Anti-inflammatory effects of a methanol extract of Dictamnus dasycarpus Turcz. root bark on imiquimod-induced psoriasis

Abstract

BackgroundThe root bark of Dictamnus dasycarpus Turcz. has been successfully used for the treatment of inflammatory skin conditions such as eczema and pruritus. However, the anti-psoriatic effect of this plant has not until now been investigated.MethodsThe aim of this project was to investigate whether a methanol extract of Dictamnus dasycarpus Turcz. root bark (MEDD) can be used as a therapeutic agent for psoriasis in C57BL/6 mice model of imiquimod (IMQ)-induced psoriasis. IMQ and MEDD was applied to mouse skin continuously for 7 days. The skin phenotype and the levels of inflammatory cytokines, such as interferon (IFN)-γ and interleukin (IL)-17, were analyzed. The immune cell population was determined by flow cytometry, and STAT1 and 3 protein levels were measured.ResultsAn alleviation of scaly skin phenotype, immune cell infiltration in the dermis, and epidermal hyperplasia was observed after daily MEDD treatment in the lesion-affected area. It was also found that MEDD reduced IL-17 cytokine levels decreased by 44.37% (p < 0.05), the number of IL-17-producing Th17 cells and γδT cells, and the size of the Th1 population secreting IFN-γ decreased by 45.98, 62.21, and 44.42%, respectively (p < 0.05), compared with the vehicle control group. STAT3 signals, associated with IL-17 are also reduced by MEDD.ConclusionsAn anti-psoriatic effect of MEDD was observed, as determined by decreased skin inflammation, reduced number of inflammatory cytokines, and a smaller population of inflammatory cells. These results contribute to the validation of the use of MEDD in the treatment of psoriasis.

Chemical Composition of a Novel Distillate from Fermented Mixture of Nine Anti-Inflammatory Herbs and Its UVB-Protective Efficacy in Mouse Dorsal Skin via Attenuating Collagen Disruption and Inflammation

“…In addition, it has been reported that Lonicera japonica inhibits the NF-κB and signal transducer and activator of transcription 3 pathway (STAT3) in acute inflammation through a component called chrysoeriol [23]. Furthermore, Choi et al (2019) have demonstrated that Dictamnus dasycarpus Turcz has an anti-inflammatory effect through lowering inflammatory cytokines such as interferon-γ and interleukin (IL)-17 [10]. As another example, avarol, a marine sesquiterpenoid hydroquinone derived from Dysidea avara (Dysideidae family), displays beneficial properties such as anti-inflammatory and antioxidant effects and it has been suggested as a material possessing potential UVB photoprotective candidates [24,25].…”

“…For example, many plants have been proven to show anti-inflammatory effects on the skin as follows: Angelica gigas [ 8 ], Lonicera japonica [ 9 ], Dictamnus dasycarpus Turcz. [ 10 ], D. opposita Thunb. [ 11 ], Ulmus davidiana var.…”

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“…The extract treated lesions exhibited infiltration of the immune cells in the dermis, reduction in scaly skin and epidermal hyperplasia. The extract reduced interleukin IL-17 and interferon IFN-γ levels, the number of Th17 cells and γδT cells, and the size of the Th1 cells and STAT3 signals 94 .…”

Clinical efficacy and target signaling pathways of natural products in psoriasis treatment: a systematic review

“…A methanolic extract of root bark of Dictamnus dasycarpus Turcz. improved scaly skin lesions, reduced the number of in ammatory cell in ltration, and decreased epidermal thickness in IMQ-induced psoriasis mice by inhibiting STAT3 signaling pathway and reducing the number of Th17 cells as well as IL-17 production [84]. 9,19cycloartenol glycosides G3, the main component of Cimicifuga simplex exhibited anti-psoriatic effects by suppressing the differentiation of CD4 + T cell into Th17 phenotype and inhibiting IFN-γ-induced JAK/STAT activation [85].…”