Echinacea intake induces an immune response through altered expression of leukocyte hsp70, increased white cell counts and improved erythrocyte antioxidant defences

Many compounds have been postulated to modulate the immune response including the constituents found in Echinacea preparations. Echinacea, also known as purple coneflower and Rudbeckia is a flowering plant member of the Compositae family that is mainly used for the treatment of upper respiratory tract infections. It is, however, also used prophylactically as an immunomodulator and antioxidant and for the treatment of urinary tract infections, eczema and psoriasis as well as to aid wound healing. Although Echinacea and its effects on the immune system have been studied since the late 1930's, its mode of action is still unclear. In the current studies expression of leukocyte heat shock protein 70 (hsp70), erythrocyte haemolysis, plasma antioxidant status, serum chemistry, haematological values and plasma alkylamide concentrations were evaluated in eleven healthy individuals (26 to 61 years of age) at baseline (day 1) and on day 15 after consuming two commercially blended Echinacea tablets per day for 14 days. Echinacea supplementation enhanced the fold increase in leukocyte hsp70 expression after a mild heat shock (p; 0.029). White cell counts were also increased (p; 0.043). A preventative effect against free radical induced erythrocyte haemolysis (p; 0.006) indicative of an antioxidant effect was also observed. The results of this pilot study suggest that supplementation with Echinacea may invoke an immune response through altered expression of hsp70 and increased white cell counts.