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U.S. Department of Health and Human Services

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J Agric Food Chem 2012 Oct 24;60(42):10456-60

Determination of the concentration of potential efflux pump inhibitors, pheophorbide a and pyropheophorbide a, in the feces of animals by fluorescence spectroscopy.

Barnes CA, Rasmussen SL, Petrich JW, Rasmussen MA


Efflux pumps are vital bacterial components, and research has demonstrated that some plant compounds such as pheophorbide a (php) possess efflux pump inhibitor (EPI) activity. This study determined the quantity of php present in feces as an indicator of EPI activity. Feces were collected from different species of animals fed a variety of feeds. The chlorophyll metabolites php and pyropheophorbide a (pyp) were determined using fluorescense spectroscopy. The average concentrations [mug/g dry matter (DM) feces] of pyp/php in feces were as follows: guinea pig, 180; goat, 150; rabbit, 150; dairy cow, 120; feedlot cattle, 60; rat, <1; pig, <1; chicken, <1. These data indicate that animals consuming "green" diets will excrete feces with concentrations of php/pyp that exceed levels demonstrated to be inhibitory to bacterial efflux pumps (0.5 mug/mL). The natural presence EPIs in the gastrointestinal tract may modulate the activity of microbial efflux pumps and exert selection pressure upon resident microbial populations.

Category: Journal Article
PubMed ID: #23002917 DOI: 10.1021/jf3023063
Includes FDA Authors from Scientific Area(s): Animal and Veterinary
Entry Created: 2012-12-03