Original paperModulation of inflammation response to murine cutaneous Leishmaniosis by homeopathic medicines: Thymulin 5cH

•Murine infection with Leishmania amazonensis leads to a known pattern of immune response.•This pattern is decisive to the disease evolution.•Thymulin 5cH modulates systemic immune cell kinetics.•This modulation leads to stronger and more organized inflammatory response in the site of infection.•Homeopathic thymulin can influence the evolution of murine leishmaniasis.

BackgroundIn previous studies, we observed that thymulin 5cH could modulate BCG (Bacillus Calmette-Guerin) induced chronic inflammation by increasing peritoneal B1 stem cells differentiation into phagocytes and improving phagocytosis efficiency.MethodsWe used the same protocol to study the effects of thymulin 5cH in the experimental murine Leishmaniasis, in order to elucidate some aspects of the parasite-host relation under this homeopathic treatment. Male Balb/c mice were orally treated with thymulin 5cH or vehicle during 60 days, after the subcutaneous inoculation of 2 × 106 units of Leishmania (L.) amazonensis into the footpad. Washied inflammatory cell suspension from peritoneal cavity, spleen, local lymph node and infected subcutaneous tissue were harvested after 2 and 60 days from infection to quantify the inflammation cells by flow cytometry and histometry methods.ResultsAfter a transitory increase of peritoneal T reg cells, treated mice presented, chronically, increase in the peritoneal and spleen B1 cells percentage (p = 0.0001) in relation to other cell types; more organized and exuberant inflammation response in the infection site, and decrease in the number of parasites per field inside the primary lesion (p = 0.05). No difference was seen in local lymph node histology.ConclusionsThymulin 5cH is able to improve B1 cell activation and Leishmania (L) amazonensis phagocytosis efficiency in mice, similarly to that observed previously in BCG experimental infection.