除湿止痒软膏抗炎及止痒作用研究

Anti-inflammatory and antipruritic effects of Chushizhiyang ointment

目的：探讨除湿止痒软膏的抗炎及止痒作用。方法用2，4-二硝基氟苯（DNFB）腹部致敏和背部反复激发建立 BALB/c 小鼠特应性皮炎模型。实验动物分为正常对照组（未致敏也未治疗）、模型对照组（致敏但未治疗）、氢化可的松乳膏组（致敏＋氢化可的松）、除湿止痒软膏组（致敏＋除湿止痒软膏）。连续用药14 d，末次给药12 h 后取背部皮肤，测定皮肤厚度及质量，进行 HE 染色和甲苯胺蓝染色，ELISA 法检测皮损组织中干扰素（IFN）γ、肿瘤坏死因子（TNF）α、白细胞介素（IL）-4、IL-5含量。利用磷酸组胺诱发 Hartley 豚鼠局部皮肤瘙痒模型，观察除湿止痒软膏对豚鼠致痒阈的影响。结果用药后第15天，与模型对照组相比，氢化可的松乳膏和除湿止痒软膏均可明显减少小鼠的背部皮肤厚度和质量（P 〈0.01），减少淋巴细胞和肥大细胞浸润（P 〈0.01）以及降低皮损组织中 IFN-γ、TNF-α、IL-4及 IL-5水平（P 〈0.05或 P 〈0.01）。与正常对照组相比，氢化可的松乳膏组小鼠背部皮肤厚度和质量减小（P 〈0.01），除湿止痒软膏组无明显变化。此外，除湿止痒软膏也可显著提高豚鼠耐受磷酸组胺的致痒阈（P 〈0.01）。结论除湿止痒软膏可明显抑制 DNFB 引起的小鼠特应性皮炎，其抗炎机制可能与恢复体内 Th1/Th2型细胞因子平衡有关。除湿止痒软膏可明显减轻磷酸组胺所致豚鼠皮肤瘙痒反应。

Objective To explore the anti-inflammatory and antipruritic effects of Chushizhiyang ointment in a mouse model. Methods A total of 40 male 8-week-old BALB/c mice were included in this study, and randomly and equally divided into 4 groups. A mouse model of atopic dermatitis （AD）was established in three groups of mice by repeated application of 2,4-dinitroflurobenzene （DNFB）to shaved abdominal skin for sensitization and to shaved dorsal skin for stimulation. After establishment of the AD model, the three groups were topically treated with sodium chloride physiological solution （model group）, hydrocortisone cream （hydrocortisone group）and Chushizhiyang ointment （Chushizhiyang group）respectively for 14 consecutive days. The remaining group receiving no sensitization or treatment served as the normal control group. All the mice were sacrificed 12 hours after the final treatment, and the dorsal skin of mice was resected followed by the determination of skin thickness and weight as well as hematoxylin-eosin（HE）staining and toluidine blue staining for the counting of leukocytes and mast cells respectively. Moreover, enzyme-linked immunosorbent assay（ELISA）was performed to measure the levels of interferon-gamma（IFN-γ）, tumor necrosis factor alpha（TNF-α）, interleukin 4（IL-4）and IL-5 in dorsal skin lesions. In addition, a local skin itching model was induced by histamine phosphate in Hartley guinea pigs, which was used to explore the effect of Chushizhiyang ointment on itch thresholds. Results Compared with the model group, both the Chushizhiyang group and hydrocortisone group showed reduced thickness and weight of dorsal skin in mice （all P 〈 0.01）, numbers of infiltrating lymphocytes and mast cells （all P 〈 0.01）and levels of IFN-γ, TNF-α, IL-4 and IL-5 in skin lesions （P 〈 0.05 or 0.01）on day 15 after the start of treatment. The thickness and weight of dorsal skin in mice were significantly decreased in the hydrocortisone group （P 〈0.01）, but experienced no significant changes in the Chushizhiyang group compared with the normal control group. Additionally, Chushizhiyang ointment could significantly increase itch thresholds in guinea pigs induced by histamine phosphate（P 〈 0.01）. Conclusions Chushizhiyang ointment can significantly inhibit DNFB-induced AD in mice, likely by restoring the balance between Th1 and Th2 type cytokines. Moreover, Chushizhiyang ointment could markedly relieve itching induced by histamine phosphate in guinea pigs.