Formononetin attenuates psoriasiform inflammation by regulating interferon signaling pathway

BACKGROUND

Psoriasis is a long-lasting, inflammatory, continuous illness caused through T cells and characterized mainly by abnormal growth and division of keratinocytes. Currently, corticosteroids are the preferred option. However, prolonged use of traditional topical medication can lead to adverse reactions and relapse, presenting a significant therapeutic obstacle. Improved alternative treatment options are urgently required. Formononetin (FMN) is a representative component of isoflavones in Huangqi (HQ) [Astragalus membranaceus (Fisch.) Bge.]. It possesses properties that reduce inflammation, combat oxidation, inhibit tumor growth, and mimic estrogen. Although FMN has been shown to ameliorate skin barrier devastation via regulating keratinocyte apoptosis and proliferation, there are no reports of its effectiveness in treating psoriasis.

OBJECTIVE

Through transcriptomics clues and experimental investigation, we aimed to elucidate the fundamental mechanisms underlying FMN's action on psoriasis.

MATERIALS AND METHODS

Cell viability was examined using CCK8 assay in this study. The results of analysis of differentially expressed genes (DEGs) between FMN-treated HaCaT cells and normal HaCaT cells using RNA-sequencing (RNA-seq) were presented on volcano plots and heatmap. Enrichment analysis was conducted on DEGs using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO), and results were validated through RT-qPCR verification. After 12 days of FMN treatment in psoriasis mouse model, we gauged the PASI score and epidermis thickness. A variety of techniques were used to assess FMN's effectiveness on inhibiting inflammation and proliferation related to psoriasis, including RT-qPCR, HE staining, western blot, and immunohistochemistry (IHC).

RESULTS

The findings indicated that FMN could suppress the growth of HaCaT cells using CCK8 assay (with IC50 = 40.64 uM) and 20 uM FMN could reduce the level of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) to the greatest extent. FMN-treated HaCaT cells exhibited 985 up-regulated and 855 down-regulated DEGs compared to normal HaCaT cells. GO analysis revealed that DEGs were linked to interferon (IFN) signaling pathway. Furthermore, FMN improved pathological features, which encompassed decreased erythema, scale, and thickness scores of skin lesions in psoriasis mouse model. In vivo experiments confirmed that FMN down-regulated expression of IFN-α, IFN-β, IFN-γ, decreased secretion of TNF-α and IL-17 inflammatory factors, inhibited expression of IFN-related chemokines included Cxcl9, Cxcl10, Cxcl11 and Cxcr3 and reduced expression of transcription factors p-STAT1, p-STAT3 and IFN regulatory factor 1 (IRF1) in the imiquimod (IMQ) group.

CONCLUSIONS

In summary, these results suggested that FMN played an anti-inflammatory and anti-proliferative role in alleviating psoriasis by inhibiting IFN signaling pathway, and FMN could be used as a potential therapeutic agent.

Large-scale separation of alkaloids from Corydalis decumbens by pH-zone-refining centrifugal partition chromatography and their anticomplement activity

Centrifugal partition chromatography in the pH-zone-refining mode was successfully applied to the separation of alkaloids from the crude extract of Corydalis decumbens. The experiment was performed with a two-phase solvent system composed of petroleum ether-ethyl acetate-ethanol-water (5:5:3:7, v/v/v/v) where triethylamine (10 mM) was added to the stationary phase and hydrochloric acid (10 mM) to the mobile phase. From 1.6 g of the crude extract, 43 mg protopine, 189 mg (+)-egenine, and 158 mg tetrahydropalmatine were obtained with a purity of 98.2%, 94.6%, and 96.7%, respectively. Tetrahydropalmatine showed an interesting anticomplement effect with CH50 0.11 and AP50 0.25 mg/mL, respectively. In a mechanistic study, tetrahydropalmatine interacted with C1, C3, C4, and C5 components in the complement activation cascade.

Analysis of quality nursing of postoperative incision infection in urological patients

To study the effect of quality nursing on postoperative incision infection in urological patients, 200 subjects admitted to our hospital between June 2016 and June 2017 were included in this study and divided into a quality nursing group (group A) and a general nursing group (group B), 100 in each group. Blood loss, blood transfusion, hospital stay, incision healing, incision infection, and self-rating depression scale (SDS) scores in both groups were compared. It was found that the bleeding volume in group A was significantly less than that in group B, and there was significant difference between the two groups (P less than 0.05) while the difference in blood transfusion rate and hospital stay between the two groups was not significant (P> 0.05); the number of patients of level 1 healing in group A was larger than that of group B while the number of patients of level 2 and level 3 healing was smaller than that of group B, with significant differences (P less than 0.05); the number of infection cases in group A was significantly lower than that in group B, and the difference was significant (P less than 0.05); the SDS score of group A was lower than that of group B, with significant differences (P less than 0.05). Therefore, quality nursing had a certain effect on the infection of postoperative incision of urological patients, which had positive significance for incision healing. Reducing the effect of bacterial infections in operated patients is important for rapid healing and patient health. Using a long-lasting antibacterial can protect the patient and reduce the incidence of other infections.

Chemokine CXCL1 may serve as a potential molecular target for hepatocellular carcinoma

The purpose of this study was to screen for changes in chemokine and chemokine‐related genes that are expressed in hepatocellular carcinoma (HCC) as potential markers of HCC progression. Total RNA was extracted from tumor and peritumor tissues from mice with HCC and analyzed using a PCR microarray comprising 98 genes. Changes in gene expression of threefold or more were screened and subsequently confirmed by immunohistochemical analyses and western blotting. Furthermore, whether chemokine knockdown by RNA interference (RNAi) could significantly suppress tumor growth in vivo was also evaluated. Finally, total serum samples were collected from HCC patients with HBV/cirrhosis (n = 16) or liver cirrhosis (n = 16) and from healthy controls (n = 16). The serum mRNA and protein expression levels of CXCL1 in primary liver cancer patients were detected by qRT‐PCR and western blot analysis, respectively. Several genes were up‐regulated in tumor tissues during the progression period, including CXCL1, CXCL2, CXCL3, and IL‐1β, while CXCR1 expression was down‐regulated. CBRH‐7919 cells carrying CXCL1 siRNA resulted in decreased tumor growth in nude mice. The differences in serum CXCL1 mRNA and protein levels among the HCC, hepatic sclerosis (HS), and control groups were significant (P < 0.001). The mRNA and protein levels of CXCL1 in the HCC group were up‐regulated compared with the HS group or the control group (P < 0.001). Several chemokine genes were identified that might play important roles in the tumor microenvironment of HCC. These results provide new insights into human HCC and may ultimately facilitate early HCC diagnosis and lead to the discovery of innovative therapeutic approaches for HCC.

Targeted silencing of CXCL1 by siRNA inhibits tumor growth and apoptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive malignancy and a major cause of cancer-related mortality worldwide. Our previous study shows that chemokine (C-X-C motif) ligand 1 (CXCL1) was upregulated and CXCR1 was downregulated in tumor tissues as compared to peritumor tissues by chemotaxis assay. As the status of CXCL subgroups and their receptors affect progression of HCC, we evaluated potential mechanisms of CXCL1 associated with anticancer effects in HCC based on our previous study. The effects of targeting CXCL1 by RNA interference (RNAi) on the proliferation and apoptosis of CBRH-7919 cells were observed in vitro and in vivo. Additionally, whether CXCL1 knockdown significantly reduce the activity of STAT3, NF-κB and HIF-1 or not were also estimated. RNAi of CXCL1 in the CBRH-7919 cells decreased the growth of tumors in nude mice by inhibited cells proliferation and induced apoptosis. In conclusion, these findings suggest that CXCL1 plays critical roles in the growth and apoptosis of HCC. RNAi of CXCL1 inhibits the growth and apoptosis of tumor cells, which indicates that CXCL1 may be a potential molecular target for use in HCC therapy.

Inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma

AIM: To study the inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma (HCC) in nude mice.

METHODS: CBRH-7919 HCC cells were injected into the subcutaneous region of nude mice. Beginning two weeks after the challenge, tumor growth was measured every week for six weeks. The stromal microenvironment and inflammatory cell infiltration was assessed by immunohistochemistry in paired tumor and adjacent peritumoral samples, and macrophage phenotype was assessed using double-stain immunohistochemistry incorporating expression of an intracellular enzyme. A chemokine PCR array, comprised of 98 genes, was used to screen differential gene expressions, which were validated by Western blotting. Additionally, expression of identified chemokines was knocked-down by RNA interference, and the effect on tumor growth was assessed.

RESULTS: Inflammatory cell infiltrates are a key feature of adjacent peritumoral tissues with increased macrophage, neutrophil, and T cell (specifically helper and activated subsets) infiltration. Macrophages within adjacent peritumoral tissues express inducible nitric oxide synthase, suggestive of a proinflammatory phenotype. Fifty-one genes were identified in tumor tissues during the progression period, including 50 that were overexpressed (including CXCL1, CXCL2 and CXCL3) and three that were underexpressed (CXCR1, Ifg and Actb). RNA interference of CXCL1 in the CBRH-7919 cells decreased the growth of tumors in nude mice and inhibited expression of CXCL2, CXCL3 and interleukin-1β protein.

CONCLUSION: These findings suggest that CXCL1 plays a critical role in tumor growth and may serve as a potential molecular target for use in HCC therapy.

Transient receptor potential vanilloid-1 participates in the inhibitory effect of ginsenoside Rg1 on capsaicin-induced interleukin-8 and prostaglandin E2 production in HaCaT cells

OBJECTIVES

Ginsenoside Rg1 (GRg1), one of the major active constituents of Panax notoginseng, has shown anti-inflammatory and antinocioceptic activity, but its role in keratinocytes needs further study. We have examined the inhibitory effect of GRg1 on transient receptor potential vanilloid-1 (TRPV1) activation in keratinocyte HaCaT cells and explored its involved mechanism.

METHODS

HEK 293T cells over-expressing exogenous TRPV1 were constructed and named HEK 293T-TRPV1 cells. The effects of GRg1 on production of interleukin-8 (IL-8) and prostaglandin E(2) (PGE(2) ), calcium influx, the expression of cyclooxygenase-2 (COX-2) and nuclear factor-κB (NF-κB) transcriptional activity in HEK 293T-TRPV1 and HaCaT cells were examined by ELISA, Fluo 3-AM fluorescence probe, Western blot and Dual-Luciferase Reporter Assay, respectively.

KEY FINDINGS

The results showed that GRg1 blocked intracellular calcium by both capsaicin and proton activation in a TRPV1-dependent manner. Furthermore, GRg1 inhibited the expression of COX-2 and NF-κB transcriptional activity induced by capsaicin in keratinocytes. The inhibitory effect of GRg1 was similar to capsazepine, an antagonist of TRPV1. More importantly, GRg1 dose-dependently inhibited capsaicin-induced PGE(2) and IL-8 secretion in HaCaT cells and HEK 293T-TRPV1 cells.

CONCLUSIONS

These data showed that GRg1 could inhibit TRPV1 mediated responses in HaCaT cells, indicating that GRg1 acted as a TRPV1 antagonist.

Mannose 6-phosphate-modified bovine serum albumin nanoparticles for controlled and targeted delivery of sodium ferulate for treatment of hepatic fibrosis

Objectives

The aim was to prepare neoglycoprotein-based nanoparticles for targeted drug delivery to hepatic stellate cells, and to evaluate their characteristics in vitro and in vivo.

Methods

The neoglycoprotein of bovine serum albumin modified with mannose 6-phosphate was synthesised from mannose, and used as wall material to nanoencapsulate the model natural antifibrotic substance sodium ferulate using a desolvation method. The morphology, drug loading capacity, release in vitro and biodistribution in vivo of the nanoparticles were studied. Selectivity of the nanoparticles for hepatic stellate cells was evaluated by immunohistochemical analysis of fibrotic rat liver sections.

Key findings

The spherical nanoparticles were negatively charged with zeta potential ranging from −2.73 to −35.85 mV, and sizes between 100 and 200 nm with a narrow size distribution. Drug entrapment efficiency of about 90% (w/w) and loading capacity of 20% (w/w) could be achieved. In vitro, the nanoparticles showed an initial rapid continuous release followed by a slower sustained release. After intravenous injection into mice, the nanoparticles showed a slower elimination rate and a much higher drug concentration in liver compared with the sodium ferrate solution, and less distribution to the kidneys and other tissues. Immunohistochemistry indicated that the neoglycoprotein-based nano-particles were taken up specifically by hepatic stellate cells.

Conclusions

The nanoparticles may be an efficient drug carrier targeting hepatic stellate cells.

Mannose 6-phosphate-modified bovine serum albumin nanoparticles for controlled and targeted delivery of sodium ferulate for treatment of hepatic fibrosis

OBJECTIVES

The aim was to prepare neoglycoprotein-based nanoparticles for targeted drug delivery to hepatic stellate cells, and to evaluate their characteristics in vitro and in vivo.

METHODS

The neoglycoprotein of bovine serum albumin modified with mannose 6-phosphate was synthesised from mannose, and used as wall material to nanoencapsulate the model natural antifibrotic substance sodium ferulate using a desolvation method. The morphology, drug loading capacity, release in vitro and biodistribution in vivo of the nanoparticles were studied. Selectivity of the nanoparticles for hepatic stellate cells was evaluated by immunohistochemical analysis of fibrotic rat liver sections.

KEY FINDINGS

The spherical nanoparticles were negatively charged with zeta potential ranging from -2.73 to -35.85 mV, and sizes between 100 and 200 nm with a narrow size distribution. Drug entrapment efficiency of about 90% (w/w) and loading capacity of 20% (w/w) could be achieved. in vitro, the nanoparticles showed an initial rapid continuous release followed by a slower sustained release. After intravenous injection into mice, the nanoparticles showed a slower elimination rate and a much higher drug concentration in liver compared with the sodium ferrate solution, and less distribution to the kidneys and other tissues. Immunohistochemistry indicated that the neoglycoprotein-based nanoparticles were taken up specifically by hepatic stellate cells.

CONCLUSIONS

The nanoparticles may be an efficient drug carrier targeting hepatic stellate cells.

[Effect of cetirizine hydrochloride on the expression of substance P receptor and cytokines production in human epidermal keratinocytes and dermal fibroblasts]

To investigate the effect of cetirizine hydrochloride on the expression of neurokinin 1 receptor (NK-1R) and cytokines production induced by substance P (SP) in HaCaT cells (a human epidermal keratinocyte cell line) and dermal fibroblasts. The effect of cetirizine on the expression of NK-1R protein was detected by flow cytometry and Western blotting analysis. The modulation of cetirizine on the production of interferon (IFN)-gamma, interleukin (IL)-1beta, IL-6 and IL-8 in HaCaT cells and fibroblasts was measured by ELISA. The results showed that cetirizine significantly inhibited the expression of NK-1R in HaCaT cells and fibroblasts. SP induced the production of IFN-gamma, IL-1beta and IL-8 in both cell types. Cetirizine 1-100 micromol x L(-1) inhibited SP-induced IL-1beta and IL-8 production in HaCaT cells and fibroblasts, while had no effect on the production of IFN-gamma in both cells. Both SP and cetirizine had no effect on the secretion of IL-6 in HaCaT cells and fibroblasts. These findings suggest that cetirizine may be involved in the treatment of SP-induced skin inflammation by inhibiting the expression of substance P receptor and regulation the production of IL-1beta and IL-8 in epidermal keratinocyte and dermal fibroblasts.

Preparation and characterization of sodium ferulate entrapped bovine serum albumin nanoparticles for liver targeting

Sodium ferulate (SF) loaded nanoparticles were prepared by desolvation procedure and subsequent cross-linking of the wall material of bovine serum albumin (BSA). Several factors in the nanoencapsulation process, such as the addition rate of the desolvation agent, composition of BSA and SF solution, amount of the cross-linker glutaraldehyde, were investigated to elucidate their influences on the particle size, zeta potential, drug loading and encapsulation efficiency of the resulted nanoparticles. The obtained spherical nanoparticles were negative charged with zeta potential from -20 to -40 mV, and characterized between 100 and 200 nm with a narrow size distribution. In the condition of introducing 1.0 mL 8% glutareldehyde per mg of BSA, the drug entrapment efficiency (EE) of 80% (w/w) and loading capacity of about 16% (w/w) could be achieved for the cross-linked BSA nanoparticles with SF encapsulated (SF-BSA-NP). And the drug EE was decreased along with the increasing amount of glutareldehyde used for cross-linking. The in vitro drug release properties of SF-BSA-NP behaved with an initial burst effect and then sustained-release stage. To some extent, the drug release rate could be adjusted by cross-linking with different amount of glutaraldehyde. Compared with SF solution, SF-BSA-NP showed a much higher drug distribution into liver and a lower drug concentration in other tissues, after intravenously injected to mice. So, BSA based nanoparticles might be a suitable controlled released carrier for the freely water-soluble drug SF and further hepatic targeted drug delivery.

[Studies on cutaneous permeation in vitro of Kushen recipe gel]

OBJECTIVE

To establish a suitable dosage form for a traditional anti-anaphylaxis Chinese medicine of Kushen recipe, and investigate the effect of cutaneous permeation in vitro of the recipe.

METHOD

Techniques of extracting with ethanol and purifying with absorbent resin to obtain alkaloids from Kushen recipe were adopted, while volatile oil was extracted by steam distillation. The extraction was made to gel. The skin from SD rats' abdomen was used as permeability barriers. Then effects of permeation of the aqueous extraction, the purifying extraction and the gel were compared by Valia-Chien and Franz diffusion cell method. HPLC was utilized to quantitate the alkaloids in permeating liquid.

RESULT

In view of the permeation cumulation quantity, the permeation velocity and the lag time of the four kinds of alkaloids, the effect of permeation of purifying extraction was better than the aqueous extraction, and the purifying extraction gel surpassed both the aqueous extraction and the purifying extraction.

CONCLUSION

It was certified that the purifying extraction gel had improved the effect of cutaneous permeation of alkaloids, and it is the befitting dosage form for Kushen recipe to treat anaphylaxis disease in skin.

Effect of matrine on the expression of substance P receptor and inflammatory cytokines production in human skin keratinocytes and fibroblasts

Matrine is a kind of alkaloid found in certain Sophora plants, which has been extensively used in China for the treatment of viral hepatitis, cancer, cardiac diseases and skin diseases (such as atopic dermatitis and eczema). It also has been confirmed that substance P (SP) and its receptor (neurokinin-1 receptor, NK-1R) are involved in the pathogenesis of inflammatory skin disorders. So the present study was designed to investigate the effect of matrine on the expression of NK-1R and cytokines production induced by SP in HaCaT cells (a human epidermal keratinocyte cell line) and dermal fibroblasts. In addition, cell viability was also evaluated. The results showed that matrine inhibited the expression of NK-1R in HaCaT cells and fibroblasts. SP induced the production of interleukin (IL)-1beta, IL-8, interferon (IFN)-gamma, and monocyte chemotactic protein (MCP)-1 in both cell types. Matrine 5-100 microg/mL had little effect on cell viability. It inhibited SP-induced IL-1beta, IL-8 and MCP-1 production in HaCaT cells and fibroblasts, while it increased the production of IFN-gamma in HaCaT cells. Both SP and matrine had no effect on the secretion of IL-6. These findings suggest that matrine may have potential treatment function on SP related cutaneous inflammation by inhibition of the expression of substance P receptor and regulation of the production of inflammatory cytokines.

Stereoselective Characteristics and Mechanisms of Epidermal Carboxylesterase Metabolism Observed in HaCaT Keratinocytes

There is increasing evidence that epidermal carboxylesterase may be involved in the stereoselective hydrolysis of prodrugs in percutaneous absorption. The present study was designed to evaluate the stereoselective characteristics and mechanisms of ketoprofen ethyl ester hydrolysis by epidermal carboxylesterase expressed in HaCaT keratinocytes. Ketoprofen ethyl ester was mainly hydrolyzed to R-ketoprofen by carboxylesterase of human HaCaT keratinocytes. Human carboxylesterase-1 (hCE-1) and human carboxylesterase-2 (hCE-2) were intensively detected in L02 hepatocytes, hCE-2 was also intensively detected in HaCaT keratinocytes, but hCE-1 was not detected in HaCaT keratinocytes. hCE-2 is thus an abundant carboxylesterase in HaCaT keratinocytes which may be responsible for stereoselective hydrolysis of ketoprofen ethyl ester.

In Vivo and in Vitro Evaluation of Essential Oils from Ligusticum chuanxiong HORT on the Transdermal Delivery of Flurbiprofen in Rabbits

The present study was designed to evaluate skin permeation enhancement effect of essential oils from Ligusticum chuanxiong Hort (chuanxiong oil) in rabbits and to compare the in vivo absorption and in vitro permeation using flurbiprofen as a model drug. In vivo results demonstrated that chuanxiong oil showed a rapid and marked permeation enhancement effect. The group with 10% oil exhibited the highest value of area under the curve (AUC) of 418+/-124 microg/ml x h, which was 2.43 times the high of control. The AUC value of 3% oil group (245+/-81.6 microg/ml x h) was similar to that of 5% oleic acid group (235+/-74.5 microg/ml x h). Whereas in vitro results indicated the enhancement of chuanxiong oil was relatively weak. The group with 3% oil appeared to the highest flurbiprofen flux (84.9+/-19.3 microg/cm2/h), to some extent lower than 5% oleic acid group (107+/-5.85 microg/cm2/h). At 10% and 15% concentrations, chuanxiong oil even decreased the flux of flurbiprofen compared with the control. Both in vitro results with pretreated skin and flurbiprofen content accumulated in skin indicated the potential mechanism for the in vitro enhancement of chuanxiong oil was the weakened barrier function by improving in the partitioning of flurbiprofen to the stratum corneum. The discrepancy was noted between the in vivo and in vitro results, indicating only about the weakened barrier function was not enough to explain the sharply increment of in vivo absorption of flurbiprofen by chuanxiong oil. The GS-MS results indicated phthalides identified from chuanxiong oil might mainly contribute to enhance in vivo absorption of flurbiprofen because of its large quantities (91.15%).

[Percutaneous penetration of ketoprofen and ketoprofen isopropyl ester through a tissue engineering skin reconstructed with HaCaT cells]

AIM

To reconstruct of a tissue engineering skin in vitro for the study of the use of drug percutaneous penetration and metabolism.

METHODS

Dermal fibroblasts were embedded in collagen type I. HaCaT cells were seeded on the top of the gel. The skin was generated through air-liquid interface culture. Effects of various culture media on tissues morphology were investigated. Sections of the cultured skin were stained with hematoxylin and eosin and examined under microscope. Permeation and metabolism of ketoprofen and its isopropyl ester through the cultured skin were investigated.

RESULTS

HaCaT cells initially developed a multilayer epithelium at the air-liquid interface, but it showed a parakeratotic stratum corneum. Vitamin C enhanced cell proliferation obviously. Vitamin D3 promoted cell differentiation. And estradiol showed little effect on the tissue engineering skin. Ketoprofen isopropyl ester was hydrolyzed into ketoprofen when penetrated through the cultured skin, which resembled in the skin cell homogenates metabolism.

CONCLUSION

Cultured at the air-liquid interface, HaCaT cells developed a parakeratotic mutilayer epithelium. Enzyme activity was reserved. This cultured skin could serve as an appropriate model for drug percutaneous metabolism and skin irritation.

[Effect of cetirizine hydrochloride on the expression of substance P in IgE-mediated triphasic cutaneous reaction]

AIM

To investigate the effect of cetirizine hydrochloride on the expression of neuropeptide substance P (SP) in IgE-dependent triphasic cutaneous reaction induced by dinitrofluorobenzene (DNFB) in the ears of BALB/c mice.

METHODS

BALB/c mice were passively sensitized by intravenous infection of anti-DNP IgE monoclonal antibody 24 h before DNFB challenge. Skin reaction was elicited by applying DNFB to both sides of each ear of sensitized mice. Mice were treated with cetirizine (1 and 10 mg x kg)-1), ig). The ears were removed for pathohistological examination and immunohistochemical staining of SP at different designated times after challenge. The contents of SP in the skin of mouse ear were determined by radioimmunoassay (RIA).

RESULTS

The mice exhibited a triphasic cutaneous reaction with an immediate-phase response (IPR) at 1 h, a late-phase response (LPR) at 24 h and a very late-phase response (vLPR) at 7 days after challenge with DNFB. The expression of SP in different phases increased gradually. Cetirizine (1 and 10 mg x kg(-1)) was shown to significantly inhibit the ear swellings induced by the IPR (P < 0.01), while no obvious effect on the vLPR. The SP contents in ear skin of triphasic cutaneous reaction were decreased by cetirizine.

CONCLUSION

SP is considered to be involved in the pathogenesis of allergic dermatitis. Cetirizine hydrochloride can inhibit the expression of SP in IgE-dependent triphasic cutaneous reaction. It might be part of the mechanisms of anti-anaphylaxis of cetirizine.