Arnica Tincture Fot the Treatment of Cutaneous Leishmaniasis

Arnica tincture is a topical preparation based on the plant legally authorized in the countries of the European community, and it is included in the vademecun of medicinal plants in Colombia. The research product is the commercial phytotherapeutic product ARNICA TINTURA Gehrlicher 100 mL manufactured by Gehrlicher Pharmazeutische Extrakte GmbH. (www. https://www.wer-zu-wem.de/firma/gehrlicher-extrakte.html). The product will be imported from Germany through the University of Munster (project co-investigator). According to the European Pharmacopoeia, the solution is a 70% hydroethanolic tincture prepared from the flowers of Arnica montana L, and composed at least 0.04% of sesquiterpene lactones. Sesquiterpenic lactones (helenalin and 11-α-13 dihydrohelenaline) are the constituents responsible for its anti-inflammatory activity, these molecules decrease inflammation mediated by the transcription factor NF-kB. There are other properties demonstrated in the literature such as antioxidant, antimicrobial or insecticidal activities. Given the plant's anti-inflammatory, healing, anti-echemotic, analgesic and antineuralgic properties, in a previous study the leishmanicidal activity of arnica tincture was evaluated in vitro for intracellular amastigotes of L. braziliensis and L. tropica. Arnica tincture at a concentration of 4.8 mg / mL produced a decrease in the parasite load (amount of intracellular amastigotes) of 91.9% and 99.6% in cells infected by L. braziliensis and L. tropica, respectively. . The mean maximum Effective Concentrations (EC50) were determined at 2.9 ± 0.13 and 2.7 ± 0.02 respectively, and with selectivity indices> 69 and> 74, for L. braziliensis and L. tropica, respectively. This activity was validated in in vivo studies in hamsters experimentally infected with L. braziliensis. Applying the tincture once a day for 30 days produced a cure of 60 and for the remaining 40% of the hamsters a reduction of more than 80% of the lesions was observed (Robledo et al., 2018). When applied once a day for 60 days, 75% of the hamsters were cured and the remaining 25% showed improvements between 70 and 96% regarding the size of the lesion before treatment. According to the observations made, it is part of the natural evolution of the healing process that, during the first weeks of use of the compound and until the end of the treatment, a flattening of the edges is perceived, with intensification of the erythema, which produces a Optical sensation of enlargement of the lesion, which subsequently (from day 28) gives rise to the re-epithelialization process, which is slightly slower compared to traditional systemic schemes. The percentage of epithelialization of the lesion (s) is calculated by comparing the size of the ulcer at baseline against the size observed at the follow-up visit. Arnica tincture is not cytotoxic on epithelial cells (Detroit) at any concentrations tested. In liver cells (HepG2) the tincture showed a slight cytotoxicity when evaluated at 100%, with a toxicity percentage of 75%. Weight, clinical appearance, and behavior data, as well as ALT, alkaline phosphatase, creatinine, and urea test results; and the histological studies obtained from the tests in hamsters allowed to conclude that the contact of the ulcerated skin with the product for up to 60 days does not generate toxic effects at the local level (application site) or at the systemic level, so it can be considered as safe for use. Corrosion and irritation tests to evaluate arnica skin tincture according to OECD guidelines suggest that it is neither corrosive nor irritating. Although it is difficult to calculate accurately, it has been estimated that approximately 2 drops (80uL) of the solution will be used per cm2 in each application. If we consider an average lesion size of 4 cm2, a maximum of 320 uL is used X 3 times a day X 45 or 30 days = 43,200 uL or 28,800uL (equivalent to 43.2 or 28.8 mL) per lesion. 1. Main Objectives - Evaluate the safety and tolerability of Arnica tincture in individuals with uncomplicated CL, by measuring the occurrence and severity analysis of local and systemic ADs. - Evaluate the therapeutic response of Arnica tincture in individuals with uncomplicated CL, according to the percentage of individuals with initial clinical cure on day 90. Regimen 1: Arnica tincture applied 3 times a day for 30 days (Group 1: 4 weeks) Regimen 2: Arnica tincture applied 3 times a day for 45 days (Group 2: 6 weeks) 2. Secondary Objectives - Evaluate the frequency and severity of AEs associated with the use of the Arnica tincture solution. - Assess the status of the lesions over time, up to 100% epithelialization of ulcerated lesions and proportion of individuals with 100% epithelialization of non-ulcerated lesions over time. - Assess the relapse rate.