Chemoprevention of smoke-induced alopecia in mice by oral administration of l-cystine and vitamin B6.

J Dermatol Sci. 2007 Mar 17
D’Agostini F, Fiallo P, Pennisi TM, De Flora S.
Section of Hygiene and Preventive Medicine, Department of Health Sciences, University of Genoa, Via A. Pastore 1, I-16132 Genoa, Italy.

BACKGROUND: We previously demonstrated that high doses of environmental cigarette smoke (ECS) induce alopecia in mice. This effect was prevented by the oral administration of N-acetylcysteine (NAC), an analogue and precursor of l-cysteine and reduced glutathione.
 
OBJECTIVES: The present study aimed at assessing whether l-cystine, the oxidized form of l-cysteine, which is a key hair component, may behave like NAC in inhibiting ECS-induced alopecia and modulating the mechanisms responsible for this condition.

METHODS: C57BL/6 mice were exposed whole-body to ECS in a smoking machine. Groups of mice received in the diet, at three dose levels, a mixture of l-cystine with vitamin B6, which plays a role in l-cystine incorporation in hair cells. Occurrence of alopecia areas and apoptosis of hair bulb cells were evaluated for up to 6 months of exposure, and the time course induction of micronucleated erythrocytes in peripheral blood was investigated.

RESULTS: The frequency of micronucleated erythrocytes was increased by ECS, irrespective of treatment with l-cystine/vitamin B6. ECS-induced alopecia and apoptosis of hair bulb cells in all exposed mice. l-Cystine/vitamin B6 inhibited alopecia in a dose-dependent fashion.

CONCLUSIONS: High-dose ECS induces apoptosis-related alopecia in mice, and oral administration of l-cystine/vitamin B6 is an effective preventive treatment.

PMID: 17374475