title: Effect of fatty acids on herbicide transport across Caco-2 cell monolayers.
abstract: Oral ingestion of pesticides can be a major exposure route. These compounds are frequently consumed in the presence of triacylglycerides, which are then hydrolyzed to free fatty acids. The purpose of this work was to examine the effect of two common fatty acids, palmitic (PA) and oleic (OA) acids, and the biological emulsifier sodium taurocholate (TC) on the absorption of three herbicides (trifluralin, alachlor and atrazine) by Caco-2 cell monolayers. Trifluralin's absorption was enhanced (p < 0.05) in the presence of OA whereas the greatest absorption of atrazine and alachlor occurred with PA and the control media, respectively. Trifluralin had significantly lower absorption through the monolayer than either alachlor or atrazine (p < 0.001). A mass balance study demonstrated that trifluralin accumulated within the cell monolayer (13.85% of the donor after 3 h of exposure), but alachlor and atrazine (1.27% and 0.85%, respectively) did not. This response was linear with time (21.89% trifluralin after 6 h of exposure), and demonstrated the potential for continued release of trifluralin after source removal. These experiments demonstrated that fatty acids and an emulsifier can influence absorption of herbicides across small intestinal epithelium.
authors.affiliation: Division of Emergency Medicine of Evanston, Northwestern Healthcare and Department of Medicine, Fienberg School of Medicine at Northwestern University, Evanston, IL 60201, USA. rhbrand@enh.org
authors.forename: Rhonda M
authors.initials: RM
authors.lastname: Brand
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Cetin
authors.forename: Cynthia
authors.initials: C
authors.lastname: Mueller
authors.forename: Susan L
authors.initials: SL
authors.lastname: Cuppett
mesh_terms: D000081:Acetamides / Q000493:pharmacokinetics; D001280:Atrazine / Q000493:pharmacokinetics; D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D006540:Herbicides / Q000493:pharmacokinetics*; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D019301:Oleic Acid / Q000494:pharmacology*; D019308:Palmitic Acid / Q000494:pharmacology*; D014274:Trifluralin / Q000493:pharmacokinetics
chemical_list: D000081:Acetamides; D006540:Herbicides; C000188:alachlor; D019301:Oleic Acid; D019308:Palmitic Acid; D014274:Trifluralin; D001280:Atrazine