There are available data on in vivo studies of monotherapy of zoonotic cutaneous leishmaniasis with some antibacterial drugs (doxycycline) and their comparison with meglumine antimoniate (glucantime). We used golden Syrian hamsters as a laboratory model. Experimental groups were formed, each of which was treated with one of the tested drugs. Infection of animals was carried out with Leishmania major promastigotes. We selected highly virulent strains of L. major culture isolated from human ulcers or rodents. Meglumine antimoniate monotherapy and doxycycline monotherapy are quite effective and do not differ by the 30th day of their use in such indicators as the average degree of local damage and the average number of Leishmania in the lesions. The main differences were recorded in terms of average body weight gain and average clinical recovery in favour of doxycycline. Leishmania in the lesion on the 60th day were completely absent in treatment with doxycycline. The experiment proved the effectiveness of doxycycline monotherapy: Leishmania in the lesions were absolutely absent by the end of the treatment.

Hepatocytes constitute the majority of hepatic cells, and play a key role in controlling systemic innate immunity, via pattern-recognition receptors (PRRs) and by synthesizing complement and acute phase proteins. Leishmania infantum, a protozoan parasite that causes human and canine leishmaniasis, infects liver by establishing inside the Kupffer cells. The current study proposes the elucidation of the immune response generated by dog hepatocytes when exposed to L. infantum. Additionally, the impact of adding leishmanicidal compound, meglumine antimoniate (MgA), to parasite-exposed hepatocytes was also addressed. L. infantum presents a high tropism to hepatocytes, establishing strong membrane interactions. The possibility of L. infantum internalization by hepatocytes was raised, but not confirmed. Hepatocytes were able to recognize parasite presence, inducing PRRs [nucleotide oligomerization domain (NOD)1, NOD2 and Toll-like receptor (TLR)2] gene expression and generating a mix pro- and anti-inflammatory cytokine response. Reduction of cytochrome P 450s enzyme activity was also observed concomitant with the inflammatory response. Addition of MgA increased NOD2, TLR4 and interleukin 10 gene expression, indicating an immunomodulatory role for MgA. Hepatocytes seem to have a major role in coordinating liver's innate immune response against L. infantum infection, activating inflammatory mechanisms, but always balancing the inflammatory response in order to avoid cell damage.