丹皮酚对湿疹模型小鼠SP、NK1R表达及肥大细胞活化的影响

Effects of paeonol on expressions of SP,NK1R and mast cell activation in eczema model mice

目的探究丹皮酚对湿疹模型小鼠P物质(SP)、神经激肽1受体(NK1R)表达及肥大细胞活化的影响。方法选取健康清洁级C57BL小鼠100只,用2,4-二硝基氯苯(DNCB)涂于小鼠双耳内侧致敏,建立湿疹模型,造模成功后采用随机数字表法分为湿疹模型组,丹皮酚低(25 mg/kg)、中(50 mg/kg)、高(100 mg/kg)剂量组及阳性药物(地塞米松0.65 mg/kg)组,每组20只。另取20只小鼠于双耳内侧涂抹等量生理盐水作为空白对照(Control)组。各组均于造模成功后开始给药,丹皮酚低、中、高剂量组和阳性药物组均经腹腔注射相应剂量药物,1次/d,共14 d,Control组和湿疹模型组经腹腔注射等量生理盐水。肉眼观察小鼠耳部湿疹皮损程度并进行评分;苏木精-伊红(HE)染色检测各组小鼠耳部组织病理变化;酶联免疫吸附测定法检测SP含量;免疫组化法检测耳部皮损组织NK1R及肥大细胞活性标志物类胰蛋白酶(Tryptase)表达。结果与Control组相比,湿疹模型组小鼠耳部皮肤可见红肿、角化结痂、渗出等损伤及表皮角化过度、真皮层炎症细胞浸润等病理损伤,皮损程度评分、SP含量、NK1R及Tryptase表达水平均升高(P<0.05);与湿疹模型组相比,丹皮酚低、中、高剂量组及阳性药物组小鼠耳部皮肤红肿、角化及炎性浸润等病理损伤程度减缓,皮损程度评分、SP含量、NK1R及Tryptase表达水平均降低(P<0.05),且丹皮酚各剂量组呈剂量依赖性;丹皮酚高剂量组上述指标与阳性药物组相比差异无统计学意义(P>0.05)。结论丹皮酚可能通过抑制湿疹模型小鼠耳部皮损组织中SP、NK1R表达,抑制肥大细胞活化,缓解湿疹炎性损伤症状。

Objective To investigate the effects of paeonol on the expressions of substance P(SP)and neurokinin 1 receptor(NK1R)and mast cell activation in eczema model mice.Methods One hundred healthy and clean grade C57BL mice were selected,and 2,4-dinitrochlorobenzene(DNCB)was applied to the insides of both ears of the mice to sensitize to establish an eczema model.After successful modeling,a random number table method was used to divide model mice into eczema model group,paeonol low(25 mg/kg),medium(50 mg/kg)and high(100 mg/kg)dose groups and positive drug(dexamethasone 0.65 mg/kg)group,20 mice in each group.The another 20 mice were used as control group(apply the same amount of normal saline on the inner sides of both ears).Each group began to administer the drug after successful modeling.The paeonol low,medium and high dose groups and the positive drug group were intraperitoneally injected with the corresponding dose of drugs,once per day for 14 days.Control group and eczema model group were injected with the same amount of normal saline.The skin damage of eczema was observed and scored with naked eyes in ears of mice.Hematoxylin eosin staining(HE)was used to detect the pathological changes in ears of mice in each group.SP secretion was detected by ELISA method.The expressions of NK1R and Tryptase,a marker of mast cell activity in ear lesions,were detected by immunohistochemistry.Results Compared with the control group,the mice in eczema model group showed redness,keratosis scab,exudation and other damages,hyperkeratosis of epidermis,inflammatory cell infiltration of dermis and other pathological damages.The skin damage degree score,SP content,NK1R and Tryptase expression levels were increased(P<0.05).Compared with eczema model group,mice of the paeonol low,medium and high dose groups and positive drug group showed a reduced pathological damage such as redness,keratinization,inflammatory infiltration in ears,the reduced degree of skin lesion score,SP content,NK1R and Tryptase expression levels(P<0.05).Moreover,each dose group of paeonol was dose-dependent,and there was no significant difference between the high dose paeonol group and the positive drug group(P>0.05).Conclusion Paeonol may inhibit the activation of mast cells and alleviate the symptoms of eczema inflammatory damage by inhibiting the expressions of SP and NK1R in ear lesions of eczema model mice.