Photodynamic Therapy With Bengal Rose and Derivatives Against Leishmania amazonensis

Abstract

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. 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. Results: RB derivates RBMET (IC 50 9.83 µM), and RBBUT (IC 50 45.08 µM) showed leishmanicidal activity, however, were toxic to J774.A1 macrophages, resulting in low selectivity index. 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.

Multivariate analysis of protolytic and tautomeric equilibria of Erythrosine B and its ester derivatives in ionic and non-ionic micelles

“…Halogenated xanthenes are a class of molecules that present several applications. They are used as dyes for LASER [1], initiators in photopolymerization reactions [2], solar energy conversions [3], and Photodynamic Therapy (PDT) when correctly combined with visible light [4][5][6][7][8][9]. The latter is a procedure that uses a light-activated photosensitizer (PS) to produce reactive oxygen species as singlet oxygen ( 1 O 2 ), which when generated in situ can lead to cell death [4,6].…”

Proteomic Investigation over the Antimicrobial Photodynamic Therapy Mediated by Rose Bengal Against Staphylococcus aureus

“…With this in mind, xanthene dyes that have anionic forms have shown different actions in Gram-negative and Gram-positive, being this group more susceptible (17)(18)(19)(20). The use of xanthene dyes has been important for PDT studies in several areas, as well as antimicrobial therapy (21)(22)(23)(24). Photoinactivation studies obtained better results in Gram-positive compared with Gram-negative bacteria considering two important conditions to aPDT that are illumination time and PS concentration (8,(17)(18)(19).…”