Mechanism Of Activation Of Human Peripheral Blood NK Cells At The Single Cell Level By Echinacea Water Soluble Extracts: Recruitment Of Lymphocyte-Target Conjugates And Killer Cells And Activation Of Programming For Lysis
Gan XH, Zhang L, Heber D, Bonavida B
Int ImmunoPharmacol 2003 Jun;3(6):811-24
UCLA School of Medicine, Department of MicroBiology, Immunology, and Molecular Genetics, 10833 Le Conte Avenue, A2-060 CHS, Los Angeles, CA 90095-1747, USA
Echinacea purpurea, a plant originally used by native Americans to treat respiratory infections, has also been shown to exert ImmunoModulatory activities both in vivo and in vitro.
However, the mechanism underlying Echinacea-induced ImmunoModulation remains largely unknown. This study examined in vitro the effects of soluble extracts of E. purpurea on Natural Killer (NK) Cells present in human Peripheral Blood Mononuclear Cells (PBMC).
Flow cytometric methods were used to examine activation, CytoToxicity, NK-target binding, and Killer Cell frequency.
Treatment of PBMC with Echinacea overnight resulted in the activation of CD69 expression and increase in mean fluorescence intensity in both the CD16+ and CD16+CD56+ NK subsets.
However, the frequency of CD16+ Cells was decreased as well as the mean fluorescence intensity was down-regulated. NK CytoToxicity was augmented 100% at the concentration of 0.1 microg/ml of Echinacea in a short time (4-h) assay.
Examination at the single cell level revealed augmentation of the frequency of CD56+ NK-target conjugates and a plateau was reached after 30-60 min of incubation.
Likewise, the frequency of CD56+ Killer Cells in the conjugates was also significantly increased by Echinacea.
There was recruitment of non-conjugated CD56+ Cells into CD16+ NK-target conjugates and activation of the NK-target Non-Killer conjugates into Killer Cells.
These findings demonstrate that Echinacea extracts are potent activators of NK CytoToxicity. Echinacea augments the frequency of NK target conjugates and activates the programming for lysis of NK Cells.
Echinacea Alkylamides Inhibit InterLeukin-2 Production By Jurkat T-Cells
Sasagawa M, Cech NB, Gray DE, Elmer GW, Wenner CA
Int ImmunoPharmacol 2006 Jul;6(7):1214-21
Bastyr University,School of Natural Health Sciences, Department of Basic Sciences, Kenmore, WA 98028, USA
Alkylamides present in Echinacea species have reported ImmunoModulatory actions, yet their direct effects on T-Lymphocytes, key mediators of AntiViral Immunity, are poorly understood.
We hypothesized that constituents present in ethanolic extracts of Echinacea species exert direct ImmunoModulatory effects on human Jurkat T-Cells.
Modulation of IL-2 production by submaximally stimulated Jurkat cells was determined in response to treatment with extracts prepared from dried aerial parts of Echinacea purpurea.
Cells were treated with the extracts, with Alkylamides or Caffeic Acid derivatives isolated from Echinacea species, or with corresponding ethanol vehicle.
In the absence or presence of Phytohemagglutinin and phorbal ester. E. purpurea extracted in a solvent mixture of 95:5 ethanol/water dose-dependently inhibited IL-2 production.
This IL-2 inhibitory activity correlated with the presence of Alkylamides but not Caffeic Acid derivatives, as determined by high performance liquid chromatography/electrospray ionization-mass spectrometry analysis.
Simultaneous measurement of secreted IL-2 by ELISA and cell viability by the XTT assay showed that the 95:5 ethanol/water extract of E. purpurea was both IL-2 suppressive and CytoToxic at 50 and 100 microg/mL.
Lower concentrations from 6.25 to 25 microg/mL significantly decreased IL-2 production but not cell viability.
Alkylamides at concentrations found in a 50 microg/mL extract decreased IL-2 production by approximately 50%.
Two Echinacea-derived Alkylamides significantly depressed IL-2 production but not cell viability in a dose-dependent manner.
Thus, Alkylamides present in E. purpurea suppress the ability of activated Jurkat T-Cells to produce IL-2 independently of direct, CytoToxic effects.
AntiInflammatory And Cicatrizing Activity Of Echinacea Pallida Nutt. Root Extract
Speroni E, Govoni P, Guizzardi S, Renzulli C, Guerra MC
J EthnoPharmacol 2002 Feb;79(2):265-72
University of Bologna, Department of Pharmacology, Via Irnerio, 48, 40126 Bologna, Italy
Among the different species belonging to the Echinacea family, largely used in traditional medicine, Echinacea pallida, Echinacea purpurea and Echinacea angustifolia were investigated.
These different species, due to their difficult identification, were commonly confused in the past and probably used indifferently for the same therapeutic purposes.
In fact, the three species have in common, some pharmacological activities, based on the presence of active compounds that act additively and synergistically.
Nevertheless, the composition of each species has slight variation in the amount of each active component.
In particular, Echinacoside, a Caffeoyl derivative, is present in E. pallida and only in traces in E. angustifolia. It seems to have protective effects on skin connective tissue and to enhance wound healing.
The AntiInflammatory and wound healing activities of Echinacoside, compared with the ones of the total root extract of E. pallida and E. angustifolia, were examined in rats, after topical application.
The tissues of the treated animals were evaluated after 24, 48 and 72 h treatment and excised for histological observation at the end of the experiment.
Results confirm the good AntiInflammatory and wound healing properties of E. pallida and of its constituent Echinacoside, with respect to E. purpurea and control. This activity probably resides in the AntiHyaluronidase activity of Echinacoside.
ImmunoPharmacological Activity Of Echinacea Preparations Following Simulated Digestion On Murine Macrophages And Human Peripheral Blood Mononuclear Cells
Rininger JA, Kickner S, Chigurupati P, McLean A, Franck Z
J Leukoc Biol 2000 Oct;68(4):503-10
Paracelsian, Incorporated, Ithaca, New York, USA
We have investigated the ImmunoStimulatory, AntInflammatory, and AntiOxidant activities of various Echinacea raw materials and commercially available products on murine Macrophages and human Peripheral Blood Mononuclear Cells (PBMCs).
To emulate oral dosing, a simulated digestion protocol was employed as a means of sample preparation.
Echinacea-induced Macrophage activation was used as a measure of ImmunoStimulatory activity determined via quantitative assays for Macrophage-derived factors including Tumour Necrosis Factor-, InterLeukin (IL-1alpha), IL-1beta, IL-6, IL-10, and Nitric Oxide.
Echinacea herb and root powders were found to stimulate murine Macrophage Cytokine secretion as well as to significantly enhance the viability and/or proliferation of human PBMCs in vitro.
In contrast, Echinacea extracts chemically standardized to Phenolic Acid or Echinacoside content and fresh pressed juice preparations were found to be inactive as ImmunoStimulatory agents but did display, to varying degrees, AntiInflammatory and AntiOxidant properties.