Metabolism of sanguinarine: the facts and the myths.

Sanguinarine, a quaternary benzo[c]phenanthridine alkaloid, exhibits antimicrobial and anti-inflammatory activities and for this reason it is used in dental hygiene products and feed additives. Its metabolism and disposition is the subject of constant scientific discourse. In this paper we summarize current knowledge on sanguinarine metabolism. We show in particular that: (i) Sanguinarine is not transformed to 3,4-benzacridine and that the literature reporting this compound as a metabolite of sanguinarine is based on artifacts and misinterpretations that in course of time have created a dogma; (ii) Sanguinarine is converted to dihydrosanguinarine in vivo, the conversion being tentatively a detoxication pathway; (iii) Aryl hydrocarbon receptor metabolic signaling pathways modulate sanguinarine biological activity.