Abstract
Purpose: :
To evaluate the toxicity of bromophenol blue (BrB) on human retinal pigment epithelial cells (ARPE-19) and Müller cells (MIO-M1) in vitro.
Methods: :
ARPE-19 and MIO-M1 were exposed for 5 minutes to different concentrations of BrB (2%, 0.2% [clinical dose], and 0.02%) with surgical light (Greishaber halogen light source; Alcon, FortWorth, TX, USA). In addition, cells were also exposed to 2% BrB alone. Cell viability (CV) and mitochondrial membrane potential (ΔΨµ) were then measured using a trypan blue dye-exclusion assay and a cationic dye assay (JC-1), respectively.
Results: :
In ARPE-19 cells, CV was decreased following exposure to 2% BrB + light (43.9±2.9%,p<0.0001) and 0.2% BrB with surgical light (93.5±0.6%,p=0.007) versus controls (97.7±0.4%). 2% BrB alone decreased cell viability to 47.1±1.0% (P<0.0001). There was no change in CV in ARPE-19 cells following exposure to 0.02 % BrB + light. In MIO-M1 cells, CV was unchanged following exposure to 2% BrB + light (90.40±0.62%), 0.2% BrB + light (91.50±1.3%), and 0.02% of BrB + light (91.07±1.44%) versus controls (92.50±0.84%). 2% BrB alone did not decrease CV for MIO-M1 cells. Surgical light alone did not change cell viability for either cell line. The ΔΨµ of ARPE-19 cells was decreased following exposure to 2% BrB + light (3.2±0.3,p=0.006), 0.2% BrB + light (4.4±0.4,p=0.02), and 2% BrB alone (2.7± 0.3,p=0.004) versus controls (7.1±0.6). There was no change in ΔΨµ following exposure to 0.02% BrB + light and surgical light alone in ARPE-19 cells. The ΔΨµ in MIO-M1 cells was decreased following exposure to 2% BrB + light (2.0±0.1,p<0.0001), 0.2% BrB + light (4.1±0.2,p<0.0002), 0.02% BrB + light (5.9±0.3,p=0.002), 2% BrB alone (2.4±0.1,p<0.0001), and light alone (7.4±0.2,p=0.01) versus controls (9.1±0.3).
Conclusions: :
Significant toxicity was observed in ARPE-19 (decreased CV and ΔΨµ) and MIO-M1 (decreased ΔΨµ) cells following exposure to BrB, included the clinical dose (0.2%), in combination with 5 minutes surgical light exposure. As such, caution should be taken when using bromophenol blue as a surgical dye.
Keywords: drug toxicity/drug effects • retina