Echinacea purpurea (L.) Moench modulates human T-cell cytokine response

Int Immunopharmacol. 2014 Mar;19(1):94-102. doi: 10.1016/j.intimp.2013.12.019. Epub 2014 Jan 13.

Abstract

The study objective was to evaluate the composition of a neutral and weakly acidic water-soluble extract from Echinacea purpurea (L.) Moench (EchNWA) previously shown to modify murine influenza infection, and to assess immunomodulatory effects on human T-cells. EchNWA extract from fresh aerial parts was extracted with water, ethanolic precipitation, and size-exclusion chromatography. The chemical profile of EchNWA was characterized by chromatography (size-exclusion, HPLC, GC-MS), and small molecule fingerprint analysis performed by HPLC-PDA. Jurkat T-cells at high and low cell density were pretreated or not with doses of EchNWA, followed by activation with phorbol 12-myristate 13-acetate plus ionomycin (PMA+I). Interleukin-2 (IL-2) and interferon gamma (IFNg) cytokine secretions were measured by multi-cytokine luminex technology. Results showed that EchNWA contains 80% polysaccharides, predominantly a 10kDa entity; phenolic compounds, cynarin, cichoric and caftaric acids, but no detectable alkylamides. Cytokine production required stimulation and was lower after PMA+I activation in high-density compared to low-density conditions. EchNWA mediated a strong dose-dependent enhancement of high-density T-cell production of IL-2 and IFNg response to PMA+I. EchNWA alone did not stimulate T-cells. EchNWA enhanced mean fluorescence intensity of IL-2 in Jurkat T-cells activated by PMA+1 or ionomycin alone. Conversely EchNWA mediated modest but significant suppression of IFNg response and reduced the percentage of CD25+ T-cells under low-density conditions. Conclusions are that EchNWA polysaccharides, but not phenolic compounds have dose-related adjuvant effects on human T-cell cytokine responses characterized by enhancing and suppressive effects that are regulated by T-cell density.

Keywords: Cytokine response; Echinacea; Human T-cell density; Immune modulation; Neutral and weakly acidic water-soluble extract; Polysaccharides and phenolic compounds; Small molecule fingerprint-analysis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Caffeic Acids / analysis
  • Cytokines / immunology*
  • Echinacea* / chemistry
  • Humans
  • Immunologic Factors / chemistry
  • Immunologic Factors / pharmacology*
  • Jurkat Cells
  • Monosaccharides / analysis
  • Phenols / analysis
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Polysaccharides / analysis
  • Succinates / analysis
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / immunology

Substances

  • Caffeic Acids
  • Cytokines
  • Immunologic Factors
  • Monosaccharides
  • Phenols
  • Plant Extracts
  • Polysaccharides
  • Succinates
  • chicoric acid
  • caftaric acid