title: Ellagic acid and its methyl-derivatives inhibit a newly found nitratase activity.
abstract: We have recently shown that low density lipoprotein (LDL) was able to denitrate albumin-bound 3-NO(2)-Tyr residues and to concomitantly release NO(3)(-) through a Ca(2+)-dependent process that has been ascribed to a specific protein structure. A lipophilic food component (gamma-tocopherol), which is easily loaded into LDL has been found to totally inhibit denitrating activity. We presently found that ellagic acid (EA) and its methylated derivatives, 4,4'O-methyl- and 3,3'O-methyl-ellagic acids (MeEA1 and MeEA2, respectively), amphipathic phenolic components of certain fruits and beverages, were also able to inhibit this activity, with a total inhibition for EA and a 60% inhibition for MeEA1 and MeEA2. EA exhibited the highest affinity for protein plasma, whereas a higher affinity of MeEA1 and MeEA2 (with MeEA1 > MeEA2) than EA was found for lipoprotein fractions, suggesting that the inhibition-driving property is protein affinity. As a result of this nitratase-inhibition property EA and its natural metabolite MeEA2 may have a beneficial role in special physiopathological conditions.
authors.affiliation: EA 2993 Nutrition Humaine et Athérogénèse, Université Montpellier 1, F-34000 Montpellier, France. claude.leger@univmed.fr
authors.forename: Claude L
authors.initials: CL
authors.lastname: Léger
authors.forename: Enrique
authors.initials: E
authors.lastname: Torres-Rasgado
authors.forename: Gilles
authors.initials: G
authors.lastname: Fouret
authors.forename: Céline
authors.initials: C
authors.lastname: Lauret
authors.forename: Marie-Annette
authors.initials: MA
authors.lastname: Carbonneau
mesh_terms: D001628:Beverages; D001798:Blood Proteins / Q000378:metabolism; D004610:Ellagic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D008074:Lipoproteins / Q000378:metabolism; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*; D012709:Serum Albumin / Q000378:metabolism
chemical_list: C551432:3,3'-O-methylellagic acid; C551431:4,4'-O-methylellagic acid; D001798:Blood Proteins; D008074:Lipoproteins; D012709:Serum Albumin; D004610:Ellagic Acid; D010088:Oxidoreductases; C045258:nitratase