Project description:Arnica m. effects were associated with a purported anti-inflammatory and tissue healing actions after trauma, bruises, or tissue injuries, but its cellular and molecular mechanisms are largely unknown. Here Arnica m. dilutions were tested using an in vitro model of macrophages polarized towards a “wound-healing” phenotype. The monocyte-macrophage human THP-1 cell line was cultured and differentiated with phorbol-myristate acetate and Interleukin-4, then exposed for 24 h to Arnica m. centesimal (c) dilutions 2c, 3c, 5c,9c, 15c or Control. None of these treatments affected cell viability. A total of 20 genes were differentially expressed comparing cells treated with Arnica m. 2c with those treated with Control only. Of these, 7 genes were up-regulated and 13 were down-regulated. Functional gene enrichment analysis showed that the most significantly upregulated function concerned 4 genes with a conserved site of EGF-like region (p<0.001) and three genes of proteinaceous extracellular matrix, including heparin sulphate proteoglycan 2 (HSPG2), fibrillin 2 (FBN2), and fibronectin (FN1) (p <0.01). Protein assay in supernatants confirmed a statistically significant increase of fibronectin production in Arnica m. 2c treated cells (p<0.05). Pooled extracts of cells treated with increasing dilutions of Arnica m. (3c, 5c, 15c) showed up-regulation of the same group of genes although with lower effect size. The down-regulated transcripts derive from mitochondrial genes coding for some components of electron transport chain. These findings provide new insights into the action of Arnica m. in tissue healing and repair, identifying increased fibronectin production by macrophages as a major therapeutic target.
Project description:Arnica m. effects were associated with a purported anti-inflammatory and tissue healing actions after trauma, bruises, or tissue injuries, but its cellular and molecular mechanisms are largely unknown. Here Arnica m. dilutions were tested using an in vitro model of macrophages polarized towards a “wound-healing” phenotype. The monocyte-macrophage human THP-1 cell line was cultured and differentiated with phorbol-myristate acetate and Interleukin-4, then exposed for 24 h to Arnica m. centesimal (c) dilutions 2c, 3c, 5c,9c, 15c or Control. None of these treatments affected cell viability. A total of 20 genes were differentially expressed comparing cells treated with Arnica m. 2c with those treated with Control only. Of these, 7 genes were up-regulated and 13 were down-regulated. Functional gene enrichment analysis showed that the most significantly upregulated function concerned 4 genes with a conserved site of EGF-like region (p<0.001) and three genes of proteinaceous extracellular matrix, including heparin sulphate proteoglycan 2 (HSPG2), fibrillin 2 (FBN2), and fibronectin (FN1) (p <0.01). Protein assay in supernatants confirmed a statistically significant increase of fibronectin production in Arnica m. 2c treated cells (p<0.05). Pooled extracts of cells treated with increasing dilutions of Arnica m. (3c, 5c, 15c) showed up-regulation of the same group of genes although with lower effect size. The down-regulated transcripts derive from mitochondrial genes coding for some components of electron transport chain. These findings provide new insights into the action of Arnica m. in tissue healing and repair, identifying increased fibronectin production by macrophages as a major therapeutic target.
Project description:In this study, differentially prepared Arnica extracts and the lead compounds Thymol and Helenalin were directly compared for their immunomodulatory potential using primary human T cells. Extracts from different plant parts (root or whole plant) and prepared by different manufacturing processes inhibited T cell activation and proliferation. nCounter gene expression analysis and subsequent gene set enrichment analysis showed that Arnica preparations intervene in T cell receptor (TCR) signaling. Interestingly, the three tested extracts were, however, found to mediate their effects via interfering with different TCR signaling pathways. The hydroethanolic root extract selectively inhibited the binding of NFκB to DNA, while the aqueous fermented whole plant extract preferentially inhibited NFAT-dependent gene expression. The hydroethanolic whole plant extract (by trend) diminished both, NFκB DNA-binding and NFAT-dependent gene expression.
Project description:<p><em>Arnica montana</em> L. (Arnica) has a long history of use in treating inflammation and soft tissue injury, yet its immunomodulatory mechanisms remain largely unexplored. In this study, we investigated the effects of distinct Arnica extracts - derived from different plant parts (root or whole plant) and manufacturing processes - on primary human T cells. We also compared their effects with those of the pure compounds helenalin and thymol. All extracts inhibited T cell activation and proliferation. This could be traced back to reduced IL-2 responsiveness due to decreased CD25 (IL‑2Ra chain) expression, accompanied by reduced IL-2 production. Transcriptomic analysis (nCounter) and gene set enrichment revealed that the extracts target key T cell receptor (TCR) signaling pathways. Mechanistically, the hydroethanolic root extract selectively inhibited NFκB DNA binding, while the aqueous fermented extract predominantly suppressed NFAT-dependent gene expression. The hydroethanolic whole plant extract exerted a moderate effect on both pathways. These findings identify Arnica extracts as promising modulators of human TCR signaling and support their potential in regulating T cell-driven inflammatory responses, with implications for muscle healing and chronic inflammatory diseases.</p>