Pycnogenol inhibits generation of inflammatory mediators in macrophages

Pycnogenol (procyanidins extracted from the bark of Pinus maritima Aiton) is a potent free radical scavenger. In this study, we used macrophages (a major cell type in inflammation) to study the antiinflammatory effect of pycnogenol. We determined the effects of pycnogenol on peroxide generation and on glutathione (GSH)-dependent and GSH-independent antioxidant systems. J774 cells were incubated with pycnogenol at 37 degrees C and 5% CO2 for 2 h. Generation of peroxides tone of the major mediators of inflammation) was triggered by zymosan and measured with a fluorometric assay. Pycnogenol exhibited a concentration-dependent suppression of peroxide release. To investigate possible mechanisms involved in pycnogenol's suppression of peroxide release, confluent monolayers of J774 cells were incubated with pycnogenol for 18 h, washed, resuspended in phosphate buffered saline, and sonicated to obtain a cell lysate. Biochemical assays were performed with the lysate. Pycnogenol increased the intracellular GSH content and activities of GSH peroxidase and GSH disulfide reductase, indicating its ability to modulate the GSH redox cycle. The activity of antioxidant enzymes catalase and superoxide dismutase also increased with pycnogenol treatment. These results suggest that the antiinflammatory effect of pycnogenol may at least in part be due to its ability to modulate the GSH redox cycle and activities of catalase and superoxide dismutase. (C) 2000 Elsevier Science Inc.