| Background and ObjectiveAllergic rhinitis(AR) is an allergic disease of the nasal mucosa, characterized by hypersecretion and hyperreactivity. Symptoms of allergic rhinitis are nasal itching,sneezing,rhinorrhea and nasal congestion. Inflammatory mediators such as chemokines and enzyme, etc, which are responsible for most of the pathological processes occurring within the nasal mucosa. The mechanism of high expression on inflammatory mediators has been unknown. NF-κB has become one of the most important regulatory factors. Compared with glucorticosteroids, Triptolide had the same extensive effects of suppressing immunology as glucocorticosteroids without its side effects and had been successfully applied to asthma.This experiment investigated the relationship among the expressions of nuclear factor-κB(NF-κB), Eotaxin and iNOS and the effects of triptolide in nasal mucosa of rats allergic rhinitis models, discussed the possible mechanism of triptolide's therapeutic effect on allergic rhinitis and compared with glucocorticosteroids, in order to provide the evidence of applying TP to clinics.Materials and Methods48 healthy SD rats were divided into four groups randomly(n=12). They were OVA(ovalbumin)group, TP(triptolide)group, DM(dexamethasone)group and SC(sodi- um chloride)group. Model of allergic rhinitis was established referring to An Yunfang. OVA was applied on rats orderly going through two phases: basic sensitization and stimulation. TP, DM and SC group were applied on the other groups respectively before 30 minutes in phase of stimulation. 10% chloral hydrate was injected into abdominal cavity of rats after the model was established successfully, then these rats were killed by cutting open the heart. Soon afterly, nasal mucosa was separated from nasal cavity then was fixed with 4% paraformaldehyte/0.1M PBS for 4-6 hours. All samples had been collected routinely, then were cut at 4-6μm and mounted on 0.1 % polyllysine-coated slides. IH(Immunohistochemistry)was used to determine the expression of iNOS,Eotaxin and NF-κB in nasal mucosa.The numbers of each sample were calculated under microscope and expressed as x|-±s, all data were analysed by statistic sofeware spss11.0: F-test(one factor analysis of variance)and LSD(the least significant difference).Results(1)The results of the model: The symptom including sneezing,itching and rhinorrhea in AR became obvious and severe, the model animals also became unquiet in OVA group. These symptoms appeared lightly in TP and DM group and SC group seemed normal.(2)The results of hematotoxylineosin(HE)staining:The gland and vessel appeared expanded in nasal mucosa and submucosa layer which became thick,swell and were infiltrated by a large numbers of inflammation cells by mean of dot. The pathological changes of TP and DM group were lighter than that of OVA group. The SC group had no change. EOS counting: OVA group, 9.10±0.76; TP group, 3.93±0.51; DM group, 4.01±0.59; SC group, 0.52±0.43. There were significant difference between SC group and OVA group(P<0.01); TP and DM could reduce the infiltration of EOS in nasal mucosa apparently.(3)The results of toluidine blue staining: The gland and vessel appeared expanded in nasal mucosa and submucosa layer which became thick,swell and were extensively infiltrated by a large number of mast-cell along the blood vessels. The pathological changes of TP and DM group were lighter than that of OVA group. The SC group had merely mast cell in nasal mucosa. Mast cell counting: OVA group, 22.71±1.20; TP group, 11.28±1.36; DM group, 10.73±0.81; SC group, 1.35±0.76. There were significant difference between SC group and OVA group(P<0.01); TP and DM could reduce the infiltration of mast-cells in nasal mucosa significantly.(4)The results of IH(Immunohistochemistry): The positive expressing of iNOS were located in the part of glands, epithelials, endothelial of vessel, vascular smooth muscle and inflammation cells. Statistic results of iNOS in nasal mucosa was 92.41±12.23 in OVA group; 53.54±5.60 in TP group; 59.32±9.50 in DM group and 37.54±6.02 in SC group. The positive expressing signals of Eotaxin were located in the part of glands, epithelials and inflammation cells. Statistic results of Eotaxin in nasal mucosa was 98.23±11.23 in OVA group; 55.21±8.26 in TP group; 58.73±10.65 in DM group and 38.36±5.89 in SC group. The positive expressing signals of NF-κB were located in the part of epithelials, glands and inflammation cells infiltrated around endothelial of vessels. Statistic results of NF-κB in nasal mucosa was 97.10±11.16 in OVA group; 60.08±6.47 in TP group; 64.48±10.13 in DM group and 38.75±7.47 in SC group. Each of iNOS,Eotaxin and NF-κB expression had significant difference compared with other three groups in OVA group or SC group(P<0.01). And no significant difference had been seen between TP and DM groups(P> 0.05).(5)Analysis of correlation: The expression of Eotaxin in OVA group had high degree positive correlation with the expression of iNOS(r=0.886, P<0.01); The expression of NF-κB in OVA group had apparent degree positive correlation with the expression of Eotaxin and iNOS (r-=0.818,r=0.908,P<0.01) .Conclusions(1)TP can suppress obviously the symptoms of AR model established by OVA.(2)TP can reduce the infiltration of EOS and mast-cells in nasal mucosa significantly.(3)TP can inhibit expression of Eotaxin,iNOS and NF-κB in AR model established by OVA. (4)TP can inhibit expression of Eotaxin and iNOS by restaining the activation of NF-κB. It might be one of the pharmacologic mechanisms of TP to inhibit the activity of NF-κB.(5)TP has no significant difference with DM in suppressing symptoms of AR, suppressing the infiltration of EOS and mast-cells, inhibiting expressing of iNOS,Eotaxin and inhibiting the activation of NF-κB.
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