Antibacterial activity of Hydrastis canadensis extract and its major isolated alkaloids

The antibacterial activity of extract and isolated major alkaloids (berberine, beta -hydrastine, canadine and canadaline) of Hydrostis conadensis L. (Ranunculaceae) was evaluated against 6 strains of microorganism: Staphylococcus aureus (ATCC 25993 and ATCC 6538P), Streptococcus sanguis (ATCC 10 556), Escherichia coli (ATCC 25 922), Pseudomonas aeruginosa (ATCC 27853). Bactericidal activity was evaluated by contact test by measuring the killing time on a low density bacterial inoculum, and bacteriostatic activity in liquid medium by M.I.C. values. The results provide a rational basis for the traditional antibacterial use of Hydrastis canadensis.