Osthole Regulates Secretion of Pro-Inflammatory Cytokines and Expression of TLR2 and NF-κB in Normal Human Keratinocytes and Fibroblasts

Abstract

Introduction Osthole (OST), an active compound isolated from Cnidium monnieri , is used in traditional Chinese medicine to treat a variety of human diseases. Although OST has a good therapeutic effect, the underlying mechanism of its action in inflammatory skin diseases in humans is still unknown. Purpose The present study aimed to test the hypothesis that OST can be used as an herbal substance that minimizes skin inflammation and barrier dysfunction. In this study, histamine and LPS were used to induce inflammation in skin keratinocytes and fibroblasts to test whether OST can inhibit their responses. Methods Cell migration was analyzed using a wound healing assay. Changes in cell monolayer integrity were assessed by the measurement of transepithelial electrical resistance. Secretion of IL-1β, IL-6, IL-8, TNF-α, CCL2/MCP-1, CCL5/RANTES, and COX-2 was measured by ELISA, while expression of TLR2, NF-κB , and COX -2 was analyzed by qPCR. Results OST decreased the level of IL-1β, TNF-α, CCL2/MCP-1 and CCL5/RANTES, and expression of TLR2, NF-κB and COX-2 during histamine/LPS-induced inflammation in human keratinocytes and fibroblasts. OST also improved cell migration and cell barrier function. Conclusion Our results suggest that OST suppresses inflammatory responses via regulation of IL-1β, TNF-α, CCL2/MCP-1 and CCL5/RANTES secretion, and TLR2 , and COX-2 expression.

The Effect of Osthole on Transient Receptor Potential Channels: A Possible Alternative Therapy for Atopic Dermatitis

“… 80 , 81 Increased expression of NF-κB mRNA was confirmed in our previous studies, and OST significantly reduced it in 3D skin and skin cell lines. 28 , 29 It is very possible that the decreased expression of the TRPV4 channel after OST stimulation is related to the decreased activation of the NF-κB signalling and the reduction of inflammatory IL’s. Furthermore, we believe that in human keratinocytes, PLCβ activation by the Gq/11 protein-coupled receptor tremendously enhances TRPV4 currents, and stimulation of the M1 acetylcholine receptor increases the sensitivity of TRPV channel activation.…”

“…Total RNA was isolated according to the protocol described in Kordulewska et al 2022. 28 The concentration and purity of the extracted RNA (A260/A280) was determined using the NanoDrop ND −1000 spectrophotometer (NanoDrop Tech., Inc. Wilmington, DE, USA). Purified RNA was processed using the High-Capacity cDNA Reverse Transcription Kit (Applied Biosystems, Thermo Fisher Scientific, Waltham, MA, USA, cat.…”

“…These include anti-cancer 24–26 anti-inflammatory, 27–30 antioxidant, 31 anti-angiogenic, 32 anti-allergic 27 , 33 , 34 immunomodulatory 33 , 35 and hepatoprotective 36–38 activities. In our previous publications, we found that OST is immunosuppressive in peripheral blood mononuclear cells (PBMCs) isolated from children with allergies or asthma 27 , 30 , 39–43 and autism spectrum disorders (ASD), in keratinocytes and fibroblast cell lines 28 , and in a 3D skin model. 29 However, the adequate role of OST in histamine-dependent pruritus is not clear, and the molecular mechanisms of its action have not been thoroughly investigated.…”

“…Osthole (OST) (7-methoxy-8-(3-methyl-2-butenyl)-2H-1-benzopyran-2-one) is a natural coumarin and a major chemical constituent of the plant Cnidium monnieri (L) Cusson and is considered a promising natural product that could be used pharmacologically in the future. These include anti-cancer [24][25][26] anti-inflammatory, [27][28][29][30] antioxidant, 31 anti-angiogenic, 32 anti-allergic 27,33,34 immunomodulatory 33,35 and hepatoprotective [36][37][38] activities. In our previous publications, we found that OST is immunosuppressive in peripheral blood mononuclear cells (PBMCs) isolated from children with allergies or asthma 27,30,[39][40][41][42][43] and autism spectrum disorders (ASD), in keratinocytes and fibroblast cell lines 28, and in a 3D skin model.…”

Secretion of IL-6 by fibroblasts exposed to Australian honeys involves lipopolysaccharide and is independent of floral source

“…In addition to their role in extracellular matrix production and scar tissue formation, fibroblasts release cytokines to provide regulatory control over immune cell function 1 . Dermal fibroblasts basally secrete tumour necrosis factor alpha (TNF-α), interferon gamma, interleukin-6 (IL-6) and IL-12, with elevated secretions in response to stimuli such as histamine and bacterial lipopolysaccharide (LPS) 2 , 3 . The release of cytokines by wound fibroblasts during inflammation leads to the activation of nearby immune cells 1 .…”