title: In Vitro Antioxidant versus Metal Ion Chelating Properties of Flavonoids: A Structure-Activity Investigation.
abstract: Natural flavonoids such as quercetin, (+)catechin and rutin as well as four methoxylated derivatives of quercetin used as models were investigated to elucidate their impact on the oxidant and antioxidant status of human red blood cells (RBCs). The impact of these compounds against metal toxicity was studied as well as their antiradical activities with DPPH assay. Antihemolytic experiments were conducted on quercetin, (+)catechin and rutin with excess of Fe, Cu and Zn (400 μM), and the oxidant (malondialdehyde, carbonyl proteins) and antioxidant (reduced glutathione, catalase activity) markers were evaluated. The results showed that Fe and Zn have the highest prooxidant effect (37 and 33% of hemolysis, respectively). Quercetin, rutin and (+)catechin exhibited strong antioxidant properties toward Fe, but this effect was decreased with respect to Zn ions. However, the Cu showed a weak antioxidant effect at the highest flavonoid concentration (200 μM), while a prooxidant effect was observed at the lowest flavonoid concentration (100 μM). These results are in agreement with the physico-chemical and antiradical data which demonstrated that binding of the metal ions (for FeNTA: (+)Catechin, KLFeNTA = 1.6(1) × 106 M-1 > Rutin, KLFeNTA = 2.0(9) × 105 M-1 > Quercetin, KLFeNTA = 1.0(7) × 105 M-1 > Q35OH, KLFeNTA = 6.3(8.7) × 104 M-1 > Quercetin3'4'OH and Quercetin 3OH, KLFeNTA ~ 2 × 104 M-1) reflects the (anti)oxidant status of the RBCs. This study reveals that flavonoids have both prooxidant and antioxidant activity depending on the nature and concentration of the flavonoids and metal ions.
authors: Laboratory of Physiology, Pathophysiology and Biochemistry of Nutrition, Department of Biology, Faculty of Natural and Life Sciences, Earth and Universe, Abou Bekr Belkaid University, 13000 Tlemcen, Algeria.
authors: Sabri Ahmed
authors: SA
authors: Cherrak
authors: Laboratory of Physiology, Pathophysiology and Biochemistry of Nutrition, Department of Biology, Faculty of Natural and Life Sciences, Earth and Universe, Abou Bekr Belkaid University, 13000 Tlemcen, Algeria.
authors: Nassima
authors: N
authors: Mokhtari-Soulimane
authors: Laboratory of Physiology, Pathophysiology and Biochemistry of Nutrition, Department of Biology, Faculty of Natural and Life Sciences, Earth and Universe, Abou Bekr Belkaid University, 13000 Tlemcen, Algeria.
authors: Farid
authors: F
authors: Berroukeche
authors: Laboratory of Physiology, Pathophysiology and Biochemistry of Nutrition, Department of Biology, Faculty of Natural and Life Sciences, Earth and Universe, Abou Bekr Belkaid University, 13000 Tlemcen, Algeria.
authors: Bachir
authors: B
authors: Bensenane
authors: Laboratory of Bioorganic and Medicinal Chemistry, UMR 7509 CNRS, ECPM, 25 rue Becquerel, 67200 Strasbourg, France.
authors: Angéline
authors: A
authors: Cherbonnel
authors: Laboratory of Physiology, Pathophysiology and Biochemistry of Nutrition, Department of Biology, Faculty of Natural and Life Sciences, Earth and Universe, Abou Bekr Belkaid University, 13000 Tlemcen, Algeria.
authors: Hafida
authors: H
authors: Merzouk
authors: Laboratory of Bioorganic and Medicinal Chemistry, UMR 7509 CNRS, ECPM, 25 rue Becquerel, 67200 Strasbourg, France.
authors: Mourad
authors: M
authors: Elhabiri
mesh_terms: D002614:Chelating Agents / Q000737:chemistry* / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008670:Metals / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D002614:Chelating Agents; D005419:Flavonoids; D008670:Metals