Purple Coneflower and Eastern Purple Coneflower
There are 11 plants found within the Echinacea genus, and most are considered to be coneflowers, including the Sanguine purple coneflower, Echinacea sanguinea, and the narrow-leaf coneflower, Echinacea angustifolia, which was the basis of early medical research into the Echinacea genus (TWC Staff, 2013, Brinker, 2013). Echinacea purpurea is a member of the Asteraceae family.
Geographic Distribution and Habitat
While E. purpurea is native to northeast of Texas, this plant can now be found in at least 27 states and two Canadian provinces. E. purpurea is found in the eastern to central United States. E. purpurea prefers well drained soil that is sandy or loamy in texture.
E. purpurea is a perennial with lavender to pink drooping rays and a brownish central disk containing many spiny seeds. The reasoning behind the genus name Echinacea comes from the Greek word echinos meaning hedgehog in reference to the bristly seed tops. The plant is composed of smooth stems 2 to 5 feet tall and flowers are found on a single stem. The flowers bloom from April to September. The green leaves are lancolate and ovate, rough texture, with dentate or serrated margins.
Portion of the Plant Used
Echinacea purpurea has many traditional and modern medical uses, and therefore, many different parts of the plant are used to varying effect. The flowers, leaves, stems and roots flower are all used for medicinal treatments.
E. purpurea has been used to treat many different ailments. Traditional uses of this plant are centered around its anti-inflammatory properties, regardless of the location or kind of inflammation, whether it is skin inflammation or as a reaction to an immune response. The flowers are used to make herbal tea, said to help boost the immune system. The herb is historically used as a cure for colds, infections, wounds, ulcers, and skin inflammations (Van Wyk et.al., 2004). Depending on where the plant is located in the world, there are other unique uses for the plant. In India, Echinacea purpurea is used as an anti-venom, while in Italy it is used to aid in the healing of inflammation (Ross, 1999).
There is a considerable amount of recent research on E. purpurea focused on its use for the common cold. E. purpurea has been found effective for treating the symptoms of the common cold in adults but not in children (Schapowal, 2013; see reviews by Nahas and Balla, 2011; Fashner et al., 2012). Indeed, it has been found that some standardized preparations contain “potent and selective antiviral and antimicrobial activities” that act as immunomodulators (reviewed by Hudson, 2012). This effect may be mediated by modulation of cytokine expression in the immune system (reviewed by Spelman et al., 2006).
The early medical uses for the Echinacea genus used Echinacea angustifolia rather than E. purpurea. E. angustifolia use was recommended by physicians as late as 1923, where at least ten of 700 physicians mentioned the use of Echinacea in the treatment of influenza (Brinker, 2013). In 1934, a study at the Eclectic Medical College that showed subjects had an increase in leukocyte count after taking large doses (130-1975 mg) of E. angustifolia, often peaking after a single day of a large dose (Brinker, 2013). A portion of the decline of use of E. angustifolia in the medical field can be accredited to German scientists, who showed that the extract exhibited weak inhibition of Streptococcal and Staphylococcus aureus gram-positive bacteria (Brinker, 2013).
While most early studies about the viability of Echinaeca species were performed on E. angustifolia, E. purpurea began to get some notoriety in 1853 after Dr. John King mentioned its potential uses for the medicinal community in his Eclectic American Dispensary (Brinker, 2013). In 1989, a German Commission approved the use of the liquid of E. purpurea as a “supportive treatment” for chronic respiratory and urinary infections as well as wound healing, but the roots were not approved at this time (Brinker, 2013).
Recent studies have confirmed that this plant has some immuno-stimulatory effects (Crellin, 1990). In 2007, a large meta-analysis of existing studies was done to test the viability of using Echinacea for the common cold and related incidents (Brinker, 2013). Significant reductions in the occurrence and time of illness were seen after this meta-analysis (Brinker, 2013). A recent study in 2012 looked at the effects of E. purpurea and its affect on the common cold. In this study, a reduction in recurring infections were shown when patients took Echinacea extract, significantly more than the patients that were using ibuprofen (Jamal et.al, 2012; Brinker, 2013).
Side Effects, Interactions, and Contraindications
Researchers speculate that the use of the Echinacea herb would have potential risks when taken with several systemic diseases including: tuberculosis, multiple sclerosis, leukosis, collagenosis, AIDS, and certain autoimmune diseases (Brinker, 2013). This speculation is based partially on the effect E. purpurea has cytochrome P450 3A4, which affects the amounts of absorbtion of certain medications including macrolide antibiotics, such as clarithromycin and erythromycin (Brinker, 2013).