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[Testing for immunomodulating effects of ethanol-water extracts of the above-ground parts of the plants Echinaceae (Moench) and Rudbeckia L].

Ethanolic extracts of aerial parts of the plants Echinacea angustifolia DC, Echinacea purpurea L. (Moench), Rudbeckia fulgida var. sullivantii, Boyton et Beadle, and Rudbeckia speciosa Wenderoth show immunomodulating activity. The mice were treated in vivo for 5 days and the activity was tested for and observed on day 7. An immunostimulatory effect was observed on the phagocytic, metabolic and bactericidal activities of peritoneal macrophages. The ethanolic extracts of both Echinacea plants also increased the total weight of the spleens as compared to the effect of the Rudbeckia plants and the control group which received saline.

Adjuvants, Immunologic↗

Echinacea purpurea therapy for the treatment of the common cold: a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Echinacea purpurea stimulates the immune response and is promoted to reduce symptom severity and the duration of upper respiratory tract infections. We sought to determine the efficacy of a standardized preparation of E purpurea in reducing symptom severity and duration of the common cold. METHODS: A randomized, double-blind, placebo-controlled design was used. Patients received either 100 mg of E purpurea (freeze-dried pressed juice from the aerial portion of the plant) or a lactose placebo 3 times daily until cold symptoms were relieved or until the end of 14 days, whichever came first. Symptoms (sneezing, nasal discharge, nasal congestion, headache, sore or scratchy throat, hoarseness, muscle aches, and cough) were scored subjectively by the patient and recorded daily in a diary. Kaplan-Meier curves were used to estimate the survival function of time to resolution in each group. The Wilcoxon rank sum test was used to compare time to resolution between the 2 groups. RESULTS: One hundred twenty-eight patients were enrolled within 24 hours of cold symptom onset. Group demographic distribution was comparable for sex, age, time from symptom onset to enrollment in the study, average number of colds per year, and smoking history. No statistically significant difference was observed between treatment groups for either total symptom scores (P range,.29-.90) or mean individual symptom scores (P range,.09-.93). The time to resolution of symptoms was not statistically different (P =.73). CONCLUSIONS: Some studies have concluded that Echinacea effectively reduces the symptoms and duration of the common cold. We were unable to replicate such findings. Further studies using different preparations and dosages of E purpurea are necessary to validate previous claims.

Adolescent↗

Separation of alkamides from Echinacea purpurea extracts by cyclodextrin-modified micellar electrokinetic chromatography.

Separation of nine important alkyl methylbutyl- and isobutylamides (known as alkamides) obtained from Echinacea purpurea extracts was investigated by using cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC). Hydrophobic alkamides interact strongly with the micelles from the most common surfactants used in MEKC and this lead to predominant partition of the analytes into the micellar phase, resulting in poor resolution. The addition of neutral CDs to the alkaline (10 mM phosphate buffer pH 8.0) micellar system of sodium dodecyl sulfate (SDS), sodium cholate (SC) and sodium deoxycholate (SDC) was found to improve the separation of the studied alkamides. Among the several combinations surfactant/CD, three different systems showed to be particularly effective: SDS/hydroxypropyl-beta-CD (110 mM/100 mM) and SC/heptakis (2, 3, 6-tri-O-methyl)-beta-CD (200 mM/40 mM) which provided a complete separation of the studied compounds, and SDC/heptakis (2, 6-di-O-methyl)-beta-CD. The importance of appropriate surfactant vs. CD concentration ratio as well as that of total concentration of both surfactant and CD was considered. The optimization of the separation was performed by focussing the need for a rapid separation of nine alkamides diagnostically useful to define the fingerprint of Echinacea species.

Amides↗

The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD69 expression and immune cell activation in humans.

The increasing use of medicinal herbs among the general public has piqued the need for scientific-based research to determine the mechanism of action of herbs administered orally in human subjects. The ability of three herbs, Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra, to activate immune cells in human subjects was assessed in this pilot study. The effect of these herbs when ingested for 7 days was measured both when administered singly, and in combination, using flow cytometry. The primary cell activation marker measured was CD69. The results demonstrate that Echinacea, Astragalus and Glycyrrhiza herbal tinctures stimulated immune cells as quantified by CD69 expression on CD4 and CD8 T cells. This activation took place within 24 h of ingestion, and continued for at least 7 days. In addition, these three herbs had an additive effect on CD69 expression when used in combination.

Adjuvants, Immunologic↗

Polysaccharides isolated from Echinacea purpurea herba cell cultures to counteract undesired effects of chemotherapy--a pilot study.

In an open prospective study with matched historical controls we aimed to evaluate whether a polysaccharide fraction isolated from the herb Echinacea purpurea could counteract the undesired effects of chemotherapy. Fifteen patients with advanced gastric cancer undergoing palliative chemotherapy with etoposide, leucovorin and 5-fluorouracil (ELF) received for 10 days (beginning 3 days before chemotherapy) daily i.v. injections of 2 mg of a polysaccharide fraction isolated from Echinacea purpurea herb cell cultures (EPS-EPO VIIa). The median number of leukocytes 14-16 days after chemotherapy was 3630/microL (range 1470-5770) in the patients receiving EPS-EPO VIIa compared with 2370/microL (870-3950) in the patients of the historical control group (p = 0.015). EPS-EPO VIIa had no clinically relevant effects on phagocytic activity of granulocytes or on lymphocyte subpopulations. Sixty-eight adverse events including two deaths were observed, most likely due to chemotherapy and the general condition of the patients. However, an association with the test intervention cannot be ruled out completely. The results of this pilot study suggest that EPS-EPO VIIa might be effective in reducing chemotherapy-induced leukopenia. The efficacy and safety should be investigated in further studies.

Adult↗

Genetic diversity in seed populations of Echinacea purpurea controls the capacity for regeneration, route of morphogenesis and phytochemical composition.

The production of new varieties and higher quality products from Echinacea spp. requires a greater understanding of the regulation of plant growth and the production of specific phytometabolites. The current studies were designed to generate elite varieties of Echinacea purpurea based on regeneration efficiency and chemical profile. Clonal propagation of seedling-derived regenerants and screening for antioxidant potential and concentrations of caftaric acid, chlorogenic acid, cichoric acid, cynarin, and echinacoside identified 58 unique germplasm lines. Chemical profiles varied significantly among germplasm lines but were consistent within clones of each line. In temporary immersion bioreactors, exogenous application of the auxin indolebutyric acid significantly increased the cichoric acid and caftaric acid concentration in the root tissues. Together, these demonstrate the potential for selective breeding of elite, highly regenerative, chemically superior, clonally propagated varieties from the naturally occurring genetic variability in the seed populations of E. purpurea.

Caffeic Acids↗

High performance liquid chromatography/electrospray ionization mass spectrometry for simultaneous analysis of alkamides and caffeic acid derivatives from Echinacea purpurea extracts.

Extracts of the plant Echinacea purpurea are widely used for medicinal purposes. Effective quality control of these extracts requires rapid methods to determine their chemical composition. A new method for analysis of caffeic acid derivatives and alkamides from Echinacea extracts has been developed. With this method, isomeric isobutylamides and 2-methylbutylamides can be distinguished, a capability that previously published methods have lacked. Quantitative analyses carried out with this method on E. purpurea extracts that have been stored for 18 months indicate that they contain caftaric acid, cichoric acid, and undeca-2Z,4E-diene-8,10-diynoic acid isobutylamide at concentrations of 0.7, 0.71 and 2.0mg/mL, respectively.

Amides↗

Echinacea alkylamides modulate TNF-alpha gene expression via cannabinoid receptor CB2 and multiple signal transduction pathways.

Echinacea plant preparations are widely used in the prevention and treatment of common cold. However, so far no molecular mechanism of action has been proposed. We analyzed the standardized tincture Echinaforce and found that it induced de novo synthesis of tumor necrosis factor alpha (TNF-alpha) mRNA in primary human monocytes/macrophages, but not TNF-alpha protein. Moreover, LPS-stimulated TNF-alpha protein was potently inhibited in the early phase but prolonged in the late phase. A study of the main constituents of the extract showed that the alkylamides dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides (1/2), trienoic (3) and dienoic acid (4) derivatives are responsible for this effect. The upregulation of TNF-alpha mRNA was found to be mediated by CB2 receptors, increased cAMP, p38/MAPK and JNK signaling, as well as NF-kappaB and ATF-2/CREB-1 activation. This study is the first to report a possible molecular mechanism of action of Echinacea, highlighting the role of alkylamides as potent immunomodulators and potential ligands for CB2 receptors.

Cells, Cultured↗

Sequence characterized amplified region (SCAR) analysis on DNA from the three medicinal Echinacea species.

In our previous study, RAPD (Random Amplified Polymorphic DNA) analysis revealed species-specific markers for three medicinal Echinacea species (Asteraceae): E. angustifolia DC., E. pallida (Nutt.) Nutt. and E. purpurea (L.) Moench. In the present work, we have converted a RAPD marker (750 bp) for E. purpurea into a SCAR (Sequence Characterized Amplified Region) marker. SCAR-PCR, in fact, revealed the expected amplicon (330 bp) only in E. purpurea and not in the other two species, giving further evidence for differences in medicinal Echinacea spp. genome and confirming a greater similarity between E. pallida and angustifolia.

DNA Primers↗

Immunomodulatory effects of arabinogalactan-proteins from Baptisia and Echinacea.

The influences of different arabinogalactan-proteins (AGPs) on proliferation and IgM-production of mouse lymphocytes as well as nitrite- and IL6-production of mouse macrophages were investigated in vitro. AGPs have been isolated and purified from roots of Baptisia tinctoria and Echinacea pallida and suspension culture of Echinacea purpurea. Comparing the AGPs, there are differences with regard to fine structure as well as to activities. AGPs from roots of B. tinctoria and E. pallida show high activity in all test systems. AGP from cell culture of E. purpurea shows no influence on proliferation of mouse lymphocytes, only weak influence on the IgM-production of mouse lymphocytes and weak stimulation of nitrite- and IL6-production in alveolar mouse macrophage culture.

Animals↗

Diacetylenic isobutylamides of Echinacea: synthesis and natural distribution.

The syntheses of three diacetylenic isobutylamides of Echinacea angustifolia have been achieved by direct synthetic routes by way of a common intermediate. The key step is the alkylation of the anion of the silylated diacetylene. We report the presence of all three diacetylenic isobutylamides in six of the nine Echinacea species: E. angustifolia, E. sanguinea, E. simulata, E. tennesseensis, E. atrorubens and E. laevigata. The accumulation of these amides is sensitive to organ type and age.

Acetylene↗

Effect of temperature on stability of marker constituents in Echinacea purpurea root formulations.

Stability of an alkamide and a phenolic phytochemical marker in a hydro-alcoholic extract of Echinacea purpurea root and a dried powder prepared by evaporation of the extract was assessed in storage for 7 months at three temperature regimes: -20, 25 and 40 degrees Celsius. In the extract, the major alkamide, dodeca-2E, 4E, 8Z, 10E/Z-tetraenoic acid isobutyl amide, was not significantly affected by storage at any of the temperatures, but cichoric acid content declined as significantly (P = 0.05) at both 25 degrees C and 40 degrees C as compared to low-temperature storage. In the powder, the major alkamide showed a significantly reduced level at 25 degrees C and 40 degrees C while cichoric acid did not decline significantly. These results suggest that more attention should be given to the effect of formulation and temperature on storage of Echinacea products.

Caffeic Acids↗

Phytochemical variation in echinacea from roots and flowerheads of wild and cultivated populations.

Quantitative phytochemical variation was determined from roots and inflorescences of native plant populations in the genus Echinacea. Specimens were collected in situ throughout the natural range of each putative taxon and transplanted to greenhouse cultivation. Ethanolic extracts from individual plants were separated by reversed-phase HPLC to quantify the alkamides, polyenes/ynes, and phenolics, and then grouped by age and taxonomically, according to a recent morphometric taxonomic revision of the genus. Canonical discriminant analysis revealed that cichoric acid, the diene alkamides 1-3 and 7, and ketoalkene 24 were the best taxonomic markers. Mean content for each of 26 phytochemicals revealed useful agronomic information, such as those varieties and organs with the highest accumulations, as well as the optimal age and growth conditions for each variety. The highest amounts of cichoric acid were measured from the older, wild inflorescences of E. pallida var.sanguinea, whereas the highest quantities of the alkamides 1-3 and 7 were present in roots of wild and transplanted E. purpurea. Baseline phytochemical data and chromatographic profiles for all types of wild Echinacea may be used for protection of wild stands, germplasm identification, and crop improvement.

Caffeic Acids↗

Stabilization of caffeic acid derivatives in Echinacea purpurea L. glycerin extract.

Recent work has shown that enzymatic degradation and oxidation of cichoric acid and other caffeic derivatives occurs in Echinacea preparations. However, very little is known as to the means of stabilizing these phytopreparations. To stabilize the glycerin extract of Echinacea purpurea, we have evaluated the effects of 3 natural antioxidants (citric acid, malic acid, and hibiscus extract) on the stability of the major caffeic acid derivatives (caftaric acid, caffeic acid, cichoric acid, and 2-O-feruloyl-tartaric acid). Chlorogenic acid, which normally occurs in an ethanol extract of E. purpurea, was not present in the glycerin extract. The caffeic acid derivatives, with the exception of 2-O-feruloyl-tartaric acid, were subject to degradation in the control sample. 2-O-Feruloyl-tartaric acid was stable during the whole testing period. All antioxidant treatments greatly improved the stability of caffeic acid derivatives. Stability was dependent upon the concentration of antioxidant added.

Antioxidants↗

Effect of drying temperature on alkylamide and cichoric acid concentrations of Echinacea purpurea.

Root and aerial sections (flower, stem, and leaf) of Echinacea purpurea were dried with hot air at temperatures in the range of 40-70 degrees C, and the concentrations of alkylamides and cichoric acid were determined after drying. Increasing drying temperature decreased from 48 h at 40 degrees C to 9 h at 70 degrees C but resulted in a decreased concentration of cichoric acid in all plant sections with a greater loss from aerial plant parts than from the root. There was, however, no significant difference in the concentration of the alkylamides at any drying temperature. Establishment of operational parameters for the drying of echinacea must therefore be structured around the more labile cichoric acid.

Amides↗

Volatile components of roots, stems, leaves, and flowers of Echinacea species.

The headspace volatile components of roots, stems, leaves, and flowers of Echinacea angustifolia,E. pallida, and E. purpurea were analyzed by capillary gas chromatography/mass spectrometry (GC/MS). Over 70 compounds were identified in the samples. All plant tissues, irrespective of the species, contain acetaldehyde, dimethyl sulfide, camphene, hexanal, beta-pinene, and limonene. The main headspace constituents of the aerial parts of the plant are beta-myrcene, alpha-pinene, limonene, camphene, beta-pinene, trans-ocimene, 3-hexen-1-ol, and 2-methyl-4-pentenal. The major headspace components of root tissue are alpha-phellandrene (present only in the roots of E. purpurea and E.angustifolia), dimethyl sulfide, 2-methylbutanal, 3-methylbutanal, 2-methylpropanal, acetaldehyde, camphene, 2-propanal, and limonene. Aldehydes, particularly butanals and propanals, make up 41-57% of the headspace of root tissue, 19-29% of the headspace of the leaf tissue, and only 6-14% of the headspace of flower and stem tissues. Terpenoids including alpha- and beta-pinene, beta-myrcene, ocimene, limonene, camphene, and terpinene make up 81-91% of the headspace of flowers and stems, 46-58% of the headspace of the leaf tissue, and only 6-21% of the roots. Of the 70 compounds identified, >50 are reported in Echinacea for the first time.

Echinacea↗

Enzymatic degradation of cichoric acid in Echinacea purpurea preparations.

Cichoric acid (2R,3R-O-dicaffeoyltartaric acid) (1) is highly susceptible to enzymatic degradation during the preparation of Echinacea purpurea products. Degradation of 1 and other caffeic acid derivatives can be inhibited by antioxidants added to the extraction solvent or in buffered protein extracts saturated with nitrogen. Inhibitor studies conducted with protein extracts prepared from dried overground parts of E. purpurea revealed that polyphenol oxidases (PPO) but not peroxidases are responsible for the oxidative degradation of exogenous and endogenous caffeic acid derivatives. With a view to stabilizing aqueous extracts with respect to their content of 1, the effects of ascorbic acid and ethanol were tested. Compound 1 was not stable under conditions where oxidative processes could almost be excluded. It was found that an esterase hydrolyzing the ester bonds between tartaric acid and caffeic acid is still active under PPO inhibitory conditions. Finally, addition of 40% ethanol and 50 mM ascorbic acid to aqueous extracts of "Echinaceae purpureae herba" resulted in a constant amount of cichoric acid over four weeks.

Caffeic Acids↗

Permeability studies of alkylamides and caffeic acid conjugates from echinacea using a Caco-2 cell monolayer model.

BACKGROUND: Echinacea is composed of three major groups of compounds that are thought to be responsible for stimulation of the immune system--the caffeic acid conjugates, alkylamides and polysaccharides. This study has focussed on the former two classes, as these are the constituents found in ethanolic liquid extracts. OBJECTIVE: To investigate the absorption of these two groups of compounds using Caco-2 monolayers, which are a model of the intestinal epithelial barrier. RESULTS: The caffeic acid conjugates (caftaric acid, echinacoside and cichoric acid) permeated poorly through the Caco-2 monolayers although one potential metabolite, cinnamic acid, diffused readily with an apparent permeability (Papp) of 1 x 10(-4) cm/s. Alkylamides were found to diffuse through Caco-2 monolayers with Papp ranging from 3 x 10(-6) to 3 x 10(-4) cm/s. This diversity in Papp for the different alkylamides correlates to structural variations, with saturation and N-terminal methylation contributing to decreases in Papp. The transport of the alkylamides is not affected by the presence of other constituents and the results for synthetic alkylamides were in line with those for the alkylamides in the echinacea preparation. CONCLUSION: Alkylamides but not caffeic acid conjugates are likely to cross the intestinal barrier.

Amides↗