Photodynamic therapy with bengal rose and derivatives against leishmania amazonensis

Introduction: The treatment of cutaneous leishmaniasis [CL] is based primarily on the use of pentavalent antimonials, which may lead to many side effects limiting their use. Photodynamic therapy [PDT] is an alternative for the treatment of CL, and some xanthene dyes have the potential for use in PDT

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Methods: The xanthenes rose bengal B [RB] and its derivatives rose bengal methyl ester [RBMET], and butyl ester [RBBUT] were analyzed for leishmanicidal activity against promastigotes and intracellular amastigotes of Leishmania amazonensis. Cytotoxicity was assessed in J774.A1 macrophages

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Results: RB derivates RBMET [IC50 9.83 microM], and RBBUT [IC50 45.08 microM] showed leishmanicidal activity, however, were toxic to J774.A1 macrophages, resulting in low selectivity index

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Conclusion: The RBMET and RBBUT showed to be effective against the L. amazonensis and the low selectivity index presented may not be a limitation for their use in PDT to CL treatment