“Goldenseal (Hydrastis canadensis L.) is used to combat inflammation and infection. Its antibacterial activity in vitro has been attributed to its alkaloids, the most abundant of which is berberine” – Source, Planta Medica 2011 May;77(8):835-40. doi: 10.1055/s-0030-1250606. Epub 2010 Dec 14.
“Exposure to sunlight or artificial light sources emitting UVA should be avoided when topical preparations derived from Goldenseal or containing berberine are used.” Source – Chemical Research in Toxicology, 2001 Nov;14(11):1529-34.
Goldenseal & MRSA infection
“Our results show that H. canadensis leaf extracts possess a mixture of constituents that act against MRSA via several different mechanisms. These findings lend support for the traditional application of crude H. canadensis extracts in the prevention of infection.” – Source Planta Medica 2012 Sep;78(14):1556-61. Epub 2012 Jul 18.