Modulatory effects of Echinacea purpurea extracts on human dendritic cells: A cell- and gene-based study

Abstract

Echinacea spp. are popularly used as an herbal medicine or food supplement for enhancing the immune system. This study shows that plant extracts from root [R] and stem plus leaf [S+L] tissues of E. purpurea exhibit opposite (enhancing vs inhibitory) modulatory effects on the expression of the CD83 marker in human dendritic cells (DCs), which are known as professional antigen-presenting cells. We developed a function-targeted DNA microarray system to characterize the effects of phytocompounds on human DCs. Down-regulation of mRNA expression of specific chemokines (e.g., CCL3 and CCL8) and their receptors (e.g., CCR1 and CCR9) was observed in [S+L]-treated DCs. Other chemokines and regulatory molecules (e.g., CCL4 and CCL2) involved in the c-Jun pathway were found to be up-regulated in [R]-treated DCs. This study, for the first time, demonstrates that E. purpurea extracts can modulate DC differentiation and expression of specific immune-related genes in DCs.

Plant-derived medicines: A novel class of immunological adjuvants

“…Furthermore, the suppression of LPS-induced MHC Class II, CD80 and CD86 expression on DCs by the polyacetylene compound, falcarindiol (from Notopterygium incisum) was due to inhibition of the transcription factor, NF-κB [44]. Differential effects on human DC maturation in vitro was observed for various Echinacea purpurea extracts, with increased expression of CD83 by the root and flower extracts whereas whole plant and stem/leaf extracts reduced this expression [45]. This effect was further supported by another study of E. purpurea root and leaf extracts, where the polysaccharide-rich root extracts increased and the alkylamide-rich leaf extract inhibited murine DC marker expression [46].…”

Immuno-Modulatory Effects of Phytomedicines Evaluated Using Omics Approaches

“…Genome-wide analysis has been adopted as a less selective approach for measuring the holistic or global changes in gene expression [17,[61][62][63][64]. It can be anticipated that the activation and functional maturation of DCs, as drastic cellular activities, are likely to be associated with changes in the levels of a spectrum of gene expressions that are responsible for: (a) intracellular metabolic processes; (b) control of cell motility (including those regulating intercellular communication and interactions with the tissue matrix); (c) cytokine and chemokine production, and (d) cell growth regulation and survival [17,61] …”

“…Functional genomics experimental approaches were employed in our previous studies on the modulatory effect of Echinacea plant extracts (e.g., the butanol-fractionated Leaf and Stem tissue extract designated as BF/S+L/Ep) on both mouse and human DCs [17,63,64]. Using the same defined phytochemical extracts in the study, we analyzed the genome-wide transcriptional response in the context of known functional activities and interrelationships among specific protein molecules and/or different cell phenotypes.…”

Anti-Respiratory Syncytial Virus Agents from Phytomedicine

“…One such candidate agent is the herbal medicine Echinacea purpurea, which has become one of the most popular commercial herbal preparations in North America and Europe (Brevoort, 1998;Barnes et al, 2005). There have been numerous reports of immune modulatory properties in various preparations derived from different parts of several species of Echinacea (Gertsch et al, 2004;Barnes et al, 2005;Sharma et al, 2006Sharma et al, , 2008Wang et al, 2006), although the composition of these preparations is inconsistent, a fact that has made it difficult to propose a mechanism of action (Woelkart and Bauer, 2007). Widely varied anti-viral properties among different Echinacea species and component parts have been reported Vimalanathan et al, 2005).…”