Echinacea purpurea is native to North America, diploid with 22 chromosomes in somatic cells, It belongs to the family Asteraceae.

There are several types of Echinacea, slightly different, but with the common characteristic of resembling a large daisy.

Echinacea contains various bioactive compounds, including polysaccharides, flavonoids, alkylamides, and essential oils. These compounds give the plant immunomodulatory, antioxidant, antimicrobial, and anti-inflammatory properties.

Biological Activities

Echinacea Purpurea extracts have been shown to activate macrophages, natural killer cells, and polymorphonuclear leukocytes. Although changes in the activities of T and B cells have been reported, the results are less certain.

Therapeutic Potential

Echinacea is traditionally used to prevent and treat upper respiratory infections, such as the common cold. Despite promising data, efficacy in treating illness or in enhancing human health has not yet been proven beyond a reasonable doubt.

Industrial and Pharmaceutical Applications

Echinacea extracts are used in the production of dietary supplements and pharmaceutical products. They are also employed in cosmetics for their beneficial properties on the skin.

Studies

It is a plant known for its immune-defensive properties (1) especially against colds, flu, coughs, and, in general, cold-related diseases (2) as well as anti-inflammatory properties.

Doubts (3) about the efficacy of this and other seedlings have been positively resolved by laboratory experiments.

References_____________________________________________________________________

(1) Fonseca FN, Papanicolaou G, Lin H, Lau CB, Kennelly EJ, Cassileth BR, Cunningham-Rundles S. Echinacea purpurea (L.) Moench modulates human T-cell cytokine response. Int Immunopharmacol. 2014 Mar;19(1):94-102. doi: 10.1016/j.intimp.2013.12.019. Epub 2014 Jan 13.
PMID: 24434371

(2) Di Pierro F, Rapacioli G, Ferrara T, Togni S. Use of a standardized extract from Echinacea angustifolia (Polinacea) for the prevention of respiratory tract infections.  Altern Med Rev. 2012 Mar;17(1):36-41.PMID: 22502621

Abstract. Echinacea preparations are extensively used for the prevention and the management of the common cold. Despite this popularity, the clinical studies on Echinacea have produced mixed results, possibly in part because of the poor characterization of the extracts investigated and the use of different species and/or plant parts for the preparations investigated in the various trials. To address this issue, Polinacea, a highly standardized extract from a well-defined botanical source (roots of Echinacea angustifolia) with a specific phytochemical profile (presence of the complex polysaccharide IDN5405, the phenylethanoid echinacoside, and substantial lack of alkamides) was developed. We have studied whether Polinacea could enhance the immune response subsequent to the influenza vaccination, and whether the use of this preparation could translate into a decreased morbidity from influenza. The preliminary results were encouraging, and suggest that Polinacea could be used for improving the immune response to influenza vaccine.

(3) Vetvicka V, Vetvickova J. Natural immunomodulators and their stimulation of immune reaction: true or false? Anticancer Res. 2014 May;34(5):2275-82. PMID: 24778031

 Abstract. Natural immunomodulators are getting more and more popular. The popularity, however, often brings over-optimistic claims and mediocre effects. The purpose of the present study was to directly compare eleven most commonly used immunomodulators. Through testing both cellular and humoral branches of immune reactions, we found that most of the immunomodulators tested have limited, if any, effects, with glucan being consistently the most active molecule strongly stimulating every reaction evaluated. These data were also confirmed using a Lewis lung cancer model, where only glucan and resveratrol lowered the number of metastases.

Echinacea purpurea extract has demonstrated good effects for the management of hyperglycemia and hypertension, thanks to phenols (27.04%), caffeic acid derivatives and ethanol, all components with antioxidant properties (1).

Effective against inflammation and chronic pain in osteoarthritis of the knee (2).

Most studies have not reported any significant reduction in cough symptoms. Only Cohen et al (3) found a significant improvement in nocturnal coughing. However, Echinacea decreased the symptoms of the common cold, reducing its duration (4).

This other study, which was also provided to support a commercial product, Echinaforce®, demonstrated the efficacy of Echinacea extract as an option for long-term preventive cold treatment (4 months) (5).

Pharmacodynamic studies have confirmed significant bronchodilator and anti-inflammatory effects of Echinacea, similar to the effects of classical synthetic drugs. Therefore, the results provide a scientific basis for the application of this herb in traditional medicine as an additional treatment for allergic respiratory disorders, such as asthma (6).

It is used as a supplement for athletes in order to increase performance. Echinacea was thought to improve oxygenation by increasing erythropoietin, a glycoprotein that regulates red blood cell formation. However, the published literature does not support the use of Echinacea as an ergogenic aid to improve aerobic capacity in untrained or healthy individuals (7).

Overall, even when ingested into Echinacea preparations up to 6 months at the recommended doses, no toxicological concern has emerged (8).

References___________________________________

(1) Antioxidant, Antidiabetic, and Antihypertensive Properties of Echinacea purpurea Flower Extract and Caffeic Acid Derivatives Using In Vitro Models.
Chiou SY, Sung JM, Huang PW, Lin SD.
J Med Food. 2017 Jan 6. doi: 10.1089/jmf.2016.3790

(2) The effect and safety of highly standardized Ginger (Zingiber officinale) and Echinacea (Echinacea angustifolia) extract supplementation on inflammation and chronic pain in NSAIDs poor responders. A pilot study in subjects with knee arthrosis.
Rondanelli M, Riva A, Morazzoni P, Allegrini P, Faliva MA, Naso M, Miccono A, Peroni G, Degli Agosti I, Perna S.
Nat Prod Res. 2016 Oct 13:1-5.

(3) Cohen HA, Varsano I, Kahan E, Sarrell EM, Uziel Y: Effectiveness of an herbal preparation containing Echinacea, propolis, and vitamin C in preventing respiratory tract infections in children: a randomized, double-blind, placebo-controlled, multicenter study. Arch Pediatr Adolesc Med 2004;158:217-221

(4) Herbal Medicine for Cough: a Systematic Review and Meta-Analysis.
Wagner L, Cramer H, Klose P, Lauche R, Gass F, Dobos G, Langhorst J.
Forsch Komplementmed. 2015;22(6):359-68. doi: 10.1159/000442111.

(5) Echinacea purpurea: A Proprietary Extract of Echinacea purpurea Is Shown to be Safe and Effective in the Prevention of the Common Cold.
Ross SM.
Holist Nurs Pract. 2016 Jan-Feb;30(1):54-7. doi: 10.1097/HNP.0000000000000130.

(6) Echinacea complex--chemical view and anti-asthmatic profile.
Šutovská M, Capek P, Kazimierová I, Pappová L, Jošková M, Matulová M, Fraňová S, Pawlaczyk I, Gancarz R.
J Ethnopharmacol. 2015 Dec 4;175:163-71. doi: 10.1016/j.jep.2015.09.007

(7) Echinacea Supplementation: Does it Really Improve Aerobic Fitness?
Baumann CW, Kwak D.
J Exerc Nutrition Biochem. 2016 Sep;20(3):1-6. 

Echinacea-Based Dietary Supplement Does Not Increase Maximal Aerobic Capacity in Endurance-Trained Men and Women.
Stevenson JL, Krishnan S, Inigo MM, Stamatikos AD, Gonzales JU, Cooper JA.
J Diet Suppl. 2016;13(3):324-38. doi: 10.3109/19390211.2015.1036189.

(8) Review and Assessment of Medicinal Safety Data of Orally Used Echinacea Preparations.
Ardjomand-Woelkart K, Bauer R.
Planta Med. 2016 Jan;82(1-2):17-31. doi: 10.1055/s-0035-1558096