Effects of simvastatin on the mouse model of sclerotic skin / 中华皮肤科杂志

ABSTRACT

Objective To study the effect of simvastatin on the mouse model of sclerotic skin. Methods A total of 44 mice were divided into two groups, i.e., early administration group (n=24) and post-induction administration group (n=20), and the former was classified into three subgroups, including negative group, model group and simvastatin-treated group, and the latter into two groups, namely blank control group, simvastatin-treated group. The mouse model of sclerotic skin was established by local injec-tions of bleomycin in the back of BALB/c mice. Simvastatin was administered by gavage at a dose of 5 μg per kilogram body weight per day for 4 weeks to mice at the same time when bleomycin was injected in the early group or after 4-week bleomycin injection in the post-induction group. Skin sections were prepared 24 hours after the last administration of simvastatin for histopathological examination and measurement of derma l thickness with HE staining, determination of hydroxyproline content via colorimetry, and mRNA expression of procollagen α1 (Ⅰ) by RT-PCR. Results In the early administration group, a significant increment was observed in the diameter of dermal collagen, skin thickness, and hydroxyproline content in model group compared with the negative control group (all P <0.01), whereas decreased dermal thickness, hydroxyproline content and mRNA expression of procollagen α1(Ⅰ) were noticed in simvastatin-treated group in comparison with the model group (P<0.05, 0.01 and 0.05, respectively). No obvious improvement was achieved in dermal thickness or hydroxyproline content in simvastatin-treated group compared with blank control group (both P0.05), but the mRNA expression of procollagen α1 (Ⅰ) was inhibited in the former group (P<0.05). Conclusion Skin sclerosis is relieved significantly by administration of simvastatin at the induction of scle- rosis but not by that after the induction of sclerotic skin.