title: An enzyme-linked immunosorbent assay for the measurement of plasma flavonoids in mice fed apigenin-C-glycoside.
abstract: BACKGROUND
  In the Chenopodiaceae family, the apigenin flavonoids vitexin-2-O-xyloside (VOX) and vitexin-2-O-rhamnoside (VOR) are important chemopreventive components. To investigate their bioavailability in in vivo animal studies an enzyme-linked immunosorbent assay (ELISA) method has been developed.
  
  
  RESULTS
  The ELISA was based on polyclonal antibodies elicited in mice by injecting, as an immunogen, 4',6″-O-biapigenin (hinokiflavone, HF) conjugated to bovine serum albumin (BSA-HF). A second immunogen was synthesised by coupling an equimolar mixture of VOX and VOR to BSA (BSA-F1). The BSA-HF elicited a significant antibody response, due to 17 HF hapten groups, coupled to each BSA molecule, whereas BSA-F1 provided a very low antigenicity in respect to control animals. Antiserum raised against BSA-HF showed an antibody titre of 1:1600. Antibodies were found to be specific for the flavonols. Our results show that VOX and its metabolic products reached the concentration of 3.42 ± 0.72 µg mL⁻¹ in plasma of VOX fed animals, at the net of the control value.
  
  
  CONCLUSIONS
  By using the ELISA, the concentration of apigenin flavonoids and their metabolites can be detected in VOX- or VOR-supplemented animals. The assay represents a useful tool for rapid screening to compare bioavailability of apigenin flavonoids in respect to control animals.
authors.affiliation: Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino 61029 (PU), Italy. paolino.ninfali@uniurb.it
authors.forename: Paolino
authors.initials: P
authors.lastname: Ninfali
authors.forename: Sabrina
authors.initials: S
authors.lastname: Dominici
authors.forename: Donato
authors.initials: D
authors.lastname: Angelino
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Gennari
authors.forename: Costantina
authors.initials: C
authors.lastname: Buondelmonte
authors.forename: Luca
authors.initials: L
authors.lastname: Giorgi
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000097:blood / Q000493:pharmacokinetics*; D047310:Apigenin / Q000097:blood / Q000493:pharmacokinetics*; D044946:Biflavonoids / Q000032:analysis; D001682:Biological Availability; D001711:Biotransformation; D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay; D005419:Flavonoids / Q000097:blood* / Q000493:pharmacokinetics; D006027:Glycosides / Q000097:blood / Q000493:pharmacokinetics*; D006241:Haptens; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011897:Random Allocation
chemical_list: D016588:Anticarcinogenic Agents; D044946:Biflavonoids; D005419:Flavonoids; D006027:Glycosides; D006241:Haptens; C586694:vitexin-2-O-rhamnoside; C586695:vitexin-2-O-xyloside; C060299:hinokiflavone; D047310:Apigenin
keywords: ELISA; bioavailability; flavonoids; polyclonal antibodies; vitexin-2-O-xyloside