Phytochemical and immunomodulatory properties of an Echinacea laevigata (Asteraceae) tincture.

Background: Echinacea preparations are consumed for the prevention or treatment of upper respiratory infections.

Objective: The objective of this study was to provide the first data regarding the in vitro immunomodulatory properties of the American federally endangered species Echinacea laevigata (Asteraceae).

Methods: Human peripheral blood mononuclear cells were cultured with root tinctures from E.