The intake of maqui (Aristotelia chilensis) berry extract normalizes H(2)O(2) and IL-6 concentrations in exhaled breath condensate from healthy smokers - an explorative study

BACKGROUND: Respiratory diseases are associated with pulmonary oxidative stress and inflammatory processes. Though studies in animal models suggest that dietary polyphenols improve lung injury, no intervention studies were carried out in humans. The aim of this study was to determine whether the intake of an anthocyanin-rich maqui extract improved H(2)O(2) and IL-6 concentrations in exhaled breath condensates (EBCs) from asymptomatic smokers. FINDINGS: 15 asymptomatic smokers with mild cigarette smoking (3 pack-year [2.4 - 7.7]) (mean [CI(95%)]) were recruited in this exploratory longitudinal study. They ingested 2 g of maqui extract (polyphenol content = 5.18 ± 2.00 g GAE/100 g; FRAP value = 27.1 ± 2.0 mmol Fe(++)/100 g), twice daily for two weeks. EBCs were collected before and after treatment and the changes in H(2)O(2) and IL-6 concentrations were determined by fluorimetry and Elisa, respectively. The EBC contents of H(2)O(2) and IL-6 H(2)O(2) before and after treatment in smokers were also compared with those determined in single EBC samples from 8 healthy non-smokers subjects. At baseline, the H(2)O(2) concentrations were higher and those of IL-6 lower in the smokers than in the non-smokers. Maqui extract significantly decreased H(2)O(2) (p < 0.0002) and increased IL-6 (p < 0.004) in the EBC from smokers. The EBC concentrations of H(2)O(2) and IL-6 after maqui administration did not differ between smokers and non-smokers. CONCLUSIONS: Maqui extract normalizes IL-6 and H(2)O(2) concentrations in EBC from humans with mild smoking habits. If confirmed, these results suggest that dietary polyphenols might be considered as an interesting alternative for the dietary management of respiratory disorders.