Effects of Yangxue-Jiedu decoction on imiquimod-induced psoriasis-like lesions in STAT3 transgenic mice

AIM: To observe the effects of Yangxue-Jiedu (YXJD) decoction on imiquimod-induced psoriasis-like lesions in STAT3 transgenic mice.METHODS: STAT3 transgenic mice (n=24) were randomly divided into 4 groups: control group (using purified water for oral administration), model group (topical 5% imiquimod 42 mg and using purified water for oral administration), YXJD groups (topical 5% imiquimod 42 mg and using YXJD decoction for oral administration), and methotrexate (MTX) group (1 mg/kg MTX solution for oral administration, with the same topical imiquimod as model group). On day 7, the skin lesions were collected for examination. The lesions were evaluated according to the psoriasis area and severity index (PASI). The skin barrier function was evaluated by assessing oil and water components in the skin. The inflammation of psoriasis-like lesions was assessed by histological method. The expression of proliferating cell nuclear antigen (PCNA) and CD3 was assessed by immunohistochemical staining. The mRNA expression of IL-17A, IL-17C, IL-22 and RORγt was detected by real-time PCR. The levels of JAK/STAT3 pathway-related proteins in isolated T cells were determined by Western blot.RESULTS: Administration of YXJD decoction inhibited imiquimod-induced keratinocyte proliferation and infiltration of CD3⁺ T cells in psoriatic lesions, and ameliorated the epidermal barrier by up-regulation of the oil and water components in psoriatic lesions. Meanwhile, administration of YXJD decoction improved the systemic immune responses by reducing the weight of the spleen. The inflammatory cytokines IL-17A, IL-17C, IL-22 and RoRγt, and the levels of JAK/STAT3 pathway-related proteins STAT3, p-STAT3, JAK3 and p-JAK3 were decreased by administration of YXJD decoction.CONCLUSION: YXJD decoction likely alleviates imiquimod-induced psoriasis-like lesions in the STAT3 transgenic mice by inhibiting the phosphorylation of STAT3, and reducing the expression of IL-17A, IL-17C, IL-22 and RORγt.     

Effects of Xiaoyaosan on imiquimod induced psoriatic lesions and depression neurotransmitters in mouse model

AIM: To observe the effect of Xiaoyaosan decoction on the psoriatic lesions and depression neurotransmitters induced by imiquimod in mice. METHODS: BALB/c male mice were randomly divided into control group, model group, methotrexate group and Xiaoyaosan high, medium and low dose groups, 6 mice in each group. Imiquimod (IMQ, 5%) was used on the back of the animals to induce psoriasis-like lesions in the mice. The psoriasis area and seve-rity index (PASI) were evaluated for daily scoring. The sugar water preference experiment was conducted to explore the behavioral differences in the mice. The morphological changes and epidermal thickness of the lesions were observed under light microscopy. Immunohistochemical method was used to detect the expression of CD3 on T lymphocyte surface. The expression of Ki67 in the skin lesions was detected by immunofluorescence. The contents of monoamine neurotransmitters such as adrenaline (AD), gamma-aminobutylic acid (GABA), glutamate (Glu), dopamine (DA) and their metabolites in the hippocampus and hypothalamus of mice were detected by high performance liquid chromatography-mass spectrometry (HPLC-MS). RESULTS: Compared with model group, the back skin lesions of Xiaoyaosan each dose group and methotrexate group were significantly improved, and the PASI score and epidermal thickness were both lower than those in model group (P<0.05). The expression levels of Ki67 and CD3⁺ T cells in Xiaoyaosan group and methotrexate group were lower than those in model group (P<0.05). Compared with model group, the body mass change range of Xiaoyaosan high-dose group and blank control group was significantly smaller than that in model group (P<0.05). The sugar water preference rate in blank control group was significantly higher than that in model group (P<0.01). Compared with model group, the sugar water preference rate in methotrexate and Xiaoyaosan groups showed a certain increase trend, but no statistical diffe-rence was observed. Compared model group, the levels of 3, 4-Dihydroxypheny-lacetic acid (DOPAC), AD, GLU and GABA levels in the mouse hippocampus in blank control group were decreased significantly (P<0.01), while the levels of DA and homovanillic acid (HVA) had no significant difference (P>0.05). No significant difference of DA, DOPAC, HVA and GLU levels in the mouse hypothalamus was observed between blank control group and model group (P>0.05), while the content of AD and GABA in the mouse hypothalamus in blank control group was lower than that in model group. The AD content of the hypothalamus in high-dose Xiaoyaosan group was significantly higher than that in model group (P<0.01), and the HVA content of the hypothalamus in low-dose Xiaoyaosan group was significantly higher than that in model group (P<0.01). PASI score was negatively correlated with the content of DOPAC, AD, GLU and GABA in the hippocampus and the content of AD, GLU and GABA in the hypothalamus, those were, the more severe the back skin lesion was, the lower the expression of depression-related neurotransmitters were, indicating the aggravation of depression in the mice. CONCLUSION: Xiaoyaosan improves the skin lesions induced by imiquimod in the mice with psoriasis, improves the behavior of depression in the mice with psoriasis, and up-regulates the expression of depression-related monoamine neurotransmitters. The expression of depression-related neurotransmitters is negatively correlated with the skin lesions induced by imiqumod in the mice with psoriasis. The degree of depression is increased with the aggravation of psoriatic lesions.     

Effect of Liang Xue Huo Xue capsules on mouse psoriasis-like lesions induced by imiquimod

AIM: To observe the effects of Liang Xue Huo Xue (LXHX) capsules on mouse psoriasis-like lesions induced by imiquimod (IMQ). METHODS: BALB/c female mice (n=48) were randomly divided into 6 groups: normal group, model group, LXHX capsules groups with high, medium or low doses, and glycosides of Tripterygium wilfordii (GTW) group. On day 8, skin lesions were determined by pathological examination. The lesions were evaluated according to the psoriasis area and severity index (PASI). The histology and epidermal thicknesses were observed under light microscope. The expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical staining. Meanwhile, the positive expression of CD3, CD11c, F4/80, CD31 and Gr-1 was counted by immunohistochemical staining. RESULTS: Compared with model group, the cutaneous symptoms in LXHX capsules groups were alleviated, with PASI scores decreased, epidermal parakeratosis and epidermal over-proliferation relived, the numbers of dermal T lymphocytes, dendritic cells, macrophages, neutrophils and monocytes reduced significantly. CONCLUSION: LXHX capsules improve imiquimod-induced mouse psoriasis-like lesions by inhibiting over-proliferation of keratinocytes, parakeratosis, inflammatory infiltration and angiogenisis.     

Reproductive and developmental toxicity evaluation of a purified Arabinogalactan-Protein (AGP) composition in Wistar rats

A purified Arabinogalactan-Protein composition (LL-4218) was prepared from the leaves of Argemone mexicana to treat psoriasis. The effect of (LL-4218) was evaluated on reproductive (male and female fertility) and developmental toxicity in rats. LL-4218 was administered orally at the doses of 250, 500 and 1000 mg kg^− 1. The results showed that LL-4218 did not produce any significant dose related changes in reproductive and developmental toxicity studies. Therefore, it is concluded that LL-4218 did not produce any significant toxic effect on reproduction and developmental parameters of rats and NOAEL for reproductive and developmental toxicity studies in rats was 1000 mg kg^− 1.     

Effects of Yangxue decoction and Yangxue-Jiedu decoction on imiquimod-induced psoriasis-like mouse model

AIM: To investigate and compare the effects of Yangxue (YX) decoction and Yangxue-Jiedu (YXJD) decoction on psoriasis-like mouse skin lesions. METHODS: BALB/c mice (n=50) were randomly divided into control group, model group, methotrexate (MTX) group, YX group and YXJD group (10 mice in each group). The psoriasis-like mouse model was induced by topical application of imiquimod cream on the back. The skin water/oil test pen was used to detect the water/oil content of the skin in the back of the mice. The pathological changes of the lesions were observed by HE staining and the thickness of the epidermis was measured. The immunohistochemical staining was used to observe the skin lesions, and the mRNA expression levels of interleukin (IL)-17, IL-23 and IL-1β in skin lesions were detected by real-time PCR. RESULTS: The skin lesions in YX, YXJD and MTX group were better than those in model group, with lower psoriasis area and severity index (PASI) score and skin thickness. The skin water/oil content in YXJD group was higher than that in model group (P<0.05). The expression of proliferating cell nuclear antigen (PCNA) and the positive expression of CD3⁺ T cells in the skin of YXJD group were lower than those in YX group, and the skin thickness was lower than that in YX group (P<0.05). The results of real-time PCR showed that relative mRNA expression of IL-17, IL-23 and IL-1β in YX group and YXJD group was lower than that in model group (P<0.05), and the relative mRNA expression of IL-1β in YXJD group was lower than that in YX group. Administration of YXJD decoction showed better therapeutic effect than MTX. CONCLUSION: YX decoction and YXJD decoction relieve imiquimod-induced skin lesions by reducing immune response. Meanwhile, the effect of YXJD decoction is better than that of YX decoction.     

Inhibitory effects of paeonol on keratinocyte viability,cytokines secretion stimulated by IL-17A via STAT3 signaling pathway

AIM To observe the effect of paeonol on interleukin-17A （IL-17A）-induced human keratinocyte viability， cytokine secretion， and related signal transduction pathways. METHODS In vitro HaCaT cells stimulated by IL-17A （200 μg/L） were co-cultured with paeonol （200 mg/L and 100 mg/L） for 24 h. The cell viability was measured by CCK-8 assay. The Th1/Th2/Th17 cytokine （including IL-6， etc.） levels were measured by cytometric bead array assay. The IL-23 level was measured by ELISA. The mRNA expression of IL-23， IL-6， CXCL2， CXCL8， CCL20 and STAT3 was detected by real-time PCR， and Western blot was used to determine the protein levels of STAT3 and ERK1/2. RESULTS Paeonol significantly inhibited IL-17A-induced HaCaT cell viability （P<0.05）， as well as reduced IL-6 level. Meanwhile， paeonol decreased mRNA levels of IL-23， CXCL2， CXCL8， and CCL20. Paeonol also inhibited the expression of STAT3 at mRNA and protein levels. However， no significant effect of paeonol on ERK1/2 protein expression was observed. CONCLUSION Paeonol inhibits HaCaT cell viability and cytokine secretion induced by IL-17A， and its mechanism might be related to STAT3 singaling pathway.     

Role of IL-23/IL-17 inflammatory axis in the pathogenesis of psoriasis-like lesions induced by imiquimod in mice

AIM: To observe the dynamic changes of IL-23/IL-17 inflammatory axis in psoriasis-like lesions of mice induced by imiquimod (IMQ).METHODS: BALB/c female mice were randomly divided into control group and IMQ group. The morphological changes of lesional skin in mice were evaluated according to the psoriasis area and severity index (PASI) and HE staining. cytokine antibody chips were used to determine the cytokine changes in serum and lesions. The mRNA and protein expression of cytokines were analyzed by cytometric bead array, real-time PCR and Western blotting. Moreover, the changes of cellular constituents in the peripheral blood and splenic cells of mice were detected by flow cytometry.RESULTS: Typical psoriasis-like skin lesions, such as red scaly skin plaques, caused by topical IMQ showed a parabolic dynamic change. There was a dynamic increase in proinflammatory cytokines of the IL-23/IL-17 axis in IMQ-treated skin. IMQ application resulted in elevated expression of cytokines related with IL-23/IL-17 inflammatory axis,Th1-type cytokines,Th2-type cytokines and Treg-type cytokines at day 4. IMQ-treated BALB/c mice showed an increased pericentage of dentric cells in peripheral blood and spleen compared with control animals. Percentages of Th17 and Treg in IMQ-treated mice were increased by 3~4 times and twice as compared with control mice, respectively.CONCLUSION: The skin lesions, histopathological features and cytokine changes in mice induced by IMQ are similar to human psoriasis, which are suitable for investigating the pathogenesis of psoriasis as a psoriasis-like model. IL-23/IL-17 axis is involved in the formation of psoriasis-like skin lesions in mice induced by IMQ and presents a dynamic change. Besides, Th1 cell-mediated inflammatory response is also activated in the formation of lesional skin, accompanied by the increase expression of Th2 and Treg cytokines in a feedback mechanism.