Study of the efficacy of N-methyl glucamine antimoniate (SbV) associated with photodynamic therapy using liposomal chloroaluminium phthalocyanine in the treatment of cutaneous leishmaniasis caused by Leishmania (L.) amazonensis in C57BL6 mice.

Abstract

Pentavalent antimonials remain first-line drugs in the treatment of cutaneous leishmaniasis (CL); however, adverse effects and drug resistance have led to the search for less toxic and more effective treatments. As an alternative, topical phthalocyanine has been studied and its efficacy and low toxicity demonstrated. We aimed to study the in vivo efficacy of N-methyl glucamine antimoniate (NMG) associated with photodynamic therapy (PDT) with topical liposomal chloroaluminium phthalocyanine (AlClPC) in the treatment of experimental CL by L. amazonensis. Experimental study with 54 C57BL6 isogenic mice divided into 9 groups including uninfected control, untreated control, PDT with AlClPC + NMG at doses of 10 and 20 mgSbV/Kg/day. The criteria to evaluate the treatment efficacy were: paw diameter, amastigote count, culture, viability test and parasite counts using MTT (3-bromo-4,5-dimethylthiazol-2,5-diphenyl-tetrazolium bromide). Treatment of CL with the association of NMG20 + PDT with AlClPC showed significant reduction of paw diameter, amastigote count, cultures, viability test and parasite counts. Parasite reduction occurred at the 10th and 20th days of treatment and 60 days after treatment ended, indicating that parasites did not multiply again. The NMG10 + PDT group with AlClPC presented results equivalent to gold-standard treatment (20 mgSbV/kg/day). Biochemical and histopathological evaluation showed minor changes. Treatment of CL caused by L. amazonensis with NMG20 mgSbV/kg/day + PDT with AlClPC was more effective than the traditional NMG20 mgSbV/kg/day.