Protocatechuic acid supplement alleviates allergic airway inflammation by inhibiting the IL-4Rα-STAT6 and Jagged 1/Jagged2-Notch1/Notch2 pathways in allergic asthmatic mice.

OBJECTIVE AND DESIGN: To clarify the effects of dietary supplementation of protocatechuic acid (PCA) and in-depth mechanisms on allergic asthma in ovalbumin (OVA)-induced mice. MATERIALS: Female BALB/c mice were randomly divided into three groups (n = 10 in each group): control group, OVA-induced allergic asthma group, and OVA plus PCA group. TREATMENT: Dietary supplementation of PCA was achieved by adding 50 mg/kg PCA to AIN 93G diet for 25 days. METHODS: Peripheral blood cells, pulmonary inflammatory cell infiltration, the levels of IL-4, IL-5, and IL-13 in bronchoalveolar lavage fluid (BALF), the mRNA levels of Th2-related genes in the lungs, and the protein expressions of the IL-4Rα-STAT6 and the Jagged1/Jagged2-Notch1/Notch2 signaling pathways were measured. RESULTS: Significantly reduced inflammatory cells infiltration and mucosal hypersecretion in the lung tissues, repaired levels of interleukin IL-4, IL-5, and IL-13 in the BALF, and decreased mRNA expression of IL-4, IL-5, and GATA3 were observed in OVA plus PCA group. Moreover, PCA treatment down-regulated the protein levels of IL-4Rα-STAT6 and Jagged1/Jagged2-Notch1/Notch2 signaling pathways. CONCLUSIONS: Dietary supplement of PCA alleviated allergic asthma partly through suppressing the IL-4Rα-STAT6 and Jagged1/Jagged2-Notch1/Notch2 signaling pathways in mice. Our study provided the theoretic basis of PCA used as functional food in preventing allergic asthma.

Notch signaling pathway mediates the immunomodulatory mechanism of Yangfei Huoxue decoction alleviating bleomycin-induced pulmonary fibrosis in rats.

OBJECTIVE: To investigate the immunomodulatory mechanism by which Yangfei Huoxue decoction (YHD) alleviates bleomycin (BLM)-induced pulmonary fibrosis (PF) in rats. METHODS: Rats were randomly divided into two time-point groups (day 14 and 28), and each time-point group comprised the following six subgroups: control, BLM, dexamethasone (DXM), YHD high dose (YHD-H), YHD middle dose (YHD-M), and YHD low dose (YHD-L). Haematoxylin and eosin and Masson staining, flow cytometry, enzyme-linked immunosorbent assay, Western blotting and UPLC-QT of analyses were examined. RESULTS: The results showed that YHD reduced the degree of alveolar inflammation and fibrosis; downregulated the expression of CD28, CD80, CD86, Delta-like 1, Notch2, and Notch3; and upregulated the proportions of Th1/Th2 and Tc1/Tc2. The seven components of YHD were detected. CONCLUSION: The current study indicates that YHD mainly functions by regulating the immune system and that the molecular mechanism may be related to the regulation of the Notch signaling pathway.