Applications of the phytomedicine Echinacea purpurea (Purple Coneflower) in infectious diseases.

Extracts of Echinacea purpurea (EP, purple coneflower) have been used traditionally in North America for the treatment of various types of infections and wounds, and they have become very popular herbal medicines globally. Recent studies have revealed that certain standardized preparations contain potent and selective antiviral and antimicrobial activities. In addition, they display multiple immune-modulatory activities, comprising stimulation of certain immune functions such as phagocytic activity of macrophages and suppression of the proinflammatory responses of epithelial cells to viruses and bacteria, which are manifested as alterations in secretion of various cytokines and chemokines. These immune modulations result from upregulation or downregulation of the relevant genes and their transcription factors. All these bioactivities can be demonstrated at noncytotoxic concentrations of extract and appear to be due to multiple components rather than the individual chemical compounds that characterize Echinacea extracts. Potential applications of the bioactive extracts may go beyond their traditional uses.

Echinacea and trypanasomatid parasite interactions: growth-inhibitory and anti-inflammatory effects of Echinacea.

CONTEXT/OBJECTIVE: Herbal preparations derived from various species and parts of Echinacea (Asteraceae) have been advocated for various medical applications, as a result of the many antimicrobial and immunomodulatory activities attributed to them. MATERIALS AND METHODS: In order to investigate their effects on parasites, four preparations of Echinacea, with distinct chemical compositions, were evaluated for growth inhibition of three species of trypanosomatids: Leishmania donovani, Leishmania major, and Trypanosoma brucei. In addition one Echinacea preparation was tested for anti-inflammatory activity in cell culture models designed to measure pro-inflammatory cytokines induced by L. donovani. RESULTS AND DISCUSSION: All Echinacea preparations inhibited growth of the organisms, though with different relative potencies, and in some cases morphological changes were observed. However, there was no obvious correlation with the composition of the marker compounds, alkylamides, caffeic acid derivatives, and polysaccharides. L. donovani stimulated the production of the pro-inflammatory cytokines IL-6 and IL-8 in human bronchial epithelial cells and in human skin fibroblasts, but in both cases the standardized ethanol extract of E. purpurea (L.) Moench (Echinaforce) abolished the stimulation, indicating anti-inflammatory activity of this extract. CONCLUSIONS: Thus various Echinacea extracts can inhibit the proliferation of these parasites and at least one can reverse the pro-inflammatory activity of Leishmania donovani.

Actividad de un extracto de equinácea purpúrea frente a los virus de la influenza H1N1, H5n1 y H7N7 / Activity of an extracto f purple corneflower against the influenza virus H1N1, H5N1 and H7N7

Las infecciones producidas por los virus de la influenza (VI) representan un problema de grandes dimensiones epidemiológicas en todo el mundo. La terapia antiviral incluye vacunas y algunos medicamentos antivirales. Sin embargo no siempre se dispone de las vacunas adecuadas y los virus desarrollan resistencia a los inhibidores de la neuraminidasa como Tamiflu (oseltamivir). Se estudió la actividad antiviral de un extracto comercial estandarizado de Echinacea purpurea (Echinaforce, EF), comprobándose su capacidad para inactivar, en cultivos celulares, los virus de la influenza tipo H1N1, H1N5 y H7N7, inhibiendo la capacidad de unión del virus al receptor y su entrada en la célula. A diferencia del Tamifú, no sólo las incubaciones sucesivas con EF no desarrollan resistencias virales, si no que EF fu activo frente a los virus resistentes al oseltamivir. En conclusión, este preparado de equinácea puede constituir un complemento útil para el control de la replicación y difusión de los virus de la influenza (AU)

Infections caused by influenza virases represent a large epidemiological problema Worl wide. Antiviral therapy includes vaccines and few antiviral drugs. However vaccines are not always available in time and viruses develop resistance to neuraminidase inhibitors such as Tamiflu (oseltamivir). We studied the antiviral activity of a commercial standardized extract of Echinacea purpurea (Echinaforce, EF), that demonstrated its ability to inactivate, in cell culture, the influenza viruses H1N1, H5N1 and H7N7, inhibiting the virus binding capacity to the cell receptor and its entry into the cell. Unlike Tamiflu, not only successive incubations with EF did not develop viral resistance, but EF was active against oseltamivir-viruses. In conclusion, this preparation of Echinacea could be a useful addition for the control of replication and spread on influenza virus (AU)

Anti-viral properties and mode of action of standardized Echinacea purpurea extract against highly pathogenic avian influenza virus (H5N1, H7N7) and swine-origin H1N1 (S-OIV).

BACKGROUND: Influenza virus (IV) infections are a major threat to human welfare and animal health worldwide. Anti-viral therapy includes vaccines and a few anti-viral drugs. However vaccines are not always available in time, as demonstrated by the emergence of the new 2009 H1N1-type pandemic strain of swine origin (S-OIV) in April 2009, and the acquisition of resistance to neuraminidase inhibitors such as Tamiflu (oseltamivir) is a potential problem. Therefore the prospects for the control of IV by existing anti-viral drugs are limited. As an alternative approach to the common anti-virals we studied in more detail a commercial standardized extract of the widely used herb Echinacea purpurea (Echinaforce, EF) in order to elucidate the nature of its anti-IV activity. RESULTS: Human H1N1-type IV, highly pathogenic avian IV (HPAIV) of the H5- and H7-types, as well as swine origin IV (S-OIV, H1N1), were all inactivated in cell culture assays by the EF preparation at concentrations ranging from the recommended dose for oral consumption to several orders of magnitude lower. Detailed studies with the H5N1 HPAIV strain indicated that direct contact between EF and virus was required, prior to infection, in order to obtain maximum inhibition in virus replication. Hemagglutination assays showed that the extract inhibited the receptor binding activity of the virus, suggesting that the extract interferes with the viral entry into cells. In sequential passage studies under treatment in cell culture with the H5N1 virus no EF-resistant variants emerged, in contrast to Tamiflu, which produced resistant viruses upon passaging. Furthermore, the Tamiflu-resistant virus was just as susceptible to EF as the wild type virus. CONCLUSION: As a result of these investigations, we believe that this standard Echinacea preparation, used at the recommended dose for oral consumption, could be a useful, readily available and affordable addition to existing control options for IV replication and dissemination.

Induction of multiple pro-inflammatory cytokines by respiratory viruses and reversal by standardized Echinacea, a potent antiviral herbal extract.

Several viruses associated with upper respiratory diseases have been shown to stimulate the secretion of pro-inflammatory cytokines, including chemokines, sometimes in the absence of viral cytopathology. We evaluated the ability of a standardized preparation of the popular herbal medicine Echinacea (Echinaforce, an ethanol extract of herb and roots of E. purpurea, and containing known concentrations of marker compounds) to inhibit the viral induction of various cytokines in a line of human bronchial epithelial cells (BEAS-2B), and in two other human cell lines. All of the viruses tested, rhinoviruses 1A and 14, influenza virus, respiratory syncytial virus, adenovirus types 3 and 11, and herpes simplex virus type 1, induced substantial secretion of IL-6 and IL-8 (CXCL8), in addition to several other chemokines, depending on the virus, although only viable viruses were able to do this. In every case however Echinacea inhibited this induction. The Echinacea preparation also showed potent virucidal activity against viruses with membranes, indicating the multi-functional potential of the herb. These results support the concept that certain Echinacea preparations can alleviate "cold and flu" symptoms, and possibly other respiratory disorders, by inhibiting viral growth and the secretion of pro-inflammatory cytokines.