Planta Med 2016; 82(14): 1258-1265
DOI: 10.1055/s-0042-108590
Biological and Pharmacological Activity
Original Papers
Georg Thieme Verlag KG Stuttgart · New York

Activities and Prevalence of Proteobacteria Members Colonizing Echinacea purpurea Fully Account for Macrophage Activation Exhibited by Extracts of This Botanical

Mona H. Haron*
1   National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
,
Heather L. Tyler*
2   Department of Biology, The University of Mississippi, University, MS, USA
3   Present address: Crop Production Systems Research Unit, USDA Agricultural Research Service, P.O. Box 350, Stoneville, MS, USA
,
Nirmal D. Pugh
1   National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
,
Rita M. Moraes
1   National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
,
Victor L. Maddox
4   Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, USA
,
Colin R. Jackson
2   Department of Biology, The University of Mississippi, University, MS, USA
,
David S. Pasco
1   National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
5   Department of BioMolecular Sciences, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, USA
› Author Affiliations
Further Information

Publication History

received 24 March 2016
revised 27 April 2016

accepted 30 April 2016

Publication Date:
10 June 2016 (online)

Abstract

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.

* These authors contributed equally to this research.


Supporting Information