Purple Coneflower

Botanical Profile

Note on herbal-drug differentiation: Statements on purple coneflower should distinguish between root, herb and extracts; monographs frequently relate to specific herbal drugs.

Echinacea purpurea is a North American Asteraceae species with purple ray florets and a conspicuous cone-shaped receptacle. From a raw-material perspective, herb, flowering herb, root, expressed juice and various extracts are distinguished; their composition and regulatory classification are not identical.

Echinacea purpurea is a perennial herbaceous plant of the Asteraceae family. It forms upright stems, roughly hairy ovate to lanceolate leaves and large capitula with purple-pink ray florets and a spiny, prominently cone-shaped receptacle. The species originates from North America and is now cultivated in Europe and other regions. In medicinal-plant and botanical raw-material contexts, aerial parts at flowering time and roots are particularly important. Freshly expressed juices from the flowering herb and alcoholic or hydroalcoholic extracts also have their own raw-material profiles. The species must be distinguished from Echinacea angustifolia and Echinacea pallida, which are related but differ in morphology, constituent profiles, monographs and raw-material history.

Phytochemistry

Echinacea purpurea contains various phenolic compounds, including chicoric acid, caftaric acid and other caffeic-acid derivatives, as well as alkamides, polysaccharides, glycoproteins, flavonoids and small amounts of essential-oil constituents. The distribution of these groups depends strongly on plant part and preparation method. Expressed juices from fresh herb, ethanolic herb extracts and root extracts differ in their relative contents of hydrophilic caffeic-acid derivatives, more lipophilic alkamides and polymeric fractions. Chicoric acid is regarded as an important analytical marker for Echinacea purpurea herb, while alkamides are often considered in more lipophilic fractions. Processing, drying, storage and extraction solvent substantially influence the stability of sensitive phenolic components.

Traditional Uses

Echinacea species were described in North American Indigenous traditions and later in North American Eclectic Medicine as botanical raw materials. The European history of use is more recent and is closely associated with the twentieth century and with standardised expressed juices and extracts. Purple coneflower became particularly well known in European phytotherapy in the context of traditional herbal preparations made from fresh herb. The respective species and raw-material details are essential because older literature and commercial designations may concern different Echinacea species. Traditional information describes documented contexts of use and does not replace modern assessment of efficacy, safety and the permissibility of product-related statements.

Current Research

Echinacea purpurea is one of the most intensively studied medicinal plants in the field of botanical immunomodulation and cold-related contexts. Research focuses on expressed juices, hydroalcoholic extracts, alkamides, caffeic-acid derivatives, polysaccharides and cell-based immunological models. Clinical studies investigate different Echinacea products, species, plant parts and extract types, which makes comparability difficult. European assessments therefore distinguish carefully between specific preparations and traditional uses. Experimental work shows diverse effects in cell models, but findings depend strongly on extract, dose, standardisation and test system. Product identity, species differentiation and preparation definition are crucial for professional assessment.

Sources

• Plants of the World Online: Echinacea purpurea (L.) Moench; Royal Botanic Gardens, Kew.
• EMA/HMPC/48704/2014. European Union herbal monograph on Echinacea purpurea (L.) Moench, herba recens.
• EMA/HMPC documents on Echinacea purpurea radix and herba.