Vitamin E, ?-tocopherol, reduces airway neutrophil recruitment after inhaled endotoxin challenge in rats and in healthy volunteers.

ABSTRACT: Epidemiologic studies suggest that dietary vitamin E is an important candidate intervention for asthma. Our group has shown that daily consumption of vitamin E (?-tocopherol, ?T) has anti-inflammatory actions in both rodent and human phase I studies. The objective of this study was to test whether ?T supplementation could mitigate a model of neutrophilic airway inflammation in rats and in healthy human volunteers. F344/N rats were randomized to oral gavage with ?T versus placebo, followed by intranasal LPS (20?g) challenge. Bronchoalveolar lavage fluid and lung histology were used to assess airway neutrophil recruitment. In a phase IIa clinical study, 13 nonasthmatic subjects completed a double-blinded, placebo-controlled crossover study in which they consumed either a ?T-enriched capsule or a sunflower oil placebo capsule. After 7 days of daily supplementation, they underwent an inhaled LPS challenge. Induced sputum was assessed for neutrophils 6 h after inhaled LPS. The effect of ?T compared to placebo on airway neutrophils post-LPS was compared using a repeated-measures analysis of variance. In rats, oral ?T supplementation significantly reduced tissue infiltration (p<0.05) and accumulation of airway neutrophils (p<0.05) that are elicited by intranasal LPS challenge compared to control rats. In human volunteers, ?T treatment significantly decreased induced sputum neutrophils (p=0.03) compared to placebo. Oral supplementation with ?T reduced airway neutrophil recruitment in both rat and human models of inhaled LPS challenge. These results suggest that ?T is a potential therapeutic candidate for prevention or treatment of neutrophilic airway inflammation in diseased populations.

SUBMITTER: Hernandez ML 

PROVIDER: S-EPMC3654053 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature