Hispidulin: antioxidant properties and effect on mitochondrial energy metabolism
| Autor: | Priscila Dabaghi-Barbosa, Andreia Mariante Rocha, Anderson Franco da Cruz Lima, Brás Heleno de Oliveira, Maria Benigna Martinelli de Oliveira, Eva Gunilla Skare Carnieri, Sílvia M.S.C. Cadena, Maria Eliane Merlin Rocha |
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| Rok vydání: | 2005 |
| Předmět: |
Male
Antioxidant Free Radicals medicine.medical_treatment Iron Flavonoid Respiratory chain Mitochondria Liver In Vitro Techniques Biochemistry Antioxidants chemistry.chemical_compound Oxygen Consumption Picrates medicine Animals chemistry.chemical_classification Adenosine Triphosphatases Biphenyl Compounds Glutamate receptor Substrate (chemistry) General Medicine Flavones Oxidants Rats Enzyme Mitochondrial respiratory chain chemistry Ferritins Hispidulin Energy Metabolism Mitochondrial Swelling |
| Zdroj: | Free radical research. 39(12) |
| ISSN: | 1071-5762 |
| Popis: | Hispidulin (6-methoxy-5,7,4'-trihydroxyflavone) and eupafolin (6-methoxy-5,7,3',4'-tetrahydroxyflavone), are flavonoids found in the leaves of Eupatorium litoralle. They have recognized antioxidant and antineoplastic properties, although their action mechanisms have not been previously described. We now report the effects of hispidulin on the oxidative metabolism of isolated rat liver mitochondria (Mit) and have also investigated the prooxidant and antioxidant capacity of both flavonoids. Hispidulin (0.05-0.2 mM) decreased the respiratory rate in state III and stimulated it in state IV, when glutamate or succinate was used as oxidizable substrate. Hispidulin inhibited enzymatic activities between complexes I and III of the respiratory chain. In broken Mit hispidulin (0.2 mM) slightly inhibited ATPase activity (25%). However, when intact Mit were used, the flavonoid stimulated this activity by 100%. Substrate energized mitochondrial swelling was markedly inhibited by hispidulin. Both hispidulin and eupafolin were able to promote iron release from ferritin, this effect being more accentuated with eupafolin with the suggestion of a possible involvement of H2O2 in the process. Hispidulin was incapable of donating electrons to the stable free radical DPPH, while eupafolin reacted with it in a similar way to ascorbic acid. The results indicate that hispidulin as an uncoupler of oxidative phosphorylation, is able to release iron from ferritin, but has distinct prooxidant and antioxidant properties when compared to eupafolin. |
| Databáze: | OpenAIRE |
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