In Vitro Investigation of Traditional Medicine Recipes Used in Bukavu (DR-Congo) to Treat Trichophyton rubrum Dermatophytosis

Twenty natural products used in traditional medicine to treat dermatophytosis were evaluated for their efficacy against Trichophyton rubrum, the most frequent dermatophyte infecting humans. For this purpose, aqueous and methanolic extracts were prepared from ash, honey, and plant organs as pure (100%) or diluted (75%, 50%, 25%, 12.5%, 6.25%, 3.125%, and 1.56%) preparations. The extracts were then evaluated by incorporating them into a Sabouraud medium and seeding them with T. rubrum as a fungal culture. The results identify fourteen extracts as being able to completely inhibit T. rubrum growth through either fungistatic or fungicidal activity. The five extracts with the highest efficacy to inhibit T. rubrum growth were further analyzed for their potential to alter in vitro reconstructed human epidermis (RHE). An aqueous extract from Allium sativum produced no tissue alteration in RHE, unlike the extracts from Conyza sumatrensis, Rumex abyssinicus, or Pentas longiflora. The data suggest that preparations used in traditional medicine by rural population in South-Kivu (DR-Congo) might represent valid alternatives to fight dermatophytosis. However, they also illustrate that several preparations remain inefficient and that others may be detrimental to the epidermis. This work reveals that traditional preparations, although affordable and easily available, require an evaluation of their efficacy and safety.