| Objective: To investigate the effect of neuro-acid,an active component of Acer truncatum Bunge,on the inflammatory response and skin barrier in atopic dermatitislike animal model.Method: ABALB/c mouse model of atopic dermatitis was established by DNCB.BALB/c mice were divided into four groups: normal group,model group,matrix group,and neuric acid group,with 6 in each group.On days 1-3 of the experiment,0.5% DNCB was applied to the back of BALB/c mice in the model group,matrix group,and neuric acid group for sensitization,and then 1% DNCB was applied every3 days from day 10 to sensitize the back of BALB/c mice in the model group,matrix group,and neuric acid group for a total of 7 times.Starting from the 15 th day of the experiment,the back of BALB/c mice in the matrix group and the nerve acid group were coated with matrix and nerve acid,respectively,once a day.On the 0th,15 th,and 28 th days of the experiment,the skin lesions on the back of BALB/c mice were photographed,the eczema area and evaluation of dermatitis severity was performed,and the body weight was recorded.On the 29 th day,the weight of the spleen was recorded,the orbital blood of BALB/c mice was collected,and the bleeding serum was isolated.The total serum Ig E was detected by ELISA.Take back skin samples from BALB/c mice in each group,observe the histopathological changes of the back skin of BALB/c mice in each group by HE staining,and analyze the thickness of epidermis and dermis;The number of mast cells was statistically analyzed by toluidine blue staining,and IL-4 and TNF in the back lesions were detected by ELISA-α、 IFN-γ、 IL-1 β、 Expression of IL-6,IL-10,IL-13,and IL-33.The m RNA expression of skin lipid synthesis related enzymes(SPT,Cer S,SMase,FASN,HMGCo A)was detected by RT-q PCR.Results: 1.After 15 days of DNCB inducing BALB/c mice’s skin,the model group,matrix group,and neuric acid group all showed large erythema,a small amount of scales,and itching,with a significant increase in evaluation of dermatitis severity scores(P<0.0001).After 28 days of DNCB inducing BALB/c mice’s skin,the model group mice showed small patches of erythema,a large number of scales,more obvious itching,significantly thickened skin,and decreased evaluation of dermatitis severity scores and TEWL,but still higher than the normal group(P<0.0001);HE staining showed that the epidermis of the model group was significantly thickened(P<0.0001),with a large number of inflammatory cells infiltrating;The number of mast cells in the model group was significantly increased by toluidine blue staining(P<0.0001);In the model group,the spleen enlarged and the spleen index increased(P>0.05);The total Ig E level in the serum of the model group measured by ELISA was significantly higher than that of the normal group(P<0.0001);The levels of various inflammatory factors in the skin lesions of the model group measured by ELISA were significantly higher than those of the normal group,corresponding to P values: IL-4(P<0.0001),TNF-α(P<0.0001)、IFN-γ(P<0.0001)、IL-1 β(P<0.05)、IL-6(P<0.01)、IL-10(P<0.001)、IL-13(P<0.0001)、IL-33(P<0.01).The above results demonstrate that DNCB has successfully induced the establishment of an atopic dermatitis model in BALB/c mice.2.After 2 weeks of treatment of DNCB induced BALB/c mice,the clinical symptoms were observed.The evaluation of dermatitis severity scores of the model group,matrix group,and neuric acid group mice decreased,but there was no statistical difference between the model group and matrix group.There was a significant statistical difference between the matrix group and neuric acid group(P<0.001).When calculating the spleen index,the model group,matrix group,and nerve acid group all increased,but there was no statistical difference.Neuroic acid can significantly improve the symptoms of erythema,edema,and scales in atopic dermatitis like mouse models,but it cannot affect the spleen index.3.After 2 weeks of treatment with DNCB-induced BALB/C mice,the TEWL values decreased in different degrees,and there was no significant difference between the model group and the Matrix Group,there was significant difference between the two groups(p <0.01).The results indicated that the neuroacids could obviously decrease the TEWL value of the back skin of mice and repair the skin barrier.4.After 2 weeks of treatment of DNCB induced BALB/c mice,HE staining showed that compared to the model group,the epidermal thickness of the matrix group and the neuric acid group mice became thinner,the degree of edema was reduced,and the infiltration of inflammatory cells in the dermis was reduced,but the neuric acid group was more obvious than the matrix group.There was no statistical difference in dermal thickness between the groups.This indicates that nerve acid can improve the epidermal thickness,edema degree,and infiltration of inflammatory cells in a mouse model of atopic dermatitis at the histopathological level.5.After 2 weeks of treatment of DNCB induced BALB/c mice,toluidine blue staining showed that compared to the model group,the number of mast cells in the matrix group and the neuric acid lesions decreased,but there was no statistical difference between the model group and the matrix group,while the neuric acid group decreased more significantly than the matrix group(P<0.001).This indicates that neuric acid can reduce the infiltration of mast cells and further alleviate inflammation.6.After 2 weeks of treatment of DNCB induced BALB/c mice,the total Ig E in the serum of the mice was measured by ELISA.The results showed that compared with the model group and matrix group,the neuric acid group significantly decreased(P<0.05).It is suggested that neuric acid can significantly inhibit the secretion of total Ig E in serum.7.After 2 weeks of treatment of DNCB induced BALB/c mice,the expression of inflammatory factors in the skin lesions of the mice was detected by ELISA.It was found that there was no significant difference in the expression of inflammatory factors between the model group and the matrix group,while the levels of various inflammatory factors in the skin lesions of the neuric acid group were significantly decreased,including IL-4(P<0.001)and TNF-α(P < 0.001)、 IFN-γ(P <0.05)、IL-1 β(P<0.01)、IL-6(P<0.05)、IL-10(P<0.05)、IL-13(P<0.05)、 IL-33(P < 0.01).This suggests that neuric acid may exert antiinflammatory effects by inhibiting the release of inflammatory factors.8.After two weeks of treatment,the m RNA expression of SPTLC1,CERS2,SMPD3,FASN and HMGCR2 were detected by RT-q PCR,s PTLC1,CERS2,SMPD3,FASN,HMGCR2 were higher in the neuroacid group than in the matrix group,but there was no statistical difference.Conclusion: 1.The establishment of an atopic dermatitis model in Balb/c mice induced by DNCB was successful.2.The active ingredient of Acer truncatum,neuric acid,can significantly improve clinical symptoms such as erythema,edema,scales,and itching in mice with atopic dermatitis.3.The active component of Acer truncatum,neuric acid,has anti-inflammatory effects on atopic dermatitis like mouse models,and its mechanism may be related to reducing the number of mast cells,inhibiting the secretion of total Ig E in serum,and reducing the release of inflammatory factors.4.Neuro-acid,the active component of Acer truncatum,may repair the skin barrier function indirectly by improving the inflammatory reaction of atopic dermatitis. |
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