CXCL8 and viral infectious disease: This study tested the antiviral and cytokine regulatory activity of an E. purpurea root ethanol extract and various pure alkylamides and found that one specific alkylamide, Dodeca-2E,4E-Dienoic acid isobutylamide, had potent antiviral activity against the rhinovirus (the causative agent of most common colds) and the influenza virus and potent inhibition of IL-8 cytokine production, which is responsible for many symptoms associated with these viral infections.