Neutrophil Elastase Responses in Smokers and Nonsmokers Consuming Dried Plums

JOURNAL: This study was funded by the California California Prune Board.

AUTHORS: Nelson Stephanie, Zawilski Alexandra, McGill Brittany, McIntosh Marian, Hong Mee Young, Shirin Hooshmand, Kern Mark

Neutrophil elastase, a marker of pulmonary inflammation, is secreted by macrophages within minutes of cigarette smoking to combat inflammation. Excessive levels of neutrophil elastase have been implicated in the pathogenesis of emphysema. Oxidative stress induced by smoking destroys the inhibitors of neutrophil elastase, further exacerbating the uncontrolled release and activity of the enzyme. To determine the effect of dried plums, a high antioxidant food, on neutrophil elastase, nonsmokers (n=14) and smokers (n=5) underwent two trials in which they consumed 100 g dried plums at one visit and an isocaloric control food  (muffins) during the other. Neutrophil elastase concentrations were evaluated in blood samples that were taken at baseline and at 60, 75, 90, and 120 minutes post-feeding, and smokers smoked one cigarette at 45 minutes post-feeding. Results demonstrated that there were no significant changes in neutrophil elastase from baseline in nonsmokers at any time point. However, smokers, experienced a significant decrease in neutrophil elastase 90 minutes after consuming dried plums (p<0.05) that did not occur after consuming muffins. The results suggest that dried plums may control the secretion and activity of neutrophil elastase, which could potentially prevent the pathogenesis of emphysema associated with smoking cigarettes.