Research Highlight

Caffeine mouthwash to prevent oral cancer

doi:10.1038/nindia.2012.110 Published online 28 July 2012

New research has shown that caffeine could protect DNA from carcinogens. The study, in which micelles mimicked protein and DNA surfaces, reveals that caffeine could bind to and remove ethidium bromide — a dye and a potent mutagen. Caffeine therefore seems to be a potential drug for keeping cancer at bay.

Micelles are substances that mimic biological membranes and macromolecules. Until now, scientists have not used nanoscopic micelles to understand caffeine-mediated molecular recognition of DNA and the disposal of carcinogens.

To explore such roles, the researchers took three micelles: cationic hexadecyl trimethyl ammonium bromide (CTAB), neutral (polar) Triton X-100 (TX-100) and anionic sodium dodecyl sulphate (SDS). CTAB is a good mimic of histone protein, and SDS serves as an alternative to a DNA surface. They used ethidium bromide salt — a fluorescent dye and a potent mutagen. Through changes of fluorescence lifetimes and emission features, they explored the removal of ethidium from micelles and human cell lines in both the absence and presence of caffeine.

Ethidium showed three distinct fluorescence lifetimes of 1.4 nanoseconds (ns), 2.5 ns and 7.2 ns in water, CTAB micelles, and on forming complexes with caffeine outside micelles, respectively. Adding caffeine to the micellar solution changed the lifetime from 2.5 ns to 7.2 ns, which indicates a complex formation between ethidium and caffeine. In anionic SDS micelles, the researchers observed a significant detachment of ethidium in the caffeine solution.

"Caffeine could be used as an active ingredient of mouthwash to stop the onset of oral cancer," says lead researcher Samir Kumar Pal.

The authors of this work are from: Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata, India, and National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.


  1. Banerjee, S. et al. Caffeine-mediated detachment of mutagenic ethidium from various nanoscopic micelles: an ultrafast Förster resonance energy transfer study. J. Phys. Chem. B 116, 7841-7848 (2012)  | Article |