Activities and Prevalence of Proteobacteria Members Colonizing Echinacea purpurea Fully Account for Macrophage Activation Exhibited by Extracts of This Botanical.
Evidence supports the theory that bacterial communities colonizing Echinacea purpurea contribute to the innate immune enhancing activity of this botanical. Previously, we reported that only about half of the variation in in vitro monocyte stimulating activity exhibited by E. purpurea extracts could be accounted for by total bacterial load within the plant material. In the current study, we test the hypothesis that the type of bacteria, in addition to bacterial load, is necessary to fully account for extract activity. Bacterial community composition within commercial and freshly harvested (wild and cultivated) E. purpurea aerial samples was determined using high-throughput 16S rRNA gene pyrosequencing. Bacterial isolates representing 38 different taxa identified to be present within E. purpurea were acquired, and the activity exhibited by the extracts of these isolates varied by over 8000-fold. Members of the Proteobacteria exhibited the highest potency for in vitro macrophage activation and were the most predominant taxa. Furthermore, the mean activity exhibited by the Echinacea extracts could be solely accounted for by the activities and prevalence of Proteobacteria members comprising the plant-associated bacterial community. The efficacy of E. purpurea material for use against respiratory infections may be determined by the Proteobacterial community composition of this plant, since ingestion of bacteria (probiotics) is reported to have a protective effect against this health condition.
National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA.
Mona H
MH
Haron
Department of Biology, The University of Mississippi, University, MS, USA.
Heather L
HL
Tyler
National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA.
Nirmal D
ND
Pugh
National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA.
Rita M
RM
Moraes
Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, USA.
Victor L
VL
Maddox
Department of Biology, The University of Mississippi, University, MS, USA.
Colin R
CR
Jackson
National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA.
David S
DS
Pasco
D000818:Animals; D020900:Echinacea / Q000276:immunology / Q000382:microbiology*; D008262:Macrophage Activation; D051379:Mice; D010936:Plant Extracts / Q000276:immunology*; D020560:Proteobacteria / Q000276:immunology*; D000067996:RAW 264.7 Cells
D010936:Plant Extracts