Effects of bloodroot (Sanguinaria canadensis L.) rhizome ethanol extracts on cytokine production by blood mononuclear cells during flowering and fruiting

Abstract

Extracts from bloodroot (Sanguinaria canadensis L., Papaveraceae) are used in herbal medicines due to their anti-bacterial, anti-inflammatory, immunomodulatory, and tumouricidal properties. Benzophenanthridine alkaloids are the purported bioactive molecules. Although substantial investigative attention has been given to isolated alkaloids, little attention has been given to whole-plant extracts such as those used in both traditional and contemporary herbal medicine. The purposes of this investigation were to: (a) investigate the immunomodulatory properties of bloodroot rhizome ethanol extracts using a human peripheral blood mononuclear cell model of in vitro cytokine production and cell proliferation; (b) characterize alkaloid content of the extracts using liquid chromatography–tandem mass spectrometry (LC/MS); and, (c) determine if the flowering and fruiting status of bloodroot influenced the preceding outcomes by sampling plants over a 6-week springtime period. LC/MS detected seven quaternary benzophenanthridine alkaloids, six which could be quantified (chelerythrine, chelilutine, chelirubine, sanguilutine, sanguirubine, and sanguinarine) and one detected in trace amounts (protopine). Sanguinarine was most abundant. Extracts demonstrated immunosuppressive effects on production of the cytokines interleukin (IL)-2 and IL-8, and cell proliferation. Production of other cytokines including IL-1β, IL-4, IL-6, IL-10, and tumour necrosis factor was not influenced by treatment. Extract immunomodulatory activities were consistent across all time points sampled. Alkaloid content did not differ significantly across the time points sampled and could not be correlated to immune outcomes, suggesting that traditional marker components may not adequately explain bloodroot rhizome extract immunomodulatory activity.