Inflammatory Process Modulation by Homeopathic Arnica montana 6CH: The Role of Individual Variation

The effects of Arnica montana 6cH on the individual modulation of acute inflammation kinetics in rats were evaluated. Adult male Wistar rats were inoculated with 1% carrageenan into the footpad and treated with Arnica montana 6cH, dexamethasone (4.0 mg/kg; positive control) or 5% hydroalcoholic solution (negative control), per os, each 15 minutes, between 30 and 180 minutes after the irritant inoculation. Histopathological and immunohistochemistry procedures were done in order to get a panel of inflammatory positive cells for CD3 (T lymphocytes), CD45RA (B lymphocytes), CD18 (beta 2 integrin), CD163 (ED2 protein), CD54 (ICAM-1), and MAC 387 (monocytes and macrophages). The statistical treatment of data included a posteriori classification of animals from each group (N = 20) in two subgroups presenting spontaneous precocious or late oedema. Animals that presented precocious oedema were less responsible to Arnica montana 6cH in relation to hemodynamic changes. Instead, rats that exhibited late oedema presented less intense oedema (P = .01), lower percentage of mast cell degranulation (P = .0001), and increase in lymphatic vessels diameter (P = .05). The data suggest an individually qualitative adjustment of inflammatory vascular events by Arnica montana 6cH.