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


OBJECTIVE
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.
D'Agostini
Francesco
F
Section of Hygiene and Preventive Medicine, Department of Health Sciences, University of Genoa, Via A. Pastore 1, I-16132 Genoa, Italy. fda@unige.it
Fiallo
Paolo
P
Pennisi
Tanya M
TM
De Flora
Silvio
S
D000111:Acetylcysteine / Q000008:administration & dosage / Q000494:pharmacology; D000284:Administration, Oral; D000505:Alopecia / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D017209:Apoptosis; D001835:Body Weight; D018890:Chemoprevention / Q000379:methods*; D003553:Cystine / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D018859:Hair Follicle / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D025101:Vitamin B 6 / Q000008:administration & dosage / Q000494:pharmacology*
D014028:Tobacco Smoke Pollution; D003553:Cystine; D025101:Vitamin B 6; D000111:Acetylcysteine