Disease relevance of ROSE BENGAL

• MATERIALS AND METHODS: Stationary-phase cells of Deinococcus radiodurans (Gram-positive) and Escherichia coli (Gram-negative) were exposed to visible light in a buffer solution containing up to 5 microg/ml sensitizer rose bengal (RB) and to X-rays at dose rates of 32.8 Gy/min or 14.6 Gy/min, respectively [1].
• Under conditions of RB treatment, where hemolysis was absent or minimal, 125I anti-D IgG binding decreased to 38-49% of the level seen in controls [2].

High impact information on ROSE BENGAL

• Collectively, a model for the PDT-triggered apoptotic signalling cascade with RB is proposed, which involves singlet oxygen, JNK, caspase-3 and PAK2, sequentially [3].
• Our previous work showed that absorption of visible light by rose bengal (RB) produces singlet oxygen exclusively, whereas absorption of ultraviolet A produces RB-derived radicals in addition to singlet oxygen [4].
• Singlet oxygen, but not the RB-derived radicals, induced nuclear condensation and DNA fragmentation into nucleosome-size fragments in a dose dependent manner [4].
• RESULTS: Survival of both cell types decreased with increasing exposure time to visible light and increasing concentration of RB, and therefore with an increase in singlet oxygen production [1].

References