ECHINACEA: A MEDICINE IN YOUR GARDEN

 

Purple coneflower (Echinacea purpurea)

Echinacea (ek-in-AY-shee-a or ek-in-AY-see-a; derived from Greek word ekhinos, meaning urchin or porcupine, due to the spiny central disk of the composite flowers head) is a genus of flowering plants from the Aster family (Asteraceae/Compositae) including nine accepted species. Most of the species are native to Eastern and Central North America. The most common species grown in the gardens and used medicinally are E. purpurea (purple coneflowers or hedgehog coneflowers) and E. angustifolia (narrow-leaf coneflower). E. pallida (pale-purple coneflower) also forms a part of the pharmaceutical supply chain. Echinacea angustifolia is used for hundreds of years for treating flu, cold, sore throat, respiratory tract infections and difficult to heal wounds by the native Americans. However, many herbalists are also using E. purpurea for all these symptoms. According to a report published in HerbalGram (The Journal of the American Botanical Council) in the Fall issue of 2021, Echinacea stands at No. 9 in the list of top-selling herbal supplements and the total sales stand at $12,856,524 in the USA alone.

Spiny head of the inflorescence (capitulum)

MORPHOLOGY
Echinacea is a genus of herbaceous perennials growing up to 150 cm (60 cm in E. angustifolia; 90 cm in E. purpurea; 120 cm in E. pallida) in height. The stem, arising from a fusiform (wider in the center and narrowing at the ends) taproot, is green or mottled with purple and green. The leaves are lanceolate or linear-lanceolate with three veins in E. angustifolia and ovate, coarsely toothed, with basal ones often cordate in E. purpurea. Two types of flowers, ray florets and disc florets, are aggregated in a conical flower head (known as capitulum) up to 10 cm in diameter and with spiny projections of the receptacle scales on the surface. The ray florets (with long purplish strap-like petals; white petals in ‘White Swan’ cultivar of E. purpurea), which are 8-21 in number, are arranged on the periphery of the head, while the disc florets (approximately 200-300 in number) occupy the central area. The fruits, known as cypselae, are 3-4-angled, tan or bicolored with dark brown bands and have a distal crown of persistent pappi with teeth.

Echinacea purpurea ‘White Swan’

Purple coneflowers (Echinacea purpurea) blooming at Jakhoo Temple

CULTIVATION

Coneflowers are beautiful seasonal flowering plants for gardens. They can be propagated through seeds, which can be sown in September or October or the seeds can be stratified during the winter and sown in February. In colder parts of India, flowering starts in June and continues till September. The vegetative propagation is generally done through the division of the basal clumps into smaller bunches during the spring or autumn.

Two cultivar of Echinacea purpurea growing in a flower bed

CHEMICAL CONSTITUENTS
Major chemical constituents in the roots are echinacoside, cynarin, cichoric acid, arabinogalactan, rhamnoarabinogalactan, xyloglucan, inulin, fructans, heteroxylan, alkylamides, borneol, bornylacetate, pentadeca-8-en-2-one, vanillin, p-hydroxycinnamic acid methyl ester, germacrene D, dimethyl sulfide, 2- and 3-methylbutanal, 2-propanal, 2-methylpropanal, acetaldehyde, camphene, limonene, caryophyllene, caryophyllene epoxide, palmitic acid and glycine betaine.

The aerial parts contain α-phellandrene, β-myrcene, α- and β-pinene, limonene, camphene, trans-ocimene, 3-hexen-1-ol, 2-methyl-4-pentenal, chlorogenic acid, rutoside, luteolin, kaempferol, quercetin, quercetagetin-7-glucoside, luteolin-7-glucoside, kaempferol-3-glucoside, apigenin and isorhamnetin.

Young flower heads

MEDICINAL USES

Dr. James A. Duke, an American botanist and an author of many publications on botanical medicine, has kept this plant in high esteem and suggested its use in curing many ailments. All parts of this plant are used as medicine. However, dried roots find predominant use in the herbal industry. In case of E. purpurea, dried tops or fresh flowering herbage are generally used. Some of the medicinal uses of Echinacea spp. are listed below: 

1.   For Cold and Flu: Root extract of E. angustifolia, E. purpurea and E. pallida is used to treat cold and flu-like diseases by North American and European herbalists for centuries. A recent double-blind, placebo-controlled study has proved that ethanolic extract of E. purpurea significantly relieves the severity and duration of cold and flu-like symptoms.

2.   Antioxidant Activity: Root extract has been reported to have anti-oxidant properties due to the presence of a large number of phytochemicals present. Caffeoyl derivatives such as echinacoside and cynarine are capable of scavenging reactive oxygen species (ROS) and other free radicals. An extract of E. purpurea is reported to upregulate the serum superoxide dismutase (SOD) activity resulting in an enhanced antioxidant effect.

3.   Stimulation of the Immune System: Extracts of Echinacea species have been reported to stimulate the immune system in a nonspecific manner through an overall increase in phagocytosis by macrophages and granulocytes. High molecular weight polysaccharides from an aqueous extract stimulated T-lymphocyte activity by 20-30% as compared to a potent T-cell stimulator. Immunomodulation is reported to be a combined action of several phytoconstituents including alkylamides and cichoric acid.

4.   Anti-Inflammatory Activity: Alkamides present in E. angustifolia and E. purpurea induce a strong anti-inflammatory activity by downregulating the seminal microsomal cyclooxygenase and porcine leukocyte 5-lipooxygenase activity.

5.   Wound Healing: The expressed juice from fresh flowering tops of E. purpurea has been reported to heal the wounds by promoting the formation of mesenchymal mucopolysaccharides, stimulating histogenic and haematogenic phagocytes, through differentiation of fibrocytes from fibroblasts and by stimulating the anterior pituitary-adrenal cortex. This activity is primarily attributed to four caffeoyl acid esters (cynarine, chicoric, caftaric and chlorogenic acids).

6.   Bacteriostatic and Fungistatic Activities: The plant extracts are reported to have anti-bacterial (against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa) and anti-fungal (against Trichomonas vaginalis, Epidermophyton interdigitale, Saccharomyces cerevisiae and Candida spp.) activity due to the presence of polyacetylenes and alkamides.

7.   Anti-Viral Activity: Anti-viral activity, primarily due to the presence of alkamide constituents, has been reported against influenza, herpes, and poliovirus.

Echinacea as Homeopathic Medicines (Photograph source: Internet)

COMMERCIAL PREPARATIONS
Extracts, capsules, tablets, tea, tinctures, ointment, etc.

CAUTION

Most of the studies report Echinacea as ‘safe’ for most people when used for a short duration. However, some people may develop stomachache, constipation, diarrhoea or vomiting. Some people have a tendency to allergic reactions to members of the Aster family and may suffer from acute asthma and urticaria. It is not recommended for pregnant women, lactating mothers and young children as sufficient pieces of evidence are not available. As this plant has immunomodulatory properties, it may worsen the conditions of persons suffering from auto-immune disorders such as multiple sclerosis, lupus erythematosus and rheumatoid arthritis.

NOTE: This information is only for knowledge. Do not use herbal medicines without a prescription by a medical practitioner.

FURTHER READING

1. Armstrong, D. (2001). Herbs That Work. Ulysses Press, Berkeley.
2. Barnes, J., Anderson, L.A. and Phillipson, J.D. (2007). Herbal Medicine. Pharmaceutical Press, London, UK.
3. Capasso, F., Gaginella, T.S., Grandolini, G. and Izzo, A.A. (2003). Phytotherapy: A Quick Reference to Herbal Medicine. Springer-Verlag Berlin Heidelberg.
4. Duke, A. (1999). Dr. Duke’s Essential Herbs. Rodale Books, Pennsylvania.
5. Gladstar, R. (2014). Herbs for Common Ailments. Storey Publishing, Maryland, USA.
6. Karch, S.B. (1999). The Consumers Guide to Herbal Medicine. Advanced Research Press, New York.
7. Kunkele, U. and Lohmeyer, T.R. (2007). Herbs for Healthy Living. Paragon Books, Bath, UK.