Anti-inflammatory effects of Arnica montana (mother tincture and homeopathic dilutions) in various cell models

ETHNOPHARMACOLOGICAL RELEVANCE: The plant Arnica montana L. has been shown to alleviate inflammation, pain and swelling associated with trauma, and post-operative clinical conditions, yet the mechanism of action is not well understood. AIM OF THE STUDY: The study was designed to investigate the effect of Arnica montana (A. montana) mother tincture and homeopathic dilutions on inflammation markers, oxidative stress and cell migration in diverse cell culture models. MATERIALS AND METHODS: We tested A. montana mother tincture and a range of homeopathic dilutions in different human and murine cell culture models to demonstrate their anti-inflammatory properties by measuring the inflammatory markers: tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2), monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule (ICAM-1), reactive oxygen species (ROS) and cell migration. The inflammatory markers were measured by ELISA assays. The intracellular oxidative stress (ROS) in microglial cells was measured using Deep Red CellROX probe. The cell migration was examined by wound healing using the Oris Cell migration assay. RESULTS: These data showed the ability of A. montana (mother tincture and mainly 1C dilution) to significantly reduce TNFα production in inflamed macrophages compared with vehicle (control). They significantly reduced both IL-6 and MCP-1 in inflamed human microglial cells and significantly decreased COX-2 expression in inflamed murine fibroblasts. Moreover, A. montana mother tincture reduced the cell migration whereas 9C dilution significantly enhanced the migration of fibroblast cells compared with vehicle. The expression of ICAM-1 was significantly reduced with A. montana mother tincture and 1C, 3C, 5C, and 9C dilutions in inflamed human endothelial cells compared with vehicle. A. montana mother tincture and 1C, 3C, 5C and 9C dilutions induced a significant and consistent effect on ROS production in inflamed murine microglial cells. A. montana 1C had the largest impact on ROS production. CONCLUSIONS: Mother tincture and 1C dilution of A. montana showed anti-inflammatory properties assessed by measurement of several markers (pro-inflammatory cytokines, adhesion molecule, ROS) in various human and murine cell models. In addition, A. montana 3C, 5C, 9C dilutions have anti-inflammatory and antioxidant effects as highlighted on both primary endothelial cells and murine microglial cells.