Ethanol extract of Thuja orientalis L. seeds ameliorated skin lesions in a dinitrofluorobenzene-induced mouse model of contact dermatitis

Background: Seed oils like sesame and camellia oils are used in herbal medicine to treat skin diseases and it has been reported that the seeds of Thuja orientalis have antioxidant, antibacterial, anti-inflammatory, and anti-allergic effects. Objectives: We investigate the anti-inflammatory effects of an ethanol extract of the seeds of T. orientalis (EETO) on a dinitrofluorobenzene-induced mouse model of contact dermatitis (CD). Materials and Methods: We investigated the effects of EETO on CD lesions and skin thickness, skin color, histopathologic findings, and cytokine production in mouse skins. Results: EETO ameliorated skin roughness, excoriation, scabs, and erythema. EETO also reduced erythema, melanin index, and inhibited skin thickness increases in CD mice. In addition, histopathologic examinations showed that EETO decreased epidermal hyperplasia, keratinization, and the productions of inflammatory cytokines (i.e., interleukin [IL]-6, tumor necrosis factor [TNF]-α, and monocyte chemotactic protein [MCP]-1). Conclusion: These results suggest that ethanolic extracts of the seeds of T. orientalis might provide relatively safe treatments for CD and that its therapeutic effect is exerted through inhibitions of IL-6, TNF-α, and MCP-1.