Alpha-tocopherol and ascorbic acid supplementation reduced acute lung inflammatory response by cigarette smoke in mouse

Abstract

Objective: Short-term cigarette smoke (CS) exposure leads to acute lung inflammation through its influence over oxidants/antioxidants imbalance. Antioxidant vitamins such as ascorbic acid and alpha-tocopherol interact with oxidizing radicals. It is not clear if antioxidant supplementation can reduce inflammatory lung responses. Thus our aim was to analyze the effects of vitamin supplementation on the lungs of mice exposed to six cigarettes per day with histologic, cytological, and biochemical methods.

Methods: C57BL/6 mice were exposed to ambient air (control) or CS from 3, 6, 9, 12, or 15 cigarettes daily for up to 5 d. Mice alveolar macrophages and polymorphonuclear cells were counted in the bronchoalveolar lavage. Groups of CS animals received 50 mg/kg of ascorbic acid daily and/or 50 mg/kg of alpha-tocopherol daily as an oral supplementation (CS+C, CS+E, CS+C+E, respectively) 12 h before CS exposure. Thiobarbituric acid-reactive substances were detected and western blot to nuclear factor-kappaB were performed in lung extracts; metalloprotease-12 and tumor necrosis factor-alpha positive alveolar macrophages were quantified in the lungs processed for immunohistochemistry of the animals exposed to the smoke from six cigarettes daily for 5 d.

Results: The number of alveolar macrophages and polymorphonuclear cells in bronchoalveolar lavage (cells x 10(3)/mL) in mice exposed to CS were increased and CS with vitamin supplementation groups presented bronchoalveolar lavage cells similar to those of control. Thiobarbituric acid-reactive substances values were reduced in vitamin supplementation groups when compared with CS and the lower value was found in the CS+C+E group. Metalloprotease-12 and tumor necrosis factor-alpha were more evident in CS as much as nuclear factor-kappaB activation when compared with control and vitamin supplementation groups.

Conclusion: Our results showed that CS induced acute lung inflammation. The inflammatory process after cigarette exposures was reduced by ascorbic acid, alpha-tocopherol, or more efficiently by both vitamin supplementations.