ABSTRACT
Asthma is an inflammatory disease closely associated with activated T cells in the lung. Imbalances in Th1/Th2 and Treg/Th17 have been found in asthmatic patients. Ligustrazine from the Chinese herb chuanxiong has been used in China in combination with glucocorticoids to treat asthma. Previous studies have proved that ligustrazine can modulate the expression of transcription factors for Th1 (T-bet) and Th2 (Gata-3) in asthma. In the present study, ligustrazine alleviated allergic airway inflammation in a mouse asthmatic model by reducing the influx of eosinophils and neutrophils, which was mediated, at least in part, by the regulation of Th1/Th2 and Treg/Th17 via the re-balance of cytokine profiles and of ratios of transcription factors, T-bet/Gata-3 and Foxp3/RORγt, thus providing new insights into the mechanisms of action for asthma treatment with ligustrazine.
Subject(s)
Asthma/drug therapy , Drugs, Chinese Herbal/administration & dosage , Eosinophils/drug effects , Neutrophils/drug effects , Pyrazines/administration & dosage , T-Lymphocytes, Regulatory/drug effects , Th17 Cells/drug effects , Animals , Asthma/immunology , Cells, Cultured , Cytokines/metabolism , Disease Models, Animal , Eosinophils/immunology , Female , Gene Expression Regulation/drug effects , Homeostasis/drug effects , Humans , Mice , Mice, Inbred C57BL , Neutrophils/immunology , Ovalbumin/immunology , T-Lymphocytes, Regulatory/immunology , Th1-Th2 Balance/drug effects , Th17 Cells/immunology , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
OBJECTIVE: To observe the effects of astragaloside IV on the airway remodeling and the expressions of transforming growth factor (TGF)-ß1 and thymic stromal lymphopoietin (TSLP) in a murine model of asthma. METHODS: Forty-eight BALB/c mice were randomly divided into 4 groups, i.e. control group, asthma group, astragaloside IV group and budesonide group (n = 12 each). The BALB/c mice sensitized to ovalbumin (OVA) were chronically challenged with aerosolized OVA for 8 weeks while the mice in the astragaloside IV group were intragastrically administered with astragaloside IV (50 mg/kg) daily for 8 consecutive weeks. Pulmonary functions were measured to evaluate the resistance of expiration. And pulmonary histopathological analysis was performed to observe the infiltration of inflammatory cells, the hyperplasia of airway global cells and the deposition of collagen. The levels of interleukin (IL)-4 and IL-13 in bronchoalveolar lavage fluid (BALF) were measured by ELISA (enzyme linked immunosorbent assay). The pulmonary expression of α-SMA (alpha-smooth muscle actin) was evaluated by immunohistochemistry. The mRNA and protein expressions of TGF-ß1 and TSLP were measured by real-time PCR (polymerase chain reaction) and Western blot respectively. RESULTS: The treatment of astragaloside IV or budesonide led to a sharp decrease in airway resistance compared with the asthma group at a concentration of acetylcholine in 30 µg/kg (P < 0.05). The PAS(+) epithelial/bronchial epithelial cells, the area of collagen staining and α-SMA staining area were significantly elevated in the asthma group compared with the control group (all P < 0.01) while those in the astragaloside and budesonide groups were obviously inhibited compared with the asthma group (all P < 0.05). The BALF levels of IL-4 and IL-13 were markedly elevated in the asthma group versus the control group (P < 0.01) while those markedly decreased in the astragaloside and budesonide groups versus the asthma group (all P < 0.05). The relative expressions of TGF-ß1 and TSLP mRNA (5.23 ± 1.44, 5.70 ± 1.65) were significantly up-regulated in the asthma group versus the control group (1.02 ± 0.21, 1.02 ± 0.25) (P < 0.01) while those in the astragaloside (2.27 ± 0.65, 2.97 ± 1.03) and budesonide groups (2.10 ± 0.57, 3.32 ± 1.11) were obviously down-regulated versus the asthma group (all P < 0.05). The protein levels of TGF-ß1 and TSLP in the asthma group (0.89 ± 0.11, 0.74 ± 0.10) were markedly elevated versus the control (0.39 ± 0.04, 0.44 ± 0.05), the astragaloside (0.51 ± 0.08, 0.59 ± 0.12) and the budesonide groups (0.55 ± 0.08, 0.60 ± 0.08) (all P < 0.05). CONCLUSION: Astragaloside IV can suppress the progression of airway inflammation, airway hyperresponsiveness and remodeling in a murine model of asthma. The above effects may be partially due to the inhibited expressions of TGF-ß1 and TSLP.
Subject(s)
Asthma/metabolism , Cytokines/metabolism , Saponins/pharmacology , Transforming Growth Factor beta1/metabolism , Triterpenes/pharmacology , Animals , Asthma/pathology , Drugs, Chinese Herbal/pharmacology , Female , Interleukin-13/metabolism , Interleukin-4/metabolism , Mice , Mice, Inbred BALB C , Thymic Stromal LymphopoietinABSTRACT
OBJECTIVE: To study the effect and mechanism of arsenic trioxide (As2O3) on apoptosis of pulmonary eosinophiles (PE) in asthmatic guinea-pigs. METHODS: Thirty guinea-pigs were divided into 3 groups at random, the control group, the asthmatic group and the As2O3 group. The dosage of As2O3 used was 2 mg/kg. The apoptotic PE were labelled by TdT-mediated dUTP nick end labelling technique, and the PE infiltration and apoptosis were detected quantitatively using computerized image analysis technique. RESULTS: In the control group, the amount of infiltrating PE was 4.4 +/- 2.5 cells/HP and the PE apoptotic index (AI) was 0.42 +/- 0.08%. In the asthmatic group, the amount increased (P < 0.01) and AI decreased significantly (P < 0.01). After the asthmatic animals had been treated with As2O3, the two parameters changed reversedly significantly (P < 0.01), and there was a significantly negative correlation between them (r = -0.949, P < 0.01). CONCLUSION: The PE apoptosis abnormality is one of the important mechanisms that cause bronchial asthma, As2O3 could alleviate the airway inflammation through promoting PE apoptosis and lower PE infiltration. Low dose of As2O3 is proved to be effective with relative safety, it also has potential value in treating asthma.