Comparison of characteristics of mouse alopecia models established by paraffin/rosin mixed depilation method,sodium sulfide depilation method,and depilatory cream depilation method

GUAN Tangfei; HONG Canhui; YANG Xin; WU Guangjun; XIAO Peiyun; ZHANG Chenggui; HE Zhengchun

doi:10.3969/j.issn.1002-266X.2025.03.011

Abstract：Objective To comparatively observe the characteristics of alopecia models established in C57BL/6J mice using the paraffin/rosin mixed depilation method,sodium sulfide depilation method,and depilatory cream depila-tion method,aiming to provide a theoretical basis and technical reference for the selection of mouse alopecia models.Methods Forty-four SPF-grade female C57BL/6J mice were divided into four groups,namely groups A,B,C,and D,with 11 mice in each group.Mice in the group A were normally raised without depilation treatment and served as the nor-mal control.In the group B,the mouse alopecia model was established using the paraffin/rosin mixed depilation method.In the group C,the model was established using the sodium sulfide depilation method.In the group D,the model was es-tablished using the depilatory cream depilation method.The depilation area was approximately 2.5 cm×4.0 cm.Taking the successful preparation of the mouse alopecia model as day 0,the hair growth status of mice in each group after the suc-cessful model preparation was observed,and the skin color and hair regeneration of mice were scored.On day 15 and 21,the hair length in the depilated area of mice was measured,and on day 21,the hair weight in the depilated area of mice was measured.On day 21,a fully automated blood cell analyzer was used to detect the numbers of white blood cells(WBC),granulocytes(Gran),lymphocytes(Lym),and monocytes(Mon)in the eyeball blood to determine the inflamma-tory situation in mice.On day 1 and 21,HE staining was used to observe the pathological changes and skin damage degree of mouse skin tissues,including vellus hair follicles,terminal hair follicles,total hair follicles,and the ratio of terminal hair follicles to vellus hair follicles.Results Alopecia models were successfully established in mice by all three meth-ods.After depilation,the hair in the depilated area of mice in the groups B,C,and D grew slowly,and the hair growth sta-tus in the group B was better,with higher scores for skin color and hair regeneration.On day 15 and 21,the hair length in the depilated area of mice in the groups C and D were lower than those in the group B(all P<0.05).The hair weight in the depilated area of mice in the group A was higher than that in the other groups,and the hair weight in the depilated area of mice in the group B was higher than that in the groups C and D(all P<0.05).Compared with mice in the group A,Gran decreased and Mon increased in the group B,WBC,Lym,and Mon increased in the group C,and Mon increased in the group D.Compared with mice in the group B,WBC,Gran,Lym,and Mon increased in the group C.Compared with mice in the group C,WBC,Gran,Lym,and Mon decreased in the group D(all P<0.05).On day 21,the number of hair follicles increased and the number of terminal hairs increased in the group B.The number of skin hair follicles was relative-ly small in the group C.A small number of terminal hairs and vellus hairs were visible in the group D,and the hair follicle structure was relatively complete.Compared with mice in the group A,the number of terminal hair follicles,the total num-ber of hair follicles,and the ratio of terminal hair follicles to vellus hair follicles decreased in the group C,and the number of vellus hair follicles,the number of terminal hair follicles,the total number of hair follicles,and the ratio of terminal hair follicles to vellus hair follicles decreased in the group D.Compared with mice in the group B,the ratio of terminal hair folli-cles to vellus hair follicles decreased in the groups C and D(all P<0.05).Conclusions The paraffin/rosin mixed depil-ation method,sodium sulfide depilation method,and depilatory cream depilation method can all successfully establish mouse alopecia models.Among them,the hair growth is fast after depilation using the paraffin/rosin mixed depilation method,and the sodium sulfide depilation method can continuously induce skin inflammation after depilation,which is suitable for the construction of different types of alopecia models caused by different pathogenesis.