Positive Health Online

Abstract

KOIKE and COLLEAGUES, (1)1 Division of Respiratory Medicine, Juntendo University Faculty of Medicine and Graduate School of Medicine, Tokyo, Japan investigated in mice the action of Vitamin C (VC) in the prevention and restoration of cigarette smoke-induced pulmonary emphysema.

Background

Vitamin C (VC) is a potent antioxidant and is essential for collagen synthesis.

Methodology

The authors investigated whether VC treatment prevents and cures smoke-induced emphysema in senescence marker protein-30 knockout (SMP30-KO) mice, which cannot synthesize VC. Two smoke-exposure experiments using SMP30-KO mice were conducted. In the first one (a preventive study), 4-month-old mice received minimal VC (0.0375 g/l) [VC(L)] or physiologically sufficient VC (1.5 g/l) [VC(S)] and exposed to cigarette smoke or smoke-free air for 2 months. Pulmonary evaluations followed when the mice were 6 months of age. The second study began after the establishment of smoke-induced emphysema (a treatment study). These mice no longer underwent smoke exposure but received VC(S) or VC(L) treatment for 2 months. Morphometric analysis was performed, and measurements of oxidative stress, collagen synthesis, and vascular endothelial growth factor in the lungs were evaluated.

Results

Chronic smoke exposure caused emphysema (29.6% increases of mean linear intercepts [MLI] and 106.5% increases of destructive index compared with the air-only group) in 6-month-old SMP30-KO mice, and this emphysema closely resembled human chronic obstructive pulmonary disease. Smoke-induced emphysema persisted in the VC(L) group after smoking cessation, whereas VC treatment provided pulmonary restoration (18.5% decrease of MLI and 41.3% decrease of destructive index compared with VC(L) group). VC treatment diminished oxidative stress, increased collagen synthesis, and improved vascular endothelial growth factor levels in the lungs.

Conclusion

CONCLUSIONS: The authors’ results suggest that VC not only prevents smoke-induced emphysema in SMP30-KO mice but also restores emphysematous lungs. Therefore, VC may provide a new therapeutic strategy for treating chronic obstructive pulmonary disease in humans.

References

Koike K(1), Ishigami A, Sato Y, Hirai T, Yuan Y, Kobayashi E, Tobino K, Sato T, Sekiya M, Takahashi K, Fukuchi Y, Maruyama N, Seyama K. Vitamin C prevents cigarette smoke-induced pulmonary emphysema in mice and provides pulmonary restoration.  Am J Respir Cell Mol Biol. 50(2):347-57. doi: 10.1165/rcmb.2013-0121OC. Feb 2014.

Comment

This results provides supports for the further development of clinical therapeutic strategies using Vitamin C for the treatment of chronic obstructive pulmonary disease (COPD) in humans.