ABSTRACT
Cytokines play a fundamental role in the regulation of immune responses in remission and/or relapsing of leishmaniasis. Therefore, immunotherapy for the treatment of canine visceral leishmaniasis [CVL] has represented a principle approach in control of the infection. The present research aimed to evaluating the immunotherapeutic potential of a novel herbal immunomodulator drug [IMOD] on CVL. Twelve mongrel dogs were intravenously infected with Iranian strain of L. infantum and randomly divided into three groups; 1: negative control [non-infected], 2: immunotherapy with IMOD and 3: positive control [non-treated]. Cell proliferation and Th1-/Th2-type cytokines were measured in peripheral blood mononuclear cell [PBMC] by cell proliferation kit I [MTT] and enzyme-linked immunospot [ELISpot] assays, respectively. At the 60 days follow-up assessment, no adverse effects were observed in treated interventional group. Cellular proliferation assay indicated that PBMCs of IMOD group had higher stimulation index [SI] than positive control group [p <0.05]. Enhancement of CD4+ T cells such as IL-2, IL-4 and IL-10 were detected in negative control group due to in vitro IMOD stimulation 30 days post-treatment. In accordance to decreasing trends of Th1 and Th2 cytokines in positive control group, the mean number of IFN-gamma, IL-2, IL-4 and IL-10 spot forming cells [SFCs] down regulated for IMOD group during the study. These data indicate that IMOD had immunomodulatory potential but is not sufficient for total parasitic cure due to balance of Th1/Th2 cytokines. This is a preliminary study and we propose to undertake a series of experiments to evaluate the CVL due to in vitro modulatory effects of IMOD