Benefits of Echinacea purpurea in boosting the immune system and decreasing tumor recurrence in cancer patients: A letter to editor

Patients with cancer consistently suffer from a decreased immune response that leads to opportunistic infections and increased morbidity and mortality in these patients. Boosting the immune system in these patients is accomplished by appropriate diet, psychological support and certain drugs such as granulocyte colony-stimulating factor in a clinical setting. Echinacea purpurea also can be used to boost the immune system in cancer patients. Theoretically, E. purpurea can boost the immune system through several mechanisms, including (1, 2) Activating phagocytosis and stimulating granulocytes; Increasing the production of cytokines, especially interleukin 1 and interleukin 6; and Increasing the leukocyte activity. The leachate of E. purpurea aerial parts dramatically increases the percentage of phagocytic action of human granulocytes and increases the phagocytosis of yeast particles under laboratory conditions (in vitro) (1). Interruption of hyaluronidase activity, stimulation of cortex parts of adrenal glands, stimulation of the production of properdin (a serum protein that can neutralize the actions of bacteria and viruses) have also been reported after treatment with this plant (1,2). The pharmacological activity of E. purpurea is related to its compounds and volatile essential oils. The immune system-boosting effect of this plant is related to lipophilic amides, alkamides and caffeic acid derivatives, which is produced by stimulating the phagocytosis of multinucleated granulocytes (2,4). In several studies, E. purpurea effect on preventing or treating infections (3, 4) and on reducing the side effects of anti-cancer drugs was investigated. It was concluded that the products containing E. purpurea exhibit a definite and pronounced effect on stimulating the immune system. As a pediatric oncologist, I used to prescribe E. purpurea for my patients with different types of cancers (hematopoietic and solid malignancies) in recent years and I observed a decrease in opportunistic infections and better immune response in them. Regarding the improved immune system, this plant can probably inhibit the proliferation of malignant cells and tumor recurrence by stimulating NK cells (2) in these patients. This tentative argument should be investigated in future studies. If it is proven, we can use this plant as an adjuvant agent in chemotherapy protocols.