Formation of phosphoglycosides in Caenorhabditis elegans: a novel biotransformation pathway.
BACKGROUND
Caenorhabditis elegans (C. elegans) has become a widely used model to explore the effect of food constituents on health as well as on life-span extension. The results imply that besides essential nutrients several flavonoids are able to impact the aging process. What is less investigated is the bioavailability and biotransformation of these compounds in C. elegans. In the present study, we focused on the soy isoflavone genistein and its metabolism in the nematode as a basis for assessing whether this model system mimics the mammalian condition.


RESULTS
C. elegans was exposed to 100 µM genistein for 48 hours. The worm homogenate was extracted and analyzed by liquid chromatography (LC). 11 metabolites of genistein were detected and characterized using LC electrospray ionization mass spectrometry. All genistein metabolites formed by C. elegans were found to be sugar conjugates, primarily genistein-O-glucosides. The dominant metabolite was identified as genistein-7-O-phosphoglucoside. Further interesting metabolites include two genistein-di-O-glycosides, a genistein-O-disaccharide as well as a genistein-O-phosphodisaccharide.


CONCLUSIONS
Our study provides evidence for a novel biotransformation pathway in C. elegans leading to conjugative metabolites which are not known for mammals. The metabolism of genistein in mammals and in C. elegans differs widely which may greatly impact the bioactivity. These differences need to be appropriately taken into consideration when C. elegans is used as a model to assess possible health or aging effects.
Department of Safety and Quality of Fruit and Vegetables, Federal Research Institute of Nutrition and Food, Max Rubner-Institut, Karlsruhe, Germany.
Sebastian T
ST
Soukup
Britta
B
Spanier
Gregor
G
Grünz
Diana
D
Bunzel
Hannelore
H
Daniel
Sabine E
SE
Kulling
D000818:Animals; D001711:Biotransformation / Q000187:drug effects; D017173:Caenorhabditis elegans / Q000187:drug effects / Q000378:metabolism*; D002853:Chromatography, Liquid; D019833:Genistein / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D021241:Spectrometry, Mass, Electrospray Ionization; D013403:Sugar Phosphates / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors; D014020:Tissue Extracts
D006027:Glycosides; D013403:Sugar Phosphates; D014020:Tissue Extracts; D019833:Genistein