Antimicrobial action of sanguinarine.

Sanguinarine is a benzophenanthridine alkaloid derived from rhizomes of Sanguinaria canadensis L. (bloodroot). It is a cationic molecule which converts from an iminium ion form at pH less than 6 to an alkanolamine form at pH greater than 7. Sanguinaria extract is composed of sanguinarine and five other closely related alkaloids. The safety profile of both sanguinarine and sanguinaria extract provide a broad margin for their safe use in oral health products. Sanguinarine has broad antimicrobial activity as well as antiinflammatory properties. In vitro studies indicate that the anti-plaque action of sanguinaria is due to its ability to inhibit bacterial adherence to newly formed pellicle, its retention in plaque being 10-100 times its saliva concentration, and due to its antimicrobic properties. The MIC of sanguinarine ranges from 1 to 32 micrograms/mL for most species of plaque bacteria. Long term use of sanguinaria-containing toothpaste and oral rinse products does not predispose users to detrimental shifts in oral flora. Electron microscopic studies of bacteria exposed to sanguinarine demonstrate that bacteria aggregate and become morphologically irregular. Sanguinarine-containing slow release polymer systems are currently being developed for use in periodontitis treatment applications.