Daphnetin inhibits proliferation and inflammatory response in human HaCaT keratinocytes and ameliorates imiquimod-induced psoriasis-like skin lesion in mice

Abstract

Background Psoriasis is a common chronic inflammatory skin disease. Keratinocytes hyperproliferation and excessive inflammatory response contribute to psoriasis pathogenesis. The agents able to attenuate keratinocytes hyperproliferation and excessive inflammatory response are considered to be potentially useful for psoriasis treatment. Daphnetin exhibits broad bioactivities including anti-proliferation and anti-inflammatory. This study aims to evaluate the anti-psoriatic potential of daphnetin in vitro and in vivo, and explore underlying mechanisms. Methods HaCaT keratinocytes was stimulated with the mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish psoriatic keratinocyte model in vitro. Cell viability was measured using Cell Counting Kit-8 (CCK-8). Quantitative Real-Time PCR (qRT-PCR) was performed to measure the mRNA levels of hyperproliferative marker gene keratin 6 (KRT6), differentiation marker gene keratin 1 (KRT1) and inflammatory factors IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. Western blotting was used to detect the protein levels of p65 and p-p65. Indirect immunofluorescence assay (IFA) was carried out to detect p65 nuclear translocation. Imiquimod (IMQ) was used to construct psoriasis-like mouse model. Psoriasis severity (erythema, scaling) was scored based on Psoriasis Area Severity Index (PASI). Hematoxylin and eosin (H&E) staining was performed to examine histological change in skin lesion. The expression of inflammatory factors including IL-6, TNF-α, IL-23A and IL-17A in skin lesion was measured by qRT-PCR. Results Daphnetin attenuated M5-induced hyperproliferation in HaCaT keratinocytes. M5 stimulation significantly upregulated mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. However, daphnetin treatment partially attenuated the upregulation of those inflammatory cytokines. Daphnetin was found to be able to inhibit p65 phosphorylation and nuclear translocation in HaCaT keratinocytes. In addition, daphnetin significantly ameliorate the severity of skin lesion (erythema, scaling and epidermal thickness, inflammatory cell infiltration) in IMQ-induced psoriasis-like mouse model. Daphnetin treatment attenuated IMQ-induced upregulation of inflammatory cytokines including IL-6, IL-23A and IL-17A in skin lesion of mice. Conclusions Daphnetin was able to attenuate proliferation and inflammatory response induced by M5 in HaCaT keratinocytes through suppression of NF-κB signaling pathway. Daphnetin could ameliorate the severity of skin lesion and improve inflammation status in IMQ-induced psoriasis-like mouse model. Daphnetin could be an attractive candidate for future development as an anti-psoriatic agent.

Coptisine Alleviates Imiquimod-Induced Psoriasis-like Skin Lesions and Anxiety-like Behavior in Mice

“…In this study, M5 stimulation could induce NF-κB activation in HaCaT cells by increasing the p-IKK level, decreasing the IκB-α level in the cytoplasm, and increasing NF-κB p65 nuclear translocation, which was recovered by pretreatment with coptisine, suggesting that the anti-inflammatory effects of coptisine could be mediated by regulating the NF-κB pathway. These findings concur with a previous study reporting that daphnetin, a natural compound from Daphne odora, reduced M5-induced inflammation in HaCaT cells by inhibiting the NF-κB signaling pathway activation [56].…”

A Modified Hyaluronic Acid–Based Dissolving Microneedle Loaded With Daphnetin Improved the Treatment of Psoriasis

“…The treatment of psoriasis is a challenge because of its pathogenic complexity ( Greb et al, 2016 ; Dainichi et al, 2018 ). Some potential drugs and methods for the treatment of psoriasis were proposed in some studies recently ( Hawkes et al, 2017 ), among which Daph showed a good symptom relief effect in the mouse psoriasis model ( Gao et al, 2020 ). However, during the onset of psoriasis, Daph does not penetrate the thickened epidermis readily, making it difficult to reach the subcutaneous layer.…”

“…Daphnetin (7,8-dihydroxycoumarin) is isolated from Daphne Korean Nakai and used for cancer and inflammatory disease treatment because of its antiproliferation and anti-inflammation effects ( Pei et al, 2021 ). Previous research has shown the therapeutic effectiveness of Daph (in a cream form) in a psoriasis mouse model ( Gao et al, 2020 ). Daph was reported to inhibit the abnormal proliferation of keratinocytes by inhibiting the NF-κB signaling pathway, thus reducing the release of inflammatory factors and alleviating the symptoms of psoriasis.…”

Curcumol may alleviate psoriasis-like inflammation by inhibiting keratinocyte proliferation and inflammatory gene expression via JAK1/STAT3 signaling

“…M5 ((IL-1α, IL-17A, IL-22, oncostatin M, and TNF-α) can induce keratinocytes to exhibit some of the characteristics of psoriatic keratinocytes in vitro [ 16 ]. Meanwhile, it has been reported that IL-17 and IL-22 enhance cutaneous inflammation, leading to epidermal thickening of psoriatic lesions and adherence of psoriatic scales [ 17 ].…”