Inhibitory effect of Qingpeng ointment on experimental irritant contact dermatitis in mice and its possible mechanisms / 中华皮肤科杂志

ABSTRACT

Objective To investigate the inhibitory effect of Qingpeng ointment,a topical Tibetan medicine,on induced irritant contact dermatitis (ICD) in mice and its possible mechanisms.Methods An ICD model was developed in 180 seven-week-old BALB/c mice by applying sodium dodecyl sulfate (SDS,10％ in distilled water) on shaved backs,and the mice were then equally divided into 5 groups to remain untreated (model control),be treated with 100％,75％,50％ Qingpeng ointment and vehicle of the ointment (vehicle control),respectively,for 11 days.Thirty-six mice receiving no irritation or treatment served as the blank control.At day 8 and 12 after the beginning of treatment,drill biopsy specimens were gained from induced lesions of these mice and subjected to the measurement of skin thickness and weight,observation of histopathological changes with hematoxylin and eosin staining,and calculation of inflammatory cells infiltrating the dermis; blood samples were also obtained,and enzyme linked immunosorbent assay (ELISA) was performed to quantify the expression level of interleukin (IL)-2,tumor necrosis factor (TNF)-α and interferon (IFN)-γ in sera and homogenates of skin lesions.Results Compared with the model control and vehicle control mice,those treated with 100％ Qingpeng ointment showed an attenuated inflammation and swelling,together with a decreased neutrophil skin infiltration.At day 12,the levels of IL-2,TNF-α and IFN-γ were significantly lower in the sera ( (5.55 ± 0.33) vs.(6.41 ± 0.96) and (6.25 ± 0.92) pg/ml,(70.88 ± 1.55 )vs.(76.67 ± 1.14) and (76.95 ± 1.08) pg/ml,(76.99 ± 1.85) vs.(82.20 ± 2.36) and (81.76 ± 3.19) pg/ml,respectively,all P ＜ 0.05) and homogenates of skin lesions ((17.75 ± 0.97) vs.(23.92 ± 0.82) and (23.11 ± 0.82) pg/ml,(66.95 ± 3.58) vs.(70.66 ± 2.68) and (71.17 ± 3.30) pg/ml,(46.85 ± 2.43) vs.(55.14 ± 2.68) and (53.55 ± 3.24) pg/ml.all P ＜ 0.05) in mice treated with 100％ Qingpeng ointment than those in the model control and vehicle control groups.Conclusion The 100％ Qingpeng ointment can suppress the inflammatory response in experimental ICD in mice,with a decrease in the level of IL-2,TNF-α and IFN-γ in sera and skin lesions.