PYCNOGENOL INHIBITS MACROPHAGE OXIDATIVE BURST, LIPOPROTEIN OXIDATION, AND HYDROXYL RADICAL-INDUCED DNA-DAMAGE

Pycnogenol (procyanidins extracted from Pinus maritima) has been reput ed as a potent free-radical scavenger and an antioxidant phytochemical . We previously reported that pycnogenol prevents vascular endothelial cells from injury induced by an organic oxidant t-butyl hydroperoxide . In this study, we determined the effects of pycnogenol on (a) oxidat ive burst of macrophages, (b) oxidation of plasma low density lipoprot ein (LDL), and (c) hydroxyl radical-induced breakage of plasmid DNA. P ycnogenol was incubated with J774 murine macrophages at 37 degrees C a nd 5% CO2 and oxidative burst was triggered by zymosan. The intensity of fluorescence was measured. Pycnogenol exhibited a concentration-dep endent inhibition of oxidative burst. CuSO4 was used to oxidize human plasma LDL and the formation of thiobarbituric acid reactive substance s (TEARS) was determined. Go-incubation with pycnogenol resulted in a concentration-dependent inhibition of LDL oxidation. Exposure of pBR32 2 plasmid DNA to iron/ascorbic acid system resulted in cleavage/damage of DNA by hydroxyl radical, measured by agarose gel electrophoresis. Pycnogenol significantly minimized this cleavage. The results indicate that pycnogenol exhibits an extensive antioxidant effect in all three in vitro systems.