N-3 fatty acid-induced lipid peroxidation in human platelets is prevented by catechins.
The effects of catechins were studied in both unstimulated platelets and platelets submitted to a mild oxidative stress induced by docosahexaenoic acid (DHA). Human unstimulated platelets were incubated in the presence of catechin or epicatechin (1, 10 or 100 microM) for 2 h at 37 degrees C. Treatment by 1 microM epicatechin was sufficient to induce a significant inhibition (-30%) of basal thromboxane B2 formation. This result is consistent with the observed inhibitory effects of flavonoids on platelet aggregation. DHA treatment of platelets decreased the amount of alpha-tocopherol and increased the malondialdehyde (MDA) formation. The presence of epicatechin or catechin prevented the oxidative stress induced by DHA. Indeed, the platelet alpha-tocopherol level was significantly increased when compared to that of platelets treated by DHA alone, to reach the control level, whereas MDA was depressed to a level even lower than the control one. Our results indicate that catechin and especially epicatechin protect platelets from a peroxidative stress.
Polette
A
A
Institut National de la Santé et de la Recherche Médicale U.352, Chimie Biologique INSA-Lyon, Villeurbanne, France.
Lemaitre
D
D
Lagarde
M
M
Véricel
E
E
D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D002392:Catechin / Q000494:pharmacology*; D002478:Cells, Cultured; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D004336:Drug Antagonism; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D018384:Oxidative Stress; D010974:Platelet Aggregation / Q000187:drug effects
D004281:Docosahexaenoic Acids; D002392:Catechin