Journal of molecular recognition : JMR

Role of caffeine in DNA recognition of a potential food-carcinogen benzo[a]pyrene and UVA induced DNA damage.

PMID 24984868


Electron transfer (ET) reactions are important for their implications in both oxidative and reductive DNA damages. The current contribution investigates the efficacy of caffeine, a xanthine alkaloid in preventing UVA radiation induced ET from a carcinogen, benzo[a]pyrene (BP) to DNA by forming stable caffeine-BP complexes. While steady-state emission and absorption results emphasize the role of caffeine in hosting BP in aqueous medium, the molecular modeling studies propose the energetically favorable structure of caffeine-BP complex. The picosecond-resolved emission spectroscopic studies precisely explore the caffeine-mediated inhibition of ET from BP to DNA under UVA radiation. The potential therapeutic activity of caffeine in preventing DNA damage has been ensured by agarose gel electrophoresis. Furthermore, time-gated fluorescence microscopy has been used to monitor caffeine-mediated exclusion of BP from various cell lines including squamous epithelial cells, WI-38 (fibroblast), MCF-7 (breast cancer) and HeLa (cervical cancer) cells. Our in vitro and ex vivo experimental results provide imperative evidences about the role of caffeine in modified biomolecular recognition of a model carcinogen BP by DNA resulting dissociation of the carcinogen from various cell lines, implicating its potential medicinal applications in the prevention of other toxic organic molecule induced cellular damages.