Antioxidant and antiinflammatory activity of pine pollen extract in vitro

To determine the medicinal properties of pine pollen, the antioxidant and antiinflammatory activities of the ethanol extract of pine pollen extract (PPE) were investigated. PPE displayed a strong free radical scavenger activity on 1,1‐diphenyl‐2‐picrylhydrazyl radical and hydrogen peroxide. It was observed also that the antioxidant activity, measured by the ferric thiocyanate method, increased with the addition of PPE to the linoleic acid emulsion system. PPE was also found to inhibit significantly the amount of malondialdehyde and protein carbonyls formed from liver homogenate. Like the antioxidant activity, the reducing power of PPE was excellent. Thereafter, the study investigated the effects of PPE in modulating the production of pro‐inflammatory mediators in lipopolysaccharide (LPS)‐activated RAW 264.7 macrophages, and the effect of PPE on interleukin (IL)‐1β‐induced matrix metalloproteinases (MMPs) production and mitogen‐activated protein kinases (MAPKs) activation in the human synovial sarcoma cell line, SW982. PPE was found to inhibit the production of nitric oxide, tumor necrosis factor‐α, IL‐1 and IL‐6 in LPS‐activated macrophages. Treatment with PPE at 10 µg/mL significantly (p < 0.05) inhibited IL‐1β‐induced MMPs (MMP‐1 and ‐3) production in SW982 cells. IL‐1β‐induced JNK activation was inhibited by PPE (10 µg/mL), whereas p38 and ERK1/2 were not affected. These findings suggest that pine pollen is a potential antioxidant and beneficial for inflammatory conditions through down‐regulation of JNK and MMPs. Copyright © 2008 John Wiley & Sons, Ltd.