Study On The Regulatory Mechanism Of Tibetan Medicine Ershiwuwei Catechu Gel On ICAM-1/LFA-1 And VCAM-1/VLA-4 In Rat Chronic Eczema Model

OBJECTIVE:1 To observe the effect of Tibetan medicine ershiwuwei catechu gel(the following:catechu gel)on chronic eczema caused by DNCB,compared with butyric acid Hydroc-ortisone ointment(You Zhuoer),The experimental significance of Tibetan medicine er shiwuwei catechu gel on body mass,spleen and thymus index,model skin lesion and pathological morphology,which providing an experimental basis for the development of a safe and effective Tibetan medicine gel for the treatment of this disease.2 Through detecting the expression level of intercellular adhesion molecule-1(ICAM-1),vascular endothelial cell adhesion molecule-1(VCAM-1),lymphocyte function related molecule-1(LFA-1),extremely late antigen-4(VLA-4)protein and mRNA gene in skin lesions after the trial,parsing the molecular biological mechanism of catechu gel curing chronic eczema and its specific targets,the theoretical basis for the treatment of chronic eczema was supplied.METHODS:60 Wistar rats were randomly divided into control group and the building model group according to the weight,after successful modeling,the building model group was randomly divided into model group,Youzhuoer group,catechu gel high,medium,low dose treatment group.Except control group,the residual group abdominal 2.0cm�2.0cm skin,to hold the pipette 7% DNCB acetone solution 100?L embrocating rat abdominal sensitization before the experiment 1d,to strengthen 1 times day 2,Hairs having and hair removal on the back of rat 3.0cm�3.0cm on day 5,from day 6 back skin area with 1%DNCB acetone liquid 200?L excitation,1 times 3 days each interval,a total of 6 times.The end of the model: 1 rats were randomly selected out of the blank group.HE staining of skin lesions and skin lesions was observed,conforms to the skin lesions and pathological forms of chronic eczema,that is to suggest the model is su-ccessful.The area and the severity of EASI were scored in each group after the lastmodel 48 h,Youzhuoer,catechu gel high,medium and low dose treatment were res-pectively given percutaneous,catechu gel,high gel(0.35g/kg),medium(0.21g/kg),low(0.14g/kg)dose,2 times a day,continuous 14d;(1)EASI score and body mass(2)With 24 hours' interval,spleens and thymus(weighing the index)and the skin tissue of the drug area(partial 4% polyformaldehyde,partial-80 centigrade cryopreservation),observation of tissue morphology by HE staining,the expression levels of ICAM-1,VCAM-1,LFA-1,VLA-4 and mRNA genes were detected respectively by Western blot and qPCR.RESULTS:1 Comparison of spleen and thymus index: The spleen and thymus index of each group after the experiment,compared with the blank group,the statistical difference be-tween the model group was extremely significant(P<0.001).Compared with the model group,Youzhuoer,catechu gel high,medium and low dose group had statistical signifi-cance(P<0.05).Compared with theYouzhuoer group,the statistical difference among catechu gel high and low dose groups were very significant(P<0.01).Compared with catechu gel medium group,there was Statistical difference between the high and low dose groups of catechu gel(P<0.01).2 Comparison of integral difference of skin lesions: The skin lesions of erythema in each group(E)and scleroderma(edema)/papules(I),epidermal stripping(Ex),licheniza-tion(L)integral of the difference between before and after treatment were statistically significant(P<0.01).Compared with the model group,there were differences in Youzhuo er group,catechu gel high,medium,low dose groups(P<0.05).Compared with the You zhuoer group,and there were statistical difference between catechu gel high and low dose group(P<0.05).Compared with catechu gel medium dose group,there was statisti-cal difference between the high and low dose group of catechu gel(P<0.05).3 HE staining: Compared with the blank group,epidermal sudden extension,aca-nthosis,hyperkeratosis or incomplete,intercellular edema and infiltration of lymphocyt-es of model group were evident.Compared with the pathological of model group,You zhuoer group,catechu gel high,medium,low dose group had phase difference.Com-pared with Youzhuoer group,catechu gel medium and normal group organization simi-lar,catechu gel high and low dose group still had pathological changes.4 Western blot: ICAM-1,LFA-1,VCAM-1,VLA-4 relative protein expression,Com-pared with the blank group,model group had statistical difference(P<0.05).Compared with the model group,Youzhuoer group,catechu gel high,medium and low dose group significant difference(P<0.01).Compared with the Youzhuoer group,there was statistical difference between catechu gel high and low dose group(P<0.05).Compared with catechu gel medium dose group,catechu gel high and low dose group statistical significant difference(P<0.001).5 qPCR: ICAM-1,LFA-1,VCAM-1,VLA-4mRNA expression level,compared with the blank group,model group statistical significant difference(P<0.001).Compared with the model group,Youzhuoer group,catechu gel high,medium,low dose group were statistically significant(P<0.001).Compared with the Youzhuoer group,catechu gel high and low dose group statistical significant difference(P<0.001).Compared with catechu gel medium dose group,catechu gel high and low dose group statistical significant difference(P<0.001).CONCLUSION:1 The expression of ICAM-1,VCAM-1,LFA-1 and VLA-4 protein content and mRNA in the model group was higher than that in the blank group,which was positi vely correlated with the EASI score,suggesting that it might be involved in the mor-bidity of chronic eczema.2 Tibetan medicine ershiwuwei catechu gel can reduce thymus and spleen index;can effectively fade papules,erythema,edema,prevention and control of desquamation,inhibition of lichenification symptoms,rectify the changes of pathological tissue such as epidermis hyperkeratosis,epidermal protrusion,and spinous layer thickening;and can down regulate the expression of cell adhesion molecules ICAM-1,VCAM-1,LFA-1 and VLA-4 protein content and mRNA;the dose was equivalent to the effect of the medi-cine Youzhuoer,and showed a dose effect relationship,which is an effective mechanism for external treatment of chronic eczema skin lesions in rats.