Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2008
Publication Date: 11/26/2008
Citation: Tamta, H., Pugh, N.D., Balachandran, P., Moraes, R., Sumiyanto, J., Pasco, D.S. 2008. Variability in In Vitro Macrophage Activation by Commercially Diverse Bulk Echinacea Plant Material is Predominantly Due to Bacterial Lipoproteins and Lipopolysaccharides. Journal of Agricultural and Food Chemistry. 56(22):10552-10556. Interpretive Summary: This manuscript reports that extracts of bulk Echinacea plant material from six major growers/commercial suppliers within North America exhibit substantial differences in their ability to activate macrophages. These differences in activity were due predominantly to the presence of bacterial lipopolysaccharides and lipoproteins. This paper also showed that different post-harvest drying conditions did not significantly influence the content/activity of the bacterial components within Echinacea plant material.
Technical Abstract: We previously reported that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea and other botanicals depends upon bacterial lipopolysaccharides and Braun-type bacterial lipoproteins. We determined the contribution made by these bacterial components to the overall immune-enhancing activity detected in E. purpurea and E. angustifolia bulk root and aerial material obtained from six major growers/suppliers in North America. Substantial variation in activity (up to 200-fold) was observed in extracts of these materials when tested in two monocyte/macrophage cell lines. The majority of activity was negated by treatment with agents that target bacterial lipoproteins (lipoprotein lipase) and lipopolysaccharides (polymyxin B). Experiments comparing the activity of freeze-dried, freshly harvested Echinacea plants to those harvested and dried using various commercially relevant conditions suggest that postharvesting procedures do not substantially contribute to the variation observed in the commercial material.