Effects of Qingpeng ointment on skin barrier function in volunteers with xerosis and atopic dermatitis-like mouse models

Abstract

Objective To estimate effects of Qingpeng ointment on skin barrier function, and to explore their potential mechanisms. Methods A total of 12 female volunteers with xerosis on the extensor surfaces of legs were enrolled into this study. All the volunteers were topically treated with Qingpeng ointment on the right leg (Qingpeng side) and its vehicle on the left leg (vehicle side) twice daily for 7 consecutive days. Skin barrier function-associated indexes including transepidermal water loss (TEWL) and the water content of the stratum corneum were measured before the treatment, after 3-and 7-day treatment separately. Thirty-six BALB/c female mice were randomly and equally divided into 6 groups: a blank control group receiving no induction or treatment, a model group induced by 2, 4-dinitrofluorobenzene (DNFB) on the back for 5 consecutive weeks, 3 Qingpeng groups and a vehicle group induced by DNFB on the back for 5 consecutive weeks followed by topical treatment with different concentrations (50%, 75%, 100%) of Qingpeng ointment or its vehicle twice a day for 2 consecutive weeks. At the end of treatment, skin appearance of mice was observed with naked eyes, skinfold thickness and TEWL were measured. Then, all the mice were sacrificed, and skin tissue specimens were resected from the back of mice followed by histopathologic examination and immunohistochemical staining for the detection of filaggrin (FLG), involucrin (IVL) and kallikrein 7 (KLK7) expressions in the epidermis. Results After start of treatment, both the Qingpeng side and vehicle side showed significantly decreased TEWL on day 3 (t = 2.651, 2.996, respectively, both P 0.05). In addition, there were no marked differences in mouse skin appearance, skinfold thickness or histopathologic manifestations between the vehicle groupand model group, while the manifestations of dermatitis were attenuated to different extents in the three Qingpeng groups compared with the model group. Both TEWL and KLK7 expression levels were significantly decreased in the vehicle group and three Qingpeng groups compared with the model group (all P 0.05). Conclusion The vehicle of Qingpeng ointment can improve skin barrier function. Key words: Dermatitis, atopic; Models, animal; Mice; Skin; Volunteer; Qingpeng ointment; Skin barrier