Echinacea Extract Interferes With Peripheral Blood Mononuclrar Cells Functions In Dairy Cows

Echinacea represents one of the most common traditional American herbal medicines that are commonly believed to act as an immunostimulant and market commercially as a cold and flu remedy. There are three predominant species of Echinacea used for such purposes: angustifolia, purpurea, and pallida. In recent years, Echinacea has been introduced to China. Validation of immune activity of Echinacea and its utilization may contribute to improve animal health and welfare. The Echinacea is represented by a purified dry extract from Echinacea angustifolia (PolinaceaTM, Indena s.p.a). In first test, the Echinacea was added to culture media at concentration of 6.3, 20.0, 60.0, and 180.0μg/mL with or without concanavalin A (1μg/mL) or pokeweed mitogen (0.6μg/mL). PBMC proliferation was assessed by measuring the 5-bromo-2'-deoxyuridine incorporated during DNA synthesis.In second test, the four concentrations of PolinaceaeTM in vitro gamma interferon (IFN-γ) production were tested using concanavalin A (ConA) at final concentration 2.27μg/mL. Echinacea was added to culture media at concentrations of 6.3, 20.0, 60.0, and 180.0μg/mL with or without concanavalin A by the method ELISA.The results of first test showed that four concentrations of PolinaceaeTM without mitogen enhanced spontaneous proliferation of PBMC and only the two highest concentrations (60.0μg/mL and 180.0μg/mL) had significant effects (P<0.01). The other concentrations of PolinaceaeTM did not affect significantly proliferation of PBMC.The highest concentration of PolinaceaeTM (180.0μg/mL) had negative effect (P<0.01) on proliferation of PBMC in presence of ConA. Positive effect of PolinaceaeTM of 20.0μg/mL and 60.0μg/mL on proliferation of PBMC was observed (P<0.01) when PWM was present. The results of second test showed that PolinaceaTM induced IFN-γand different concentrations of PolinaceaTM had no significant difference (P>0.05).These results suggested that the Echinacea extract exerts immunomodulation by stimulating mitogen driven proliferation of bovine peripheral blood mononuclear cells (PBMC).