activity of the ethanol extract of M. oleifera leaf was investigated in vitro and in vivo.

METHODS: For the in vitro study, HaCaT human keratinocytes were used for cytokines and MAPKinase assay. In the in vivo study, M. oleifera leaf ethanolic extract (MO) was topically applied to BALB/c mice with Dermatophagoides farinae extract (DFE; house dust mite extract)- and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD).

RESULTS: The expression of TNF-α, CCL17, IL-1β, IL-6 pro-inflammatory cytokine-related mRNA, and mitogen-activated protein kinases (MAPKs) in TNF-α/IFN-γ-induced HaCaT keratinocytes were reduced by MO. Epidermal and dermal ear thickness, mast cell infiltration, serum immunoglobulin levels, as well as gene expression of various cytokines in the ear tissue, lymph nodes, and splenocytes were improved by treatment with MO. In addition, MO reduced the expression of retinoic acid-related orphan receptor γT (RORγT), thymic stromal lymphopoietin (TSLP), and mannose receptor (CD206) mRNA in the ear tissue and improved cervical lymph node size.

CONCLUSION: The results of this study strongly suggest the beneficial effects of MO on AD via the regulation of inflammatory responses.