Protoberberine compounds extracted from Chelidonium majus L. as novel natural photosensitizers for cancer therapy.

Background: It has been shown that secondary metabolites occur in Chelidonium majus L. (C. majus) crude extract and milky sap (alkaloids such as berberine, coptisine, chelidonine, chelerythrine, sanguinarine, and protopine) are biologically active compounds with a wide spectrum of pharmacological functions.