John Livesey

Echinacea purpurea. Aerial Parts Contain Multiple Antiviral Compounds

Abstract Stems, leaves, and flowers of Echinacea purpurea. (L.) Moench (Heliantheae: Asteraceae) were fractionated by various solvents and the fractions evaluated for antiviral activity in relation to chemical composition and distribution within the plant. All of the aqueous fractions contained potent activity against herpes simplex virus and influenza virus. However, although some of this activity could be attributed to polysaccharide and cichoric acid components, their individual contributions could not account for the total antiviral activity; other potent antivirals must be present. In addition, the ethanol- and ethyl acetate–soluble fractions from leaves and stem contained an uncharacterized but potent antiviral photosensitizer, which was absent from the flower extract. None of the fractions, however, contained anti-rhinovirus activity. Thus, part of the alleged benefits of Echinacea purpurea. extracts can be attributed to the presence of anti-influenza and anti-HSV compounds, and some of these activities are likely to be present in various commercial tinctures, teas, capsules, and tablets.

A quantitative HPLC method for the quality assurance of Echinacea products on the North American market.

A rapid and quantitative method of quality assurance for marker phytochemicals in products containing material derived from Echinacea species has been developed. In order to assess the efficiency of extraction of phytochemicals from the roots and aerial parts of Echinacea purpurea and E. angustifolia, a study of solvent mixtures and extraction methods was carried out to determine the recovery of known compounds from plant materials. Ultrasonic extraction of dried samples with methanol:water (7:3) or ethanol:water (7:3) gave good yields of cichoric acid, echinacoside and the alkamides, undeca-2E,4Z-diene-8,10-diynoic acid isobutylamide and a mixture of dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides (recoveries of 89%, 85%, 80% and 90%, respectively). The HPLC separation of the phenolic compounds cichoric acid, chlorogenic acid and echinacoside was also improved by careful attention to the pH of the mobile phase. A shortened HPLC column allowed turnaround times of 22 min for phenolic components and 15 min for alkamides with lower solvent use. Assessment of commercial raw materials from the North American market using the new method was useful for confirmation of species and showed a very large variation in concentration of markers in the products sold in this market. Copyright

Predicting quantitative phytochemical markers in single Echinacea plants or clones from their DNA fingerprints.

Amplified restricted fragment length polymorphism (AFLP) data analysis was found to be a statistically significant predictor of phytochemical markers in cultivated Echinacea purpurea germplasm and some related wild species. Over 50 accessions grown under greenhouse conditions were subjected to AFLP analysis and the same assessed for content of tetraene and cichoric acid by high pressure liquid chromatography. The first and second canonical correlation of DNA variables and the phytochemical variables were significant. Individual regressions of cichoric acid and dodeca-2E, 4E, 8Z, 10E/Z-tetraenoic acid isobutyl amide predicted by DNA polymorphism analysis against actual HPLC determined values were nearly linear. Mantels test showed that there was a weak correlation but a strong association of values of the phytochemical variables and the DNA polymorphism data.

Characterization of Antiviral Activities in Echinacea. Root Preparations

Abstract The roots of three commonly used taxa of Echinacea.—E. purpurea., E. pallida. var. pallida., and E. pallida. var. angustifolia.—were extracted and fractionated by means of accelerated solvent extraction to reflect the most commonly used methods for commercial preparations. These fractions were analyzed by HPLC for their content of caffeic acid derivatives and alkamides and for antiviral activities against three viruses often implicated in colds and influenza. Aqueous extracts of E. purpurea. root contained a relatively potent activity against herpes simplex virus (HSV) and influenza virus (FV) but not against rhinovirus (RV). These fractions had low amounts of caffeic acids and alkamides. The ethyl acetate fraction contained significant but weak activity against both HSV and FV and contained significant levels of cichoric acid. In contrast, E. pallida. var. angustifolia. gave no water-soluble antiviral activity, but the ethanolic and ethyl acetate fractions contained significant activity against all three viruses, and this activity correlated with the presence of alkamides. E. pallida. var. pallida., however, gave no antiviral activity in any of the fractions, and this observation accorded well with the near absence of the marker compounds. Thus, we have detected a relatively potent water-soluble antiviral activity in E. purpurea. root, together with the weaker antiviral cichoric acid; an antiviral alkamide fraction in E. pallida. var. angustifolia.; but no antiviral activity in E. pallida. var. pallida.. Therefore, different types of Echinacea. root preparations, such as tinctures, tablets, and teas, based on different species and extraction methods, would be expected to offer quite different antiviral profiles.

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.

In Vitro Activity of St. John's Wort Against Cytochrome P450 Isozymes and P-Glycoprotein

The inhibitory activity of 18 commercial St. Johns wort products (Hypericum perforatum L. Hypericaceae) against human cytochrome P450 enzymes was assessed because recent studies have found that this herb can markedly affect disposition of concurrently used conventional drugs. For the most part, these studies have employed ethanolic extracts. However, many of the two dozen reported constituents or groups of compounds having pharmacological effects in Hypericum extracts have widely differing solubility characteristics and hence the interpretation of the results is problematic. Sequential extracts from hexane through to water demonstrated a strong effect of several lipophilic fractions on the cytochrome P450 3A4 mediated-metabolism of 7-benzyloxyresorufin (7-BR), suggesting that many different classes of compounds are active. In this study we sought to investigate 18 single-entity and blended products containing St. Johns wort, including 7 caplets/tablets, 6 capsules, 4 teas and 1 tincture, for biomarker content and affect on cytochrome P450-mediated metabolism. Our results show that there is a wide variation in hyperforin, hypericin and pseudohypericin levels and that most standardized products did not meet specification. Furthermore, all aqueous extracts from the products tested exhibited a marked capacity to inhibit cytochrome P450-mediated metabolism. Four of the five extracts tested also inhibited P-glycoprotein activity. These findings support the notion that a wide range of therapeutic products used in conjunction with St. Johns wort could lead to adverse side effects.

Chemical Marker Profile and Biological Effects of Natural Products Containing Echinacea

Natural health products containing Echinacea have been used by many patient populations and although there are reports of adverse effects with products containing Echinacea, few clearly characterized the nature of the product with respect to constituent content, the nature of the products and the mechanism underlying the interaction. The objective of this study was to examine blended and single-entity Echinacea products containing ground plant material or extracts in commercial capsules, herbal teas, tablets, tinctures and soft gel liquid-filled capsule formulations in an attempt to correlate biomarker constituent content and effects on cellular and subcellular parameters of interest. HPLC analysis indicated significant variability in the major biomarker constituent content in extracts from these Echinacea products. These extracts were also examined for their potential to affect cytochrome P450 CYP1A1/2, 2C9*1, 2C9*2, 2C19, 2D6, 3A4, 3A5, 3A7, and flavin-containing monooxygenase 3 (FMO3); CYP3A5-mediated metabolism, and expression of CYP3A4 and ABCB1. The extracts of some products were also examined for their effect cellular processes such as cell proliferation, nitric oxide formation as a marker of immunostimulatory capacity, and lactate dehydrogenase release as a marker for cell toxicity. The present study indicated that key Echinacea constituents varied widely within and between the products tested and that these levels did not correlate with the ability of these products to markedly affect the cellular processes studied.