Abstract:
Leishmaniasis is a growing health problem in many parts of the world. Efforts to find new chemotherapeutics for
leishmaniasis remain a priority. This study was carried out to determine the effect using glucocorticoid drugs to
reduce production of chemokine production in a bid to control Leishmania major infection in BALB/c mice.A total
of 48 mice were used. In the therapeutic arm (post‐infection), 24 Mice were infected with L major parasiteswere
treated with dexamethasone (0.69 mg/ml), hydrocortisone (2mg/ml) LPS (10 ng/ml) and PBS for 28 days and lesion
development monitored for five weeks. For immunoprophylaxia (pre‐infection), 24 other mice were treated with
the above drugs and then infected with L major. LPS was used as the positive control while PBS was the negative.
Serum samples were collected before and after infection for cytokine analysis for MIP 1α, MCP 1 and IFNγ using
ELISA. Parasite quantification was done by calculating the LDU. Lesion measurement was done by use of a vernier
caliper.Lesion sizes after infection of BALB/c mice were similar in all the experimental groups till the onset of
therapeutic treatments (P > 0.05). At 0.5 months post‐treatment, significant differences (P < 0.05) were discerned
in the lesion sizes of the BALB/c mice in the control groups. However, hydrocortisone and dexamethasone caused
substantial elimination of the parasites from the lesions and significantly reduced parasite burden in spleen
compared to the controls at the end of the experiment. Generally, hydrocortisone gave better results as compared
to dexamethasone. Both hydrocortisone and dexamethasone resulted in substantial clearance of parasitemia from
both the lesions on footpads and spleens of infected BALB/c mice. They also led to significantly reduced levels of
MCP 1 and MIP‐1α and high levels of IFN γ. These results show that glucocorticoids substantially reduce
Parasitemia in Leishmania infected mice by decreasing production of MCP 1 and MIP‐1α chemokines while
increasing IFN γ levels. In this regard, a further investigation into the modes of action of the glucocorticoids and
probably their efficacy against other Leishmania strains should be explored further.
