Photophysical, Photochemical, and Tumor‐selectivity Properties of Bromine Derivatives of Rhodamine‐123

Abstract

The conceptual basis for the development of mitochondrial targeting as a novel therapeutic strategy for both chemotherapy and photochemotherapy of neoplastic diseases rests on the observation that enhanced mitochondrial membrane potential is a common tumor cell phenotype. The potential of this strategy is highlighted by the fact that the toxic effects associated with a number of cationic dyes known to localize in energized cell mitochondria are much more pronounced in tumor cells than in normal cells. Here we evaluate the phototoxic properties of four bromine derivatives of rhodamine-123 toward human uterine sarcoma (MES-SA) and green monkey kidney (CV-1) cells and compare the degrees of tumor cell selectivity associated with these dyes with those associated with two model mitochondrial triarylmethanes (crystal violet and ethyl violet). Selective phototoxicity toward tumor cells was found to be highly dependent upon the lipophilic/hydrophilic character of the cationic photosensitizer. Our experimental data have indicated that the probability of success of mitochondrial targeting in (photo)chemotherapy of neoplastic diseases is higher when the octan-1-ol/water partition coefficient of the drug candidate falls within approximately two orders of magnitude from that of the prototypical mitochondria-specific dye rhodamine-123.

Porphycenes: Facts and Prospects in Photodynamic Therapy of Cancer

“…Generally, cationic PSs localize in both the nucleus and mitochondria, whereas lipophilic ones tend to incorporate into membranes [42,232,[249][250][251].…”

Search for cytotoxic agents in multiple Laurencia complex seaweed species (Ceramiales, Rhodophyta) harvested from the Atlantic Ocean with emphasis on the Brazilian State of Espírito Santo

“…24 h), show desirable morphology, are large enough to facilitate counting/analysis of drug-induced mechanisms of damage via microscopic analysis, are highly susceptible to a large variety of anticancer drugs (i.e., relatively easy to perform in vitro assays of mortality), and are also easy to manipulate and maintain (Larroque-Lombard, 2010;Lacerda et al, 2005;Belostotsky et al, 2011). The susceptibility of MES-SA cells to doxorubicin is analogous to that observed for HeLa cells (compare panels A and B in Figure 2).…”

New azine compounds as photoantimicrobial agents against Staphylococcus aureus

“…Several reports showed that the brominated derivatives present low to nondeterminable toxicity in different cells [48,49]. In addition, brominated thiazine derivatives exhibit decreased phototoxicity in culture cell compared to the starting reagent [50].…”