山柰酚对特应性皮炎小鼠炎症反应的影响

Effects of kaempferol on inflammatory response in mice with atopic dermatitis

目的研究山柰酚对特应性皮炎(AD)小鼠炎症反应及信号转导和转录激活因子3(STAT3)/丝裂原活化蛋白激酶(MAPK)/核因子-κB(NF-κB)信号通路的影响。方法将BALB/c小鼠背部去毛后,涂抹2,4-二硝基氯苯(DNCB)溶液,诱导AD模型,随机分为模型组(10 mg·kg^(-1)生理盐水)、山柰酚低、中、高剂量实验组(分别给予25,50和75 mg·kg^(-1)山柰酚)、阳性药组(10 mg·kg^(-1)泼尼松龙),再次选出12只小鼠背部去毛后,涂抹等量无水乙醇,设为对照组(10 mg·kg^(-1)生理盐水),各分组灌胃给药21 d。观察各组小鼠皮炎症状,比较其皮炎评分及搔抓次数;检测各组小鼠皮肤经皮水分丢失量(TEWL)及皮褶厚度;采用苏木精-伊红染色检测各组小鼠皮肤组织病理形态改变;采用试剂盒检测各组小鼠皮肤组织活性氧(ROS)及血清免疫球蛋白E(IgE)、白细胞介素(IL)-17、IL-6水平;采用蛋白质印迹法检测各组小鼠皮肤组织STAT3/MAPK/NF-κB信号通路蛋白的表达。结果对照组、模型组、山柰酚高剂量实验组、阳性药组小鼠皮炎评分分别为0,(6.12±0.31),(0.45±0.12),(0.40±0.09)分;IgE水平分别为(2.19±0.25),(12.83±1.82),(2.23±0.34)和(2.21±0.44)pg·mL^(-1);p-p38 MAPK/p38 MAPK分别为0.09±0.02,0.98±0.13,0.11±0.03和0.10±0.02;STAT3表达水平分别为0.20±0.02,1.28±0.20,0.22±0.07和0.21±0.04;核内NF-κB p65表达水平分别为0.14±0.01,1.36±0.22,0.16±0.05和0.15±0.03。上述指标,模型组与对照组相比,山柰酚高剂量实验组与模型组比较,差异均有统计学意义(均P<0.05);山柰酚高剂量实验组与阳性药组相比,差异均无统计学意义(均P>0.05)。结论山柰酚可减轻AD小鼠的炎症反应,保护皮肤组织,改善皮炎症状,可能是通过下调STAT3/MAPK/NF-κB信号通路表达实现的。

Objective To study the effects of kaempferol on the inflammatory response and signal transducer and activator of transcription 3(STAT3)/mitogen-activated protein kinase(MAPK)/nuclear factor-κB(NF-κB)signaling pathway in atopic dermatitis(AD)mice.Methods After dehairing the back of BALB/c mice,the AD model was induced by applying 2,4-dinitrochlorobenzene(DNCB)solution,and it was randomly divided into model group(10 mg·kg^(-1)normal saline),kaempferol low,medium and high(25,50 and 75 mg·kg^(-1))dose experimental group,positive(10 mg·kg^(-1))group,another 12 mice were selected to apply the same amount of absolute ethanol on the back after dehairing,as control group(10 mg·kg^(-1)normal saline).After grouping and intragastric administration for 21 days,the dermatitis symptoms of mice in each group were observed,and their dermatitis scores and scratching times were compared;the transcutaneous water loss(TEWL)and skinfold thickness of the skin of mice in each group were detected;hematoxylin and eosin staining was used to detect the pathological and morphological changes of the skin tissues of mice in each group;the kits were used to measure the levels of reactive oxygen species(ROS)and serum immunoglobulin E(IgE),interleukin(IL)-17,and IL-6 in the skin tissues of mice in each group;Western blotting was used to detect the expression of STAT3/MAPK/NF-κB signaling pathway protein in mouse skin tissues of each group.Results The dermatitis scores in control group,model group,kaempferol high dose experimental group and positive group were respectively 0,(6.12±0.31),(0.45±0.12),(0.40±0.09)points;IgE level were(2.19±0.25),(12.83±1.82),(2.23±0.34),(2.21±0.44)pg·mL^(-1),respectively;p-p38MAPK/p38 MAPK were 0.09±0.02,0.98±0.13,0.11±0.03 and 0.10±0.02,respectively;STAT3 protein expression levels were 0.20±0.02,1.28±0.20,0.22±0.07,0.21±0.04,respectively;nuclear NF-κB p65protein expression levels were 0.14±0.01,1.36±0.22,0.16±0.05,0.15±0.03,respectively.There were significant differences in the above indexes between the model group and the control group,and between the kaempferol high dose experimental group and the model group(all P<0.05).There was no significant difference between the high experimental group and the positive group(all P>0.05).Conclusion Kaempferol can reduce the inflammatory response in AD mice,protect the skin tissue,and improve the symptoms of dermatitis,which may be achieved by down-regulating the expression of the STAT3/MAPK/NF-κB signaling pathway.