Equisetum arvense (common horsetail) modulates the function of inflammatory immunocompetent cells
1 Center for Complementary Medicine, Department of Environmental Health Sciences, Medical Center, University of Freiburg, Breisacherstr. 115B, 79106 Freiburg, Germany
2 Department of Pharmacognosy, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
BMC Complementary and Alternative Medicine 2014, 14:283 doi:10.1186/1472-6882-14-283Published: 4 August 2014
In Europe, extracts of Equisetum arvense (common horsetail) have a long tradition in the treatment of inflammatory disorders. To understand the molecular basis for its use, we investigated the immunomodulatory capacity of a standardized commercially available common horsetail extract on human primary lymphocyte function in vitro.
The standardized extract of Equisetum arvense was phytochemically characterized. Effects on proliferation, viability and activity of mitogen-activated human lymphocytes were assessed in comparison to cyclosporine A using annexin V/propidium iodide staining assays and flow cytometry-based surface receptor characterization, respectively. Intracellular levels of effector molecules (IL-2, IFN-γ and TNF-α) were analyzed with cytokine assays.
T cell proliferation was inhibited dose dependently by the Equisetum extract without induction of apoptosis or necrosis. This effect was mediated through inhibition of lymphocyte activation, specifically by diminishing CD69 and IL-2 surface receptor expression and intracellular IL-2 production. Furthermore, treatment with Equisetum arvense inhibited effector functions, as indicated by reduced production of IFN-γ and TNF-α.
The data indicate that the used extract of Equisetum arvense interferes with the polyfunctionality of immunocompetent cells thereby providing an anti-inflammatory mode-of-action.