Antioxidant diet protects against emphysema, but increases mortality in cigarette smoke-exposed mice.

Abstract

Oxidative stress plays an important role in cigarette smoke-induced lung inflammation and emphysema. We produced an enriched diet by adding freeze-dried fruits and vegetables and additional supplements to the 8604 Teklad Rodent Diet, a standard rodent diet. In this study, we examined the effects of the antioxidant-enriched diet on cigarette smoke-induced lung inflammation and emphysema. CH3/HeN mice were fed either a regular diet or the supplemented diet. These mice were exposed to filtered air, a low concentration of cigarette smoke (total particulate matter: 100 mg/m3) or a high concentration of cigarette smoke (total particulate matter: 250 mg/m3) for 6 h/day, 5 days/week for total 16 weeks. Surprisingly, increased mortality (53%) was observed in the high concentration of cigarette smoke-exposed mice fed the antioxidant diet compared to the high concentration of cigarette smoke-exposed mice that were fed a regular diet (13%). The necropsy analysis revealed nasal passage obstruction due to mucous plugging in cigarette smoke-exposed mice on the antioxidant diet. However, the antioxidant diet significantly reduced neutrophilic inflammation and emphysema in the high concentration of cigarette smoke-exposed mice as compared to the regular diet /high concentration of cigarette smoke controls. The antioxidant capacity in the bronchoalveolar fluid or oxidative damage to the lung tissue was not affected by the antioxidant diet. Pro-MMP-2, MMP-2, and MMP-9 activity did not correlate with the protective effects of AOD on cigarette smoke-induced emphysema. These data suggest that the antioxidant diet reduced cigarette smoke-induced inflammation and emphysema, but increased mortality in the obligate nose-breathing mice.

• Authors: Toru Nyunoya, Thomas H March, Yohannes Tesfaigzi, JeanClare Seagrave
• Journal: COPD (COPD) Vol. 8 Issue 5 Pg. 362-8 (Oct 2011) ISSN: 1541-2563 [Electronic] England
• PMID: 21834692 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Antioxidants
• Enzyme Precursors
• Smoke
• Gelatinases
• progelatinase
• Matrix Metalloproteinase 2
• Matrix Metalloproteinase 9

Topics

• Animals
• Antioxidants (administration & dosage, analysis)
• Bronchoalveolar Lavage Fluid (chemistry, cytology)
• Cell Count
• Diet
• Enzyme Precursors (analysis)
• Female
• Fruit
• Gelatinases (analysis)
• Kaplan-Meier Estimate
• Lymphocytes
• Macrophages, Alveolar
• Matrix Metalloproteinase 2 (analysis)
• Matrix Metalloproteinase 9 (analysis)
• Mice
• Mice, Inbred C3H
• Nasal Obstruction (etiology)
• Neutrophils
• Oxidative Stress
• Pulmonary Emphysema (pathology, prevention & control)
• Smoke (adverse effects)
• Tobacco
• Vegetables