|Howell, J Lynn|
Submitted to: International Immunopharmacology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2008
Publication Date: 4/12/2008
Citation: Pugh, N., Tamta, H., Balachandran, P., Wu, X., Howell, J., Dayan, F.E., Pasco, D. 2008. The Majority of In Vitro Macrophage Activation Exhibited by Extracts of Some Immune Enhancing Botanicals is Due to Bacterial Lipoproteins and Lipopolysaccharides. International Immunopharmacology. 8:1023-1032. Interpretive Summary: Plant extracts and botanicals are sold over the counter for a number of health enhancing properties. We have identified in common botanicals (Echinacea, American ginseng and alfalfa Sprouts) compounds that stimulate the immune system. It turns out these compounds are probably produced by microorganisms leaving in symbiosis with the plants. These bacterial lipoproteins were very active in monocyte/macrophage activation systems. Other experiments showed that most of the activity within extracts from eight immune enhancing botanicals could be removed by treatments known to degrade bacterial components. Also, the amount of activity of greatly reduced in Alfalfa sprouts grown in the presence of antibiotics. Therefore, it is likely that the majority of the in vitro macrophage activating properties in extracts from these botanicals can be attributed to the presence of lipoproteins and lipopolysaccharides produced by bacterial endophytes.
Technical Abstract: We have identified potent monocyte/macrophage activating bacterial lipoproteins within commonly used immune enhancing botanicals such as Echinacea, American ginseng and alfalfa sprouts. These bacterial lipoproteins, along with lipopolysaccharides, were substantially more potent than other bacterially derived components when tested in in vitro monocyte/macrophage activation systems. In experiments using RAW 264.7 and mouse peritoneal macrophages the majority (85-98%) of the activity within extracts from eight immune enhancing botanicals was eradicated by treatment with agents (lipoprotein lipase and polymyxin B) known to target these two bacterial components. Alfalfa sprouts exhibited the highest activity of those botanicals tested but the appearance of this activity during the germination of surface sterilized seeds was abolished by the presence of antibiotics. These studies indicate that the majority of the in vitro macrophage activating properties in extracts from these botanicals can be attributed to the presence of lipoproteins and lipopolysaccharides derived from bacteria and that bacterial endophytes may be a significant source of these components.