Antibacterial Activity of Pharmaceutical-Grade Rose Bengal: An Application of a Synthetic Dye in Antibacterial Therapies

• Published in: Molecules (Basel, Switzerland) Switzerland), 2022-01, Vol.27 (1), p.322
• Main Authors: Kurosu, Michio, Mitachi, Katsuhiko, Yang, Junshu, Pershing, Edward V, Horowitz, Bruce D, Wachter, Eric A, Lacey, 3rd, John W, Ji, Yinduo, Rodrigues, Dominic J
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - chemical synthesis; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Antibacterial activity; Antibiotics; Bacteria; Bacteria - drug effects; Bacteria - genetics; Bacterial infections; Bactericidal activity; Biofilms; Cell Line; Cell Survival - drug effects; Cytotoxicity; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; drug-resistant gram-positive pathogens; Dyes; Experiments; FDA approval; Fluorescence; Good Manufacturing Practice; Gram-negative bacteria; Gram-positive bacteria; high-purity form of rose bengal (HP-RB); Humans; Impurities; Kinetics; Light; Liver diseases; Low concentrations; Manufacturing; Manufacturing industry; methicillin-resistant Staphylococcus aureus; Microbial Sensitivity Tests; Microorganisms; Multidrug resistance; Multidrug resistant organisms; multidrug-resistant bacteria; Mycobacterium - drug effects; Natural lighting; Pathogens; Pharmaceuticals; Research programs; rose bengal (RB); Rose Bengal - chemical synthesis; Rose Bengal - chemistry; Rose Bengal - pharmacology; Rose Bengal - therapeutic use; Salmonella; Skin; Soft tissues; Solid tumors; Staphylococcus infections; Streptococcus infections
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27010322

Rose bengal has been used in the diagnosis of ophthalmic disorders and liver function, and has been studied for the treatment of solid tumor cancers. To date, the antibacterial activity of rose bengal has been sporadically reported; however, these data have been generated with a commercial grade of rose bengal, which contains major uncontrolled impurities generated by the manufacturing process (80-95% dye content). A high-purity form of rose bengal formulation (HP-RBf, >99.5% dye content) kills a battery of Gram-positive bacteria, including drug-resistant strains at low concentrations (0.01-3.13 μg/mL) under fluorescent, LED, and natural light in a few minutes. Significantly, HP-RBf effectively eradicates Gram-positive bacterial biofilms. The frequency that Gram-positive bacteria spontaneously developed resistance to HP-RB is extremely low (less than 1 × 10 ). Toxicity data obtained through our research programs indicate that HP-RB is feasible as an anti-infective drug for the treatment of skin and soft tissue infections (SSTIs) involving multidrug-resistant (MDR) microbial invasion of the skin, and for eradicating biofilms. This article summarizes the antibacterial activity of pharmaceutical-grade rose bengal, HP-RB, against Gram-positive bacteria, its cytotoxicity against skin cells under illumination conditions, and mechanistic insights into rose bengal's bactericidal activity under dark conditions.