Cytokine- and Interferon-Modulating Properties of Echinacea spp. Root Tinctures Stored at −20°C for 2 Years

Echinacea spp. phytomedicines are popular for treating upper respiratory infections. The purpose of this investigation was to examine the immunomodulatory properties of Echinacea tinctures from seven species after being stored at -20 degrees C for 2 years. Two experimental techniques were employed using human peripheral blood mononuclear cells (PBMC). In the first set of experiments, PBMCs were stimulated in vitro with tinctures alone and assayed for proliferation and production of interleukin-10 (IL-10), IL-12, and tumor necrosis factor-alpha (TNF-alpha). In the second set of experiments, subjects were immunized with influenza vaccine. PBMCs from vaccinated individuals were stimulated in v…