Antibacterial activity of Hydrastis canadensis extract and its major isolated alkaloids

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