Synergistic effect of glucantime and a liposome-encapsulated muramyl dipeptide analog in therapy of experimental visceral leishmaniasis.

A regimen of immunostimulation with 6-0-stearoyl-N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine, a lipophilic analog of muramyl dipeptide, combined with antimonial drug therapy was evaluated in the treatment of visceral leishmaniasis of mice and hamsters. The combined treatment was found to be more effective in the elimination of Leishmania donovani amastigotes from infected tissue macrophages than was either of the two treatments applied individually. In mice, it was found that immunostimulation of animals prophylactically, therapeutically, or both enhanced the effects of the antimonial drug (Glucantime) administered more than 1 week after a challenge of BALB/c and C57BL/6 mice. The superiority of the combined treatment of the parasite infection was demonstrable in both short-term (14 days) and long-term (40 to 45 days) infections of the two inbred strains of mice. The combined therapy was also effective in preventing the lethal course of leishmaniasis in hamsters which succumb to disseminated disease in the absence of therapeutic intervention. The efficacy of this dual approach to the therapy of disseminated leishmaniasis of experimental animals holds promise for similar application in the treatment of similarly afflicted human populations.