Study of the action mechanisms of Arnica montana effects on macrophages

Objective: To test the effect of Arnica montana (Arnica m.) on human macrophages. Method: The human monocytic leukaemia cell line THP-1 was cultured and differentiated in mature macrophages with PMA and other differentiating agents. Macrophages were exposed to Arnica m. homeopathic dilutions (2c, 3c, 5c, 9c and 15c) or Control solvent. Total RNA was isolated and sequenced to perform quantitative evaluation. Results: Screening sorted out with a list of 20 genes that were significantly changed by Arnica m. 2c treatment: 7 up-regulated and 13 down-regulated. Most notably, a clearly up-regulated function concerned the proteinaceous extracellular matrix (ECM), including genes HSPG2, FBN2, FN1 (p