(−)-Epigallocatechin-(3)-gallate prevents oxidative damage in both the aqueous and lipid compartments of human plasma
| Autor: | Robert M. Russell, Giancarlo Aldini, Marina Carini, Norman I. Krinsky, Kyung-Jin Yeum |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Antioxidant
medicine.medical_treatment Radical alpha-Tocopherol Biophysics In Vitro Techniques Biochemistry Antioxidants Catechin Plasma chemistry.chemical_compound Phenols medicine Humans heterocyclic compounds Molecular Biology Carotenoid chemistry.chemical_classification Aqueous solution Dose-Response Relationship Drug Chemistry Electron Spin Resonance Spectroscopy food and beverages Cell Biology Compartment (chemistry) Ascorbic acid Cell Compartmentation Radical initiator lipids (amino acids peptides and proteins) BODIPY Hydrophobic and Hydrophilic Interactions Oxidation-Reduction |
| Zdroj: | Biochemical and Biophysical Research Communications. 302:409-414 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/s0006-291x(03)00192-x |
| Popis: | When human plasma was exposed to the hydrophilic radical initiator, AAPH, (-)-epigallocatechin-(3)-gallate (EGCG) dose-dependently inhibited the aqueous compartment oxidation (IC(50)=0.72 microM) (monitored by DCFH oxidation) and spared the lipophilic antioxidants, alpha-tocopherol, and carotenoids, but not ascorbic acid. When radicals were selectively induced in the lipid compartment by the lipophilic radical initiator, MeO-AMVN, EGCG spared alpha-tocopherol, but not carotenoids and inhibited the lipid compartment oxidation (monitored by BODIPY 581/591) with a potency lower than that found in the aqueous compartment (IC(50)=4.37 microM). Our results indicate that EGCG, mainly localized in the aqueous compartment, effectively quenches aqueous radical species, thus limiting their diffusion into the lipid compartment and preventing lipid-soluble antioxidant depletion. Further, ESR experiments confirmed that EGCG recycled alpha-tocopherol through a H-transfer mechanism at the aqueous/lipid interface affording an additional protective mechanism to the lipid compartment of plasma. |
| Databáze: | OpenAIRE |
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